The International Water Management Institute (IWMI) has correlated cases of malaria in sub-Saharan Africa with large dams in the region.
“Malaria risk associated with dams is considered in Environmental Impact Assessments," Jonathan Lautze from IWMI South Africa said. "This should lead to efforts to control malaria around water reservoirs. Our study nonetheless showed that – despite these efforts – malaria transmission is elevated around water reservoirs in sub-Saharan Africa. This indicates current malaria intervention efforts are not sufficient around dams and thus should be strengthened.”
With the construction of 78 major new dams on tap for the next few years as Africa seeks faster economic growth, researchers predict that will lead to an additional 56,000 malaria cases annually. Also, climate change may affect conditions around dams, making them more suited to malaria transmission.
Lautze, explained they have two approaches to fixing the problem.
“A first approach is to better understand the degree and dynamics of malaria transmission around different reservoirs," he said. "The adverse malaria impacts of dams are indeed not uniform. Identifying the degree of impact around particular dams can allow disease control measures to be matched to that impact. And more specific understanding of the dynamics, e.g., transmission pathways, can improve selection of the optimal mix of interventions to combat the disease.
"A second approach is to complement conventional malaria control tools with unconventional ones," Lautze said. "Around reservoirs, one unconventional tool that has fallen into disuse is water level management. Targeted manipulation of water levels may help to disrupt larval development and reduce mosquito abundance and malaria transmission, and employing this measure with others can contribute to more robust approaches to mitigating dams’ adverse impacts.”