Estimated #Transmissibility and #CFR of #Bundibugyo Virus, #Uganda, 2007

 

Abstract

Because the epidemiology of Bundibugyo virus remains unclear, we reanalyzed the first recognized outbreak (Uganda, 2007). Adjusting for case under-ascertainment and the effect of control measures, we estimated the effective reproduction number (1.55, falling to <1 after intervention) and case-fatality rate (31%, declining to 25%). The underascertainment rate was 15%.

Source: 

Link: https://doi.org/10.3201/eid3210.261175

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Experimental Highly Pathogenic Avian #Influenza #H5N1 Clade 2.3.4.4b Virus #Infection in #Alpacas, 2026

 

Abstract

Highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus continues to spread globally and sporadically transmits from avian reservoirs to mammalian hosts. In May 2024, H5N1 infections in young goats and alpacas in the United States were reported. Nevertheless, the overall susceptibility of camelids to clade 2.3.4.4b virus remains unclear. We conducted a controlled experimental infection study in 6 alpacas, assessing clinical signs, viral shedding, tissue distribution, and serologic responses after intranasal inoculation with HPAI H5N1 genotype B3.13 virus. Observed illness was generally mild; body temperature increased slightly and food intake reduced for up to 3 days postinfection. We detected viral RNA in nasal swab samples and confirmed infectious HPAI H5N1 virus. Immunohistochemistry and RNA in situ hybridization detected virus only in the nasopharyngeal tonsil and nasal conchae at 4 days postinfection. Our findings suggest alpacas are susceptible to productive H5N1 infection, highlighting implications for livestock surveillance and biosecurity in regions with ongoing circulation.

Source: 

Link: https://doi.org/10.3201/eid3210.260491

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Rapid #risk #assessment: #Diphtheria, African Region (WHO, September 17 '26, summary)

 

(...)

Risk statement

    Diphtheria remains a public health threat in the WHO African Region. Since 1 March 2026, transmission has continued in Chad, Guinea, Mali,  Mauritania, Niger, Nigeria and South Africa, and a new outbreak has been  detected in Senegal. 

    The current situation in Algeria could not be assessed as no updated  epidemiological information for 2026 was available when this RRA was performed. 

    Most recent incidence data came in week 32/2026 (ending 9 August  2026) from Senegal, reporting 12 laboratory-confirmed diphtheria cases,  including two deaths, reported between 21 July and 10 August 2026.

    Based on the most recent information available through epidemiological  week 33 of 2026, Nigeria continues to report the largest number of cases (68%  of all cases). 

    Guinea has reported a recent increase in morbidity and mortality, with  over 100 recorded deaths and a persistently high case fatality ratio (CFR) of 15.8%. 

    Geographically extensive transmission is reported in Mauritania and Niger, as well as new cases identified in Senegal. 

    Mali has reported cases across several regions, although incidence has declined substantially. 

    In Niger, the number of cases and deaths reported, and the CFR remain  lower than during the corresponding period of 2025. 

    South Africa continues to report clusters and sporadic respiratory cases,  albeit with good contact tracing and case investigation. 

    Comparisons across countries should be interpreted cautiously because  reporting periods, case definitions and classification practices differ.

    National authorities, WHO and partners continue to implement  coordination, surveillance, laboratory testing, vaccination, case and contact  management, and risk communication and community engagement activities. However, persistent population-immunity gaps, very low laboratory confirmation  rates in most countries, delayed and incomplete reporting, uneven access to  timely treatment (antibiotics and diphtheria antitoxin (DAT)), insecurity, displacement and population movements continue to impede outbreak control.

    Assuming that no additional interventions are implemented beyond  those already in place, transmission is likely to persist, with the potential for further spread among susceptible populations and continued severe  outcomes where case detection, referral and treatment are delayed.

    The overall risk at the regional level is assessed as moderate, unchanged from RRA v2. 

    Factors sustaining the risk include:

        • Ongoing transmission in eight countries (Chad, Guinea, Mali,  Mauritania, Niger, Nigeria, Senegal, and South Africa), indicating persistent  circulation across the Region.

        • In Nigeria, the epidemic is highly geographically concentrated, with  90% of reported cases originating from Kano, Bauchi, Katsina, Borno and Sokoto States.

