ETIDIOH - NEW

  Abstract A human infection with clade 2.3.4.4b H5N1 influenza A virus in Canada revealed minority variants E190D and Q226H in the hemagglutinin (HA) receptor-binding site (RBS). Because mutations at positions 190 and 226 have been associated with altered receptor specificity in other influenza subtypes, we investigated their impact on receptor binding in H5 HA . Using a recombinant protein approach and an ELISA-based glycan-binding assay , we assessed binding to representative avian- and human-type sialylated glycans . Both single mutations and their combination resulted in a complete loss of detectable binding to the tested glycans . To evaluate whether this phenotype was background-dependent, Q226H was additionally introduced into two other H5 HA proteins , each representing a distinct clade . In both cases, the mutation similarly abolished receptor binding . These findings independently validate recent glycan microarray observations and demonstrate that the patient-derived E19...

  {Summary} Risk Statement   -- This Rapid Risk Assessment (RRA) evaluates the global public health risk posed by Nipah virus (NiV), considering the distinct epidemiological profiles of  - i) enzootic countries , where recurrent zoonotic spillover and limited human‑to‑human transmission continue to occur, and  - ii) non‑enzootic regions , where the risk remains primarily associated with infected travellers or importation of infected livestock.  -- The assessment considers the ecological and seasonal drivers of spillover , the constrained efficiency of human‑to‑human transmission , and the capacity of health and community systems to detect, confirm, and rapidly contain outbreaks.  -- Given that NiV has not demonstrated sustained transmission beyond outbreak settings and no human cases have ever been reported outside Asia , the global risk is largely determined by localized outbreaks in endemic areas and the very low likelihood of onward transmission fol...

  Abstract Antibodies to the influenza hemagglutinin protein (HA) confer the strongest protection against infection . Immunity elicited by endemic, seasonal, human viruses is correlated with diminished disease severity and death caused by antigenically novel viruses. Antibodies to the HA head interface are broadly protective and abundant in human serologic and memory repertoires . Notably, few head interface antibodies from H5 naive donors are reported to bind H5 HAs . We find head interface antibodies engage a wide range of H5 isolates but fail to engage most isolates from the goose Guangdong (GsGd) lineage . We identify a single substitution, P221S, largely dictates antibody binding. Phylogenetic analysis indicates that P221S arose in a Chinese avian reservoir by the year 2000 . Descendants of these viruses have caused the current global panzootic and have achieved sustained mammal-mammal transmission in farmed and wild mammals. Our findings demonstrate that viral evolution in no...

  Abstract Middle East respiratory syndrome coronavirus (MERS-CoV) is assessed to have high pandemic risk , and dromedary camels are the source of zoonotic spillover . More than 75% of MERS-CoV–infected dromedary camels are found in Africa , but no zoonotic disease has been reported from Africa where there is little awareness of MERS-CoV as a potential cause of respiratory disease . Antibody responses are a poor indicator of mild infection . We found that 47 of 60 (78%) dromedary camel abattoir workers in Kano, Nigeria, had MERS-CoV–specific T-cell responses while none of 18 controls did, suggesting that zoonotic infection is common in camel-exposed individuals in Africa. Source:  Link:  https://academic.oup.com/jid/advance-article-abstract/doi/10.1093/infdis/jiag095/8504072?redirectedFrom=fulltext ____

  Abstract In China, low pathogenic avian influenza (LPAI) H3N8 virus is widespread among chickens and has recently caused three zoonotic infections , with the last one in 2023 being fatal . Here we evaluated the relative pandemic risk of this 2023 zoonotic H3N8 influenza virus , utilizing our previously published decision tree . Serological analysis indicated that a large proportion of the human population does not have any cross-neutralizing antibodies against this H3N8 strain. LPAI H3N8 displayed a dual affinity for α2–3 and α2–6 sialic acids and replicated efficiently in human bronchial epithelial cells . Furthermore, we observed H3N8 transmission via direct contact but not aerosols to ferrets with pre-existing H3N2 immunity . Although pre-existing H3N2 immunity resulted in a shortened disease course in ferrets, it did not reduce disease severity or replication in the respiratory tract. This study suggests that this zoonotic H3N8 strain has moderate pandemic potential and empha...

