#India - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

A tiger and three leopards in the Widlife Rescue Centre, Gorewada Zoo, Maharashtra State.

Source: WOAH, https://wahis.woah.org/#/in-review/6218

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#Perpetuation of Avian #Influenza from Molt to Fall #Migration in Wild Swan #Geese (Anser cygnoides): An Agent-Based Modeling Approach

Abstract

Wild waterfowl are considered to be the reservoir of avian influenza, but their distinct annual life cycle stages and their contribution to disease dynamics are not well understood. Studies of the highly pathogenic avian influenza (HPAI) virus have primarily focused on wintering grounds, where human and poultry densities are high year-round, compared with breeding grounds, where migratory waterfowl are more isolated. Few if any studies of avian influenza have focused on the molting stage where wild waterfowl congregate in a few selected wetlands and undergo the simultaneous molt of wing and tail feathers during a vulnerable flightless period. The molting stage may be one of the most important periods for the perpetuation of the disease in waterfowl, since during this stage, immunologically naïve young birds and adults freely intermix prior to the fall migration. Our study incorporated empirical data from virological field samplings and markings of Swan Geese (Anser cygnoides) on their breeding grounds in Mongolia in an integrated agent-based model (ABM) that included susceptible–exposed–infectious–recovered (SEIR) states. Our ABM results provided unique insights and indicated that individual movements between different molting wetlands and the transmission rate were the key predictors of HPAI perpetuation. While wetland extent was not a significant predictor of HPAI perpetuation, it had a large effect on the number of infections and associated death toll. Our results indicate that conserving undisturbed habitats for wild waterfowl during the molting stage of the breeding season could reduce the risk of HPAI transmission.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/196

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#NASA Shares #Observations of Recently-Identified Near Earth #Asteroid {2024 YR4}

NASA analysis of a near-Earth asteroid, designated 2024 YR4, indicates it has a more than 1% chance of impacting Earth on Dec. 22, 2032 – which also means there is about a 99% chance this asteroid will not impact. Such initial analysis will change over time as more observations are gathered.  

Currently, no other known large asteroids have an impact probability above 1%. 

Asteroid 2024 YR4 was first reported on Dec. 27, 2024, to the Minor Planet Center– the international clearing house for small-body positional measurements – by the NASA-funded Asteroid Terrestrial-impact Last Alert System station in Chile. 

The asteroid, which is estimated to be about 130 to 300 feet wide, caught astronomers’ attention when it rose on the NASA automated Sentry risk list on Dec. 31, 2024. 

The Sentry list includes any known near-Earth asteroids that have a non-zero probability of impacting Earth in the future.  

An object that reaches this level is not uncommon; there have been several objects in the past that have reached this same rating and eventually dropped off as more data have come in. 

New observations may result in reassignment of this asteroid to 0 as more data come in. 

More information about asteroids, near-Earth objects, and planetary defense at NASA can be found at: https://nasa.gov/planetarydefense

Source: NASA, https://blogs.nasa.gov/planetarydefense/2025/01/29/nasa-shares-observations-of-recently-identified-near-earth-asteroid/

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The #hospital and #mortality #burden of #COVID19 compared with #influenza in #Denmark: a national observational cohort study, 2022–24

Summary

Background

The COVID-19 pandemic has been on a downward trend since May, 2022, but it continues to cause substantial numbers of hospital admissions and deaths. We describe this burden in the 2 years since May, 2022, and compare it with the burden of influenza in Denmark.

Methods

This observational cohort study included residents in Denmark from May 16, 2022, to June 7, 2024. Data were obtained from national registries, including admissions with COVID-19 or influenza (ie, having a positive PCR test for either virus from 14 days before and up to 2 days after the hospital admission date), deaths, sex, age, COVID-19 and influenza vaccination status, comorbidities, and residence in long-term care facilities. Negative binomial regression was used to estimate adjusted incidence rate ratios (aIRRs) to compare rates of hospital admissions between COVID-19 and influenza. To compare the severity of COVID-19 versus influenza among patients admitted to hospital, we used the Kaplan–Meier estimator to produce weighted cumulative incidence curves and adjusted risk ratios (aRRs) of mortality at 30 days between COVID-19 and influenza admissions.

Findings

Among 5 899 170 individuals, COVID-19 admissions (n=24 400) were more frequent than influenza admissions (n=8385; aIRR 2·04 [95% CI 1·38–3·02]), particularly during the first year (May, 2022, to May, 2023) versus the second year (May, 2023, to June, 2024; p=0·0096), in the summer versus the winter (p<0·0001), and among people aged 65 years or older versus younger than 65 years (p<0·0001). The number of deaths was also higher for patients with COVID-19 (n=2361) than patients with influenza (n=489, aIRR 3·19 [95% CI 2·24–4·53]). Among patients admitted in the winter (n=19 286), the risk of mortality from COVID-19 was higher than for influenza (aRR 1·23 [95% CI 1·08–1·37]), particularly among those without COVID-19 and influenza vaccination (1·36 [1·05–1·67]), with comorbidities (1·27 [1·11–1·43]), and who were male (1·36 [1·14–1·59]).

Interpretation

COVID-19 represented a greater disease burden than influenza, with more hospital admissions and deaths, and more severe disease (primarily among non-vaccinated people, those with comorbidities, and male patients). These results highlight the continued need for attention and public health efforts to mitigate the impact of SARS-CoV-2.

Funding

Danish Government.

Source: The Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(24)00806-5/fulltext?rss=yes

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#Zika virus disease - #India

Situation at a glance

Between 1 January and 31 December 2024, a cumulative total of 151 Zika virus disease (ZVD) cases were reported from three states in India (Gujarat, Karnataka, and Maharashtra states). Maharashtra State reported a cumulative total of 140 ZVD cases through the Integrated Disease Surveillance Programme (IDSP). Additionally, Karnataka and Gujarat states reported ten and one cases, respectively, in 2024. As of 31 December 2024, no cases of microcephaly and/or Guillain-Barre syndrome (GBS) associated with this outbreak have been reported. Zika virus (ZIKV) is transmitted to humans by the bite of an infected Aedes mosquito. Zika virus is also transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products, and possibly through organ transplantation. There is no specific treatment available for Zika virus infection or disease.

Description of the situation

Between 1 January and 31 December 2024, a cumulative total of 151 ZVD cases were reported from three states in India (Gujarat, Karnataka, and Maharashtra states). Maharashtra State reported a cumulative total of 140 ZVD cases through the Integrated Disease Surveillance Programme (IDSP). Among the 140 cases, the majority (125 cases) were reported from Pune district, 11 from Ahmednagar district, and one case from each of Kolhapur, Sangli and Solapur districts and Mumbai suburban area. Additionally, Karnataka state reported ten cases in 2024, with seven reported from Bengaluru urban district and three from Shivamogga district. Gujarat state reported one Zika case in Gandhinagar Corporation in 2024.

The number of ZVD cases reported in 2024 in Maharashtra state is the highest since 2021 compared with respectively one, three and 18 ZIKV disease cases reported in 2021, 2022 and 2023. The number of cases reported in Karnataka state in 2024 is also the highest number reported since the first case reported in 2022.

The State IDSP Unit does not routinely disaggregate the number of ZVD cases (e.g. pregnancy status), therefore the number of ZIKV infection among pregnant women is unknown.

As of 31 December 2024, no cases of microcephaly and/or Guillain-Barre syndrome (GBS) associated with this outbreak have been reported.