        • In Guinea, recent increases in cases and deaths and a persistently  high CFR potentially indicate continuing gaps in early detection, timely referral, and access to appropriate treatment.

        • Geographically extensive transmission in Mauritania and Niger, as  well as continued transmission across several regions of Mali, including in settings  affected by insecurity, displacement, population movements, and limited access to  health services.

        • Persistent gaps in primary vaccination and limited booster-dose  coverage, leaving susceptible cohorts among older children, adolescents, and  adults, particularly within displaced, mobile, and hard-to-reach populations.

        • Decline in the coverage of DTP1 (76% in 2024 to 67% in 2025) and  DTP3 (74% in 2024 to 65% in 2025) in South Africa – according to WHO/UNICEF  estimates released in July 2026.

        • Low laboratory confirmation rates, due to limited laboratory supplies,  lack of reagents, challenges with sample collection and shipment, and shortages  of trained personnel.

        • Delayed and incomplete reporting, retrospective reporting, and  inconsistent use of standard case definitions and case classification across affected  countries, which constrain timely detection and interpretation of  epidemiological trends.

        • Limited availability of diphtheria antitoxin (DAT) in national stocks,  hindering appropriate clinical care for respiratory diphtheria.

        • Limited availability of specialized trained clinical and laboratory  personnel 

        • Cross-border population movements and gaps in information  exchange, which sustain the risk of spreading between neighbouring countries.

    These concerns are moderated by established national coordination and  response mechanisms and continued technical and operational support from  WHO and partners. Incidence has declined substantially in Mali, while the number  of cases and CFR reported in Niger remain lower than during the corresponding  period of 2025. However, cases in Guinea remain higher than in the comparable  period in 2025. Declining or relatively stable trends have also been observed in  some other affected countries. 

    Surveillance, case investigation, contact management, laboratory testing,  reactive vaccination and catch-up activities continue, although their  implementation and performance vary across countries. Case-management  capacity has been strengthened and essential supplies distributed in selected  settings, while risk communication and community engagement activities remain  ongoing. 

    Although transmission persists and localized cross-border spread remains possible, despite Senegal reporting cases, available information does  not indicate widespread regional acceleration or sustained transmission in  additional countries.

    The risk at the global level is assessed as low, unchanged from RRA v2.  Reported transmission remains concentrated in affected countries in the WHO  African Region, with no documented sustained transmission beyond the Region.  Nevertheless, international spread through travel and population movements  remains possible, particularly among susceptible populations.

    Confidence in the assessment is moderate because of low laboratory  confirmation in most settings, differences in reporting periods and case definitions, retrospective reporting and reclassification, and delayed or incomplete reporting from some countries.

(...)

Source: 

Link: https://www.who.int/publications/m/item/who-rapid-risk-assessment---diphtheria--african-region-v.3

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Near real-time data on the #human neutralizing #antibody #landscape to #influenza virus in summer of 2026 shows antigenic advance of #H3N2 subclade K region D mutants and #H1N1 D.3.1.1 Sa mutants

 

Abstract

Human seasonal influenza evolves rapidly, necessitating twice yearly decisions about whether to update the strains in the vaccine. To help inform this decision, we have been using high-throughput sequencing-based neutralization assays to make twice yearly measurements of how recent human sera neutralize current human H3N2 and H1N1 strains. Here we provide the third installment in this series of measurements by reporting 47,851 titers representing neutralization of 148 viral strains by 325 human sera collected between April and August of 2026. Our measurements show that new H3N2 subclade K strains with mutations in antigenic region D and new H1N1 subclade D.3.1.1 strains with mutations in antigenic region Sa (such as G155E) have reduced neutralization by human sera, with notable heterogeneity in the impact of some of these mutations across sera from different individuals. This paper is accompanied by an interactive summary (https://jbloomlab.github.io/flu-seqneut-2026/summary.html) that enables detailed exploration of the results, and all titer data are publicly available for further analysis to aid vaccine antigen selection and studies of viral evolution.

