Seroprevalence of pertussis in adult population

Abstract

Introduction/Objective. Seroepidemiological studies are crucial for better understanding of pertussis epidemiology. The aim of this study was to assess the seroprevalence of anti-Bordetella pertussis toxin antibodies (anti-PT IgG) in the adult population of Novi Sad, and to evaluate the differences by age and sex. Methods. A cross-sectional study was conducted in 468 healthy adults aged ? 20 years stratified into seven age groups. The youngest of our participants received the last dose of the vaccine at least 18 years ago. Positive results of anti-PT IgG concentrations were considered a consequence of natural pertussis infection or reinfection. A commercial ELISA kit (EuroimmunR, Lubeck, Germany), with anti-PT IgG with four calibrators (5 IU/mL, 25 IU/mL, 100 IU/mL, and 200 IU/mL) was used. Results. Most of the subjects (53.8%) had anti-PT IgG of > 5 to < 62.5 IU/mL. The proportion of participants with high concentrations (62.5 to < 125 IU/mL) was statistically significantly higher in females than in males (5.4% vs. 0.4%, p = 0.002). The highest values of anti-PT IgG were detected among subjects in the age group of 20?24 years (17.5 ?} 22.2 IU/mL), and in the participants ? 60 years of age (15.0 ?} 29.4 IU/ mL). The percentage of anti-PT IgG concentration of ? 62.5 IU/mL was the highest among subjects aged ? 60 years (6.6%) and among those aged 20?24 years (5%). Conclusions. The limited duration of vaccine-induced immunity with subsequent infection or reinfection enables the circulation of pertussis in the adult population of Novi Sad that serves as the reservoir of infection for transmission to vulnerable persons.