Zhiyun Chen1, Jing Zhang2, Lina Cao1, Nan Zhang1, Junping Zhu1, Guoling Ping1, Jianhong Zhao3, Shuming Li4, Qiushui He5. 1. Department of Medical Microbiology, Capital Medical University, Beijing, China. 2. Beijing Youan Hospital, Capital Medical University, Beijing, China; Collaborative Innovation Center of Infectious Diseases, Capital Medical University, Beijing, China. 3. Centre for Disease Control and Prevention, Chaoyang District, Beijing, China. 4. Centre for Disease Control and Prevention, Chaoyang District, Beijing, China. Electronic address: kszz_001@126.com. 5. Department of Medical Microbiology, Capital Medical University, Beijing, China; Department of Medical Microbiology and Immunology, University of Turku, Turku, Finland. Electronic address: Qiushui.He@utu.fi.
Abstract
OBJECTIVE: To estimate the true incidence of pertussis in Chinese adults who are at a childbearing age. METHODS: A total of 897 serum samples from healthy individuals aged 20-39 years were selected randomly from a large number of serum samples collected in 2010 in Beijing, China. Anti-pertussis toxin (Ptx) IgG antibodies were determined with the Virion/Serion ELISA kits using purified Ptx as a coating antigen. RESULTS: Only 124 (13.8%) were found to have undetectable anti-Ptx IgG antibodies. The mean concentration was 13.76 IU/ml (95% CI, 12.37-15.15). Forty-six (5.1%) subjects had anti-Ptx IgG levels greater than or equal to 40 IU/ml, indicative of a pertussis infection, and nine (1%) had IgG antibodies greater than or equal to 100 IU/ml, indicative of a recent infection within a year. No significant differences were observed between age groups of 20-29 and 30-39 years, or between genders. CONCLUSIONS: Our study showed that about 5% of adults aged 20-39 years had positive anti-Ptx IgG antibodies, suggesting that adult pertussis is common in China. Giving a booster vaccination to pregnant women should possibly be considered in order to protect young infants who are too young to be vaccinated in this country.
OBJECTIVE: To estimate the true incidence of pertussis in Chinese adults who are at a childbearing age. METHODS: A total of 897 serum samples from healthy individuals aged 20-39 years were selected randomly from a large number of serum samples collected in 2010 in Beijing, China. Anti-pertussis toxin (Ptx) IgG antibodies were determined with the Virion/Serion ELISA kits using purified Ptx as a coating antigen. RESULTS: Only 124 (13.8%) were found to have undetectable anti-Ptx IgG antibodies. The mean concentration was 13.76 IU/ml (95% CI, 12.37-15.15). Forty-six (5.1%) subjects had anti-Ptx IgG levels greater than or equal to 40 IU/ml, indicative of a pertussis infection, and nine (1%) had IgG antibodies greater than or equal to 100 IU/ml, indicative of a recent infection within a year. No significant differences were observed between age groups of 20-29 and 30-39 years, or between genders. CONCLUSIONS: Our study showed that about 5% of adults aged 20-39 years had positive anti-Ptx IgG antibodies, suggesting that adult pertussis is common in China. Giving a booster vaccination to pregnant women should possibly be considered in order to protect young infants who are too young to be vaccinated in this country.