Replication of H5N1 avian influenza viruses in guinea pigs.

aData shown are summarized from previous reports [2],[7]. Six-week-old BALB/c mice were infected i.n. with 106 EID50 of each virus in a 50-µl volume. Organs were collected on day 3 p.i., and clarified homogenates were titrated for virus infectivity in eggs at initial dilutions of 1∶10 (lung), 1∶2 (other tissues), or undiluted if negative at the lowest dilution. + and −, virus was detected or not detected, respectively, in the undiluted samples.
bGroups of four guinea pigs were slightly anesthetized and intranasally inoculated with 106EID50 of test virus in a 300µl volume, 150 µl per nostril. Two animals from each group were euthanized on day 3 p.i. and samples, including nasal wash, trachea, lung, spleen, kidney, colon and brain, were collected for virus titration in eggs. The remaining two animals were observed for two weeks and sera were collected at the end of the observation period. Virus was not detected in the spleen, kidney, colon and brain of any animals inoculated with the six viruses, therefore, the data from these samples are not shown in the table. −, virus was not detected in the undiluted sample.
cData shown are log10EID50/ml.
dVirus was only detected in one of the two animals inoculated.
eSeroconversion was confirmed by hemagglutination inhibition (HI) assay.