Volume 20, Number 3—March 2014
Research
Possible Role of Songbirds and Parakeets in Transmission of Influenza A(H7N9) Virus to Humans
Table 4
Seroconversion of birds to influenza A(H7N9)*
Species, exposure | HI titer† |
||
---|---|---|---|
Baseline‡ | Homologous virus | Heterologous virus§ | |
Zebra finch | |||
Inoculated | < | 5.3 ± 1.0 (3/4) | < |
Contact | < | 4.3 ± 0.0 (3/3) | < |
Society finch | |||
Inoculated | < | 6.9 ± 0.9 (5/5) | < |
Contact | < | 6.3 ± 0.0 (1/3) | < |
Sparrow | |||
Inoculated | ND | 5.8 ± 0.6 (4/4) | < |
Contact | ND | 4.3 ± 0.0 (2/3) | < |
Parakeet | |||
Inoculated | < | 4.8 ± 0.6 (4/5) | < |
Contact | < | < (0/2) | < |
*HI, hemagglutination inhibition; <, below the limit of detection (serum dilution<1:20); homologous virus: A/Anhui/1/2013(H7N9); heterologous viruses: A/Songbird/Hong Kong/SB102/2001 (H3N8) and A/Vietnam/1203/04 (H5N1); ND, not determined because of limited number of available birds; HA, hemagglutinin.
†Reciprocal value (log2/50 μL) of the highest titer that inhibited 4 HA units of virus (no. seropositive animals/total no. sampled). Data are the mean ± SD of positive samples.
‡Baseline HI titers (3 birds/group) were obtained before virus challenge.
§HI titers to heterologous viruses were determined in the serum (16 dpi) from the same number of birds used to determine the HI titers to the homologous virus.