ETIDIOH - NEW

Abstract Highly pathogenic H5N1 avian influenza viruses of clade 2.3.4.4b cause sporadic human infections and currently raise concerns about a new influenza pandemic . Heterogeneities in disease severity and outcome have been observed in the past and are currently reported among infected farm workers in the US. These may be attributed to differences in pre-existing H5N1 cross-reactive antibodies . In this study, we characterize H5N1 cross-reactive antibody landscapes in the current population and assess the effect of pH1N1/AS03 and non-adjuvanted seasonal influenza vaccination on H5N1 cross-neutralizing and IgG antibody titers targeting a range of influenza virus-derived antigens. We were able to detect H5N1 cross-neutralizing antibodies using a VSV-based pseudovirus system that correlated well with antibodies inhibiting the spread of authentic H5N1 viruses. Additionally, we found that pH1N1/AS03 vaccination increases H5N1 cross-reactive antibodies significantly, while non-adjuvanted i...

ABSTRACT Recently, human infections with H10 influenza viruses, including H10N8 and H10N3, have been reported. In January 2024 , a case of H10N5 and H3N2 co-infection was reported in Zhejiang Province, China , which is the first human infection with H10N5 avian influenza virus (AIV) globally. Almost simultaneously, we isolated a wild bird-derived H10N5 strain similar to the human H10N5 strain. To assess the public health risk , it is necessary to understand the zoonotic characteristics of these novel H10N5 viruses. Here, we evaluated the biological characteristics of human H10N5 , wild bird H10N5, as well as poultry H10N8 in vitro and in vivo. We demonstrate that the novel H10N5 isolates infected and replicated effectively in human lung epithelial cells . They infected BALB/c mice without adaptation , which exhibited robust pathogenicity and caused mouse death. In guinea pig transmission experiments , the H10N5 strain spread through neither direct contact nor airborne exposure , wherea...

Summary The recent emergence of highly pathogenic H5N1 avian influenza virus infections in dairy cows and humans in the U.S. has raised alarms regarding the potential for a pandemic . Over 995 dairy cow herds and at least 70 humans have been affected, including cases of severe disease and the first reported H5N1-related death in the U.S . Sporadic human infections with no known contact with infected animals highlight the possibility of viral adaptation for efficient human-to-human transmission. Concurrently, the virus continues to circulate in wild birds, backyard flocks, and hunted migratory species , further amplifying the risk to humans and domestic animals. This article provides an overview of the current outbreak status , emphasizes the importance of robust surveillance systems to detect emerging strains with pandemic potential, and highlights risks to the U.S. dairy and poultry industries. Recommendations for risk mitigation include enhanced biosecurity measures, improved surveil...

Abstract Highly pathogenic avian influenza of the H5N1 subtype has shown recent unprecedented expansion in its geographic and host range , increasing the pandemic threat . The younger age of H5N1 versus H7N9 avian influenza in humans has previously been attributed to imprinted pre-immunity to hemagglutinin stalk (HA2) epitopes shared with group 1 ( H1N1, H2N2 ) versus group 2 ( H3N2 ) influenza A subtypes predominating in the human population before versus after 1968, respectively. Here we review the complex immuno-epidemiological interactions underpinning influenza risk assessment and extend the imprinting hypothesis to include a potential role for cross-protective neuraminidase (NA) imprinting . We compare H5N1 distributions and case fatality ratios by age and birth cohort (as proxy for HA2 and/or NA imprinting epoch) not only to H7N9 but also H5N6 and H9N2 avian influenza, representing more varied conditions of zoonotic influenza relatedness to human subtypes of the past century. We...

