Alpine vegetation community patterns in the Khumbu region, Nepalese Himalaya

This is the final version. Available from Taylor & Francis via the DOI in this record. The Himalayan alpine zone (HAZ)—a high-altitude zone above approximately 4,100 m.a.s.l., is projected to experience strong eco-environmental changes with climate change. As plants expand their range in this region, other processes are likely to be impacted; for example, flows and stores of water. A first vital step in conceptualizing HAZ ecohydrology is to understand the distribution pattern of HAZ vegetation communities. Satellite remote sensing provides one means of doing so, but the often patchy distribution of alpine vegetation creates challenges when using coarse- grained satellite data whose pixels are typically coarser than the grain of vegetation pattern. Here we use fine spatial resolution satellite imagery from WorldView-2 (2 m2 per pixel) coupled with elevation model data from the Copernicus GLO-30 product to produce a land cover classification for the HAZ. Field data captured during in situ surveys in the Gokyo valley, Nepal, were used to drive and then test a random forest classifier. Grassy meadows and dwarf shrubs belonging to the Rhododendron and Juniperus families dominate the ecology of the alpine zone in this region, so we created three vegetation classes for mapping indicative major plant communities dominated by these species. We found that altitude and aspect were dominant drivers of vegetation distribution in the HAZ and that the average vegetation cover of Rhododendron spp. and Juniperus spp. reduces with increasing altitude, as expected. South- and east-facing slopes were dominated by Juniperus spp., whereas north- and west-facing slopes were dominated by Rhododendron spp., and the growth extent of Rhododendron spp. (between 4,010 and 4,820 m.a.s.l.) and meadow (between 4,010 and 4,680 m.a.s.l.) were vertically wider than that of Juniperus spp. (between 4,010 and 4,660 m.a.s.l.). Results from this study demonstrate the vegetation distribution pattern in HAZ at the plant community level and provide an impetus for further studies that seek to understand ecohydrological interactions between dwarf plants and water flows and stores in the HAZ

An outbreak investigation of visceral leishmaniasis among residents of Dharan town, eastern Nepal, evidence for urban transmission of <it>Leishmania donovani</it>

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL) is a predominantly rural disease, common in the low lands of eastern Nepal. Since 1997 VL cases have also been reported among residents of the city of Dharan. Our main research objective was to find out whether there had been local transmission of VL inside the city.</p> <p>Methods</p> <p>We conducted an outbreak investigation including a case–control study; cases were all urban residents treated for VL between 2000 and 2008 at BP Koirala Institute of Health Sciences, a university hospital in the city. For each case, we selected four random controls, with no history of previous VL; frequency-matched for age. Cases and controls were subjected to a structured interview on the main exposures of interest and potential confounders; a binominal multilevel model was used to analyze the data. We also collected entomological data from all neighborhoods of the city.</p> <p>Results</p> <p>We enrolled 115 VL patients and 448 controls. Cases were strongly clustered, 70% residing in 3 out of 19 neighborhoods. We found a strong association with socio-economic status, the poorest being most at risk. Housing was a risk factor independent from socio-economic status, most at risk were those living in thatched houses without windows. ‘Sleeping upstairs’ and ‘sleeping on a bed’ were strongly protective, OR of 0.08 and 0.25 respectively; proximity to a case was a strong risk factor (OR 3.79). Sand flies were captured in all neighborhoods; in collections from several neighborhoods presence of <it>L</it>. <it>donovani</it> could be demonstrated by PCR.</p> <p>Conclusion</p> <p>The evidence found in this study is consistent with transmission of anthroponotic VL within the city. The vector <it>P</it>. <it>argentipes</it> and the parasite <it>L</it>. <it>donovani</it> have both been identified inside the town. These findings are highly relevant for policy makers; in VL endemic areas appropriate surveillance and disease control measures must be adopted not only in rural areas but in urban areas as well.</p

Active case detection in national visceral leishmaniasis elimination programs in Bangladesh, India, and Nepal: feasibility, performance and costs

Background Active case detection (ACD) significantly contributes to early detection and treatment of visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) cases and is cost effective. This paper evaluates the performance and feasibility of adapting ACD strategies into national programs for VL elimination in Bangladesh, India and Nepal. Methods The camp search and index case search strategies were piloted in 2010-11 by national programs in high and moderate endemic districts / sub-districts respectively. Researchers independently assessed the performance and feasibility of these strategies through direct observation of activities and review of records. Program costs were estimated using an ingredients costing method. Results Altogether 48 camps (Bangladesh-27, India-19, Nepal-2) and 81 index case searches (India-36, Nepal-45) were conducted by the health services across 50 health center areas (Bangladesh-4 Upazillas, India-9 PHCs, Nepal-37 VDCs). The mean number of new case detected per camp was 1.3 and it varied from 0.32 in India to 2.0 in Bangladesh. The cost (excluding training costs) of detecting one new VL case per camp varied from USD 22 in Bangladesh, USD 199 in Nepal to USD 320 in India. The camp search strategy detected a substantive number of new PKDL cases. The major challenges faced by the programs were inadequate preparation, time and resources spent on promoting camp awareness through IEC activities in the community. Incorrectly diagnosed splenic enlargement at camps probably due to poor clinical examination skills resulted in a high proportion of patients being subjected to rK39 testing. Conclusion National programs can adapt ACD strategies for detection of new VL/PKDL cases. However adequate time and resources are required for training, planning and strengthening referral services to overcome challenges faced by the programs in conducting ACD