Want to attract more mosquitos? Just build a dam.

New research is drawing attention to the role large dams play in encouraging the spread of malaria. According to a new paper by a team scientists from Australia, large dams -- and the nesting ground they offer to mosquitos -- are to blame for over a million cases of malaria in sub-Saharan Africa each year.

And as more dam projects hit the runway, researchers expect rises in malarial injections to follow.

"Dams are at the center of much development planning in Africa," Solomon Kibret, a biologist at the University of New England in Australia, said in a press release. "While dams clearly bring many benefits -- contributing to economic growth, poverty alleviation and food security -- adverse malaria impacts need to be addressed or they will undermine the sustainability of Africa's drive for development."

Kibret is the lead author of a new report on the correlation between malaria and large dams, published in this week in the Malaria Journal.

By the comparing the malarial risk of communities living within a few miles of a large dam and those far away, researchers were able to estimate the role dams play in enabling the mosquito-borne illness. Previous research has attempted to do the same, but Kibret and his colleagues say prior estimates were too modest.

"Our study showed that the population at risk of malaria around dams is at least four times greater than previously estimated," said Kibret.

The study looked at 1,268 dams in sub-Saharan Africa, nearly two-thirds of which, 723, are in malarious areas. The researchers found that a total of 15 million people live within five kilometers of dam reservoirs and are at risk, and at least 1.1 million malaria cases annually are linked to the presence of the dams. It is estimated there are a total of 174 million cases of malaria in sub-Saharan Africa annually.

The implications are not entirely new, researchers admit. Construction projects routinely pay lip-service to the correlation in environmental reviews. But researchers say there is scant evidence that efforts to mitigate the increased risk are actually working.

If new steps aren't taken, the 78 major new dams planned for sub-Saharan Africa over several years will will result in some 56,000 additional malaria cases annually.