Epidemiology

Zika virus is a mosquito-borne virus first identified in Uganda in 1947 in a Rhesus macaque monkey and  evidence of infection and disease in humans was reported in other African countries in the 1950s. Zika virus is transmitted to humans by the bite of an infected Aedes mosquito. Zika virus is also transmitted from mother to fetus during pregnancy, as well as through sexual contact, transfusion of blood and blood products, and possibly through organ transplantation.

Zika virus (ZIKV) can cause large epidemics, particularly when introduced in immunologically naive populations, resulting in a substantial demand on the public health system including surveillance, case management, and differential laboratory diagnostic testing especially in case of co-circulation of other mosquito-borne diseases like dengue and chikungunya.  In most cases, infection with ZIKV is asymptomatic or mildly symptomatic and of short duration. However, infection during pregnancy is associated with a risk of microcephaly and other congenital malformation in infants (congenital Zika syndrome (CZS)) as well as preterm birth and miscarriage. Some ZIKV-infected adults and children may develop neurological complications including GBS, neuropathy and myelitis.  

There is no specific treatment available for Zika virus infection or disease.

Public health response

On 3 July 2024, the Government of India issued an advisory for all States following the detection of ZIKV disease cases in Maharashtra state and the following public health measures:

-- The IDSP at the National Centre for Disease Control is mandated with surveillance and response to 40 plus outbreak-prone communicable diseases, including the ZIKV. Every State has designated laboratories, such as District Public Health Laboratories and State Referral Laboratories, under the IDSP for investigation and surveillance of these diseases.

-- Technical Guidelines for Integrated Vector Management, and effective community participation disseminated to the States for implementation.

-- Under the National Health Mission, budgetary support is provided to States/Union Territories for preventive activities such as provision of domestic breeding checkers (workers who inspect homes for mosquito breeding sites and eliminate them), involvement of accredited Social Health activists, insecticide, fogging machines, training support, awareness activities.

-- In Maharashtra, the State authority conducted active surveillance following the detection of the initial ZIKV disease cases, particularly targeting pregnant women. Close monitoring of ZIKV- positive pregnant women has been conducted. Vector control measures have been intensified in affected areas.

WHO risk assessment

Zika virus can cause large epidemics, particularly when introduced in immunologically naive populations, with a substantial demand on the public health system, including surveillance, case management, and differential laboratory diagnostic testing to differentiate ZVD from illness due to co-circulating mosquito-borne viruses like dengue and chikungunya. ZIKV is primarily transmitted by Aedes species mosquitoes, it can also be transmitted from mother to fetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation. Although 60-80% of Zika virus infections are asymptomatic or only have mild symptoms, ZIKV infection can cause GBS and microcephaly and congenital Zika syndrome (CZS) during pregnancy.

India reported its first Zika case from Gujarat State in 2016. Since then, many other States namely Tamil Nadu, Madhya Pradesh, Rajasthan, Kerala, Maharashtra, Uttar Pradesh, Delhi, and Karnataka have reported cases subsequently, but no ZIKV-associated microcephaly has been reported. Although Zika virus is not unexpected in Maharashtra state, given the wide distribution of the vectors, Aedes aegypti, and Aedes albopictus, across India, the number of ZVD cases reported in Maharashtra state in 2024 is much higher than the numbers reported in previous years and is thus unusual. The actual incidence of ZVD could be higher due to the asymptomatic or mild clinical presentation in most of the ZIKV infections, combined with varied level of awareness among clinicians. Aedes mosquito density in India varies by season and location, with the highest densities occurring during the monsoon and post-monsoon seasons. 

WHO advice

Protection against mosquito bites during the day and early evening is a key measure to prevent ZIKV infection. Special attention should be given to preventing mosquito bites among pregnant women, women of reproductive age, and young children.

Aedes mosquitoes breed in small water collections inside and around homes, schools, and workplaces. It is important to eliminate these mosquito breeding sites by appropriate methods, including covering water storage containers, removing standing water in water-holding containers such as vases and flowerpots, and cleaning up trash, unused containers, and used tyres. Community initiatives are essential to support local health authorities and national public health programmes to reduce mosquito breeding sites. Health authorities may also advise the use of larvicides and insecticides to reduce mosquito populations and disease spread. Semi-urban areas should prevent the breeding of Aedes spp., in rubber plantations and other stagnant pools of water.

Basic precautions for protection from mosquito bites should be taken by people travelling to high-risk areas, especially pregnant women. These include wearing light-colored, long-sleeved shirts and pants, ensuring rooms are fitted with screens to prevent mosquitoes from entering, and using of insect repellents that contains N,N-Diethyl-meta-toluamide (DEET), IR3535 or Icaridin according to the product label instructions.

For regions with active transmission of ZIKV, all persons with suspected ZIKV infection and their sexual partners (particularly pregnant women) should receive information about the risks of sexual transmission of ZIKV.

WHO recommends that sexually active men and women be correctly counselled about ZIKV infection and offered a full range of contraceptive methods to be able to make an informed choice about whether and when to become pregnant to prevent CZS and other possible adverse pregnancy and foetal outcomes. Men and women should be informed about the possible risk of sexual transmission of Zika virus during the three months and two months, respectively, after known or presumptive infection, and should be informed about the correct and consistent use of condoms or abstinence during that time period to prevent Zika virus infection through sexual transmission.

Women who have had unprotected sex and do not wish to become pregnant due to concerns about ZIKV infection should have ready access to emergency contraceptive services and counselling. Pregnant women should practice safer sex (including correct and consistent use of condoms) or abstain from sexual activity for the entire duration of pregnancy. Pregnant women should be encouraged to attend scheduled appointments and enhanced antenatal care and follow-up, including ultrasound imaging to detect microcephaly and other developmental anomalies associated with ZIKV infection in pregnancy, in accordance with the state/national response plan.

For regions with no active transmission of ZIKV, WHO recommends practicing safer sex, including postponing sexual debut, nonpenetrative sex, correct and consistent use of male or female condoms, and reducing the number of sexual partners, or abstinence for a period of three months for men and two months for women who are returning from areas of active ZIKV transmission to prevent infection of their sex partners. Sexual partners of pregnant women, living in or returning from areas where local transmission of ZIKV occurs, should practice safer sex or abstain from sexual activity throughout pregnancy.

WHO does not recommend any travel or trade restriction to India based on the current information available.

Further information

-- India Union Health Ministry. 3 July 2024. Union Health Ministry Issues Advisory to States in view of Zika virus cases from Maharashtra(link is external)

-- India Ministry of Health and Family Welfare. 30 July 2024. Update On Efforts Taken to Control Zika Virus in The Country(link is external)

-- WHO 2018: Zika virus disease

-- WHO guidelines for the prevention of sexual transmission of Zika virus

-- WHO Zika virus factsheet

-- Vector control operations framework for Zika virus (who.int)

-- PAHO/WHO Tool for the diagnosis and care of patients with suspected arboviral diseases (link is external)

-- Disease Outbreak News: India – Zika 2017

-- Disease Outbreak News: India – Zika 2021

Citable reference: World Health Organization (29 January 2025). Disease Outbreak News; Zika virus disease in India. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON549

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Source: World Health Organization, https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON549

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Dispersal of #influenza virus #populations within the respiratory tract shapes their evolutionary #potential

Abstract

Viral infections are characterized by dispersal from an initial site to secondary locations within the host. How the resultant spatial heterogeneity shapes within-host genetic diversity and viral evolutionary pathways is poorly understood. Here, we show that virus dispersal within and between the nasal cavity and trachea maintains diversity and is therefore conducive to adaptive evolution, whereas dispersal to the lungs gives rise to population heterogeneity. We infected ferrets either intranasally or by aerosol with a barcoded influenza A/California/07/2009 (H1N1) virus. At 1, 2, or 4 days postinfection, dispersal was assessed by collecting 52 samples from throughout the respiratory tract of each animal. Irrespective of inoculation route, barcode compositions across the nasal turbinates and trachea were similar and highly diverse, revealing little constraint on the establishment of infection in the nasal cavity and descent through the trachea. Conversely, infection of the lungs produced genetically distinct viral populations. Lung populations were pauci-clonal, suggesting that each seeded location received relatively few viral genotypes. While aerosol inoculation gave distinct populations at every lung site sampled, within-host dispersal after intranasal inoculation produced larger patches, indicative of local expansion following seeding of the lungs. Throughout the respiratory tract, barcode diversity declined over time, but new diversity was generated through mutation. De novo variants were often unique to a given location, indicating that localized replication following dispersal resulted in population divergence. In summary, dispersal within the respiratory tract operates differently between regions and contributes to the potential for viral evolution to proceed independently in multiple within-host subpopulations.