  Situation at a glance Between 1 January and 1 July 2025, the World Health Organization (WHO) was notified by Cambodia’s International Health Regulations (IHR) National Focal Point (NFP) of 11 laboratory-confirmed cases of human infection with avian influenza A(H5N1) virus .  Seven of the 11 cases were reported in June , an unusual monthly increase .  Avian influenza A(H5N1) was first detected in Cambodia, in December 2003, initially affecting wild birds.  Since then, 83 cases of human infection with influenza A(H5N1), including 49 deaths (case fatality ratio [CFR] of 59%), have been reported in the country.  While the virus continued to circulate in avian species , no human cases were reported between 2014 and 2022, after which, the virus re-emerged in humans in February 2023.  Since the re-emergence of human A(H5N1) infections in Cambodia in 2023, a total of 27 cases have been reported (six in 2023, 10 in 2024, and 11 to date in 2025), of which 12 were f...

  PHNOM PENH, July 3 (Xinhua) -- A five-year-old boy from southwest Cambodia's Kampot province has been confirmed for H5N1 human avian influenza, bringing the number of cases to 12 so far this year, the Ministry of Health said in a statement on Thursday. "A laboratory result from the National Institute of Public Health showed on July 3 that the boy was positive for H5N1 virus," the statement said. "The patient has the symptoms of fever, cough, and dyspnea , and he is currently being rescued by a team of doctors." The victim lives in Kamakor village of Angkor Chey district .  Source: Xinhua,  https://english.news.cn/asiapacific/20250703/a96b269ca29f41238c41884f8b390782/c.html ____

Abstract Background From 1918 to 1920, the largest influenza A virus (IAV) pandemic known to date spread globally causing between 20 to 100 million deaths . Historical records have captured critical aspects of the disease dynamics , such as the occurrence and severity of the pandemic waves . Yet, other important pieces of information such as the mutations that allowed the virus to adapt to its new host can only be obtained from IAV genomes. The analysis of specimens collected during the pandemic and still preserved in historical pathology collections can significantly contribute to a better understanding of its course. However, efficient RNA processing protocols are required to work with such specimens. Results Here, we describe an alternative protocol for efficient ancient RNA sequencing and evaluate its performance on historical samples, including a published positive control. The phenol/chloroform-free protocol efficiently recovers ancient viral RNA , especially small fragments , an...

  PHNOM PENH, July 1 (Xinhua) -- A 36-year-old woman from northwest Cambodia's Siem Reap province has been confirmed for H5N1 human avian influenza, raising the number of the cases to 11 so far this year , the Ministry of Health said in a statement on Tuesday. "A laboratory result from the Pasteur Institute in Cambodia showed on June 30 that the woman was positive for H5N1 virus," the statement said. "The patient has the symptoms of fever, cough, and dyspnea , and she is currently being rescued by a team of doctors." The victim lives in Doun Keo village of Puok district. There were sick and dead chickens at the patient's home. She had been in contact with those dead chickens and took them to bury. Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak in the community. Tamiflu (oseltamivir), an antiviral drug to prevent the bird f...

  {Excerpt} [Date of report - Country - Province / Region - District - City - Sex - Age - Condition at time of reporting  - Subtype of virus]  1) 24/06/2025 - Cambodia - Siem Reap province  - F - 41 - Critical  - H5N1  2) 29/06/2025 - Cambodia -  Siem Reap province  - F - 46 - Stable - H5N1  3) 29/06/2025 - Cambodia -  Siem Reap province  - M - 16 - Stable - H5N1  4) 30/06/2025 - Cambodia -  Takeo province - M - 19 months  - Deceased - H5N1  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk26.pdf ____

  PHNOM PENH, June 29 (Xinhua) -- A 46-year-old Cambodian mother and her 16-year-old son have been confirmed positive for H5N1 human avian influenza, bringing the total number of cases to 10 so far this year, the Ministry of Health said in a statement on Sunday. Both victims live in Lbeuk village of Puok district in northwest Siem Reap province. "According to queries, there were sick and dead poultry at the patients' home and their neighbors' homes as well as in the village, and the patients had been in contact with sick and dead chickens and cooked them for food," it added. Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victims in order to prevent an outbreak in the community. Tamiflu (oseltamivir), an antiviral drug to prevent the bird flu from spreading, was also given out to people who had direct contact with the patients, the statement said. So far this year, the ki...

