Avian influenza H9N2 subtype in Ghana: virus characterization and evidence of co-infection

AbstractBetween November 2017 and February 2018, Ghanaian poultry producers reported to animal health authorities a dramatic increase in mortality rate and a relevant drop in egg production in several layer hens farms. Laboratory investigations revealed that the farms had been infected by the H9N2 influenza subtype. Virological and molecular characterization of the viruses identified in Ghana is described here for the first time. Whole genome analysis showed that the viruses belong to the G1-lineage and cluster with viruses identified in North and West Africa. The low pathogenicity of the virus was confirmed by the intravenous pathogenicity index assay. Further investigations revealed the co-infection with infectious bronchitis virus of the GI-19 lineage, which very likely explained the severity of the disease observed during the outbreaks.The H9N2 outbreaks in Ghana highlight the importance of performing a differential diagnosis and an in-depth characterization of emerging viruses. In addition, the detec...