Source: Proceedings of the National Academy of Sciences of the USA, https://www.pnas.org/doi/abs/10.1073/pnas.2419985122?af=R

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#Strength and durability of indirect #protection against #SARS-CoV-2 infection through #vaccine and infection-acquired #immunity

Abstract

Early investigation revealed a reduced risk of SARS-CoV-2 infection among social contacts of COVID-19 vaccinated individuals, referred to as indirect protection. However, indirect protection from SARS-CoV-2 infection-acquired immunity and its comparative strength and durability to vaccine-derived indirect protection in the current epidemiologic context of high levels of vaccination, prior infection, and novel variants are not well characterized. Here, we show that both vaccine-derived and infection-acquired immunity independently yield indirect protection to close social contacts with key differences in their strength and waning. Analyzing anonymized SARS-CoV-2 surveillance data from 9,625 residents in California state prisons from December 2021 to December 2022, we find that vaccine-derived indirect protection against Omicron SARS-CoV-2 infection is strongest within three months of COVID-19 vaccination [30% (95% confidence interval: 20–38%)] with subsequent modest protection. Infection-acquired immunity provides 38% (24–50%) indirect protection for 6 months after SARS-CoV-2 infection, with moderate indirect protection persisting for over one year. Variant-targeted vaccines (bivalent formulation including Omicron subvariants BA.4/BA.5) confer strong indirect protection for at least three months [40% (3–63%)]. These results demonstrate that both vaccine-derived and infection-acquired immunity can reduce SARS-CoV-2 transmission which is important for understanding long-term transmission dynamics and can guide public health intervention, especially in high-risk environments such as prisons.

Source: Nature Communications, https://www.nature.com/articles/s41467-024-55029-9

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A comprehensive #review of current #insights into the #virulence factors of #SARS-CoV-2

ABSTRACT

The evolution of SARS-CoV-2 pathogenicity has been a major focus of attention. However, the determinants of pathogenicity are still unclear. Various hypotheses have attempted to elucidate the mechanisms underlying the evolution of viral pathogenicity, but a definitive conclusion has yet to be reached. Here, we review the potential impact of all proteins in SARS-CoV-2 on the viral pathogenic process and analyze the effects of their mutations on pathogenicity evolution. We aim to summarize which virus-encoded proteins are crucial in influencing viral pathogenicity, defined as disease severity following infection. Mutations in these key proteins, which are the virulence factors in SARS-CoV-2, may be the driving forces behind the evolution of viral pathogenicity. Mutations in the S protein can impact viral entry and fusogenicity. Mutations in proteins such as NSP2, NSP5, NSP14, and ORF7a can alter the virus’s ability to suppress host protein synthesis and innate immunity. Mutations in NSP3, NSP4, NSP6, N protein, NSP5, and NSP12 may alter viral replication efficiency. The combined effects of mutations in the S protein and NSP6 can significantly reduce viral replication. In addition, various viral proteins, including ORF3a, ORF8, NSP4, Spike protein, N protein, and E protein, directly participate in the inflammatory process. Mutations in these proteins can modulate the levels of inflammation following infection. Collectively, these viral protein mutations can influence SARS-CoV-2 pathogenicity by impacting viral immune evasion, replication capacity, and the level of inflammation mediated by infection. In conclusion, the evolution of SARS-CoV-2 pathogenicity is likely determined by multiple virulence factors.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.02049-24?af=R

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#Lithuania - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

The State Food and Veterinary Service of the Republic of Lithuania would like to inform you about an outbreak of high pathogenicity avian influenza (HPAI) on a laying hens establishment in total 9 aviaries, 246,387 in total. On the same day then suspicion was received, officially appointed veterinarians visited the farm, samples of dead hens were taken monitoring for Avian influenza, and Newcastle disease and sent to the National Institute for Food and Veterinary Risk Assessment (National Reference Laboratory) for avian influenza testing. Temporary restrictions were imposed on the farm immediately, pending laboratory results. Highly pathogenic avian influenza was confirmed in all samples and the H5N1 subtype was identified. {Farm is located in Klaipedos Region.}

Source: WOAH, https://wahis.woah.org/#/in-review/6220

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The #Swiss national #program for #surveillance of #influenza A viruses in #pigs and #humans: genetic variability and zoonotic transmissions from 2010 – 2022

Abstract

Influenza A viruses (IAV) are likely candidates for pandemics. This report summarizes the results of the Swiss national program for surveillance of influenza viruses in pigs and transmissions to humans between 2010 and 2022. Challenges and optimization options in the program are discussed. Nasal swabs or lung tissue samples from pigs with influenza-like signs (e.g. fever, cough) were screened by real-time RT-PCR for swine influenza virus (SIV) genomes, including that of the 2009 pandemic strain A(H1N1)pdm09; positive samples were subtyped for H1, N1, H3 and N2 by RT-PCR and Sanger sequencing. In parallel, humans with influenza-like symptoms and recent contact to diseased pigs were asked to self-sample themselves with a nasal swab. Human swabs were tested for IAV and positive swabs further subtyped to identify potential cross-species transmission between swine and humans. In the pigs, SIV was detected in 375 of 674 farm visits. H1N1 is the only subtype detected in Swiss pigs so far. The (H1N1)pdm09 strain (HA clade 1A) was only detected in seven out of 375 SIV positive farm visits. Phylogenetic analyses from partial hemagglutinin (HA) and neuraminidase (NA) genome sequences indicate that the remaining pigs were infected with the Eurasian avian lineage (HA clade 1C), which is predominant in swine in Europe. The Swiss H1N1 strains form distinct clusters within HA clades 1C.2.1 and 1C.2.2 and seem to evolve comparably slowly. Infection of humans with SIV was identified in five cases. Sequence analysis assigned the five viruses to the Eurasian avian lineage (C), clades 1C.2.1 and 1C.2.2. There was no evidence for sustained human-to-human transmission. Although no critical IAV variants seem to have emerged so far in Switzerland, further surveillance of influenza viruses at the swine-human interface is of major importance.

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.01.28.24319114v1

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A mathematical #model of #H5N1 #influenza #transmission in #US dairy #cattle.