  Abstract The H7N9 avian influenza virus (AIV) has posed a major global public health concern since its first detection in China in 2013 . Transmitted among wild birds and poultry , this virus has crossed the species barrier to infect humans , causing severe respiratory disease and high mortality . Although the widespread use of H7 vaccines has markedly reduced human infections , the ongoing circulation and adaptive evolution of the virus in poultry remain a serious threat . In this study, we analyzed three highly pathogenic H7N9 isolates collected in China in 2022, representing two hemagglutinin (HA) gene evolutionary lineages : Group.y.2.3 (isolate 229-4, chicken origin; isolate 782-2, quail origin) and Group.y.2.4 (isolate 621, quail origin). Pathogenicity was compared through phylogenetic analysis , molecular characterization, and infection experiments in both avian and mammalian models . Group.y.2.3 isolates displayed stronger replication and pathogenicity in chickens and mic...

  Abstract Objective The H7N9 avian influenza virus, identified in China in 2013, has posed a significant threat to public health due to its high mortality rate . This systematic review aims to evaluate the clinical characteristics and mortality risk factors of H7N9 patients. Methods English and Chinese databases (PubMed, Web of Science, Embase, CNKI, VIP, Wanfang) were searched for studies on laboratory-confirmed H7N9 cases with available data on symptom onset, diagnosis time, clinical features, oseltamivir administration, and outcomes . Univariate and multivariate analyses were performed on the pooled case data to assess the relationship between clinical factors and mortality risk. Results A total of 166 studies including 237 H7N9 cases were analyzed , with an overall mortality rate of 41.77%. Univariate analysis showed higher mortality in patients with advanced age ≥ 66 years (62.50%), those with underlying diseases (60.20%), those who received oseltamivir ≥ 8 days after symptom...

{Excerpt} Avian Influenza Report - Reporting period: February 8, 2026 – February 14, 2026 (Week 7)   (...) - Date of report: 14/02/2026 - Country: Cambodia - Province / Region: Kampot province - District / City: Tuek Chhou district - Sex: M - Age: 30 - Condition at time of reporting: Recovered - Subtype of virus: H5N1 (...) Source:  Link:  https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk07.pdf ____

  Abstract Clade 2.3.4.4b highly pathogenic avian influenza A(H5N1) viruses continue to expand geographically and across mammalian hosts, raising concern about pandemic potential. The degree and specificity of pre-existing immunity in humans are key determinants of this risk. We analyzed hemagglutinin (HA)- and neuraminidase (NA)-specific antibody responses in 300 sera collected from adults in New York City. While HA directed binding antibodies to clade 2.3.4.4b H5 were low and hemagglutination-inhibiting antibodies were absent, we detected widespread binding and functional NA antibodies against N1 neuraminidases from clade 2.3.4.4b H5N1 viruses. Neuraminidase inhibition (NI) titers were highest against North American D1.1 genotype N1 viruses and correlated strongly with neutralizing activity, whereas HA-binding antibodies did not. An additional N-linked glycosylation site, as found in the NA of a human D1.1 isolate from British Columbia, reduced susceptibility to NI antibodies. An...

  A horse in Jönköping County and one in Norrbotten County , both of which had blisters and sores on the skin on their legs, were found to be infected with a smallpox virus called equine parapoxvirus or horse parapoxvirus . It is an infection that has not previously been detected in the country . The equine parapoxvirus was detected in our neighboring country Finland for the first time in 2021 . The State Veterinary Institute, SVA, has performed DNA analysis of the virus in the Swedish cases and it turned out to be the same type as in Finland. The virus has caused outbreaks in several Finnish stables with severe skin inflammation on the horses' legs, so-called mug or rasp. The typical symptom of parapoxvirus is small blisters (pox) that burst into round sores. The virus is transmitted by direct contact but also via equipment, clothing, hands and objects. Sick horses should be kept isolated from other horses. Use disposable gloves and special clothing when handling.    – T...