Competing Interest Statement

JDB consults for Pfizer, GSK, Apriori Bio, and Merck. JDB has received stock options in the Vaccine Company. JDB is an inventor on Fred Hutch licensed patents related to techniques to characterize the antigenic effects of viral variation. SEH is a co-inventor on patents that describe the use of nucleoside-modified mRNA as a vaccine platform. SEH reports receiving consulting fees from Sanofi, Pfizer, Lumen, Novavax, and Merck. ALG reports contract testing to UW from Abbott, Cepheid, Novavax, Pfizer, Janssen, Assembly Biosciences, Aicuris, Innovative Molecules, and Hologic, research support from Gilead, personal consulting fees from Arisan Therapeutics, outside of the described work. JAE reports support to her institution from GSK, Pfizer, Moderna, and is a consultant for GSK, Pfizer, Merck, Meissa vaccines, Moderna, and Shionogi. ST reports research funding from Pfizer for a separate study.

Funder Information Declared

National Institute of Allergy and Infectious Diseases, R01AI165821, F30AI186284, 75N93021C00015

Howard Hughes Medical Institute, https://ror.org/006w34k90

Source: 

Link: https://doi.org/10.64898/2026.09.15.751855

____

#Australia, #H5 avian #influenza events in #wildlife, daily update (DAFF, September 17 '26)

 

{Extract}

(...)

Event data

   ° 572 Positive events

    ° 45,746 Hotline reports

As of 4pm AEST, 16 September 2026, Australia has 572 confirmed events of H5 bird flu in wildlife.

    § 10 in Western Australia (WA)

    § 301 in South Australia (SA)

    § 40 in New South Wales (NSW)

    § 2 in Queensland (QLD)

    § 180 in Victoria (VIC)

    § 38 in Tasmania (TAS)

    § 1 in Other Territories*

{*} Jervis Bay Territory (Commonwealth jurisdiction)

    As H5 bird flu is confirmed in more locations and species in Australia it will not be necessary to continue testing all species in known areas of transmission, or to test every animal involved in an investigation. 

    Reporting will be targeted to provide a clear picture of the national H5 bird flu situation in wildlife in Australia and key developments.

Data disclaimer

    Data reflects information provided by state and territory governments to the Australian Government as at 17:00 AEST daily. The Australian Government publishes this information for national reporting purposes. Responsibility for the accuracy, completeness and currency of the data remains with the relevant state or territory government. Due to differences in reporting timing, information on the national dashboard may differ from information published on state or territory government websites.

{Click on Image to Enlarge}

___

(...)

Source: 

Link: https://www.agriculture.gov.au/campaigns/birdflu/latest-data#h1_bird_flu

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Human #Adenovirus B3–Induced Immune #Thrombocytopenia and #Thrombosis

 

{Extract}

(...)

We report here the case of a previously healthy 12-year-old boy in whom virus-induced immune thrombocytopenia and thrombosis developed approximately 1 week after the onset of respiratory infection symptoms. Immune thrombocytopenia was suspected, and prednisolone therapy (30 mg daily) was started at the referring hospital. 

(...)

Source: 

Link: https://www.nejm.org/doi/full/10.1056/NEJMc2605960?query=TOC

____

#Influenza at #human - #animal #interface - #Summary & #risk assessment, 8 Aug. - 6 Sept. '26 (WHO): 1 #H5N1 case in #Bangladesh, 3 #H9N2 cases in #China, 2 #H1N2v cases in #US

 

Influenza at the human-animal interface Summary and risk assessment, from 8 August to 6 September 2026 {1}

    • New human cases {2}: 

        ° From 8 August to 6 September 2026, based on reporting date,  detections of influenza A(H5N1) in one human and influenza A(H9N2) in  three humans were officially reported. Additionally, two human cases of infection with influenza A(H1N2) variant (A(H1N2)v) viruses were detected.

    • Circulation of influenza viruses with zoonotic potential in animals: 

        ° High pathogenicity avian influenza (HPAI) events in poultry and  non-poultry animal species 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} Additionally, low pathogenicity avian influenza viruses as  well as swine influenza viruses continue to circulate in animal populations.

    • Risk assessment {5}: 

        ° There have been no reports of sustained human-to-human transmission associated with the above-mentioned human infection events.  Based on information available at the time of this update, the overall public health  risk from currently known influenza A viruses detected at the  human-animal interface has not changed and, at present, these viruses are  not thought to be capable of sustained human-to-human transmission, although  this could change as they evolve. Whilst human infections with viruses of animal  origin are infrequent, they are not unexpected at the human-animal interface.