Abstract The Highly Pathogenic Avian Influenza Virus (HPAIV) H5 clade 2.3.4.4b has caused severe outbreaks in domestic and wild birds worldwide since its emergence in 2014, and especially since 2020, with outbreaks in Europe and North America . The introduction of the virus into South America was reported for the first time in Colombia in October 2022, followed by outbreaks in other South American countries affecting poultry, wild birds, mammals , and humans . In this study, a phylogenetic and mutation analysis of the hemagglutinin (HA) gene of HPAIV H5N1 2.3.4.4b viruses isolated in South America was performed to analyze its evolution and its transmission and zoonotic potential . The analysis shows an increase in the viral effective population size between April and June 2022, which was followed by multiple outbreaks of HPAIV H5N1 clade 2.3.4.4b in South America . Moreover, the virus variants evolved from a recent common ancestor estimated to have existed in June 2017. The mean rate o...

Simple Summary The present commentary deals with the pandemic risk brought about by the highly pathogenic avian influenza (HPAI) A(H5N1) virus . Such a pandemic alarm is justified, among others, by the progressively and rapidly expanding range of virus-susceptible hosts , including humans alongside a significant number of domestic and wild avian and mammalian species , several of which appear to be geographically and phylogenetically distant from each other. Despite its well-established zoonotic potential , no clear-cut evidence of a sustained and efficient HPAI A(H5N1) virus interhuman transmission has thus far been reported. Should this happen in a more or less near future, it could pave the way for a new pandemic. Based upon the above, a “ One Health, One Earth, One Ocean ”-focused, holistic approach would be the necessary prerequisite to deal in an appropriate way with the HPAI A(H5N1) virus-associated zoonotic and pandemic risk. Abstract The focus of this commentary is represented...

Highlights •  The characteristics of plasma metabolome in H7N9 patients were first revealed. •  It was discovered that lipid-like molecules were downregulated in death group. •  Metabolites of the tryptophan metabolic pathway were elevated in death group. •  The metabolite-based machine learning achieved an AUC of 0.929 on the test set. Abstract Objectives Avian influenza such as H7N9 is currently a major global public health risk, and at present, there is a lack of relevant diagnostic and treatment markers. Methods We collected plasma samples from 104 confirmed H7N9 patients , 31 of whom died. Plasma metabolites were detected by UHPLC-HRMS, and a survival prediction model based on metabolites was constructed by machine learning models. Results A total of 1536 metabolites were identified in the plasma samples of H7N9 patients, of which 64 metabolites were up-regulated and 35 metabolites were down-regulated in the death group. The enrichment analysis of Tryptophan met...

Abstract Objective :  The objective is to examine the epidemiology and clinical features of human cases infected with H5N6 avian influenza in Sichuan Province from 2014 to 2024, and to offer guidance for the prevention and management of human infections with H5N6 avian influenza. Methods :  Epidemiological survey reports of H5N6 avian influenza cases in Sichuan Province from 2014 to 2024 were compiled, and the epidemiological context and characteristics of 16 human cases infected with H5N6 avian influenza in the province were summarized and analyzed using descriptive epidemiological methods. Results :  From 2014, when the initial human case of H5N6 infection was documented in Sichuan Province, to 2024, there have been 16 human cases of H5N6 avian influenza in the region, resulting in 12 fatalities and a case fatality rate of 75%. The instances were predominantly located in the Chengdu Plain, eastern Sichuan, and southern Sichuan. Conclusion :  Human instances of H5N6...

