FIG 5.
Respiratory droplet transmission of the H4 avian influenza viruses in guinea pigs. Groups of five guinea pigs were inoculated i.n. with 106.0 EID50 of test virus. Twenty-four hours later, five naive guinea pigs were placed individually in an adjacent cage. Nasal washes were collected every 2 days from all animals beginning 2 days p.i. (1 day p.e.) for the detection of virus shedding. Each color bar represents the virus titer from an individual animal. The horizontal dashed red lines indicate the lower limit of detection.