Evidence of Infection with H4 and H11 Avian Influenza Viruses among Lebanese Chicken Growers

Abstract

Human infections with H5, H7, and H9 avian influenza viruses are well documented. Exposure to poultry is the most important risk factor for humans becoming infected with these viruses. Data on human infection with other low pathogenicity avian influenza viruses is sparse but suggests that such infections may occur. Lebanon is a Mediterranean country lying under two major migratory birds flyways and is home to many wild and domestic bird species. Previous reports from this country demonstrated that low pathogenicity avian influenza viruses are in circulation but highly pathogenic H5N1 viruses were not reported. In order to study the extent of human infection with avian influenza viruses in Lebanon, we carried out a seroprevalence cross-sectional study into which 200 poultry-exposed individuals and 50 non-exposed controls were enrolled. We obtained their sera and tested it for the presence of antibodies against avian influenza viruses types H4 through H16 and used a questionnaire to collect exposure data. Our microneutralization assay results suggested that backyard poultry growers may have been previously infected with H4 and H11 avian influenza viruses. We confirmed these results by using a horse red blood cells hemagglutination inhibition assay. Our data also showed that farmers with antibodies against each virus type clustered in a small geographic area suggesting that unrecognized outbreaks among birds may have led to these human infections. In conclusion, this study suggests that occupational exposure to chicken is a risk factor for infection with avian influenza especially among backyard growers and that H4 and H11 influenza viruses may possess the ability to cross the species barrier to infect humans.

Hemagglutinin Stalk-Based Universal Vaccine Constructs Protect against Group 2 Influenza A Viruses

“…These antibodies were not only protective against a panel of H3N2 strains and an H3N8 virus but also provided robust protection against a heterosubtypic challenge with avian H7N1 and H10N7 isolates, demonstrating a breadth that spans both clades of the group 2 HA-expressing viruses. This breadth is important in light of growing concerns about the pandemic potential of H3N2 variant (H3N2v) viruses and H3N8 viruses isolated from New England harbor seals and other zoonotic H3 strains (12,34,38), as well as H4-, H7-, and H10-expressing viruses that infect humans occasionally (11,(39)(40)(41)(42)(43). Importantly, this vaccination strategy also induced high titers of stalk-reactive antibodies against the H7 HA from the emerging Chinese H7N9 virus (10).…”

Assessment of Influenza Virus Hemagglutinin Stalk-Based Immunity in Ferrets

“…Third, the emergence of pandemic influenza virus strains is difficult to predict, and once an influenza pandemic emerges, it is even more difficult to redirect vaccine production in a timely fashion to respond to a pandemic, as happened during the 2009 H1N1 influenza pandemic (6,7). Predictions of influenza pandemics is further complicated by the realization that several influenza virus subtypes possess pandemic potential, as evidenced by the emergence of avian influenza A (H7N9) virus in March 2013 (8) and sporadic human infections with H4, H5, H6, H7, H9, and H10 avian influenza viruses (9)(10)(11)(12)(13)(14).…”

The zoonotic potential of avian influenza viruses isolated from wild waterfowl in Zambia

“…Frequent introduction of such viruses into poultry may lead to an increased risk that AIVs acquire mutations that may allow them to expand their host range [15]. In fact, a serological study has recently provided evidence of human infections with LPAIVs (subtype H4 and H11) among backyard poultry growers [18]. As clearly demonstrated by the recent human cases of H7N9 LPAIV infection in China, contact with unrecognized LPAIV-infected domestic birds may indeed lead to human infections with dire consequences.…”

“…Furthermore, IL-1 plays an important role in hemostasis deregulation through tissue factor induction. Since hemostasis deregulation emerges as a key pathway in cytokine storm induced by influenza viruses [3,4,18], it seems reasonable to speculate that human signature residues in the M2 protein of AIVs may be involved in cytokine storm via IL-1 production and hemostasis deregulation.…”