Seroprevalence of Bordetella pertussis antibodies in adults in Hungary: results of an epidemiological cross-sectional study

Introduction: Pertussis (whooping cough) is an acute respiratory tract infection caused by Bordetella pertussis that is characterized by a chronic, severe cough. The optimum immunization schedule for pertussis is unclear, so these vary by countries. Aim: To estimate the seroprevalence of pertussis in adults in Hungary. Method: Serum anti-pertussis toxin immunoglobulin G (anti-PT IgG) antibody levels were analyzed using enzyme-linked immunosorbent assay in adults in general practitioners' practices during one year. Sera were classified following manufacturer's instructions as: strongly indicative of current/recent infection (>= 1.5 optical density [OD] units); indicative of current/recent infection (>= 1.0 OD units); seropositive (>0.3 OD units); or seronegative (<= 0.3 OD units). Results: 1999 adults (60.6% female; mean age 47.4 +/- 17.7 years) were included. 14.8% were seropositive, 1.1% were indicative of current/recent infection, and 0.1% were strongly indicative of current/recent infection. Conclusions: 85.2% of the subjects were seronegative and therefore susceptible to pertussis infection. Approximately 1% was suspicious of current/recent pertussis infection, potentially transmissible to susceptible young infants. Vaccination of adults is a key way to indirectly protect infants.