The effect of dams and seasons on malaria incidence and anopheles abundance in Ethiopia

BMC Infectious Diseases

Niko Speybroeck¹  Luc Duchateau³  Wondwossen Kassahun⁵  Kifle W/Michael⁵  Kora Tushune²  Yehenew Getachew³  Delenasaw Yewhalaw⁴ 

[1]Institute of Health and Society, Faculty of Public Health, Université Catholique de Louvain, Brussels, Belgium

[2]Department of Health Service Management, College of Public Health & Medical Sciences, Jimma University, Jimma, Ethiopia

[3]Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium

[4]Department of Biology, College of Natural Sciences, Jimma University, Jimma, Ethiopia

[5]Department of Epidemiology and Biostatistics, College of Public Health & Medical Sciences, Jimma University, Jimma, Ethiopia

关键词: Ethiopia;    Season;    Dam;    Mosquito;    P. falciparum;    Malaria incidence;   

Others  :  1149040
DOI  :  10.1186/1471-2334-13-161

 received in 2012-10-06, accepted in 2013-02-10,  发布年份 2013

【 摘 要 】

Background

Reservoirs created by damming rivers are often believed to increase malaria incidence risk and/or stretch the period of malaria transmission. In this paper, we report the effects of a mega hydropower dam on P. falciparum malaria incidence in Ethiopia.

Methods

A longitudinal cohort study was conducted over a period of 2 years to determine Plasmodium falciparum malaria incidence among children less than 10 years of age living near a mega hydropower dam in Ethiopia. A total of 2080 children from 16 villages located at different distances from a hydropower dam were followed up from 2008 to 2010 using active detection of cases based on weekly house to house visits. Of this cohort of children, 951 (48.09%) were females and 1059 (51.91%) were males, with a median age of 5 years. Malaria vectors were simultaneously surveyed in all the 16 study villages. Frailty models were used to explore associations between time-to-malaria and potential risk factors, whereas, mixed-effects Poisson regression models were used to assess the effect of different covariates on anopheline abundance.

Results

Overall, 548 (26.86%) children experienced at least one clinical malaria episode during the follow up period with mean incidence rate of 14.26 cases/1000 child-months at risk (95% CI: 12.16 - 16.36). P. falciparum malaria incidence showed no statistically significant association with distance from the dam reservoir (p = 0.32). However, P. falciparum incidence varied significantly between seasons (p < 0.01). The malaria vector, Anopheles arabiensis, was however more abundant in villages nearer to the dam reservoir.

Conclusions

P. falciparum malaria incidence dynamics were more influenced by seasonal drivers than by the dam reservoir itself. The findings could have implications in timing optimal malaria control interventions and in developing an early warning system in Ethiopia.

