Species composition, seasonal occurrence, habitat preference and altitudinal distribution of malaria and other disease vectors in eastern Nepal

Particle and Fibre Toxicology

Ulrich Kuch¹  Bodo Ahrens²  Meghnath Dhimal¹ 

[1] Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University, Frankfurt am Main, Germany;Institute for Atmospheric and Environmental Sciences (IAU), Goethe University, Frankfurt am Main, Germany

关键词: Mosquito-borne diseases;    Lymphatic filariasis;    Japanese encephalitis;    Elimination;    Dengue;    Climate change;    Culex;    Anopheles;    Aedes;   

Others  :  1148969
DOI  :  10.1186/s13071-014-0540-4

 received in 2014-10-17, accepted in 2014-11-14,  发布年份 2014

【 摘 要 】

Background

It is increasingly recognized that climate change can alter the geographical distribution of vector-borne diseases (VBDs) with shifts of disease vectors to higher altitudes and latitudes. In particular, an increasing risk of malaria and dengue fever epidemics in tropical highlands and temperate regions has been predicted in different climate change scenarios. The aim of this paper is to expand the current knowledge on the seasonal occurrence and altitudinal distribution of malaria and other disease vectors in eastern Nepal.

Methods

Adult mosquitoes resting indoors and outdoors were collected using CDC light trap and aspirators with the support of flash light. Mosquito larvae were collected using locally constructed dippers. We assessed the local residents’ perceptions of the distribution and occurrence of mosquitoes using key informant interview techniques. Generalized linear models were fitted to assess the effect of season, resting site and topography on the abundance of malaria vectors.

Results

The known malaria vectors in Nepal, Anopheles fluviatilis, Anopheles annularis and Anopheles maculatus complex members were recorded from 70 to 1,820 m above sea level (asl). The vectors of chikungunya and dengue virus, Aedes aegypti and Aedes albopictus, the vector of lymphatic filariasis, Culex quinquefasciatus, and that of Japanese encephalitis, Culex tritaeniorhynchus, were found from 70 to 2,000 m asl in eastern Nepal. Larvae of Anopheles, Culex and Aedes species were recorded up to 2,310 m asl. Only season had a significant effect on the abundance of An. fluviatilis, season and resting site on the abundance of An. maculatus complex members, and season, resting site and topography on the abundance of An. annularis. The perceptions of people on mosquito occurrence are consistent with entomological findings.

Conclusions

This study provides the first vertical distribution records of vector mosquitoes in eastern Nepal and suggests that the vectors of malaria and other diseases have already established populations in the highlands due to climatic and other environmental changes. As VBD control programmes have not been focused on the highlands of Nepal, these findings call for actions to start monitoring, surveillance and research on VBDs in these previously disease-free, densely populated and economically important regions.

