• Evaluation of a mass distribution programme for fine-mesh impregnated bednets against visceral leishmaniasis in eastern Sudan.

      Ritmeijer, K; Davies, C; van Zorge, R; Wang, S J; Schorscher, J; Dongu'du, S I; Davidson, R N; Médecins Sans Frontières-Holland, Amsterdam, The Netherlands. koert_ritmeijer@amsterdam.msf.org (Wiley-Blackwell, 2007-03)
      During an epidemic of visceral leishmaniasis (VL) in eastern Sudan, Médecins Sans Frontières distributed 357,000 insecticide-treated bednets (ITN) to 155 affected villages between May 1999 and March 2001. To estimate the protective effect of the ITN, we evaluated coverage and use of ITN, and analysed VL incidence by village from March 1996 to June 2002. We provided ITN to 94% of the individuals >5 years old. Two years later, 44% (95% CI 39-48%) of nets were reasonably intact. Because ITN were mainly used as protection against nuisance mosquitoes, bednet use during the VL transmission season ranged from <10% during the hot dry months to 55% during the beginning of the rainy season. ITN were put up from 9 to 11 p.m., leaving children unprotected during a significant period of sandfly-biting hours after sunset. Regression analysis of incidence data from 114 villages demonstrated a significant reduction of VL by village and month following ITN provision. The greatest effect was 17-20 months post-intervention, with VL cases reduced by 59% (95% CI: 25-78%). An estimated 1060 VL cases were prevented between June 1999 and January 2001, a mean protective effect of 27%. Although results need to be interpreted with caution, this analysis indicates a potentially strong reduction in VL incidence following a community distribution of ITN. The effectiveness of ITN depends on behavioural factors, which differ between communities.
    • Visceral Leishmaniasis in Southern Sudan: Status of Healthy Villagers in Epidemic Conditions.

      Seaman, J; Ashford, R W; Schorscher, J; Dereure, J; MSF Holland (Artsen Zonder Grenzen), Nairobi, Kenya. (Published by: Maney Publishing, 1992-10)
      A combination of interview, serology and skin testing was used to investigate the status of apparently healthy villagers during a visceral leishmaniasis epidemic in southern Sudan. The number of people who had died equalled the number who were alive at the time of the survey. The direct agglutination test (DAT) identified 10% of the people as being serologically positive. Most young children (36/39) and 34% (22/64) of adults had neither positive serology nor skin test. About 64% (42/66) of adults had positive skin tests. In two villages, 54% and 76% of those over four years of age showed evidence of having been infected. The mortality associated with infection was estimated as at least 69%; 25% of those infected appeared to have cured spontaneously. The outcome for the remaining 6% was still doubtful. Even in this devastating epidemic there is, therefore, evidence of a considerable amount of infection without severe disease. Serological tests, while useful clinically, are apparently not useful for detecting early cases. Combined skin testing and serology produces a comprehensive though partially hypothetical picture.