RISK-FACTORS OF MALARIA INFECTION DURING PREGNANCY IN BURKINA-FASO - SUGGESTION OF A GENETIC INFLUENCE

A cohort of 570 untreated pregnant women from Burkina Faso was studied to assess the influence of epidemiologic factors on malaria infection , which was quantified as the mean of serial, season-adjusted parasite mia measurements (mean parasite density [MPD]) carried out during the last five months of gestation. A significant effect of the area of mat ernal residence on the MPD was found (P < 0.003) and was probably due to geographic differences in mosquito transmission conditions. The str ong relationship observed between parity and malaria infection (P < 0. 0001), with MPD levels decreasing as the number of gestations increase d, confirms that primigravidae are a high-risk group whose protection should be a priority. After adjustment for two relevant epidemiologic factors (i.e., area of residence and parity), the residual MPD values fitted a mixture of two distributions. This result supports the view t hat a major gene is involved in the determination of malaria infection intensities and is consistent with the results of a recent familial s tudy in Cameroon.