ETIDIOH - NEW

  Abstract The Goose/Guandong lineage of highly pathogenic avian influenza virus [A/Goose/Guangdong/1/1996(H5N1)] is the progenitor of the currently circulating Eurasian-lineage highly pathogenic avian influenza H5N1 clade 2.3.4.4b and has been the most consequential highly pathogenic avian influenza lineage globally. Despite increased reports of infections, the extent of exposure and role of wild mammals in the ecology and transmission dynamics of the virus remains poorly understood. We surveyed wild mammals in Ohio, United States to investigate the potential spillover of highly pathogenic H5N1 avian influenza clade 2.3.4.4b. While no active infections —defined as positive results indicative of viral replication and potential propagation—were detected by swab-based molecular tests, serological assays revealed antibodies against multiple avian influenza virus antigens in raccoons and opossums . Specifically, antibodies to avian influenza virus nucleoprotein were detected in 54.9% (...

  Abstract Avian influenza A viruses pose ongoing threats to human and animal health, with H7 subtypes causing outbreaks globally . In Mexico , highly pathogenic H7N3 viruses have circulated in poultry since 2012, causing sporadic human infections . Here we analyzed genetic markers in hemagglutinin sequences from Mexican H7N3 isolates and conducted serological assays on human populations with poultry exposure . Our results show conserved avian-like receptor binding sites , thus limiting human adaptation , alongside antigenic drift and acquisition of glycosylation sites likely driven by vaccination. Serological testing of 1103 individuals revealed no detectable antibodies against H7N3, indicating a naïve population . Phylogenetic analyses revealed multiple virus clades circulating regionally. These findings suggest that while current H7N3 viruses have limited capacity for sustained human transmission, the lack of population immunity underscores the importance of continued surveillan...

  Abstract Viral diseases cause significant economic losses within the equine population. Horses are susceptible to equine coronavirus (ECoV) and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), although only ECoV has been associated to clinical disease . The aim of this study was to investigate, for the first time in Algeria , the seroprevalence of ECoV and SARS-CoV-2 antibodies and the prevalence of ECoV infection in horses . In 2022, a total of 299 serum samples was collected from horses aged 1 to 27 years . Serological analysis for the presence of ECoV and SARS-CoV-2 was performed using a validated in-house and a commercially available ELISA, respectively. In addition, fecal samples of these animals were tested for the presence of ECoV RNA by RT-qPCR . SARS-CoV-2-ELISA positive sera with high S/P ratios and negative samples close to the doubtful threshold were retested using a virus neutralization test ( VNT ). The seroprevalence of ECoV and SARS-CoV-2 in the teste...

Abstract Avian influenza A viruses (AIVs) pose a significant pandemic threat due to their cross-species transmission potential . However, AIV surveillance at the critical “ migratory birds–poultry-exposed population ” interface remains limited. Between 2021 and 2024, we implemented a prospective One Health surveillance program around Nansi Lake , monitoring AIVs in migratory birds, poultry, and environmental samples, as well as serological investigations against representative AIVs among migratory birds or poultry-exposed subjects. AIVs were detected in 2.1% (30/1417) of migratory bird samples and 10.2% (100/978) of poultry samples . Among these, we identified ten highly pathogenic avian influenza (HPAI) H5 subtype viruses, one HPAI H7N9 virus, and five low pathogenic avian influenza (LPAI) H9N2 viruses. Phylogenetic analysis revealed evidence of frequent genomic reassortment events involving H5 subtype viruses among migratory birds, poultry, and humans . Serological investigation also...

Abstract While wild waterfowl are known reservoirs of avian influenza viruses and facilitate the movement of these viruses , there are notable differences in the response to infection across species. This study explored differential responses to infection with highly pathogenic avian influenza in Snow Geese (Anser caerulescens) located in the California Central Valley . Though H5 antibody prevalence was high across years among birds sampled in the winter (75% in both years via hemagglutination inhibition), these values were even higher among birds sampled in summer that failed to migrate (i.e., August 2023 = 100% and August 2024 = 93% via hemagglutination inhibition). Birds that failed to migrate were also generally lighter than birds sampled in the winter and presented notable damage to cerebrum and cerebellum . In December 2022, a single individual positive for infection with H5N1 at the time of sampling indicated reduced movement during the 14 days following sampling but completed s...

Highlights •  High seropositivity in dogs to highly pathogenic avian influenza (HPAI) H5 virus in the Netherlands during HPAI H5 endemicity in wild birds. •  HPAI H5-seropositivity higher in hunting -training dogs than companion dogs.  •  HPAI H5-seropositivity in hunting-training dogs associated with recent bird contact in/near water. •  High seropositivity in dogs to human H1N1pdm2009 influenza A virus (IAV). •  H1N1pdm2009-seropositivity higher in companion dogs than hunting-training dogs. Abstract Dogs are susceptible to the currently circulating highly pathogenic avian influenza (HPAI) H5 and human H1N1pdm2009 (pandemic H1N1) viruses, yet little is known about the extent to which dogs are exposed to both these viruses. Here we investigated HPAI H5 and human H1N1pdm2009 virus exposure in domestic dogs–including dogs that participated in hunting-training– and investigated lifestyle factors associated with HPAI H5 virus exposure. We screened sera from 538...

