Consequences of ante-natal and intrapartum exposure to Wuchereria bancrofti infection

Abstract

INTRODUCTION: It has been shown that prenatal exposure to parasite antigens may render newborns tolerant to infection and increase susceptibility to clinical disease. OBJECTIVE: To assess frequency of ante-natal and intrapartum exposure to W. bancrofti antigens among babies born to mothers living in a selected, lymphatic filariasis endemic area. METHODS: A total of 240 parturient women who delivered in the Colombo North Teaching Hospital, Ragama were surveyed, during October 2002. Microscopy and the immunochromatographic card test for filariasis were deployed to assess microfilaraemia and antigenaemia respectively in maternal and umbilical cord blood. An expert validated, pre-tested questionnaire was utilized in obtaining a detailed obstetric profile and to screen for any past or present significant clinical manifestations. RESULTS: The mean age of the study population was 27.4 years (range 17-40, SD 5.42). All mothers were free from any clinical evidence of filariasis. Antigenaemia was detected in 53/240 (22.08%) maternal blood samples while 37/240 (15.41%) cord blood samples were also positive. All the antigen positive cord blood samples were from mothers who were antigenaemic, whereas none of the offspring bom to non-ant'igenaemic mothers were positive. Microscopy of 52 night-blood samples of maternal and cord blood failed to detect any microfilaraemia. CONCLUSIONS: In utero or intrapartum transfer of filarial antigens frem mother to foetus appears to be quite common. These findings need to be taken into consideration in the national filariasis control programme.