Methods: Paired maternal and umbilical cord blood samples were collected at the time of delivery. Antibody titers to pertussis toxin (anti-PT) and filamentous hemagglutinin (anti-FHA) in each paired sample of maternal and cord blood were measured by in-house enzyme linked immunosorbent assay (ELISA). Geometric mean concentrations (GMCs) of pertussis antibodies and cord:maternal GMC ratios were calculated. Antibody levels of <10 EU/ml was accepted as non-immune, and ≥100 EU/ml was accepted as possible acute/recent infection.
Results: A total of 251 paired maternal delivery and cord blood samples were investigated in the study. The mean maternal age was 28.2 years, and the mean gestational age was 39.2 weeks. GMCs of IgG to PT and to FHA in maternal delivery serum were 4.12 and 9.89 EU/ml, respectively; GMCs of IgG to PT and FHA in cord blood were 5.49 and 12.73 EU/ml, respectively. GMCs of IgG in cord blood were 1.3 times higher than GMCs in maternal delivery serum. Placental transfer of pertussis antibodies was 133% for PT and 131% for FHA. Anti-PT levels (≥10 EU/ml) were found only in 25.1% of maternal samples and 34.7% of cord blood samples. The prevalence of recent pertussis infection in pregnant women was 3.6%.
Conclusion: Anti-pertussis antibody concentrations were low in pregnant women in Turkey. Despite antibody levels were 1.3 fold higher in cord blood than in maternal blood, cord antibody concentrations are too low, possibly placing infants at risk until their primary vaccinations against pertussis are complete. These results support the rationale for maternal pertussis immunization in order to prevent mothers and infants against pertussis.
Z. Kurugol Sr.,
N. Coplu, None
E. Ozer, None
C. Sonmez, None