Elimination of visceral leishmaniasis in Nepal: pipe-dreams and possibilities.

INTRODUCTION: Visceral Leishmaniasis (VL) re-emerged in the Indian subcontinent in the mid-1970s after an almost complete absence in the previous fifteen or so years. The disease was first noted in Nepal in 1978 and, since 1980, it has been reported regularly in increasing numbers. Elimination of visceral leishmaniasis by 2015 has been identified as regional priority program in the level of high political commitment. OBJECTIVE: The objectives of this study are the comprehensive assessment of information related to VL on the basis of past research studies conducted in Nepal, and an assessment of the prospects of control measures. MATERIALS AND METHODS: This was time line comprehensive VL epidemiological assessment study based on the research conducted by main author during the past ten years. During the period the studies were conducted using cross sectional, case control and exploratory study design. The statistical analysis was done using qualitative and quantitative methods. RESULTS: In our study in the visceral leishmaniasis endemic district, Siraha, in the population of 112,029, a total of 996 clinically suspected cases were reported (with fever of long duration and splenomegaly, with no malaria) during 1998-2002. In all, 283 subjects were found positive for visceral leishmaniasis by rK39 and 284 had positive bone marrow. There was no detectable difference in the density of Phlebotomus argentipes between high, and moderate incidence village development committees (VDC: the smallest administrative unit), but collections in the low incidence areas (in winter) were negative. P. argentipes was never numerous (maximum 4.4 females collected per man-hour), and was much less common than P. papatasi. Peaks of abundance were recorded in the March and September collections. We have found that the numbers of reported cases of visceral leishmaniasis in Nepalese villages was unaffected by indoor residual spray (IRS) indicated by parallel trends in case numbers by time series analysis in treated and untreated villages. A series of maps through ten years clearly showed that the infection can move rapidly between villages, and it is impossible to predict where transmission will occur from year to year. CONCLUSION: If maximum benefit in relation to cost is the goal, it may be preferable to put all possible efforts into active case detection (ACD) with free treatment. ACD should involve the network of Village Health Workers or Female Community Health Volunteers and the rK39 dipstick test at health centre level. Surveillance of disease and vector, communication for behavioural impacts and insecticide spraying should be important component of elimination program. If IRS is to be a part of the intervention, it is essential that it is carried out effectively, both in areas where the disease has been reported and in neighbouring areas. Integrated vector management need to be monitored for its application and effectiveness for VL elimination.

Health promotion approach for the control of food-borne parasitic zoonoses in Nepal: emphasis on an environmental assessment.

Green and Kreuter define health promotion as the use of both education and ecology to encourage and support living conditions conducive to good health. Their PRECEDE-PROCEED model delineates a practical way to cope with health problems using this definition. Applying PRECEDE to Nepal helps identify the steps needed to control the ever-increasing incidence of food-borne parasitic zoonoses (FBPZ) there and in other South Asian countries. In executing the first five steps of the model, we focused on behavioral and environmental assessments to find a method for controlling FBPZ. Through these two assessments, we identified the following behavioral and environmental objectives: establish a meat inspection system by 2003, establish training programs on safe meat production and selling practices by 2003, improve slaughterhouses and slaughtering practices by 2003. The educational and ecological assessments revealed that the necessary predisposing, reinforcing and enabling factors for appropriate control of FBPZ are present in Nepal, while an administration and policy assessment shows Nepal meets PRECEDE requirements through its recent meat inspection legislation. Although the data for each element of the PRECEDE-PROCEED model are limited in Nepal, they clearly tell us to move forward to the PROCEED stage to control FBPZ there as well as in all of South Asia.

Controlling Taenia solium in Nepal using the PRECEDE-PROCEED model.

Taenia solium is a predominant food-borne parasitic zoonosis (FBPZ) in Nepal. Using the PRECEDE framework, as defined by Green and Kreuter, we can identify the factors behind the high incidence of this disease. Armed with this information, we can define the actions necessary to control T. solium. In accordance with the first step of PRECEDE, social assessment, we set the goal of decreasing the potential for T. solium transmission in Nepal by the year 2003. This goal has yet to be endorsed by policy makers. However, an epidemiological assessment based on hospital data alone showed that T. solium is an endemic problem in urban Nepal that must be addressed. Based on behavioral and environmental assessments (Steps 1 and 2 of PRECEDE-PROCEED), we defined the following action objectives to be achieved by 2003: 1) Train meat producers and sellers to detect contaminated pork and avoid selling it, 2) Improve pig husbandry to limit the animals' access to human feces, 3) Construct hygienic model slaughterhouses. These improvements could control the meat-producing environment, thus limiting the potential for cross-carcass contamination and other hygiene deficiencies associated with the spread of T. solium. An educational and ecological assessment shows all predisposing, reinforcing and enabling factors are present in Nepal, consistent with PRECEDE requirements. While T. solium is clearly defined as a health problem according to PRECEDE, there remain significant hurdles to controlling it. These hurdles lie in administration and policy, where standardized law-enforcement and meat inspection practices are needed. Finally, the government of Nepal must assign high priority to T. solium control, as it is a preventable, yet prevalent disease.

Study of Cyclospora cayetanensis in health care facilities, sewage water and green leafy vegetables in Nepal.

Cyclospora cayetanensis, a newly emerging parasite, is endemic in Nepal. A total of 2,123 stool specimens were collected from 3 health care facilities based on clinical symptoms during the period between 1995 to October, 1998. Out of these specimens, cayetanensis oocysts were found in 632 (29.8%). To identify possible sources for Cyclospora infection, drinking water, sewage water, green-leafy vegetables including fecal samples of various animals were collected and examined. The vegetable leaves were washed in distilled water then the washings, sewage water and drinking water were centrifuged and the sediment were examined microscopically. As a result, oocyst of Cyclospora were identified in sewage water and vegetable washings on four different occasions in June, August, October and November. The positive results were also confirmed as C. cayetanensis by development of 2 sporocysts after 2 week incubation period in potassium dichromate. A survey of 196 domestic animals from the same areas demonstrated that two chickens were positive for Cyclospora-like organism and others were negative. Although further studies are needed to clarify the direct link between Cyclospora infection and these sources, the results suggest that sewage water, green leafy vegetables are possible sources of infection and chickens could be possible reservoir host of Cyclospora in Nepal.