    • IHR compliance {6}: 

        ° This includes any influenza A virus that has demonstrated the  capacity to infect a human, and its haemagglutinin (HA) 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

A(H5N1), Bangladesh

    On 30 August, Bangladesh, through the national IHR focal point, notified WHO of one laboratory-confirmed human infection with an A(H5) virus in a  child from Rangpur division. 

    On 15 August 2026, the child developed a fever, cough and rhinitis and was  admitted to hospital on 17 August. 

    On 18 August, a nasopharyngeal swab and throat swab was collected as  part of hospital-based influenza surveillance and tested positive for influenza A(H5) by real-time RT-PCR at the icddr,b laboratory on the same day. 

    The sample was subsequently confirmed positive for influenza A(H5N1)  at the Molecular and Genomic Laboratory Department of Institute of Epidemiology,  Disease Control and Research (IEDCR) and National Influenza  Centre (NIC) of Bangladesh. 

    Genetic sequencing is underway. 

    The child remained hospitalized and was improving clinically at the time  of reporting.

    There was no reported history of travel outside the area of residence. The  child had a history of exposure to duck and chickens, including some that  were sick, in the household and adjacent households. 

    Poultry meat and oropharyngeal swab specimens collected from several  backyard chickens on 26 August tested negative for influenza A(H5).

    Close contacts were identified and placed under monitoring and all  contacts remained asymptomatic during the observation period, except for two heath care workers. 

    Respiratory specimens collected from these two individuals tested negative for influenza A viruses.

    This is the 4th laboratory-confirmed human case of avian influenza A(H5)  reported in Bangladesh in 2026.

    According to reports received by WOAH, various influenza A(H5) subtypes  continue to be detected in wild and domestic birds in Africa, the Americas, Asia,  Europe and Oceania. Infections in non-human mammals are also reported,  including in marine and land mammals.{7} A list of bird and mammalian species  affected by HPAI A(H5) viruses is maintained by FAO.{8}

Risk assessment for avian influenza A(H5N1) viruses:

    1. What is the current global public health risk of additional human cases of  infection with avian influenza A(H5N1) viruses?

        ° Most human infections so far have been reported in people exposed  to A(H5N1) viruses, for example, through contact with infected poultry or  contaminated environments, including live poultry markets, and occasionally  infected mammals and contaminated environments. As long as 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 remain unusual. The impact for public health if additional sporadic cases are detected is minimal. The current overall global public health risk is low.

    2. What is the likelihood of sustained human-to-human transmission of avian  influenza A(H5N1) viruses related to the events above?

        ° No sustained human-to-human transmission has been identified  associated with the recent reported human infections with avian  influenza A(H5N1) viruses. 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(H5N1) 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.  Current evidence suggests that influenza A(H5N1) viruses related to these events did not acquire the ability to efficiently transmit between people.

      3. What is the likelihood of international spread of avian influenza A(H5N1) 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 community- level spread is  considered unlikely as current evidence suggests these viruses have  not acquired the ability to transmit easily among humans.  

A(H9N2), China

    Between 13 August and 1 September 2026, China notified WHO of three laboratory-confirmed human cases of A(H9N2) virus infection. 

(...)

    All cases had direct or indirect exposure to poultry and/or local live bird  markets. Samples from environments associated with the likely area of exposure  of some of the cases tested positive for A(H9) viruses. 

    No further cases were detected among contacts of 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. Since the  virus is endemic in poultry in multiple countries in Africa and Asia, additional human cases associated with exposure to infected poultry or  contaminated environments are expected but remain unusual. The impact to  public health if additional sporadic cases are detected is minimal. The  overall global public health risk is low.

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

        ° At the present time, no sustained human-to-human transmission  has been identified associated with the recently reported human  infections with A(H9N2) viruses. Current evidence suggests that A(H9N2) viruses  from these cases did not acquire the ability of sustained transmission among humans.

    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.