Abstract

We present a stochastic metapopulation transmission model that simulates the spread of H5N1 avian influenza through individual dairy cows in 35,974 dairy herds in the continental United States. Transmission is enabled through the movement of cattle between herds, as indicated from Interstate Certificates of Veterinary Inspection (ICVI) data. We estimate the rates of under-reporting by state and present the anticipated rates of positivity for cattle tested at the point of exportation over time. We investigate the likely impact of intervention methods to date on the underlying epidemiological dynamics, demonstrating that current interventions have had insufficient impact, preventing only a mean 175.2 reported outbreaks. Our model predicts that the majority of the disease burden is, as of January 2025, concentrated within West Coast states, due to the network of cattle movements and distribution of the respective dairy populations. We quantify the extent of uncertainty in the scale of the epidemic, highlighting the most pressing data streams to capture, and which states are most expected to see outbreaks emerge next, with Arizona and Wisconsin at greatest risk. Our model suggests that dairy herd outbreaks will continue to be a significant public health challenge in 2025, and that more urgent, farm-focused, biosecurity interventions and targeted surveillance schemes are sorely needed.

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.01.28.25321250v1

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#Lithuania - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 A wild mute swan in Alytaus Region.

Source: WOAH, https://wahis.woah.org/#/in-review/6219

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A locally administered single-cycle #influenza #vaccine expressing a non-fusogenic stabilized #hemagglutinin stimulates strong T-cell and neutralizing #antibody #immunity

ABSTRACT

Current influenza vaccination approaches protect against specific viral strains, but do not consistently induce broad and long-lasting protection to the diversity of circulating influenza viruses. Single-cycle viruses delivered to the respiratory tract may offer a promising solution as they safely express a diverse array of viral antigens by undergoing just one round of cell infection in their host and stimulate broadly protective resident memory T-cell responses in the lung. We have previously developed a vaccine candidate called S-FLU, which is limited to a single cycle of infection by inactivation of the hemagglutinin signal sequence and induces a broadly cross-reactive T-cell response and antibodies to neuraminidase, but fails to induce neutralizing antibodies to hemagglutinin after intranasal administration. This study describes the development of CLEARFLU, a derivative of S-FLU, which is designed to add a neutralizing antibody response to hemagglutinin. In contrast to S-FLU, which does not express a hemagglutinin molecule at the infected cell surface, CLEARFLU viruses express a stabilized non-fusogenic hemagglutinin. They are equally limited to a single cycle of infection, but induce a neutralizing antibody response to the expressed hemagglutinin in addition to the cytotoxic T-lymphocyte (CTL) responses to internal proteins and antibodies to neuraminidase induced by S-FLU. This represents a notable advantage as CLEARFLU viruses may provide sterile immunity against strain-matched challenge as well as non-sterile protection against a broad range of influenza viruses.

Source: Journal of Virology, https://journals.asm.org/doi/full/10.1128/jvi.00331-24?af=R

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#Influenza at the #human - #animal #interface - #Summary and #risk #assessment, from 13 December 2024 to 20 January 202

New human cases{2}: 

From 13 December 2024 to 20 January 2025, the detection of influenza A(H5) virus in five humans, influenza A(H9N2) virus in two humans, and influenza A(H10N3) virus in one human were reported officially. Additionally, five human cases of infection with influenza A(H5) viruses were detected.  

Circulation of influenza viruses with zoonotic potential in animals: 

High pathogenicity avian influenza (HPAI) events in poultry and non-poultry continue to be reported to the World Organisation for Animal Health (WOAH).{3} The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4}  

Risk assessment{5}: 

Based on information available at the time of the risk assessment, the overall public health risk from currently known influenza viruses at the human-animal interface has not changed remains low. Sustained human to human transmission has not been reported from these events and the occurrence of sustained human-to-human transmission of these viruses is currently considered unlikely. Although human infections with viruses of animal origin are infrequent, they are not unexpected at the human-animal interface.  

IHR compliance: 

All human infections caused by a new influenza subtype are required to be reported under the International Health Regulations (IHR, 2005).{6} This includes any influenza A virus that has demonstrated the capacity to infect a human and its haemagglutinin gene (or protein) is not a mutated form of those, i.e. A(H1) or A(H3), circulating widely in the human population. Information from these notifications is critical to inform risk assessments for influenza at the human-animal interface.  Avian influenza viruses in humans Current situation:  Since the last risk assessment of 12 December 2024, influenza A(H5) virus has been detected in nine humans in the United States of America (USA) and one laboratory-confirmed human case of A(H5N1) infection was reported to WHO from Cambodia. 

A(H5), USA 

On 14 December 2024, the USA notified WHO of one laboratory-confirmed human case of infection with influenza A(H5) in an adult aged over 65 years from the state of Louisiana. The patient, with underlying conditions, developed symptoms and sought care at an emergency department in early December 2024. Due to worsening symptoms, the patient returned to the emergency department a few days later, was hospitalized in critical condition with pneumonia, and started on antiviral treatment. Unfortunately, the patient passed away. No household contacts of the case tested positive for influenza viruses. The individual owned backyard poultry and had noted deaths in domestic and wild birds on the property prior to symptom onset. A(H5N1) viruses were detected in poultry on the property. The viruses identified in two clinical samples from the patent were identified as influenza A(H5N1) viruses belonging to the clade 2.3.4.4b and the genotype D1.1. Deep sequencing of the genetic sequences from the two clinical specimens were compared to A(H5N1) virus sequences from dairy cows, wild birds, poultry and other human cases in the USA and Canada. The hemagglutinin (HA) gene sequences of the viruses from the clinical specimens are closely related to other D1.1 viruses recently detected in wild birds and poultry in the Louisiana and other parts of the USA and in recent human cases detected in Canada and the USA, as well as to existing influenza A(H5N1) candidate vaccine viruses.{7} Some changes in the HA gene segment of one of the clinical specimens from the patient were detected at a low frequency. These changes have rarely been identified in specimens from previous human infections with A(H5N1) viruses and were not detected in specimens from the poultry on the property of the patient. It is possible that these changes arise during viral replication in the infected human cases. No changes in the polymerase genes associated with adaptation to mammals were identified. No changes associated with known or suspected markers of reduced susceptibility to antiviral drugs were identified.{8,9,10} Between 20 and 21 December 2024, the USA notified WHO of two additional laboratory-confirmed human case of infection with influenza A(H5) in an adult from the states of Iowa and Wisconsin. The cases developed symptoms in December 2024 and reported their illness to public health officials as part of active monitoring. The cases were not hospitalized and have recovered. Both cases were exposed to influenza A(H5N1) while working at poultry facilities. On 15 January 2025, the USA notified WHO of one additional laboratory-confirmed human case of infection with influenza A(H5) from the state of California. The case occurred in a child less than 18 years old with no known contact with influenza A(H5N1) virus-infected animals or humans. The investigation into the source of infection and contact monitoring around this case was ongoing at the time of reporting, and thus far, no human-to-human transmission has been identified. Additional analysis including genetic sequencing of the virus from the specimen from this case was underway at the time of reporting.{11}  Five additional cases of influenza A(H5) were detected in California in individuals aged over 18 years who worked at commercial dairy cattle farms in areas where highly pathogenic avian influenza (HPAI)(H5N1) viruses had been detected in cows. The individuals had mild symptoms.{12,13} Low pathogenicity and high pathogenicity avian influenza (HPAI) viruses have been detected in birds in the United States.  Since 2022, the HPAI A(H5) virus has been detected in commercial and backyard flocks in 48 states, impacting over 100 million birds. To date, 67 people have tested positive for A(H5) virus in the United States since 2022, with all but one of these cases occurring in 2024. All cases have been associated with exposure to either A(H5N1)-infected poultry or dairy cattle, except for two cases where the exposure source could not be identified.{14} To date, no humanto-human transmission of influenza A(H5) virus has been identified in the USA. A(H5N1) virus infections in dairy cattle and wild and domestic birds continue to be reported in the USA.{15} 

