Horwood PF, Fabrizio T, Horm SV, et al. Transmission experiments support clade-level differences in the transmission and pathogenicity of Cambodian influenza A/H5N1 viruses. Emerg Microbes Infect. 2020;1-36
Influenza A/H5N1 has circulated in Asia since 2003 and is now enzootic in many countries in that region. In Cambodia, the virus has circulated since 2004 and has intermittently infected humans. During this period, we have noted differences in the rate of infections in humans, potentially associated with the circulation of different viral clades. In particular, a reassortant clade 1.1.2 virus emerged in early 2013 and was associated with a dramatic increase in infections of humans (34 cases) until it was replaced by a clade 2.3.2.1c virus in early 2014. In contrast, only one infection of a human has been reported in the 6 years since the clade 2.3.2.1c virus became the dominant circulating virus. We selected three viruses to represent the main viral clades that have circulated in Cambodia (clade 1.1.2, clade 1.1.2 reassortant, and clade 2.3.2.1c), and we conducted experiments to assess the virulence and transmissibility of these viruses in avian (chicken, duck) and mammalian (ferret) models. Our results suggest that the clade 2.3.2.1c virus is more "avian-like," with high virulence in both ducks and chickens, but there is no evidence of aerosol transmission of the virus from ducks to ferrets. In contrast, the two clade 1 viruses were less virulent in experimentally infected and contact ducks. However, evidence of chicken-to-ferret aerosol transmission was observed for both clade 1 viruses. The transmission experiments provide insights into clade-level differences that might explain the variation in A/H5N1 infections of humans observed in Cambodia and other settings.
See Also:
Latest articles in those days:
- Cross-species spill-over potential of the H9N2 bat influenza A virus 9 hours ago
- Bat-borne H9N2 influenza virus evades MxA restriction and exhibits efficient replication and transmission in ferrets 9 hours ago
- Epidemiological characteristics of human infections with avian influenza A(H5N6) virus, China and Laos: A multiple case descriptive analysis, February 2014-June 2023 1 days ago
- Interim Estimates of 2023-2024 Seasonal Influenza Vaccine Effectiveness Among Adults in Korea 1 days ago
- Abundant Intra-Subtype Reassortment Revealed in H13N8 Influenza Viruses 2 days ago
[Go Top] [Close Window]