Figure 5.

Respiratory droplet transmission of H3N2 avian influenza viruses in guinea pigs. Groups of three guinea pigs were inoculated intranasally with 10⁶ EID₅₀ of test virus, and 24 h later, three naïve guinea pigs were introduced into neighbouring cages. Nasal washes were collected every 2 days from all guinea pigs beginning on Day 2 post-inoculation (p.i.) or Day 1 post-exposure (p.e.) for detection of virus shedding, and seroconversion of the animals was confirmed by use of a hemagglutinin inhibition (HI) test. Each colour bar in panels a–e represents the virus titre from an individual animal, and each colour bar in panels f–j represents the HI antibody titre from an individual animal. The horizontal dashed lines indicate the lower limit of detection.