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The incidence of human brucellosis is not documented in Rwanda despite several reports on the disease in cattle. Because brucellosis has been associated with abortion, the aim of this study was to investigate the prevalence of positive serology in women presenting with abortion and/or stillbirth. The study was done in Huye District, in the Southern Province of Rwanda, and the patients were recruited from both the University Teaching Hospital of Butare (CHUB) and Kabutare District Hospital. Serum samples were collected and the Rose Bengal plate test (RBPT) was performed on each sample. A questionnaire was also used to investigate potential contacts with animals and/or consumption of raw milk. A total of 60 women were recruited and 15 (i.e., 25%) were Brucella seropositive. The questionnaire showed that those with seropositivity either were in contact with domestic animals (cattle, goat, or sheep) or were consuming raw cow’s milk. Human brucellosis appears to be of public health importance in Rwanda and more attention should be drawn on the disease. The current study provides a basis for larger studies to establish the incidence of human brucellosis in Rwanda. More mechanistic studies will also demonstrate the pathogenicity of Brucella in human placentas.

Urogenital schistosomiasis, due to Schistosoma haematobium, is endemic in sub-Saharan Africa. Control is by targeted treatment with praziquantel but preschool age children are excluded from control programs. Immunological studies on the effect of treatment at this young age are scarce. In light of studies in older individuals showing that praziquantel alters antischistosome immune responses and responses to bystander antigens, this study aims to investigate how these responses would be affected by treatment at this young age. Antibody responses directed against schistosome antigens, Plasmodium falciparum crude and recombinant antigens, and the allergen house dust mite were measured in children aged 3 to 5 years before and 6 weeks after treatment. The change in serological recognition of schistosome proteins was also investigated. Treatment augmented antischistosome IgM and IgE responses. The increase in IgE responses directed against adult worm antigens was accompanied by enhanced antigen recognition by sera from the children. Antibody responses directed against Plasmodium antigens were not significantly affected by praziquantel treatment nor were levels of allergen specific responses. Overall, praziquantel treatment enhanced, quantitatively and qualitatively, the antiworm responses associated with protective immunity but did not alter Plasmodium-specific responses or allergen-specific responses which mediate pathology in allergic disease.

Several field studies have reported an inverse relationship between the prevalence of helminth infections and that of allergic sensitisation/atopy. Recent studies show that immune responses induced by helminth parasites are, to an extent, comparable to allergic sensitisation. However, helminth products induce regulatory responses capable of inhibiting not only antiparasite immune responses, but also allergic sensitisation. The relative effects of this immunomodulation on the development of protective schistosome-specific responses in humans has yet to be demonstrated at population level, and the clinical significance of immunomodulation of allergic disease is still controversial. Nonetheless, similarities in immune responses against helminths and allergens pose interesting mechanistic and evolutionary questions. This paper examines the epidemiology, biology and immunology of allergic sensitisation/atopy, and schistosome infection in human populations.