【 授权许可】

   
2014 Dhimal et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

【 参考文献 】

• [1]Brydon HW, Joshi G, Pradhan S: Anopheles distribution and its relation to the malaria eradication program in Nepal. Mosq News 1961, 21(2):102-105.
• [2]Rana KJ: History of Malaria and Malaria Control in Nepal. Aravail Printers and Publishers P.Ltd, New Delhi; 2001.
• [3]Darsie RF, Pradhan S: The mosquitoes of Nepal: their identification, distribution and biology. Mosquito Syst 1990, 22(2):69-130.
• [4]Parajuli MB, Shrestha SL, Vaidya RG, White GB: Nation-wide disappearance of Anopheles minimus Theobald, 1901, previously the principal malaria vector in Nepal. Trans Roy Soc Trop Med H 1981, 75(4):603.
• [5]Report of the Internal Assessment of Malaria Control and Kala-azar Elimination Activities 2007, 2008 and 2009. Epidemiology & Disease Control Division, Department of Health Services, Ministry of Health & Population, Government of Nepal, Kathmandu; 2010.
• [6]EDCD: National Malaria Control Strategic Plan: Nepal(2007/2008-2011/012). Kathmandu: Epidemiology and Disease Control Division(EDCD), Department of Health Services, Ministry of Health and Population, Goverment of Nepal; 2007.
• [7]Garros C, Van Bortel W, Trung HD, Coosemans M, Manguin S: Review of the minimus complex of Anopheles, main malaria vector in southeast Asia: from taxonomic issues to vector control strategies. Trop Med Int Health 2006, 11(1):102-114.
• [8]Dhimal M, Ahrens B, Kuch U: Malaria control in Nepal 1963–2012: challenges on the path towards elimination. Malar J 2014, 13:241. BioMed Central Full Text
• [9]Raghavendra K, Barik T, Reddy B, P S, Dash A: Malaria vector control: from past to future. Parasitol Res 2011, 108:757-779.
• [10]Ramchandra Rao T: The Anophelines of India. Malaria Research Centre (ICMR), New Delhi; 1984.
• [11]Reisen WK, Pradhan SP, Shrestha JP, Shrestha SL, Vaidya RG, Shrestha JD: Anopheline mosquito (Diptera: Culicidae) ecology in relation to malaria transmission in the inner and outer terai of Nepal, 1987–1989. J Med Entomol 1993, 30(4):664-682.
• [12]Dhimal M, Ahrens B, Kuch U: Altitudinal shift of malaria vectors and malaria elimination in Nepal. Malar J 2014, 13(Suppl 1):26. BioMed Central Full Text
• [13]Nepal Malaria Strategic Plan 2011–2016 (Revised Version- December 2011). Epidemiology and Diseases Control Division, Department of Health Services, Ministry of Health and Population, Goverment of Nepal, Kathmandu; 2011.
• [14]Nepal Malaria Programme Review (7–16 June, 2010). World Health Organization Regional Office for South - East Asia, New Delhi; 2011.
• [15]Banjara MR, Sirawaraporn W, Petmitr S, Imwong M, Joshi AB, Chavalitshewinkoon-Petmitr P: Characteristics and risk factors of Plasmodium falciparum malaria in Eastern and Central Nepal. Kathmandu Univ Med J 2009, 7(28):378-382.
• [16]Pant CP, Pradhan GD, Shrestha SL: Distribution of Anophelines in relation to Altitude in Nepal. In WHO/Mal/343. World Health Organization, Geneva; 1962:1-13.
• [17]White GB: Malaria receptivity stratification and projections for malaria vector control in Nepal. World Health Organization Regional Office for South - East Asia, New Delhi; 1982.
• [18]Shrestha SL: Dynamics of malaria transmission with reference to development projects in Nepal. J Commun Dis 1985, 17(4):287-292.
• [19]Dahal S: Climatic determinants of malaria and kala-azar in Nepal. Reg Health Forum 2008, 12(1):33-37.
• [20]Climate change 2007: The physical sciences basis. Summary for policymakers. Intergovernmental Panel on Climate Change, Geneva; 2007.
• [21]Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA; 2013.
