[A sero-epidemiological study on pertussis among the community-based populations in Tianjin during 2010-2012]

To study the sero-epidemiology of pertussis immunity and related factors among the community-based populations in Tianjin.

Antibodies to pertussis toxin immunoglobulin and IgG (PT-IgG) levels among the community-based populations were examined, using ELISA over the three consecutive years. Subjects that were older than 4 years of age, with concentration of anti-PT-IgG higher than 40 IU/ml were recognized as having recent Bordetella (B.) pertussis infection.

Of the 1 825 study subjects, the average positive rate of anti-PT-IgG was 10.96% . The highest rate appeared as 24.37%-13.61% among the 0-3 year-olds (P < 0.001). The positive rate was 8.84%, and the estimated incidence of recent infection became 10 852 per 100 000 among those age 4-83 year-olds. Peak of the estimated incidence rate of recent infection was 18 986 per 100 000 in the age group of 51-83 year-olds (P = 0.001), but increasing linearly along with the increase of age (r = 0.976, P < 0.001). There were statistically significant differences seen in the antibody positive rate of 3-year period of study (P = 0.001), and appeared linear correlation with the reported annual incidence (r = 0.992, P < 0.001). There were statistically significant differences in the antibody positive rates of the 3 monitoring areas(P = 0.034), also showing a linear correlation with the reported annual incidence (r = 0.996, P < 0.001).

Results from this study indicated that B. pertussis infection had been common, particularly in adults living in the communities in Tianjin, calling for the current pertussis immunization strategy to be improved in order to control the pertussis reemerge in China.