The seroepidemiology of Immunoglobulin G antibodies against pertussis toxin in China: a cross sectional study

Abstract

Background Pertussis is a reported vaccine-preventable respiratory disease in China. Because the routine laboratory methods for diagnosis are not in use, the reported cases are mainly in infants with classical paroxysmal cough and the true incidence related to pertussis is most likely under estimated. In China, however, few studies have attempted to address this issue. The purpose of this cross sectional study was to estimate the incidence rates using the method of sero-epidemiology of immunoglobulin (Ig) G antibodies against pertussis toxin (PT) among healthy populations in China. Methods Blood samples were obtained from 1313 healthy individuals aged 0 to 95 years in Guangdong province of China throughout September 2010. Serum IgG antibodies against PT were determined by commercial ELISA kits. Subjects with concentration of anti-PT IgG higher than 30 IU/mL were indicated to have recent Bordetella pertussis infection, if they have not received a booster dose of pertussis vaccine within one year. Results Of the 1313 study subjects, 117 (8.91%) were found to have anti-PT antibodies higher than 30 IU/mL. The estimated incidence of recent infection was thus 9395 per 100,000 for individuals older than 7 years. Peaks of the estimated incidence rate of recent infection were found to be 11561 per 100,000 in age group of 41–50 years and 11428 per 100,000 in the group aged 13–19 years. Conclusions Our study indicated that B.pertussis infections are considerablely common, particularly in adolescents and adults in China. The study also stresses the importance of laboratory diagnosis for pertussis and employment of booster dose of pertussis vaccine in adolescents and adults in this country.

Seroprevalence of Bordetella pertussis specific Immunoglobulin G antibody levels among asymptomatic individuals aged 4 to 24 years: a descriptive cross sectional study from Sri Lanka

“…Highest mean antibody levels (18.44 IU/ml) and sero-positivity (11.43%) was reported in 13–19 age group which suggests peak incidence of B. pertussis infection in this age group. This finding is very much similar to the findings of the present study [26]. …”

Brief Report: Seroprevalence of Pertussis Infection in HIV-Infected Adults in the United States

“…We found that 4.3% of subjects not vaccinated with Tdap in the last 6 months had serologic evidence of recent pertussis infection, and that the annual pertussis infection rate among subjects not vaccinated in the last 5 years was 10.5–17.5%. This rate is 1000-fold higher than the annual incidence of reported cases for the general U.S. population in 2014 20 , consistent with other seroprevalence studies that have found pertussis to be vastly underreported 15,18,19 . It is also 10-fold higher than the seroprevalence rate reported from a study among healthy American adolescents and adults in 1997–1999 4 .…”

“…Several studies have shown that mean anti-PT IgG levels drop to 9–14 units/ml by 18–36 months after Tdap vaccination 13,16,17 . In addition, other studies have used anti-PT IgG levels ≥30 units/ml to diagnose recent pertussis infections in subjects not vaccinated against pertussis for ≥2.5 years 18,19 .…”

Appearance of Macrolide-Resistant Bordetella pertussis Strains in China

“…Furthermore, B. pertussis strains isolated in the two provinces had identical genotypes and PFGE profiles, suggesting that B. pertussis with ptxA1 ptxP1 and BpFINR9 or BpSR23 are circulating in this country. Our data also indicate that the incidence of pertussis is most likely underestimated in China (7,8).…”