• [22]Shrestha UB, Gautam S, Bawa KS: Widespread climate change in the Himalayas and associated changes in local ecosystems. PLoS One 2012, 7(5):e36741.
• [23]Shrestha AB, Wake CP, Mayewski PA, Dibb JE: Maximum temperature trends in the Himalaya and its vicinity: an analysis based on temperature records from Nepal for the period 1971–94. J Climate 1999, 12(9):2775-2786.
• [24]Nepal Initial National Communication to the Conference of the Parties of the United Nations Framework Convention on Climate Change. Ministry of Population and Environment, Kathmandu; 2004.
• [25]Vulnerability Through the Eyes of Vulnerable: Climate Change Induced Uncertainties and Nepal’s Development Predicaments. Institute for Social and Environmental Transition-Nepal (ISET-N, Kathmandu) and Institute for Social and Environmental Transition (ISET, Boulder, Colorado) for Nepal Climate Vulnerability Study Team (NCVST), Kathmandu; 2009.
• [26]Temporal and Spatial Variability of Climate Change over Nepal(1976–2005). Practical Action Nepal, Kathmandu; 2009.
• [27]Shrestha AB, Aryal R: Climate change in Nepal and its impact on Himalayan glaciers. Reg Environ Change 2011, 11(Suppl. 1):S65-S77.
• [28]Kattel D, Yao T: Recent temperature trends at mountain stations on the southern slope of the central Himalayas. J Earth System Sci 2013, 122(1):215-227.
• [29]Kovats RS, Campbell-Lendrum DH, McMichael AJ, Woodward A, Cox JS: Early effects of climate change: do they include changes in vector-borne disease? Philos Trans R Soc Lond B Biol Sci 2001, 356(1411):1057-1068.
• [30]Epstein P: The ecology of climate change and infectious diseases: comment. Ecology 2010, 91(3):925-928. discussion 928–929
• [31]Confalonieri U, Menne B, Akhtar R, Ebi KL, Hauengue M, Kovats RS, Revich B, Woodward A: Human Health. In Climate Change 2007: Impacts, Adaptation and Vulnerability Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. 4th edition. Cambridge University Press, Cambridge, UK; 2007:391-431.
• [32]Liu-Helmersson J, Stenlund H, Wilder-Smith A, Rocklov J: Vectorial capacity of Aedes aegypti: effects of temperature and implications for global dengue epidemic potential. PLoS One 2014, 9(3):e89783.
• [33]Woodward A, Smith KR, Campbell-Lendrum D, Chadee DD, Honda Y, Liu Q, Olwoch J, Revich B, Sauerborn R: Climate change and health: on the lastest IPCC report. The Lancet 2014, 383(April 5):1185-1189.
• [34]Siraj AS, Santos-Vega M, Bouma MJ, Yadeta D, Ruiz Carrascal D, Pascual M: Altitudinal changes in malaria incidence in highlands of Ethiopia and Colombia. Science 2014, 343(6175):1154-1158.
• [35]Caminade C, Kovats S, Rocklov J, Tompkins AM, Morse AP, Colon-Gonzalez FJ, Stenlund H, Martens P, Lloyd SJ: Impact of climate change on global malaria distribution. Proc Natl Acad Sci U S A 2014, 111(9):3286-3291.
• [36]National Adaptation Program of Action to Climate Change (NAPA). Goverment of Nepal, Ministry of Envrionment, Kathmandu; 2010.
• [37]Manual on practical entomology in malaria part II: methods and techniques. World Health Organization, Geneva; 1975.
• [38]Nagpal BN, Shrivastav A, Saxena R, Ansari MA, Dash AP, Das SC: Pictorial identification keys for indian mosquitoes. Delhi-110 092: Malaria Research Centre (ICMR), Madhuban; 2005.
• [39]Rueda LM: Pictorial keys for identification of mosquitoes (Diptera: Culicidae) associated with dengue virus transmission. In Zootaxa (589). Magnolia Press, Auckland, Newzealand; 2004.
• [40]Animut A, Gebre-Michael T, Balkew M, Lindtjorn B: Abundance and dynamics of anopheline larvae in a highland malarious area of south-central Ethiopia. Parasite & vectors 2012, 5:117. BioMed Central Full Text
