Influenza viruses in the air: in experimental settings and within live poultry markets

Abstract

Influenza virus transmits via multiple non-mutually exclusive modes; infections are mediated via virus-laden particles of various sizes that confer fomite, droplet, or airborne transmission. The specific mode of transmission associated with efficient spread of influenza viruses among their adapted hosts are not fully understood. In experimental settings, the application of animal models offer the benefit of controlled prior exposure history while studying influenza transmission. We evaluate the significance of droplet and airborne transmission potential in ferrets by controlling the size of virus-laden particles passed from the inoculated donors to the naïve contacts in the air, as droplet nuclei less than 5 μm mediate airborne transmission. To understand if specific host factors are associated with efficient transmission, early transcriptomic responses from ferret respiratory tissues were compared after inoculation with pandemic H1N1 and swine influenza viruses that differed by the respiratory droplet transmissibility. At the human-animal interface, we assess the quantity, size and viability of influenza virus-laden particles at live poultry markets in Guangzhou city to analyze the potential modes of transmission for zoonotic infections. Dissecting the black box of influenza transmission with collaborative multidisciplinary approach and cutting edge technology will provide valuable insights for developing effective control measures.