Yuxiao Zhang1, Zhiyun Chen1, Jianhong Zhao2, Nan Zhang1, Ning Chen1, Jing Zhang3, Shuming Li2, Qiushui He4. 1. Department of Medical Microbiology, Capital Medical University, Beijing, China. 2. Center for Disease Prevention and Control, Chaoyang District, Beijing, China. 3. Beijing You'an Hospital, Capital Medical University, Beijing, China. 4. Department of Medical Microbiology, Capital Medical University, Beijing, China; Department of Medical Microbiology and Immunology, University of Turku, Turku, Finland. Electronic address: qiushui.he@ccmu.edu.cn.
Abstract
OBJECTIVES: This study was aimed to determine pertussis specific serum PT-IgG antibodies in healthy individuals during 2010 and 2015/2016 in Beijing, China. METHODS: A total of 3884 healthy individuals were included: 3058 aged 3-69 years randomly selected from an epidemiological survey conducted in 2010, and 826 aged 20-39 years selected from those who attended an annual medical examination in 2015/2016. Serum PT-IgG antibodies were determined using the Serion/Virion ELISA kits. RESULTS: Of 3058 subjects in 2010, 167 (5.5%) and 39 (1.3%) subjects had PT-IgG antibodies ≥40 IU/ml and ≥100 IU/ml, respectively. No differences were observed among different age groups. Altogether, 26.2% had undetectable PT-IgG antibodies (<5 IU/ml), and the highest undetectable rate of 56.8% was found in children aged 3-5 years. When the age group of 20-39 years was compared between the two periods, no difference was found in seroprevalence of PT-IgG antibodies ≥ 40 IU/ml (5.1% vs. 4.0%). However, an undetectable rate of PT-IgG antibodies was significantly higher in 2015/2016 than that in 2010 (57.4% vs. 29.1%, p < 0.001). CONCLUSIONS: Our results showed that about 5% of individuals had PT-IgG antibodies indicative of a recent infection, and adults at childbearing age have an increased risk to pertussis in China.
OBJECTIVES: This study was aimed to determine pertussis specific serum PT-IgG antibodies in healthy individuals during 2010 and 2015/2016 in Beijing, China. METHODS: A total of 3884 healthy individuals were included: 3058 aged 3-69 years randomly selected from an epidemiological survey conducted in 2010, and 826 aged 20-39 years selected from those who attended an annual medical examination in 2015/2016. Serum PT-IgG antibodies were determined using the Serion/Virion ELISA kits. RESULTS: Of 3058 subjects in 2010, 167 (5.5%) and 39 (1.3%) subjects had PT-IgG antibodies ≥40 IU/ml and ≥100 IU/ml, respectively. No differences were observed among different age groups. Altogether, 26.2% had undetectable PT-IgG antibodies (<5 IU/ml), and the highest undetectable rate of 56.8% was found in children aged 3-5 years. When the age group of 20-39 years was compared between the two periods, no difference was found in seroprevalence of PT-IgG antibodies ≥ 40 IU/ml (5.1% vs. 4.0%). However, an undetectable rate of PT-IgG antibodies was significantly higher in 2015/2016 than that in 2010 (57.4% vs. 29.1%, p < 0.001). CONCLUSIONS: Our results showed that about 5% of individuals had PT-IgG antibodies indicative of a recent infection, and adults at childbearing age have an increased risk to pertussis in China.