【 授权许可】

   
2013 Yewhalaw et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 1.

【 参考文献 】

• [1]Nilsson C, Reidy C, Dynesius M, Revenga C: Fragmentation and flow regulation of the world’s large river systems. Science 2005, 308(5720):405-408.
• [2]Biswas Asit K: Water Resources: Environmental Planning, Management, and Development. New York: McGraw-Hill; 1997.
• [3]Jobin William R: Dams and Disease: Ecological Design and Health Impact of Large Dams and, Irrigation Systems. London and New York: Taylor & Francis; 1999.
• [4]Dudgeon D, Arthington A, Gessner M, Kawabata Z, Knowler D, Lévêque C, Naiman R, Prieur-Richard A, Soto D, Stiassny M, et al.: Freshwater biodiversity: importance, threats, status and conservation challenges. Biol Rev 2006, 81(2):163-182.
• [5]Grillet M: Factors associated with distribution of Anopheles aquasalis and Anopheles oswaldoi (Diptera: Culicidae) in a malarious area, northeastern Venezuela. J Med Entomol 2000, 37(2):231-238.
• [6]Patz J, Graczyk T, Geller N, Vittor A, et al.: Effects of environmental change on emerging parasitic diseases. Int J Parasitol 2000, 30(12):1395-1406.
• [7]Norris Douglas E: Mosquito-borne diseases as a consequence of land use change. EcoHealth 2004, 1(1):19-24.
• [8]Poff N, Olden J, Merritt D, Pepin D: Homogenization of regional river dynamics by dams and global biodiversity implications. Proc Natl Acad Sci 2007, 104(14):5732-5737.
• [9]Van der Hoek W: Human Health in, Water Resources Development. Oxford: Eolss Publishers; 2006.
• [10]Ledec G, Quintero J: Good dams and bad dams: Environmental criteria for site selection of hydroelectric projects. Latin Am Caribb Reg Sustainable Dev Working Paper 16; 2003
• [11]Yewhalaw D, Kassahun W, Woldemichael K, Tushune K, Sudaker M, Kaba D, Duchateau L, Van Bortel W, Speybroeck N, et al.: The influence of the Gilgel-Gibe hydroelectric dam in Ethiopia on caregivers’ knowledge, perceptions and health-seeking behaviour towards childhood malaria. Malar J 2010, 9:47. BioMed Central Full Text
• [12]Yewhalaw D, Wassie F, Steurbaut W, Spanoghe P, Van Bortel W, Denis L, Tessema D, Getachew Y, Coosemans M, Duchateau L, et al.: Multiple insecticide resistance: an impediment to insecticide-based malaria vector control program. PloS ONE 2011, 6:e16066.
• [13]Bruce Chwatt L: Essential Malariology. London: William Heinemann Medical Books Ltd; 1985.
• [14]Gillies M, Coetzee M: A supplement to the Anophelinae of Africa South of the Sahara. Johannesburg: Publ South Afr Inst Med Res 1987, 55:1-43.
• [15]Hunt R, Coetzee M, Fettene M: The Anopheles gambiaecomplex: a new species from Ethiopia. Trans R Soc Trop Med Hyg 1998, 92(2):231-235.
• [16]Yewhalaw D, Van Bortel W, Denis L, Coosemans M, Duchateau L, Speybroeck N: First evidence of high knockdown resistance frequency in Anopheles arabiensis (Diptera: Culicidae) from Ethiopia. Am J Trop Med Hyg 2010, 83:122-125.
• [17]Duchateau L, Janssen P: The Frailty Model. New York: Springer; 2008.
• [18]StataCorp L: Stata Statistical Software: Release 12. StataCorp LP: College Station, Texas; 2011.
• [19]SAS Institute I: SAS/STAT 9.2 User’s Guide. Cary, NC, USA: North Carolina; 2008.
• [20]Mabaso M, Craig M, Ross A, Smith T: Environmental predictors of the seasonality of malaria transmission in Africa: the challenge. Am J Trop Med Hyg 2007, 76:33-38.
• [21]Lautze J, McCartney M, Kirshen P, Olana D, Jayasinghe G, Spielman A: Effect of a large dam on malaria risk: the Koka reservoir in Ethiopia. Trop Med Int Health 2007, 12(8):982-989.
• [22]Kibret S, Alemu Y, Boelee E, Tekie H, Alemu D, Petros B: The impact of a small-scale irrigation scheme on malaria transmission in Ziway area Central Ethiopia. Trop Med Int Health 2010, 15:41-50.
