Circulation of Bordetella pertussis in the Caribbean Netherlands: a population-based seroepidemiological study

Abstract

Objectives: Pertussis is a respiratory infectious disease caused by Bordetella pertussis. In the Caribbean Netherlands (CN), comprising the islands Bonaire, St Eustatius, and Saba, registration of cases is mandatory for disease surveillance. However, insufficient laboratory facilities hamper case confirmation, and circulation persists. The aim of this seroepidemiological study was to gain insight into B. pertussis circulation in CN, and to investigate what factors contribute to the risk of infection. Methods: Blood samples and questionnaires were collected for 1829 participants aged 0–90 years. Concentrations of B. pertussis toxin-specific IgG antibodies (anti-Pt) were determined using a bead-based immunoassay to indicate infections within the previous 12 months (based on anti-Pt ≥ 50 IU/mL) in participants without detectable vaccine-induced humoral immunity. Risk factors for recent infection were analyzed using logistic regression models. Results: An estimated 8.2% (95% CI 6.6–10.1) of CN residents aged ≥ 9 years were found to have been recently infected by B. pertussis. Risk factors for a recent infection were age 12–29 years (13.8–14.6%) and Dutch Caribbean or Surinamese origin (10.7%). Conclusions: B. pertussis infections occur frequently among CN residents aged ≥ 9 years, although few clinical pertussis cases are reported. Transmission to vulnerable individuals seems likely and should be taken into account in optimizing vaccination programs.

Keywords

• pertussis
• circulation
• seroepidemiology
• vaccination
• Caribbean Netherlands