A(H5N1), Cambodia 

On 10 January 2025, Cambodia notified WHO of one case of human infection with influenza A(H5N1) in a 28-year-old male from Kampong Cham Province. The case had onset of fever, sore throat and chest pain on 1 January 2025. He sought care at two private local clinics and after his condition did not improve, he traveled to Phnom Penh and was hospitalized due to shortness of breath on 7 January at a national hospital, which is a severe acute respiratory infection (SARI) sentinel site. The case was isolated upon admission and provided oseltamivir and symptomatic treatment before passing away on 10 January. Nasopharyngeal (NP) and oropharyngeal (OP) swab specimens tested positive on 9 January for influenza A(H5N1) by real-time reverse transcription-polymerase chain reaction (rt-PCR) at the National Institute of Public Health of Cambodia. The Institut Pasteur du Cambodge (IPC) confirmed the results on 10 January. Sequence analysis of HA gene shows the virus belongs to clade 2.3.2.1c and is closely related to those viruses circulating among birds in Cambodia in 2024. Phylogenetic and molecular analysis is ongoing.  According to the early investigation, the case was a guard of a farm in the village where he lived and raised poultry for family consumption. There were reports of sick poultry in his farm and samples from the poultry on the farm have been collected. No further cases were detected among the contacts of the case.  According to reports received by WOAH, various influenza A(H5) subtypes continue to be detected in wild and domestic birds in the Americas, Asia and Europe. Infections in non-human mammals are also reported, including in marine and land mammals.{16} A list of bird and mammalian species affected by HPAI A(H5) viruses is maintained by FAO.{17}

Risk Assessment for avian influenza A(H5) viruses:  

1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5) viruses?  

Most human cases so far have been infections in people exposed to A(H5) viruses, for example, through contact with infected poultry or contaminated environments, including live poultry markets, and occasionally infected mammals and contaminated environments. While the viruses continue to be detected in animals and related environments humans are exposed to, further human cases associated with such exposures are expected but unusual. The impact for public health if additional cases are detected is minimal. The current overall global public health risk of additional human cases is low. 

2. What is the likelihood of sustained human-to-human transmission of currently circulating avian influenza A(H5) viruses?  

No sustained human-to-human transmission has been identified associated with the recent reported human infections with avian influenza A(H5). There has been no reported human-to-human transmission of A(H5N1) viruses since 2007, although there may be gaps in investigations. In 2007 and the years prior, small clusters of A(H5) virus infections in humans were reported, including some involving health care workers, where limited human-to-human transmission could not be excluded; however, sustained human-to-human transmission was not reported.  Available evidence suggests that influenza A(H5) viruses circulating have not acquired the ability to efficiently transmit between people, therefore the likelihood of sustained human-to-human transmission is thus currently considered unlikely at this time.  

3. What is the likelihood of international spread of avian influenza A(H5) viruses by travellers?  

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further communitylevel spread is considered unlikely as current evidence suggests these viruses have not acquired the ability to transmit easily among humans.  

A(H9N2), China 

Since the last risk assessment of 12 December 2024, two human cases of infection with A(H9N2) influenza viruses were notified to WHO from China (Table 1). Both cases were detected through influenza-like illness (ILI) surveillance, were mild and have recovered. Both cases had a history of exposure to live poultry markets prior the onset of symptoms. No further cases were detected among contacts of the cases. Influenza A(H9) virus was detected in the poultry-related environments associated with these cases.

Risk Assessment for avian influenza A(H9N2):  

1. What is the global public health risk of additional human cases of infection with avian influenza A(H9N2) viruses?  

Most human cases follow exposure to the A(H9N2) virus through contact with infected poultry or contaminated environments. Most human infections of A(H9N2) to date have resulted in mild clinical illness in most cases. Nearly 130 human infections with A(H9N2) cases have been reported to date since 2003, and six of these have been severe or fatal and three of these were known to have underlying medical conditions. Since the virus is endemic in poultry in multiple continues in Africa and Asia{18}, further human cases associated with exposure to infected poultry are expected but remain unusual. The impact to public health if additional cases are detected is minimal. The overall global public health risk of additional human cases is low. 

2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H9N2) viruses?  

At the present time, no sustained human-to-human transmission has been identified associated with the event described above. Current evidence suggests that influenza A(H9N2) viruses from these cases have not acquired the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.  

3. What is the likelihood of international spread of avian influenza A(H9N2) virus by travellers?  

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community level spread is considered unlikely as current evidence suggests the A(H9N2) virus subtype has not acquired the ability to transmit easily among humans.  

A(H10N3), China 

Since the last risk assessment of 12 December 2024, one human case of infection with A(H10N3) influenza viruses were notified to WHO from China on 3 January 2025. A 23-year-old female from Guangxi Zhuang Autonomous Region, with an underlying condition, had symptom onset on 12 December 2024. She was admitted to hospital on 19 December with severe pneumonia and treated with oseltamivir. Initially, she was in critical condition but has improved. A clinical sample collected on 22 December tested positive for influenza A and influenza A(H10N3) was confirmed a on 26 December. Prior to symptom onset, the patient worked at a supermarket and was exposed to freshly slaughtered poultry. No family members have developed symptoms at the time of reporting. All close contacts tested negative for influenza A(H10N3). All environmental samples collected from various locations tested negative for influenza A(H10N3). This is the fourth case of human A(H10N3) virus infection detected in China and globally to date. 

Risk Assessment for avian influenza A(H10N3):  

1. What is the global public health risk of additional human cases of infection with avian influenza A(H10N3) viruses? 

Human infections with avian influenza A(H10) viruses have been detected and reported previously. The extent of circulation and epidemiology of these viruses in birds is unclear. Avian influenza A(H10N3) viruses with different genetic characteristics have been detected previously in migratory and other wild birds since the 1970s. As long as the virus continues to circulate in birds, further human cases can be expected but remain unusual. The impact to public health if additional sporadic cases are detected is minimal. The overall global public health risk of additional sporadic human cases is low. 

2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H10N3) viruses? 

No sustained human-to-human transmission has been identified associated with the event described Above or past events with human cases of influenza A(H10N3) viruses. Current epidemiologic and virologic evidence suggests that contemporary influenza A(H10N3) viruses assessed by the Global Influenza Surveillance and response System (GISRS) have not acquired the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely. 

3. What is the likelihood of international spread of avian influenza A(H10N3) virus by travellers? 

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community level spread is considered unlikely based on current limited evidence. 

Overall risk management recommendations: 

-- Surveillance and investigations 

• Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global strategic surveillance in animals and humans to detect virologic, epidemiologic and clinical changes associated with circulating influenza viruses that may affect human (or animal) health. Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. Close collaboration with the animal health and environment sectors is essential to understand the extent of the risk of human exposure and to prevent and control the spread of animal influenza. 

• As the extent of influenza virus circulation in animals is not clear, epidemiologic and virologic surveillance and the follow-up of suspected human cases should continue systematically. Guidance on investigation of non-seasonal influenza and other emerging acute respiratory diseases has been published on the WHO website. 