{Excerpt} Epi-Week 25 2025 Avian influenza A(H9N2) :  - Henan Province :  -- 1) A 52-year-old woman with onset on May 10, 2025.  - Hunan Province :  -- 2) A 72-year-old woman with onset on May 14, 2025.  - Sichuan Province :  --3) A six-year-old boy with onset on May 14, 2025. Avian influenza A(H10N3) :  - Shaanxi Province :  -- 1) A 70-year-old woman with onset on April 21, 2025.  (...) Source: Centre for Health Protection, Hong Kong PRC SAR,  https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk25.pdf ____

Abstract The ongoing outbreak of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 in the U.S. poses a significant public health threat. To date, 70 human cases have been confirmed in the United States , including two severe cases and one fatality. While suitable animal models are crucial for predicting the potential pandemic risk of newly emerging pathogens in humans, studies investigating contemporary HPAIV H5N1 transmission dynamics remain limited. Here, we investigated the pathogenicity and transmission efficiency of three recent clade 2.3.4.4b H5N1 viruses isolated from a bovine, mountain lion, and a human case using Syrian hamsters . Intranasal inoculation with 104 TCID50 resulted in productive virus replication in the respiratory tract and shedding for all three isolates. Transmission studies showed limited efficiency via direct contact and airborne routes for all three isolates. Although overall transmission was inefficient , the human H5N1 isolate demonstrated relat...

  PHNOM PENH, June 24 (Xinhua) -- A 41-year-old woman from northwestern Cambodia's Siem Reap province has been confirmed for H5N1 human avian influenza, raising the number of cases to seven so far this year , the Ministry of Health said in a statement Monday night. "A laboratory result from the National Institute of Public Health showed on June 23 that the woman was positive for H5N1 virus," the statement said. "The patient has the symptoms of fever, cough, and dyspnea , and she is currently in critical condition ," it added. According to queries, there were sick and dead chickens at the patient's home and her neighbor's homes, and the patient had been in contact with sick and dead chickens and cooked them for food five days before she felt ill. Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak in the community. Tamiflu (...

Highlights •  Outbreaks of H5N1 clade 2.3.4.4b in South America have challenged animal and public health. •  Outbreaks across South America affect poultry industry and wild species. •  Surveillance strategies with One Health approach for avian flu is needed Abstract The outbreaks of highly pathogenic avian influenza A (H5N1) clade 2.3.4.4b in South America , which began in 2022, have had significant repercussions across the continent and have led to significant challenges in animal and public health . This review explores the virus's transmission across South America, highlighting the spread of this panzootic through migratory birds and its severe impact on the poultry industry and various wild species , including mammals . The underreporting of influenza cases in poultry underscores the need for enhanced national regulations and strategies to promote reporting within the productive sector. Additionally, the review emphasizes the necessity for active case finding and geno...

  PHNOM PENH, June 21 (Xinhua) -- A 52-year-old man from southeastern Cambodia's Svay Rieng province had died of H5N1 human avian influenza , becoming the fifth human death from the virus so far this year , the Ministry of Health said in a press statement on Saturday. "A laboratory result from the National Institute of Public Health showed on June 20 that the man was positive for H5N1 virus ," the statement said. Health authorities are looking into the source of the infection and are examining any suspected cases or people who have been in contact with the victim in order to prevent an outbreak in the community, it added. Tamiflu (oseltamivir), an antiviral drug to prevent the bird flu from spreading, was also given out to people who had direct contact with the patient, the statement said. The Southeast Asian country recorded a total of six human cases of H5N1 so far this year, with five deaths. Source: Xinhua,  https://english.news.cn/asiapacific/20250621/e94aafa92dbc446...

Summary A recently described cestode genus, Versteria, has been implicated in disseminated human disease in North America . We report the first known case of infection with a recently reported species, Versteria rafei , localised to the liver with attempted surgical resection . Through review of other patients known to be infected with this parasite , we established that this is a rare zoonotic infection involving contact with minks and mustelids . Although Versteria belongs to the same family as Echinococcus , there are several important differences. Known Versteria infections in humans typically are symptomatic, quickly involve multiple organs without treatment, and occur in immunosuppressed hosts. Furthermore, albendazole appears to be at least parasitostatic , with a reduction but not a resolution of the lesions under treatment and development of calcifications analogous to changes seen with treatment for alveolar echinococcosis. Source: Lancet Infectious Diseases,  https://www...