Swine influenza viruses in humans

Influenza A(H1N2)v, United States of America

    Since the risk assessment of 8 August 2026, two human infections with influenza A(H1N2v) viruses were detected in the state of Michigan.{7} 

    The patients, both <18 years of age, developed illness in the week of 15  August. They were not hospitalized and have recovered. Both attended the same agricultural fair where sick swine were present. The cases did not have  contact with each other and  no additional human infections with A(H1N2)v  viruses have been detected around this event. 

    Including these two cases, there have been a total of three human  infections with variant influenza A viruses reported in the United States in 2026.

Risk Assessment:

    1. What is the public health risk of additional human cases of infection with  swine influenza viruses?

        ° Swine influenza viruses circulate in swine populations in many  regions of the world. Depending on geographic location, the genetic characteristics  of these viruses differ. Most human cases are exposed to swine  influenza viruses through contact with infected animals or contaminated environments. Human infection tends to result in mild clinical illness  in most cases. Since these viruses continue to be detected in swine  populations, further human cases are expected but remain unusual. The impact  for public health if additional cases are detected is minimal. The overall risk of additional human cases is low.

    2. What is the likelihood of sustained human-to-human transmission of swine influenza viruses? 

        ° No sustained human-to-human transmission was identified  associated with the event described above. Current evidence suggests  that contemporary swine influenza viruses 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 swine influenza viruses by travelers? 

        ° 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 suggest that these viruses have not acquired the ability to transmit easily among humans.

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. WHO has published  guidance on surveillance for human infections with avian influenza A(H5) viruses.

    • 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.{8} More  guidance can be found from WOAH and FAO.

    • 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 with pandemic  potential must be maintained at all times, including during a non-influenza  emergency. To maximize the value of influenza surveillance platform for other  respiratory threats, 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).{9,10} State  Parties to the IHR (2005) are required to immediately notify WHO of any  laboratory-confirmed {11} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic {12}. Evidence of illness  is not required for this report. 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 humans 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 {13} 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 risk elements. The results of  TIPRA  complement those of the risk assessment provided here, and those of prior TIPRA  risk assessments are published at http://www.who.int/teams/global-influenza-programme/avianinfluenza/tool-for-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/

    ° WOAH/FAO Network of Expertise on Animal Influenza (OFFLU) http://www.offlu.org/

____

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

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

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

{6} Case definitions for the four diseases requiring notification in all  circumstances under the International Health Regulations (2005). World Health Organization; 2009 (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)).

{7} Weekly US Influenza Surveillance Report: Key Updates for Week 32, ending  August 15, 2026. US Centers for Disease Control and Prevention; 2026  (https://www.cdc.gov/fluview/surveillance/2026-week-32.html).

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

{9} World Health Organization. International Health Regulations (2005), as  amended through resolutions WHA67.13 (2014), WHA75.12 (2022), and  WHA77.17 (2024) (https://apps.who.int/gb/bd/pdf_files/IHR_2014-2022-2024-en.pdf).

{10} World Health Organization. Case definitions for the four diseases requiring  notification in all circumstances under the International Health Regulations (2005)  (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)).

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

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

{13} World Health Organization. Operational guidance on sharing influenza  viruses with human pandemic potential (IVPP) under the Pandemic Influenza  Preparedness (PIP) Framework (2017) (https://apps.who.int/iris/handle/10665/259402).

Source: 

Link: https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--6-september-2026

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#Australia, #H5 avian #influenza events in #wildlife {daily update} (DAFF, September 16 '26)

 

{Excerpts}

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Event data

       ° 551 Positive events

     ° 45,115 Hotline reports

    As of 4pm AEST, 15 September 2026, Australia has 551 confirmed events of H5 bird flu in wildlife.

    § 10 in Western Australia (WA)

    § 299 in South Australia (SA)

    § 32 in New South Wales (NSW)

    § 2 in Queensland (QLD)

    § 169 in Victoria (VIC)

    § 38 in Tasmania (TAS)

    § 1 in Other Territories*

{*} Jervis Bay Territory (Commonwealth jurisdiction)

    As H5 bird flu is confirmed in more locations and species in Australia it will not be necessary to continue testing all species in known areas of transmission, or to test every animal involved in an investigation. 

    Reporting will be targeted to provide a clear picture of the national H5 bird flu situation in wildlife in Australia and key developments.

