Volume 8, Number 2—February 2002
Research
Lack of Evidence for Human-to-Human Transmission of Avian Influenza A (H9N2) Viruses in Hong Kong, China 19991
Table 2
Serologic responses of two patients from Hong Kong infected with influenza A (H9N2) virus
Patient | Age (years) | Sex | Serologic anti-H9 response | ||||
---|---|---|---|---|---|---|---|
Days post symptom onset | Neutralizing antibody titera | Western blotb | ELISA IgGc | ELISA IgMc | |||
1 | 4 | female | 39 | 135 | Positive | 51200 | 18100 |
2 | 1 | female | 35 | 40 | Positive | 6400 | 1600 |
aTiters expressed as the geometric mean of four replicate titers; titers ≥80 were considered positive for anti-H9 antibodies.
bWestern blots were performed by using a purified baculovirus-expressed recombinant HK/1073 HA as antigen.
cEnzyme-linked immunosorbent assay (ELISA) immunoglobulin (Ig) G and IgM antibodies were detected on plates coated with purified baculovirus-expressed recombinant HK/1073 HA (1 μg/mL). Titers are expressed as the geometric mean of duplicate endpoint titers estimated as described in Methods. A titer ≥1,600 was considered positive for anti-H9 antibodies.
1Presented in part at the International Conference on Emerging Infectious Diseases 2000, Atlanta, Georgia, July 2000 (Poster #55), Session 7, July 16-19, 2000.