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

Abstract

SummaryDuring 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.keywords visceral leishmaniasis, insecticide-impregnated bednets, kala azar, Sudan

The Effect of Removing Potentially Infectious Dogs on the Numbers of Canine Leishmania infantum Infections in an Endemic Area with High Transmission Rates

“…Such information is important as promoting population expansion of genetically determined resistant dogs would significantly improve VL control. However, the most feasible approach to controlling VL are likely the development of an effective vaccine 44 to protect dogs from being infectious to the sand fly vector, and identifying new methods to prevent infection in canines and humans, such as the use of insecticidal dog collars, 45,46 and insecticidetreated bednets, 47,48 which are promising in reducing canine and human incidence. Future intervention trials should show whether these new tools could be used to develop a sustainable VL prevention and control strategy.…”

Who Is a Typical Patient with Visceral Leishmaniasis? Characterizing the Demographic and Nutritional Profile of Patients in Brazil, East Africa, and South Asia

“…An example of other possible ways to improve integration might include the supplementation of nutritional interventions (e.g., vitamin A) to mass distribution programs of fine-mesh impregnated bed nets against VL. 40 Nutrition should be adequately addressed in the public sector as well. Also, it cannot be excluded that vulnerability to infection and consequent impact of anthropometrics (nutritional status) may also differ because of parasite differences in each region.…”

Kala-azar Epidemiology and Control, Southern Sudan

“…In the absence of detailed information on risk factors (cultural, demographic, epidemiologic, clinical, and geographic), use of longlasting insecticide-treated nets seems a suitable method of prevention. Results from studies in North Sudan showed that insecticide-treated nets provided 27% protection from kala-azar (12). Whether similar protection can be achieved in Southern Sudan's disease-endemic areas requires confi rmation because effectiveness is dependent on human and vector behavior (13).…”