ABSTRACT Avian influenza is one of the major threats to poultry and human health in northern Benin , while mixed-species farming systems increase the risks of viral transmission. The present study estimated the seroprevalence of avian influenza subtypes H9N2 and H5 in indigenous chickens and guinea fowls in the Atacora and Donga regions. A total of 300 birds including 191 indigenous chickens and 109 guinea fowls, from six districts were sampled through a cross-sectional survey using systematic random sampling. Hemagglutination inhibition assay was used to detect antibodies, revealing an overall H9N2 seroprevalence of 41%, with 17.5% of samples testing positive for H5 . The seroprevalence of H9N2 was notably higher in guinea fowls (51.81% in Atacora and 52% in Donga) compared to chickens (34.95% in Atacora and 34.83% in Donga). H5 antibodies were found only in guinea fowls in Atacora (46.66%). The study also found that farms with both chickens and guinea fowls had a significantly higher...

ABSTRACT The highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b has caused a human outbreak in North America since March 2024. Here, we conducted a serosurveillance study to determine the risk of A(H5N1) clade 2.3.4.4b (2024 cattle H5N1) to general population. In the initial screening of 180 serum specimens encompassing all age groups, 2.2% (4/180) had detectable neutralizing antibody (nAb) titers against reverse genetics-derived 2024 cattle H5N1, with all collected from older adults aged ≥60 years old. Further screening showed that 4.2% (19/450) of adults aged ≥60 years old had detectable nAb titers against the 2024 cattle H5N1 . 80% (4/5) serum specimens with nAb titer of ≥40 had detectable HI titer, and there was a positive correlation between nAb titer and HA binding (r = 0.3325, 95% confidence interval 0.2477 to 0.4123; P < 0.0001). The nAb titer against seasonal H1N1 virus was 4.2-fold higher for ≥60 years old individuals with detectable H5N1 nAb titer than those ≥...

ABSTRACT Unexpected outbreaks caused by the H5N1 highly pathogenic avian influenza virus (HPAIV) in dairy cows in the United States (US) have raised significant veterinary and public health concerns . When and how the H5N1 HPAIV was introduced into dairy cows and the broader epidemiology of influenza A virus (IAV) infections in cattle in the US remain unclear. Herein, we performed a retrospective study to screen more than 1,700 cattle serum samples collected from different bovine breeds in the US from January 2023 to May 2024 using an enzyme-linked immunosorbent assay (ELISA) targeting the nucleoprotein (NP) to detect IAV infections, and the positive samples were further tested by hemagglutination inhibition (HI) assay . Results showed that 586 of 1,724 samples (33.99%) from 15 US states were seropositive by the NP ELISA assay , including 78 samples collected in 2024 and 508 samples collected in 2023 . Moreover, the HI assay revealed that 45 of these ELISA-positive samples were positiv...

Summary -- What is already known about this topic? -  Highly pathogenic avian influenza (HPAI) A(H5) virus infections have been detected in humans exposed to infected dairy cattle. -- What is added by this report? -  Public health officials conducted a serosurvey among 150 bovine veterinary practitioners. Three practitioners had evidence of recent infection with HPAI A(H5 ) virus, including two without exposures to animals with known or suspected HPAI A(H5) virus infections and one who did not practice in a U.S. state with known HPAI A(H5) virus–infected cattle. -- What are the implications for public health practice? -  These findings suggest the possible benefit of systematic surveillance for rapid identification of HPAI A(H5) virus in dairy cattle, milk, and humans who are exposed to cattle to ensure appropriate hazard assessments. Abstract The current outbreak of highly pathogenic avian influenza (HPAI) A(H5) clade 2.3.4.4.b viruses, genotype B3.13, among dairy cattle...

ABSTRACT The current situation with H5N1 highly pathogenic avian influenza virus (HPAI) is causing a worldwide concern due to multiple outbreaks in wild birds, poultry, and mammals. Moreover, multiple zoonotic infections in humans have been reported. Importantly, HPAI H5N1 viruses with genetic markers of adaptation to mammals have been detected. Together with HPAI H5N1, avian influenza viruses H7N9 (high and low pathogenic) stand out due to their high mortality rates in humans . This raises the question of how prepared we are serologically and whether seasonal vaccines are capable of inducing protective immunity against these influenza subtypes. An observational study was conducted in which sera from people born between years 1925–1967, 1968–1977, and 1978–1997 were collected before or after 28 days or 6 months post-vaccination with an inactivated seasonal influenza vaccine. Then, hemagglutination inhibition, viral neutralization, and immunoassays were performed to assess the basal pro...

ABSTRACT The highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b has caused a human outbreak in North America since March 2024 . Here, we conducted a serosurveillance study to determine the risk of A(H5N1) clade 2.3.4.4b (2024 cattle H5N1 ) to general population . In the initial screening of 180 serum specimens encompassing all age groups , 2.2% (4/180) had detectable neutralizing antibody (nAb) titers against 2024 cattle H5N1, with all collected from older adults aged ≥60 years old . Further screening showed that 5.0% (15/300) of adults aged ≥70 years old had detectable nAb titers against the 2024 cattle H5N1. All serum specimens with nAb titer of ≥40 had detectable HI titer, and there was a positive correlation between nAb titer and HA binding (r=0.3311, 95% confidence interval 0.2264 to 0.4283; P<0.0001). The nAb titer against seasonal H1N1 virus was 3.9-fold higher for patients with detectable H5N1 nAb than those without (geometric mean titer: 108.5 [95% CI 56.3-209.1...