• [23]Ghebreyesus T, Haile M, Witten K, Getachew A, Yohannes A, Yohannes M, Teklehaimanot H, Lindsay S, Byass P: Incidence of malaria among children living near dams in northern Ethiopia: community based incidence survey. Br Med J 1999, 319(7211):663-666.
• [24]Kibret S, McCartney M, Lautze J, Jayasinghe G: Malaria Transmission in the Vicinity of Impounded Water: Evidence from the Koka Reservoir, Ethiopia, Volume 132. Colombo: IWMI; 2009.
• [25]Trung H, Van Bortel W, Sochantha T, Keokenchanh K, Quang N, Cong L, Coosemans M: Malaria transmission and major malaria vectors in different geographical areas of Southeast Asia. Trop Med Int Health 2004, 9(2):230-237.
• [26]Tadesse D, Mekonnen Y, Tsehaye A: Adult mosquito populations and their health impact around and far from Dams in Tigray region, Ethiopia. Momona Ethiop J Sci 2012, 4(2):40-51.
• [27]Gomez-Elipe A, Otero A, Van Herp M, Aguirre-Jaime A: Forecasting malaria incidence based on monthly case reports and environmental factors in Karuzi, Burundi, 1997–2003. Malar J 2007, 6:129. BioMed Central Full Text
• [28]Thomson M, Doblas-Reyes F, Mason S, Hagedorn R, Connor S, Phindela T, Morse A, Palmer T: Malaria early warnings based on seasonal climate forecasts from multi-model ensembles. Nature 2006, 439(7076):576-579.
• [29]Protopopoff N, Van Bortel W, Speybroeck N, Van Geertruyden J, Baza D, D’Alessandro U, Coosemans M: Ranking malaria risk factors to guide malaria control efforts in African highlands. PloS ONE 2009, 4(11):e8022.
• [30]Eskindir L, Bernt L: Model variations in predicting incidence of Plasmodium falciparum malaria using 1998-2007 morbidity and meteorological data from south Ethiopia. Malar J 2010, 9:166. BioMed Central Full Text
• [31]Louis V, Simboro S, Sauerborn R, Yé Y: Effect of meteorological factors on clinical malaria risk among children: an assessment using village-based meteorological stations and community-based parasitological survey. BMC Public Health 2007, 7:101. BioMed Central Full Text
• [32]Patz J, Epstein P, Burke T, Balbus J: Global climate change and emerging infectious diseases. J Am Med Assoc 1996, 275(3):217-223.
• [33]Lindblade K, O’neill D, Mathanga D, Katungu J, Wilson M: Treatment for clinical malaria is sought promptly during an epidemic in a highland region of Uganda. Trop Med Int Health 2000, 5(12):865-875.
• [34]Loevinsohn M: Climatic warming and increased malaria incidence in Rwanda. Lancet 1994, 343(8899):714-718.
• [35]Abeku T, van Oortmarssen G, Borsboom G, de Vlas S, Habbema J: Spatial and temporal variations of malaria epidemic risk in Ethiopia: factors involved and implications. Acta Trop 2003, 87(3):331-340.
• [36]Abeku T, De Vlas S, Borsboom G, Tadege A, Gebreyesus Y, Gebreyohannes H, Alamirew D, Seifu A, Nagelkerke N, Habbema J: Effects of meteorological factors on epidemic malaria in Ethiopia: a statistical modelling approach based on theoretical reasoning. Parasitology 2004, 128(06):585-593.
• [37]Teklehaimanot H, Schwartz J, Teklehaimanot A, Lipsitch M: Weather-based prediction of Plasmodium falciparum malaria in epidemic-prone regions of Ethiopia II. Weather-based prediction systems perform comparably to early detection systems in identifying times for interventions. Malar J 2004, 3:44. BioMed Central Full Text
• [38]Peterson I, Borrell L, El-Sadr W, Teklehaimanot A: Individual and household level factors associated with malaria incidence in a highland region of Ethiopia: a multilevel analysis. Am J Trop Med Hyg 2009, 80:103-111.
• [39]De Plaen R, Geneau R, Teuscher T, Koutoua A, Seka M, et al.: Living in the paddies: a social science perspective on how inland valley irrigated rice cultivation affects malaria in Northern Cote d’Ivoire. Trop Med Int Health 2003, 8(5):459.
• [40]Bi P, Tong S, Donald K, Parton K, Ni J: Climatic variables and transmission of malaria: a 12-year data analysis in Shuchen County, China. Public Health Rep 2003 118:65.