• Countries should increase avian influenza surveillance in domestic and wild birds, enhance surveillance for early detection in cattle populations in countries where HPAI is known to be circulating, include HPAI as a differential diagnosis in non-avian species, including cattle and other livestock populations, with high risk of exposure to HPAI viruses; monitor and investigate cases in non-avian species, including livestock, report cases of HPAI in all animal species, including unusual hosts, to WOAH and other international organizations, share genetic sequences of avian influenza viruses in publicly available databases, implement preventive and early response measures to break the HPAI transmission cycle among animals through movement restrictions of infected livestock holdings and strict biosecurity measures in all holdings, employ good production and hygiene practices when handing animal products, and protect persons in contact with suspected/infected animals.{19}  

• When there has been human exposure to a known outbreak of an influenza A virus in domestic poultry, wild birds or other animals – or when there has been an identified human case of infection with such a virus – enhanced surveillance in potentially exposed human populations becomes necessary. Enhanced surveillance should consider the health care seeking behaviour of the population, and could include a range of active and passive health care and/or communitybased approaches, including: enhanced surveillance in local influenza-like illness (ILI)/SARI systems, active screening in hospitals and of groups that may be at higher occupational risk of exposure, and inclusion of other sources such as traditional healers, private practitioners and private diagnostic laboratories. 

• Vigilance for the emergence of novel influenza viruses of pandemic potential should be maintained at all times including during a non-influenza emergency. In the context of the cocirculation of SARS-CoV-2 and influenza viruses, WHO has updated and published practical guidance for integrated surveillance. 

Notifying WHO 

• All human infections caused by a new subtype of influenza virus are notifiable under the International Health Regulations (IHR, 2005).{20} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed{21} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic22. Evidence of illness is not required for this report. 

• WHO published the case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005): https://www.who.int/teams/global-influenzaprogramme/avian-influenza/case-definitions. Virus sharing and risk assessment 

• It is critical that these influenza viruses from animals or from people are fully characterized in appropriate animal or human health influenza reference laboratories. Under WHO’s Pandemic Influenza Preparedness (PIP) Framework, Member States are expected to share influenza viruses with pandemic potential on a timely basis{23} with a WHO Collaborating Centre for influenza of GISRS. The viruses are used by the public health laboratories to assess the risk of pandemic influenza and to develop candidate vaccine viruses.  

• The Tool for Influenza Pandemic Risk Assessment (TIPRA) provides an in-depth assessment of risk associated with some zoonotic influenza viruses – notably the likelihood of the virus gaining human-to-human transmissibility, and the impact should the virus gain such transmissibility. TIPRA maps relative risk amongst viruses assessed using multiple elements. The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA analyses will be published at http://www.who.int/teams/global-influenza-programme/avian-influenza/toolfor-influenza-pandemic-risk-assessment-(tipra).  

Risk reduction 

• Given the observed extent and frequency of avian influenza in poultry, wild birds and some wild and domestic mammals, the public should avoid contact with animals that are sick or dead from unknown causes, including wild animals, and should report dead birds and mammals or request their removal by contacting local wildlife or veterinary authorities.  

• Eggs, poultry meat and other poultry food products should be properly cooked and properly handled during food preparation. Due to the potential health risks to consumers, raw milk should be avoided. WHO advises consuming pasteurized milk. If pasteurized milk isn’t available, heating raw milk until it boils makes it safer for consumption. 

• WHO has published practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses. 

Trade and travellers 

• WHO advises that travellers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal excreta. Travelers should also wash their hands often with soap and water. All individuals should follow good food safety and hygiene practices.  

• WHO does not advise special traveller screening at points of entry or restrictions with regards to the current situation of influenza viruses at the human-animal interface. For recommendations on safe trade in animals and related products from countries affected by these influenza viruses, refer to WOAH guidance.  

Links:  

-- WHO Human-Animal Interface web page https://www.who.int/teams/global-influenza-programme/avian-influenza 

-- WHO Influenza (Avian and other zoonotic) fact sheet https://www.who.int/news-room/fact-sheets/detail/influenza-(avian-and-other-zoonotic) 

-- WHO Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases https://www.who.int/publications/i/item/WHO-WHE-IHM-GIP-2018.2 

-- WHO Public health resource pack for countries experiencing outbreaks of influenza in animals:  https://www.who.int/publications/i/item/9789240076884 

-- Cumulative Number of Confirmed Human Cases of Avian Influenza A(H5N1) Reported to WHO  https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-a-h5n1-virus 

-- Avian Influenza A(H7N9) Information https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-influenza-a-(h7n9)virus 

-- World Organisation of Animal Health (WOAH) web page: Avian Influenza  https://www.woah.org/en/home/ 

-- Food and Agriculture Organization of the United Nations (FAO) webpage: Avian Influenza https://www.fao.org/animal-health/avian-flu-qa/en/ 

-- OFFLU http://www.offlu.org/ 

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{1} This summary and assessment covers information confirmed during this period and may include information received outside of this period. 

{2} For epidemiological and virological features of human infections with animal influenza viruses not reported in this assessment, see the reports on human cases of influenza at the human-animal interface published in the Weekly Epidemiological Record here.  

{3} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{4} Food and Agriculture Organization of the United Nations (FAO). Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential. 

{5} World Health Organization (2012). Rapid risk assessment of acute public health events. World Health Organization. Available at: https://iris.who.int/handle/10665/70810. 

{6} World Health Organization. Case definitions for the 4 diseases requiring notification to WHO in all circumstances under the International Health Regulations (2005). Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005).  

{7} WHO. Zoonotic influenza: candidate vaccine viruses and potency testing reagents. Available at: https://www.who.int/teams/global-influenza-programme/vaccines/who-recommendations/zoonoticinfluenza-viruses-and-candidate-vaccine-viruses. 

{8} US CDC. CDC Confirms First Severe Case of H5N1 Bird Flu in the United States, 18 Dec 2024. Available at: https://www.cdc.gov/media/releases/2024/m1218-h5n1-flu.html. 

{9} US CDC. Genetic Sequences of Highly Pathogenic Avian Influenza A(H5N1) Viruses Identified in a Person in Louisiana, 26 Dec 2024. Available at: https://www.cdc.gov/bird-flu/spotlights/h5n1-response-12232024.html. 

{10} US CDC. First H5 Bird Flu Death Reported in United States, 6 Jan 2025. Available at: https://www.cdc.gov/media/releases/2025/m0106-h5-birdflu-death.html. 

{11} US CDC. Weekly US Influenza Surveillance Report: Key Updates for Week 2, ending January 11, 2025. Available at: https://www.cdc.gov/fluview/surveillance/2025-week-02.html. 

{12} US CDC. Weekly US Influenza Surveillance Report: Key Updates for Week 50, ending December 14, 2024. Available at: https://www.cdc.gov/fluview/surveillance/2024-week-50.html. 

{13} US CDC. Weekly US Influenza Surveillance Report: Key Updates for Week 51, ending December 21, 2024. Available at: https://www.cdc.gov/fluview/surveillance/2024-week-51.html. 

{14} United States Centers for Disease Control and Prevention. H5 Bird Flu: Current Situation. Available at: https://www.cdc.gov/bird-flu/situationsummary/index.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fbird-flu%2Fphp%2Favian-flusummary%2Findex.html. 

{15}  United States Department of Agriculture. Highly Pathogenic Avian Influenza (HPAI) Detections in Livestock, 19 July 2024. Available at: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpaidetections/livestock. 

{16}  World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{17} Food and Agriculture Organization of the United Nations. Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential/bird-species-affected-by-h5nx-hpai/en. 

{18} Food and Agriculture Organization of the United Nations (FAO). Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential. 

{19} World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024. Available at: https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/. 

{20} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005).    