  {Excerpt} Avian Influenza Report - Reporting period: February 1, 2026 – February 7, 2026 (Week 6) (Published on February 10, 2026)   -- Avian influenza A(H9N2) :  1) Guangdong Province :  - A 73-year-old woman with onset on January 17, 2026.  2) Hunan Province :  - A 2-year-old boy with onset on December 29, 2025.  -- Avian influenza A(H10N3) : 1) Guangdong Province :  - A 34-year-old man with onset on December 29, 2025.   (...) Source:  Link:  https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk06.pdf ____

  6 February 2026 Situation at a glance On 3 February 2026, the International Health Regulations National Focal Point (IHR NFP) for Bangladesh notified WHO of one confirmed case of Nipah virus (NiV) infection in Rajshahi Division .  The patient developed fever and neurological symptoms on 21 January.  Nipah virus infection was laboratory-confirmed on 29 January.  The patient reported no travel history but had a history of consuming raw date palm sap .  All 35 contact-persons are being monitored and have tested negative for NiV and no further cases have been detected to date.  Bangladesh regularly has small NiV outbreaks , with cases reported at different times of the year, though outbreaks tend to occur between December and April corresponding with the harvesting and consumption of date palm sap.  The Ministry of Health and Family Welfare in Bangladesh has implemented several public health measures.  WHO assesses the overall public health risk pos...

  Abstract A case of H5N6 avian influenza was reported in Anhui Province, China . The viral titers in the patient's lungs and pharynx decreased rapidly after oseltamivir treatment , yet it still fatal . The whole genome sequencing suggested that it derived from four distinct sources and classified within the 2.3.4.4b clade . Source:  Link:  https://www.sciencedirect.com/science/article/pii/S1684118226000034?via%3Dihub ____

  Highlights •  74% pooled MERS-CoV seroprevalence in African dromedaries •  Highest MERS-CoV RNA incidence (15.3%) observed in juvenile dromedaries •  2.4% pooled MERS-CoV seroprevalence in camel -exposed humans •  African MERS-CoV clade C exhibits unique polymorphisms •  Clade-specific features might explain low MERS-CoV infection rates in Africa Abstract Objective We explored factors contributing to the low human MERS-CoV prevalence in Africa by assessing MERS-CoV epidemiological and genomic features. Methods We followed the PRISMA guidelines. We searched for articles on epidemiological and virological MERS-CoV characteristics in humans and camels in Africa until August 2025. We used a generalised linear mixed-effects model to calculate pooled proportions. We identified relevant polymorphisms in African MERS-CoV lineages compared with the prototypic EMC/2012 and contemporary Arabian MERS-CoV (clade B5). Results We included 53 articles, with 31 used in th...

  Abstract Of 19 human cases of avian influenza A(H5N1) virus infection detected during January 2023–March 2025 in Cambodia , 12 (63%) were detected directly by surveillance for severe acute respiratory infection (SARI) or indirectly by testing ill close contacts . SARI surveillance can supplement other surveillance sources for identifying H5N1 cases. Source:  Link:  https://wwwnc.cdc.gov/eid/article/32/3/25-0832_article ____

  Situation at a glance On 26 January 2026, the National IHR Focal Point for India notified WHO of two laboratory‑confirmed cases of Nipah virus (NiV) infection in West Bengal State .  Both are healthcare workers at the same private hospital in Barasat (North 24 Parganas district).  NiV infection was confirmed at the National Institute of Virology in Pune on 13 January.  One case remains on mechanical ventilation as of 21 January, the other case experienced severe neurological illness but has since improved.  Authorities have identified and tested over 190 contacts , who all tested negative for NiV with support from a mobile BSL‑3 laboratory deployed by the National Institute of Virology, Pune.  No further cases have been detected to date.  This event represents the third NiV infection outbreak reported in West Bengal (previous outbreaks reported in Siliguri in 2001 and Nadia in 2007).  Enhanced surveillance and infection prevention and control (I...