Data disclaimer

    Data reflects information provided by state and territory governments to the Australian Government as at 17:00 AEST daily. The Australian Government publishes this information for national reporting purposes. Responsibility for the accuracy, completeness and currency of the data remains with the relevant state or territory government. Due to differences in reporting timing, information on the national dashboard may differ from information published on state or territory government websites.

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Source: 

Link: https://www.agriculture.gov.au/campaigns/birdflu/latest-data#h1_bird_flu

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Increased #receptor #binding and #spike glycosylation, remodeled immune #escape of surging #SARS-CoV-2 subvariant BA.3.2.2/RE.2.2/Cicada

 

Significance

SARS-CoV-2 evolved into distinct phylogenetic clades, generating a series of mutant strains. Notably, variants such as BA.1, BA.2.86, and BA.3.2 deserve special attention as they emerged abruptly at high detection frequencies during specific periods and harbored extensive mutations in the spike protein relative to contemporaneously prevalent strains, often accompanied by unique phenotypic characteristics. In this study, we primarily evaluated the structural and functional features of the BA.3.2.2 S protein, revealing its distinct traits in receptor binding, immune evasion, cross-species transmission, and glycosylation evolution. We observed constrained viral immune escape, as certain antibodies that were nonneutralizing against previously dominant subvariants exhibited neutralizing activity against recently emerged BA.3.2.2. These findings provide mechanistic insights for viral surveillance, vaccines, and therapeutics development.

Abstract

SARS-CoV-2 continues to evolve. The subvariant BA.3.2 (Cicada), a derivative of the Omicron BA.3 subtype first detected in late 2024, harbors multiple spike protein mutations, ORF7 and ORF8 deletions, and has recently evolved sublineages (BA.3.2.1 and BA.3.2.2), rendering it a critical target for epidemiological surveillance. The BA.3.2.2 sublineage, represented by RE.2.2, shows a marked upward trend in late 2025. Using surface plasmon resonance, we found that RE.2.2’s spike (S) protein receptor-binding domain (RBD) exhibits relatively high affinity for human receptor angiotensin-converting enzyme 2, with structural analysis identifying the R493Q reverse mutation as the key determinant. Pseudovirus infection and antibody neutralization assays demonstrated that RE.2.2 exhibited a distinct neutralization profile compared to contemporaneous dominant subvariants. Notably, several antibodies that previously lacked neutralizing activity (e.g., S2K146 and L4.65) to other subvariants regained neutralizing potency against RE.2.2, which was associated with key mutations including G446D. Profiling of RE.2.2 RBD binding to ACE2 orthologs across species showed no significant difference in species tropism from the representative Omicron BA.1. Importantly, RE.2.2 exhibits the newly emerged N-linked glycosylation at spike protein N529 (absent in all other subvariants), a modification potentially associated with immune evasion or spike protein conformational dynamics. In addition, we corroborated the “O-follow-N” glycosylation observation as previously reported, where O-linked glycans preferentially localize near N-glycosylation sites, implying coordinated glycan organization as an extra layer of spike regulation. These findings illuminate the evolutionary characteristics, functional changes, and the constrained virus immune escape of BA.3.2.2 (RE.2.2), providing critical insights into antibody development and variant surveillance.

Source: 

Link: https://doi.org/10.1073/pnas.2614163123

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#Bundibugyo Virus Disease #Outbreak, #DRC, #Uganda - Weekly #Report 18, Data as of 13 Sept. '26 (WHO, summary): 7,258 cases and 3,510 deaths in DRC

{Excerpts}

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Event description

Democratic Republic of the Congo

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic  of the Congo has expanded to a seventh province, with the first confirmed  case reported in Bulu Health Zone, Sud-Ubangi, a province bordering the  Central African Republic and the Republic of the Congo. 

    This latest geographic expansion heightens concern about further spread  towards international borders, while transmission within the country remains  increasingly heterogeneous across affected provinces and health zones. 

    Since External Situation Report #17, a further 572 confirmed cases and 284 confirmed deaths have been reported, bringing the cumulative total to  7258 confirmed cases, including 3510 deaths [case fatality ratio (CFR) 48.4%], as of 13 September 2026. 

    Ituri remains the principal focus but its relative contribution continues to  decline, accounting for 78.0% of cumulative confirmed cases, while transmission  continues to increase in Nord-Kivu and persists in Haut-Uélé. 