{21} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011). Available at: https://apps.who.int/iris/handle/10665/44518 22 

{22} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition. Available at: https://iris.who.int/handle/10665/341850 23 

{23} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017). Available at: https://apps.who.int/iris/handle/10665/25940 

___

Source: World Health Organization, https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--20-january-2025

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Avian #influenza #risk of #upsurge and regional spread through increased #poultry #trade before and during #Lunar New Year #festivities in #Asia

FAO calls for increased vigilance and preparedness for avian influenza (AI) during the traditional New Year festivities that will take place across Asia on the week of 27 January 2025.

In the past year, outbreaks of AI have continued to be reported in domestic poultry, wild birds and mammals in Asia. Several AI virus subtypes including H5N1, H5N2, H5N3, H5N5, H5N6, H5N8, H7N3, H7N6, H7N8, H7N9, H10N5, and H3N2 are currently well-established in both wild and domestic bird populations in the region. In addition, subtype H5N1 subclade 2.3.4.4b continues to circulate in both wild and domestic birds worldwide.

Highly pathogenic avian influenza (HPAI) can lead to heavy losses for the poultry industry, in particular to the livelihoods of vulnerable small-scale producers. Poultry trade and related activities play a key role in AI spread and amplification in domestic bird populations, including the trade of infected live poultry and their products, handling or slaughtering infected poultry, and limited biosecurity along the poultry value chain. Before and during New Year festivities, the risk is further exacerbated by high demand for poultry meat and products, triggering increased and intensified poultry trade and movements as well as visits to live poultry markets.

In addition, a rise in mammalian species infected with HPAI has been recorded globally including outbreaks in farmed mink in Europe, marine mammals in the Americas, cats in the Republic of Korea, and more recently in red foxes and raccoon dogs in Japan, and in captive wild felids in Viet Nam. Notably in 2024, HPAI H5N1 has been found in raw milk of dairy cows – the animals experienced clinical signs including decreased milk production, thickened colostrum-like milk, reduced food intake, lethargy, fever, loose manure and dehydration.

Importantly, AI virus subtypes have demonstrated their zoonotic potential, i.e. the ability to transmit between birds and humans. During 2024, in the Region of Asia and the Pacific, human cases of influenza A(H5N1) were detected in Australia, Cambodia, and Viet Nam. HPAI A(H5N6) was also reported in China. Other subtypes have also been associated with zoonotic transmission in Asia in the past year, including influenza, A(H3N8), and A(H9N2).

Most of these cases reported exposure through close contact with infected live poultry. While human infections with AI viruses remain sporadic events and do not currently spread easily from person to person, they warrant attention since symptoms observed in humans range from asymptomatic to severe and can be fatal.

INCREASED AVIAN INFLUENZA RISK

There is an increased risk of AI spread in Asia due to intensified in-country travel around Lunar New Year (January-February 2025), specifically considering the following:

-- millions of people are expected to travel for the New Year (starting late January 2025);

-- vast majority of traffic will be within countries of the Asian region, but also to and from Asia;

-- poultry trade is increasing to serve the high demand for poultry meat and other products consumed during these festivities;

-- travel and trade increase the risk of spreading AI, since the virus can be transmitted via contact with infected animals as well as contaminated clothing, vehicles and other equipment.

RECOMMENDED ACTIONS

In light of the elevated risk, FAO is calling on all Chief Veterinary Officers (CVOs) in Asia to increase AI prevention and preparedness activities to reduce the likelihood of poultry outbreaks and subsequent impacts on livelihoods, economies, and human infections.

Specifically, FAO recommends countries to:

-- Enhance controls at national borders and along traffic routes based on risk analyses to minimize the risk of introduction of potentially infected live poultry and poultry products.

-- Promote improved biosecurity measures along the value chain, including at farms, live bird markets, slaughter points, etc. to limit further spread of the disease and mitigate the risk of human exposure.

-- Implement measures for early detection, timely reporting and rapid containment of infection, as delays can lead to rapid spread. In addition, the adoption of policies that encourage disease reporting, such as providing adequate compensation following animal culling, can help mitigate these threats.

-- On infected premises (e.g. farms or live bird markets including associated vehicles), conduct appropriate cleaning and disinfection and take action on carcasses, slurry and faecal waste to ensure they do not pose a risk for further transmission and spread of virus. Where possible, use the period immediately following the Lunar New Year festivities for short closures of live bird markets for decontamination after all birds have been sold and processed.

-- Upon detection of outbreaks, timely alert neighbouring countries as well as international organizations, including the World Organisation for Animal Health (WOAH). This includes rapid sharing of virus sequences with relevant partners to ensure appropriate actions are taken by countries in the region (e.g. ensuring the use of adapted vaccines in countries that implement vaccination programmes against AI). The OFFLU Avian Influenza Vaccine Matching (AIM) for poultry vaccines is available for guidance.

-- Implement surveillance schemes that support the detection of HPAI viruses in both domestic and wild birds. Provide mechanisms for reporting sick or dead birds (hotlines, collection points) and raise awareness about the importance of reporting. Farmers, hunters, or rangers should be encouraged to report to veterinary authorities once they see unusual clinical signs in birds including: sudden increase in mortalities; swelling of the head, eyelids, comb, wattles, and hocks; purple discoloration of the wattles, comb, and legs; gasping for air (difficulty breathing); coughing, sneezing, and/or nasal discharge (runny nose); stumbling or falling; or ruffled feathers or neurological disease in water birds.

-- Expand surveillance to relevant mammals, for better early detection of HPAI viruses, and to understand their role in the epidemiology, spread and transmission of avian influenza, including in dairy cattle. FAO Recommendations for the surveillance of influenza A(H5N1) in cattle and A list of mammalian species affected by H5Nx are available for guidance.

-- Ensure laboratories have adequate capacities to diagnose circulating H5Nx HPAI viruses and deploy point-of-need rapid tests as appropriate.

-- Implement targeted sampling of animals with a higher likelihood of detecting the virus. Targeting sick or freshly dead birds as well as sampling their environment will increase the probability of detecting AI viruses.

-- Shift to active surveillance, differential diagnosis, and increased virological screening. Active surveillance in key hotspots of the poultry value chain such as live bird markets allows for early detection of AI virus incursion/amplification.

-- Collaborate closely with forestry/environment sector and wetland, or bird reserve management authorities in contact with wild bird populations to foster information-sharing and joint AI surveillance and prevention activities well ahead of the potential introduction or spread of the virus.

-- Facilitate early reporting and response by consulting closely with the private sector (i.e. producers, traders and related businesses). Preparing and sharing communication materials prior to AI virus introduction will help minimize misunderstandings and rumours.

-- Reinforce awareness campaigns. High level of awareness should be maintained among poultry keepers, the general population, traders, market workers, hunters, and any other relevant stakeholder about AI, precautionary and personal protection measures as well as reporting and collection mechanisms for sick or dead birds.

-- Action against wild birds, particularly indiscriminate hunting or disturbances of habitat, should not be undertaken. Guidance is available to respond to HPAI in wild birds.

WHAT FAO IS DOING

-- Tracking disease rumours in Asia and the Pacific and sharing relevant information with stakeholders in the region on a bi-weekly basis. Please see FAO ECTAD event-based surveillance in Asia and the Pacific bi-weekly update for more information.

-- Conducting consultations with AI experts in Asia and the Pacific to identify innovative approaches to respond to emerging AI threats. Published consultation reports are available at this link.

-- Conducting public health assessments jointly with Tripartite partners (FAO/WHO/WOAH) of recent influenza A(H5) virus events in animals and people.

