Helminth infections and malaria are widespread in the tropics. Recent studies suggest helminth infections may increase susceptibility to malaria. If confirmed, this could be particularly important during pregnancy-induced immunosuppression.
To evaluate the geographical distribution of Plasmodium falciparum-helminth co-infection, and associations between parasite species in pregnant women in Entebbe, Uganda.
A cross-sectional study was conducted at baseline in a trial of anti-helminthics during pregnancy. Helminth and P.falciparum infections were quantified in 2507 asymptomatic women; socio-demographic and geographical details were recorded.
Hookworm and Mansonella perstans were associated with P.falciparum but the effect of hookworm was seen only in the absence of M.perstans (OR for P.falciparum, adjusted for age, tribe, socioeconomic status, HIV and location: hookworm without M.perstans 1.53 (95% CI 1.09-2.14); M.perstans without hookworm 2.33 (1.47-3.69), both hookworm and M.perstans, 1.85 (1.24-2.76)). No association was observed between Schistosoma mansoni, Trichuris or Strongyloides and P.falciparum.
Hookworm-P.falciparum and M.perstans-P.falciparum co-infection amongst pregnant women in Entebbe is more common than expected by chance. Further studies are needed to elucidate the mechanism of this association. Helminth-induced increased susceptibility to P.falciparum could have important consequences for pregnancy outcome and responses to malaria in infancy.