Seroprevalence of Bordetella pertussis antibody in pregnant women in Iran.

BACKGROUND The increasing incidence of pertussis among adolescents and adults in recent years is an alarming factor in transmission of the infection to non-immune infants and children. Vaccination of pregnant women, immediately after delivery and before being discharged from the hospital may help to protect mothers and their newborns against the disease. Decision making process, regarding maternal immunization, requires credible information and knowledge about seroepidemiology of the infection in pregnant women. The aim of this study was to determine the seroprevalence of Bordetella pertussis antibody among admitted pregnant women in Hamadan, western Iran. METHODS In this cross-sectional study, 288 pregnant women admitted to the Fatemiyeh Hospital, Hamadan, western Iran, were enrolled into the study. After obtaining consent from every patient, serum samples were taken from patients and were kept frozen until testing. Serum level of B. pertussis antibody was measured using ELISA. Level of antibody higher than 24 U/ml was considered positive. The obtained data were analyzed using the statistical software SPSS. RESULTS From 288 pregnant women, 126 (43.8%) were in their second trimester. Serological results in 103 patients (35.8%) were positive. The mean age of mothers with positive serology was 27.5±6 years old. Thirty-five percent of patients had a valid immunization record, and 1.57% of those with no vaccination record had a positive serology. CONCLUSIONS The level of immunity against B. pertussis in pregnant women was low. Immunization before or during pregnancy can stimulate newborn's immune response and gives them required protection against pertussis infection.