Zoonoses and marginalised infectious diseases of poverty: where do we stand?

Despite growing awareness of the importance of controlling neglected tropical diseases as a contribution to poverty alleviation and achieving the Millennium Development Goals, there is a need to up-scale programmes to achieve wider public health benefits. This implementation deficit is attributable to several factors but one often overlooked is the specific difficulty in tackling diseases that involve both people and animals - the zoonoses. A Disease Reference Group on Zoonoses and Marginalised Infectious Diseases (DRG6) was convened by the Special Programme for Research and Training in Tropical Diseases (TDR), a programme executed by the World Health Organization and co-sponsored by UNICEF, UNDP, the World Bank and WHO. The key considerations included: (a) the general lack of reliable quantitative data on their public health burden; (b) the need to evaluate livestock production losses and their additional impacts on health and poverty; (c) the relevance of cross-sectoral issues essential to designing and implementing public health interventions for zoonotic diseases; and (d) identifying priority areas for research and interventions to harness resources most effectively. Beyond disease specific research issues, a set of common macro-priorities and interventions were identified which, if implemented through a more integrated approach by countries, would have a significant impact on human health of the most marginalised populations characteristically dependent on livestock.

Use of triclabendazole for treatment of patients co-infected by Fasciola spp. and S. mansoni in Behera Governorate, Egypt.

Praziquantel is still very effective for the treatment of schistosomiasis, but there are rising concerns on the potential risk of developing resistances because of the extensive use of this drug. Triclabendazole, a systemic anthelmintic, is very effective against other trematodes such as Paragonimus spp. and Fasciola spp. It has been reported to be effective in vitro and in experimental animals against Schistosoma mansoni. However, its antischistosomal efficacy in humans has not yet been evaluated. The objective of the study was to evaluate the efficacy of triclabendazole at the dosage currently used for the treatment of human fascioliasis (10mg/kg body weight) in subjects co-infected with S. mansoni and Fasciola spp. The study was carried out in Behera, a highly endemic area for both parasites, by personnel of the Egyptian Ministry of Health and Population. Ten subjects (m = 4, f = 6; age, 8-58years), who were infected at the same time by Fasciola spp. and S. mansoni, were enrolled. Six weeks after therapy, seven subjects were still excreting ova of S. mansoni, whereas none was excreting Fasciola spp. ova. At the given dosage, triclabendazole appeared not to be sufficiently effective in the treatment of S. mansoni.

Human fascioliasis infection: gender differences within school-age children from endemic areas of the Nile Delta, Egypt.

Several studies have reported a higher prevalence of infection for human fascioliasis among girls than among boys. To investigate this aspect further a sufficiently large data set was assembled comprising of 21,477 subjects with 932 positive cases. Subjects were primary school children covered by a control programme implemented by the Egyptian Ministry of Health and Population in the Nile Delta from 1988 to 2002. Stool analyses were performed by the Kato-Katz thick smear technique for a quantitative diagnosis on the intensity of infection. Both prevalence and intensity of infection, indirectly measured as mean number of eggs per gram of faeces, were significantly higher among girls than boys. The higher level of infection in girls was consistent across different years and in different survey areas. Co-infection with Schistosoma mansoni was present and associated with fascioliasis, but schistosomiasis was significantly more prevalent among boys. In Egypt rural girls are often involved in household and farm work and are exposed more than boys to infected foci. The lower school attendance for girls in rural areas appears to be an important factor increasing risk of infection. The precise mode of transmission and behavioural risk factors for human infection need to be investigated further to identify those related to gender.