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;Department of Health Service Management, College of Public Health & Medical Sciences, Jimma University, Jimma, Ethiopia;Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Gent, Belgium;Department of Biology, College of Natural Sciences, Jimma University, Jimma, Ethiopia;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.

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Figure 1.

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