Abstract:

Objective      To detect levels of the antibody to swine-origin influenza A(H1N1) virus in the population under 18 years in Henan Province, and to provide data for a new preventive policy on swineorigin influenza A(H1N1) virus. Methods      A total of 2020 residents under 18 years, involved in a research program of the Ministry of Health named as  “Cross-sectional study of swine-origin influenza A (H1N1) influenza infection situation”,  were surveyed and a blood test with routine micro-hem agglutination inhibition test was done. Results      The positive rate of the antibody in the population under 18 years was 29.60%, and the rates in the three age groups were 45.70%(1318 years), 25.67%(7-12 years) and 23.71%(0-6 years), respectively. There were statistically significant differences among the three groups(χ2=80.07， P<0.01). Positive rates of the antibody in the three areas showed differences(35.47％ in the provincial capital, 36.00% in other cities and 23.67% in the rural area). The positive rate of the antibody in the vaccinated population (63.89%) was significantly higher than in the unvaccinated population(25.91%)(χ2=117.18, P<0.01). There was no significant difference between people with symptoms of influenzalike illness(ILI) and people without(χ2=0.75, P>0.01). Conclusion       Levels of the antibody to swine-origin influenza A (H1N1) virus are low in the population under 18 years in Henan Province. Strengthening vaccination and improving treatment of children are recommended strategies for swine-origin influenza A (H1N1) virus control and prevention.

Key words: Swine-origin influenza A(H1N1)  virus; Antibody to swine-origin influenza A (H1N1) virus; Positive rate