Immunization status of Iranian military recruits against Bordetella pertussis infection (whooping cough)

Abstract

Introduction: Military recruits are susceptible to respiratory pathogens because of increased antibiotic resistance and the lack of an effective vaccine. The goal of the current study was to determine the immunological status of the Bordetella pertussis among conscripts in Iranian military garrisons.

Methodology: The study population consisted of 424 conscripts aged 18 to 21 years who enrolled for military service. They were selected using cluster stratified sampling from all military garrisons in Tehra, Iran. To determine the seroprevalence of infection, blood specimens from all recruits were collected and stored at - 20°C until assayed. All serum samples were screened for immunoglobulin G (IgG) antibodies against Bordetella pertussis toxin (PT) and by using enzyme-linked immunosorbent assay (ELISA).

Results: The overall prevalence of B. pertussis seropositivity in military recruits was 60.6. Only 55.0% of the recruits had low awareness about the record of vaccination against B. pertussis during childhood. Among 424 studied individuals, 48 recruits (11.3%) had a positive history of whooping cough; prevalence of seropositivity in these recruits was 70.0%. Among these subjects, 61.7% were referred to a physician for treatment and only 39.6% of them were administered anti-pertussis therapy.

Conclusions: Our study showed that military conscripts in Tehran garrisons were not serologically immune to pertussis and also confirmed the low awareness about vaccination and medical history related to pertussis infection in this high-risk subgroup of the Iranian population. Routine acellular booster vaccination, particularly before 18 years of age, is recommended.