Multiple mosquito blood meals accelerate malaria transmission potential

"We wanted to capture the fact that, in endemic regions, malaria-transmitting mosquitoes are feeding on blood roughly every 2-3 days", says W. Robert Shaw, a lead author of this study. "Our study shows that this natural behavior strongly promotes the transmission potential of malaria parasites, in previously unappreciated ways".

The results show that an additional blood feed three days after infection with P. falciparumaccelerates the growth of the malaria parasite, thereby shortening the incubation period required before transmission to humans can occur. Incorporating these data into a mathematical model across sub-Saharan Africa reveals that malaria transmission potential is likely higher than previously thought, making disease elimination more difficult. In addition, parasite growth is accelerated in genetically modified mosquitoes with reduced reproductive capacity, suggesting that control strategies using this approach, with the aim of suppressing Anopheles populations, may inadvertently favor malaria transmission. The data also suggest that parasites can be transmitted by younger mosquitoes, which are less susceptible to insecticide killing, with negative implications for the success of insecticide-based strategies. Taken together, the results suggest that younger mosquitoes and those with reduced reproductive ability may provide a larger contribution to infection than previously thought.

According to the authors, the findings have important implications for accurately understanding malaria transmission potential and estimating the true impact of current and future mosquito control measures.