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 (Euroimmun®, Lübeck, 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.

Pertussis Epidemiology in the Autonomous Province of Vojvodina, Serbia, 1948–2023

“…Specifically, the prevalence of pertussis unrecognized infection within one year was 3.4%, equivalent to 9242 cases, while only 200 cases were officially registered (ratio 46:1). Interestingly, we have additionally identified unrecognized recent pertussis infections or reinfections following waning immunity among young or future parents, as well as among other elderly family members [27]. Due to the implementation of non-pharmaceutical measures against the COVID-19 pandemic (such as movement restrictions, closures of schools, kindergartens, and faculties, physical distancing, wearing properly fitted masks, practicing hand hygiene, and prohibiting visits to secondary and tertiary healthcare institutions as well as nursing homes) [28], there has been a decline in the number of officially registered pertussis cases.…”