Prevalence and associated risk factors of avian influenza A virus subtypes H5N1 and H9N2 in LBMs of East Java province, Indonesia: a cross-sectional study

Background. Avian influenza A virus subtypes H5N1 and H9N2 are contagious zoonotic diseases that are circulating in Indonesia and have raised increasing concern about their potential impacts on poultry and public health. A cross-sectional study was carried out to investigate the prevalence and associated risk factors of avian influenza A virus subtypes H5N1 and H9N2 among poultry in the live bird markets of four cities in East Java province, Indonesia. Methods. A total of 600 tracheal and cloacal swabs (267 from backyards, 179 from broilers, and 154 from layers) from healthy birds were collected. The samples were inoculated into specific pathogenic-free embryonated eggs at 9-day-old via the allantoic cavity. qRT-PCR was used for further identification of avian influenza. Results. The overall prevalence of circulating influenza A virus subtypes H5N1 and H9N2 was 3.8% (23/600, 95%CI [0.0229-0.0537]). Prevalence was higher in backyards at 5.99% (16/267) followed by broilers (2.23% (4/179)) and layers (1.68% (3/154)). The final multivariable model revealed five risk factors for H9N2 infections: presence of ducks (p=0:003, OR = 38.2), turkeys (p=0:017 OR = 0.032), and pheasants in the stall (p=0:04, OR = 18.422), dry (p=0:006) and rainy season (p<0:001), and household birds (p=0:002) and seven factors for H5N1 infections including: observing rodents (p=0:036, OR = 0.005), stray dogs access (p=0:004 OR <= 0.001), presence of turkeys (p = 0:03 OR = 0.007), chukars/partridges (p = 0:024 OR = 2500), and peafowls in the stalls (p=0:0043 OR <= 0.001), rainy season (p=0:001) and birds from the household sources (p=0:002) in the live bird markets. Conclusions. The findings of the current study illustrate the recurring infection and presence of both avian influenza viruses and associated risk factors in the surveyed marketplaces. Effective protective measures and mitigation strategies for risks outlined in this study could help to reduce the burden of H5N1 and H9N2 AI subtypes into the live bird markets of Indonesia.

Automated summary

This study investigated the prevalence and associated risk factors of avian influenza A virus subtypes H5N1 and H9N2 among poultry in the live bird markets of four cities in East Java province, Indonesia. The findings revealed the recurring infection and presence of both avian influenza viruses and associated risk factors in the surveyed marketplaces. Effective protective measures and mitigation strategies outlined in this study could help to reduce the burden of H5N1 and H9N2 AI subtypes in Indonesia's live bird markets.