    The outbreak now affects 62 health zones across seven provinces, with  Bulu Health Zone in Sud-Ubangi being the latest affected.

    At the national level, daily incidence remains high and fluctuating, with  the seven-day moving average declining from its mid-August peak, followed by a modest rebound in early September. This national pattern masks increasingly divergent provincial trajectories. 

    Ituri continues to decline from its mid-August peak but remains at a high  level, while Nord-Kivu is experiencing a sharp and sustained increase, reaching its  highest incidence since the start of the outbreak and increasingly driving the  national trajectory. 

    Transmission in Haut-Uélé remains sustained but has declined from its  August peak. 

    Tshopo shows a recent increase from a low baseline, while Bas-Uélé  continues to report sporadic transmission, and no recent transmission is evident in  Sud-Kivu. 

    Overall, the epidemic is becoming more geographically heterogeneous,  with declining transmission in Ituri and Haut-Uélé occurring alongside rapid  intensification in Nord-Kivu, renewed activity in Tshopo and continued geographic  expansion to new areas.

Figure 1. Daily national trend in confirmed Bundibugyo virus disease cases, with  seven-day moving average, by date of report, Democratic Republic of the Congo, as of 13 September 2026

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    During the most recent 21 days (24 August – 13 September 2026), 1674  confirmed cases were reported nationally. 

    Compared with 1782 cases during the preceding 21-day period (3 – 23 August 2026), this represents a decrease of 108 cases (−6.1%). Reported  cases declined by 25.0% in Ituri, from 1338 to 1004, and by 16.7% in Haut-Uélé,  from 120 to 100. 

    In contrast, cases increased sharply by 76.1% in Nord-Kivu, from 314 to  553, while Tshopo increased from 8 to 13 cases and Bas-Uélé from 2 to 3  cases. One case was also reported in the newly affected province of Sud-Ubangi  during the latest period. Consequently, Ituri’s contribution to newly reported cases  fell markedly from 75.1% to 60.0%, while Nord-Kivu’s contribution nearly  doubled from 17.6% to 33.0%; Haut-Uélé’s contribution declined slightly from  6.7% to 6.0%. 

    Overall, the modest 6.1% national decline masks a pronounced geographic redistribution of transmission, with the substantial decline in Ituri  increasingly offset by rapidly intensifying transmission in Nord-Kivu and continued geographic expansion.

    During the same period, 830 confirmed deaths were reported nationally,  compared with 973 deaths during the preceding 21 days, representing a decrease of 143 deaths (−14.7%). The national decline was driven largely by  Ituri, where reported deaths decreased from 706 to 495 (−29.9%), while deaths  also declined in Haut-Uélé, from 50 to 31 (−38.0%). 

    In contrast, deaths increased substantially in Nord-Kivu, from 213 to 299  (+40.4%). Consequently, Ituri’s contribution to newly reported deaths fell  markedly from 72.6% to 59.6%, while Nord-Kivu’s contribution increased from  21.9% to 36.0%; Haut-Uélé’s contribution declined from 5.1% to 3.7%. Tshopo  and Bas-Uélé each reported two deaths during the latest period, while one death  was reported in Sud-Ubangi. 

    Overall, the national reductions in both cases (−6.1%) and deaths (−14.7%) were driven predominantly by declining transmission and mortality in  Ituri and mask sharply divergent provincial trajectories. In particular, the  simultaneous increases in cases (+76.1%) and deaths (+40.4%) in Nord-Kivu  indicate substantial intensification of the outbreak there, with the province now  accounting for one-third of newly reported cases and more than one-third of  newly reported deaths nationally.

(...)

    Additionally, during the most recent 21 days (24 August – 13 September  2026), 49 of the 62 affected health zones (79.0%) reported at least one new  confirmed case, while 13 (21.0%) reported no new cases. Health zones reporting  no cases were Adja, Ariwara, Aungba, Kambala and Mahagi in Ituri; Goma in  Nord-Kivu; Gombari in Haut-Uélé; Lubunga, Tshopo and Wanie-Rukula in Tshopo;  Miti-Murhesa in Sud-Kivu; and Buta and Viadana in Bas-Uélé.

