[Seroepidemiologic survey for A/PR/8/34 (H1N1) virus from Chinese residents]

A total of 414 serum specimens were collected from the residents with ages of < or = 20 year old in eight different parts of China for detecting antibody to A/PR/8/34(H1N1) influenza virus with HI test. Of them, 24 had antibody with HI titers > or = 20 to A/PR/8/34(H1N1) virus. These 24 specimens were tested with the same method using A/swine/Iowa/15/30 (H1N1), A/Guangxi/10/94(H1N1) and A/Beijing/53/97(H1N1) viruses. The results showed that except 5 of them had antibody with HI titers 20-40 to A/Beijing/53/97(H1N1) virus, the rest had antibodies with titers < 20 to the viruses for checking test. Therefore, the antibody to A/PR/8/34(H1N1) virus in the tested sera was not caused by cross reaction of antibodies against another H1N1 viruses. The results in this paper also further demonstrated that the A/PR/8/34(H1N1) like virus was circulating in residents in China.