• [41]R: A Language and Environment for Statistical Computing 2.15.2. R Foundation for Statistical Computing, Vienna, Austria; 2012.
• [42]Venables WN, Ripley BD: Modern Applied Statistics With S. 4th edition. Springer, New York; 2002.
• [43]Pradhan JM, Shrestha SL, Vaidya RG: Malaria transmissionin high mountain valleys of west Nepal including first record of Anopheles maculatus willmori (James) as a third vector of malaria. J Nep Med Ass 1970, 8:89-97.
• [44]Devi NP, Jauhari RK: Altitudinal distribution of mosquitoes in mountainous area of Garhwal region: Part-I. J Vector Borne Dis 2004, 41(1–2):17-26.
• [45]Devi N, Jauhari RK: Mosquito species associated within some western Himalayas phytogeographic zones in the Gharwal region of India. J Insect Sci 2007, 7(32):1-10.
• [46]Shrestha SL, Pradhan S, Shrestha JPB, Shrestha JD, Rajbhamdari Y, Shrestha GL, Swar TB, Nushin MK, Reisen WK: Observations on anopheline and malaria ecology in the Far Western Region of Nepal, 1986. Bull Soc Vector Ecol 1988, 13(2):332-342.
• [47]Dhimal M, Gautam I, Kress A, Muller R, Kuch U: Spatio-temporal distribution of dengue and lymphatic filariasis vectors along an altitudinal transect in central Nepal. PLoS Negl Trop Dis 2014, 8(7):e3035.
• [48]Byanju R, Gautam I, Aryal M, Aradhana K, Shrestha HN, Dhimal M: Adult density of Culex quinquefasciatus Say, filarial vector in Thapa Gaun, Jhaukhel and Lama Tole, Nagarkot VDC, Bhaktapur District. Nepal J Sci Tech 2013, 14(1):185-194.
• [49]Aditya G, Pramanik MK, Saha GK: Larval habitats and species composition of mosquitoes in Darjeeling Himalayas. India J Vector Borne Dis 2006, 43(1):7-15.
• [50]Liu Q, Liu X, Cirendunzhu , Woodward A, Pengcuociren , Bai L, Baimaciwang , Sang S, Dazhen , Wan F, Zhou L, Guo Y, Wu H, Li G, Lu L, Wang J, Dawa , Chu C, Xiraoruodeng : Mosquitoes established in Lhasa city, Tibet, China. Parasite & vectors 2013, 6:224. BioMed Central Full Text
• [51]Narain JP: Climate change and its potential impact on vector-borne diseases. In Health in South - East Asia: A SEARO Newsletter. WHO SEARO, New Delhi; 2008:13-15.
• [52]Dhimal M, Aryal KK, Dhimal ML, Gautam I, Singh SP, Bhusal CL, Kuch U: Knowledge, attitude and practice regarding dengue fever among the healthy population of highland and lowland communities in central Nepal. PLoS One 2014, 9(7):e102028.
• [53]Annual Report 2069/2070(2012/2013). Department of Health Services, Minsitry of Health and Population, Goverment of Nepal, Kathmandu; 2014.
• [54]Babu BV, Mishra S, Mishra S, Swain BK: Personal-protection measures against mosquitoes: a study of practices and costs in a district, in the Indian state of Orissa, where malaria and lymphatic filariasis are co-endemic. Ann Trop Med Parasitol 2007, 101(7):601-609.
• [55]Biran A, Smith L, Lines J, Ensink J, Cameron M: Smoke and malaria: are interventions to reduce exposure to indoor air pollution likely to increase exposure to mosquitoes? Trans R Soc Trop Med Hyg 2007, 101(11):1065-1071.
• [56]Annual Report 2067/68 (2010/2011) Kathmandu: Department of Health Services. Ministry of Health and Population, Goverment of Nepal; 2012.
• [57]Chaudhary P, Bawa KS: Local perceptions of climate change validated by scientific evidence in the Himalayas. Biol Letters 2011, 7(5):767-770.
• [58]Dhimal M, Bhusal CL: Impacts of climate change on human health and adaptation strategies for Nepal. J Nepal Health Res Counc 2009, 7(15):140-141.
• [59]Dhimal M, O’Hara RB, Karki RC, Thakur GD, Kuch U, Ahrens B: Spatiotemporal distribution of malaria and its association with climatic factors and vector control interventions in two high-risk districts of Nepal.Malar J 2014, 13: 457.