    Provincial trends also mask important differences between health zones.  In Ituri, where cases declined by 25.0% overall, several health zones continued to  increase, notably Komanda (22 to 76; +245.5%), Mangala (92 to 116;  +26.1%), Lita (56 to 65; +16.1%) and Mongbwalu (50 to 61; +22.0%). 

    In  contrast, major transmission areas declined substantially, including Bunia (384 to 285; −25.8%), Nizi (210 to 120; −42.9%), Rwampara  (258 to 106; −58.9%) and Nia-Nia (89 to 46; −48.3%). 

    Nord-Kivu shows the opposite pattern, with broad-based intensification  rather than an increase confined to a few hotspots. Cases increased in Katwa (162  to 175; +8.0%), Beni (53 to 111; +109.4%), Butembo (51 to 101;  +98.0%) and Musienene (27 to 46; +70.4%), alongside transmission in newly or  recently affected health zones. Haut-Uélé declined overall, but this also concealed  a marked increase in Pawa, from eight to 38 cases (+375%), while Isiro and  Wamba declined.

(...)

    Weekly confirmed deaths peaked at 364 during 10 – 16 August, before  declining to 302 and 270 over the following two weeks. Deaths subsequently  increased to 276 during 31 August – 6 September and further to 284 during 7 –  13 September. 

    

    The composition of mortality, however, shifted in the latest week.  Community deaths decreased from 207 to 193 (−6.8%), while deaths in  treatment facilities increased from 69 to 91 (+31.9%). Consequently, the  proportion of deaths occurring in the community declined from its peak of 75.0%  to 68.0%, although it remains substantially higher than in most earlier weeks.

    The persistence of high community mortality may reflect multiple barriers  along the pathway to care, including delayed detection and notification, delayed  referral or transfer to treatment facilities, limited recognition of illness or  perceived severity, geographic and transport barriers, care-seeking outside formal  health facilities, and community acceptance or trust. These factors may result in  patients reaching treatment facilities late or dying before referral can be  completed.

    The continued predominance of community deaths, despite expanding  treatment capacity, therefore suggests that increasing bed capacity alone may be  insufficient and reinforces the need to strengthen early case detection, rapid 

referral and community-level pathways to timely care.

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Risk Assessment

    The risk of further spread remains very high within the Democratic Republic of the Congo. This assessment reflects sustained transmission,  continued geographic expansion, high mortality, population mobility, insecurity  and persistent response challenges. 

    

    A two-week invasion-risk forecast has identified 20 currently unaffected  health zones at elevated risk of transmission. 

    

    In descending order of predicted risk, these are Rethy, Watsa, Nyarambé,  Biringi, Dungu, Makoro, Karisimbi, Angumu, Rutshuru, Nyiragongo, Niangara,  Linga, Kirotshe, Bafwagbogbo, Alimbongo, Jiba, Poko, Rwanguba, Kamango and  Kibirizi. 

    

    The highest predicted risks are concentrated in Ituri and Haut-Uélé,  reinforcing the need for riskbased preparedness and readiness measures. 

    The risk is considered high for neighbouring countries sharing land  borders with the Democratic Republic of the Congo and low elsewhere in Africa  and globally. 

    The second IHR Emergency Committee, convened on 18 August 2026, also  reviewed the evolving situation and emphasized that the outbreak remains  far from controlled, and continues to constitute a Public Health Emergency of International Concern.

(...)

Situation interpretation

    The outbreak remains uncontrolled and increasingly heterogeneous,  with declining transmission in Ituri masking rapid intensification in Nord-Kivu, and  continued geographic expansion, including to Sud-Ubangi. Response efforts should prioritize targeted interventions in emerging and persistent hotspots,  particularly strengthening early detection, contact tracing, rapid isolation and  referral, IPC and community engagement. Approaches contributing to declining  transmission in areas of Ituri should be identified, consolidated and rapidly  adapted and scaled up in areas where transmission is increasing. Preparedness  should also be reinforced in high-risk health zones and along domestic and cross- border corridors to limit further geographic spread.

Source: 

Link: https://www.afro.who.int/countries/democratic-republic-of-congo/publication/ebola-bundibugyo-virus-disease-outbreak-3

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