-- Monitoring and assessing the evolving disease situation. To share updates on your country's situation, please contact FAO at FAO-GLEWS@fao.org.

-- Liaising with FAO/WOAH Reference Laboratories and partner organizations to assess virus characteristics and provide laboratory protocols for detection.

-- Raising awareness about important epidemiological and virological findings and their implications.

-- Providing recommendations for affected countries and those at risk addressing preparedness, prevention and disease control.

-- Providing support for risk assessment and mapping to identify hot spots for risk mitigation and the implementation of risk-based surveillance.

-- Offering support in the provision of diagnostic reagents and personal protective equipment, provided certain conditions are met (contact: EMPRES-Lab-Unit@fao.org).

-- Offering assistance to national authorities for shipment of samples as well as virus sub-typing and sequencing, provided certain conditions are met (contact: EMPRES-Shipping-Service@fao.org).

Source: Food and Agriculture Organization, https://www.fao.org/animal-health/situation-updates/global-aiv-with-zoonotic-potential#alert

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#India - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 Wild Cranes in Rajasthan State.

Source: WOAH, https://wahis.woah.org/#/in-review/6217

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#UK, #Human case of avian #influenza #H5N1 detected in #England

UKHSA has confirmed a case of influenza A(H5N1) in a person in the West Midlands region. Bird-to-human transmission of avian influenza is rare and has previously occurred a small number of times in the UK.

The person acquired the infection on a farm, where they had close and prolonged contact with a large number of infected birds. The risk to the wider public continues to be very low.

The individual is currently well and was admitted to a High Consequence Infectious Disease (HCID) unit.

The birds were infected with the DI.2 genotype, one of the viruses known to be circulating in birds in the UK this season. This is different to strains circulating among mammals and birds in the US.

Although there has been no demonstrated human-to-human transmission despite extensive recent surveillance of influenza A(H5N1), UKHSA has been tracing all individuals who have been in contact with the confirmed case of avian influenza. Those at highest risk of exposure have been offered antiviral treatment. This is done to reduce the chance that any virus they have been exposed to will be able to cause infection.

The case was detected after the Animal and Plant Health Agency (APHA) identified an outbreak of avian influenza(H5N1) in a flock of birds. UKHSA carried out routine monitoring on people who had been in close contact with the infected birds.

Professor Susan Hopkins, Chief Medical Adviser at UKHSA, said:

''The risk of avian flu to the general public remains very low despite this confirmed case. We have robust systems in place to detect cases early and take necessary action, as we know that spillover infections from birds to humans may occur.  

Currently there is no evidence of onwards transmission from this case.

People are reminded not to touch sick or dead birds and it’s important that they follow Defra advice about reporting any suspected avian influenza cases.

UK Chief Veterinary Officer Christine Middlemiss said:

''While avian influenza is highly contagious in birds, this is a very rare event and is very specific to the circumstances on this premises.

We took swift action to limit the spread of the disease at the site in question, all infected birds are being humanely culled, and cleansing and disinfection of the premises will be undertaken all to strict biosecure standards. This is a reminder that stringent biosecurity is essential when keeping animals.

We are seeing a growing number of avian flu cases in birds on both commercial farms and in backyard flocks across the country. Implementing scrupulous biosecurity measures will help protect the health and welfare of your birds from the threat of avian influenza and other diseases.

Andrew Gwynne, Minister for Public Health and Prevention, said:

''The safety of the public is paramount, and we are monitoring this situation closely.

The risk of wider or onward transmission is very low, however the UK remains prepared and ready to respond to any current and future health threats.

We recently added the H5 vaccine, which protects against avian influenza, to our stockpile as part of our preparedness plans.

UKHSA will publish further details about the confirmed human case in due course.

Source: UK Health Security Agency, https://www.gov.uk/government/news/human-case-of-avian-flu-detected-in-england#:~:text=UKHSA%20confirms%20rare%20case%20of,in%20the%20West%20Midlands%20region.&text=UKHSA%20has%20confirmed%20a%20case,of%20times%20in%20the%20UK.

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#Isolation and Characterization of #H1 Subtype #Swine #Influenza Viruses Recently Circulating in #China

Abstract

Pigs serve as a mixing vessel for influenza viruses and can independently promote the emergence of pandemic strains in humans. During our surveillance of pig populations from 2021 to 2023 in China, 11 H1 subtype swine influenza viruses (SIVs) were isolated. All viruses were reassortants, possessing internal genes of identical origins (PB2, PB1, PA, NP, M: pdm09/H1N1 origin, NS: North American triple reassortant origin). The H1N1 isolates were all the dominant G4 EA H1N1 viruses in China. Two H1N2 isolates carried early human pdm09/H1N1 HA genes, suggesting a possible pig-to-human transmission route. Mutations that dictate host range specificity were identified in all isolates, a phenomenon which may enhance the affinity to human receptors. These H1 subtype viruses effectively replicated both in vivo and in vitro without prior adaptation and exhibited different pathogenicity and growth characteristics. Some of the H1 viruses were even found to cause lethal infections in mice. Taken together, our study indicates that the H1 subtype SIVs recently circulating in China pose a potential threat to human health and emphasizes the importance of continuing to closely monitor their evolution and spread.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/185

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Improving #clinical #care of patients in #Nipah #outbreaks: moving beyond ‘compassionate use’

Summary

The 2024 Nipah outbreak in Kerala, India—its fifth in six years—and the recurring annual outbreaks in Bangladesh underscore the persistent threat posed by the Nipah virus (NiV) in the region. With a high mortality rate, human-to-human transmission potential, and the widespread presence of Pteropus bats, the natural reservoir, NiV remains a significant epidemic threat. Despite being a WHO priority pathogen, there has been no systematic effort to improve patient care for NiVD, leading to consistently poor outcomes. Current care relies on supportive measures and the ‘compassionate use’ of unapproved drugs like ribavirin and remdesivir. Drugs used ‘off-label’ during outbreaks can become the ‘standard of care’ without robust evidence of their safety or efficacy, complicating the testing of new therapies and perpetuating uncertainty about their true effectiveness. To improve NiVD care, we propose four key strategies: 1) Enhance early case detection, 2) optimize supportive care to improve outcomes and create a standard for future trials, 3) adopt a syndromic approach centered on encephalitis, and 4) explore innovative trial designs tailored to low case numbers as an alternative to ‘compassionate use’. By integrating these strategies, healthcare systems in NiV-endemic regions will be better equipped to manage both current and future outbreaks.

Source: Lancet Regional Health South-East Asia, https://www.thelancet.com/journals/lansea/article/PIIS2772-3682(24)00177-X/fulltext

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New incursions of #H5N1 clade 2.3.4.4b highly pathogenic avian #influenza viruses in wild #birds, South #Korea, October 2024

{Excerpt}

Highly pathogenic avian influenza (HPAI) subtype H5Nx viruses of the A/Goose/Guangdong/1/1996 (Gs/Gd) lineage have led to substantial economic losses within the poultry industry and represent an ongoing public health threat (1). The Gs/Gd lineage H5 viruses not only have evolved into 10 primary clades 0–9 with their subclades but are also reassorted with other influenza A viruses (2–4). Notably, since 2020, clade 2.3.4.4b HPAI H5N1 viruses have caused outbreaks across a broad geographic range, including Asia, Europe, Africa, North America, South America, and Antarctica (5–7). The infections of HPAI H5N1 viruses in mammals including wild, domestic, and humans underscore the potential zoonotic risk and pandemic potential of these evolving H5 viruses (8).

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Source: Frontiers in Veterinary Sciences, https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1526118/full

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