How malaria parasites 'go in for the kill'

A new research has revealed that malaria parasites react to mosquitoes biting their hosts in order to increase transmission.

Researchers from the French National Centre for Scientific Research (CNRS) found that when the vectors (transmitting insects) are present only some of the time, "plastic" transmission strategies that depend on the ability to sense and respond to vector availability, can outcompete constant strategies, even when evolution of the former is associated with some costs to parasite fitness.

The researchers then went on to test whether such plastic transmission strategies actually exist for malaria parasites, like Plasmodium goes through a phase of chronic infection during which most of the parasites are in a dormant (or latent) stage, and parasite numbers in the blood are very low.

The researchers summarized that in line with their theoretical predictions, they showed that Plasmodium relictum has the ability to boost its own transmission during the chronic phase of the vertebrate infection after being exposed to mosquito bites.

And, while the contribution of plastic transmission in human malaria remains to be determined, the researchers suggested that better understanding of such strategies might eventually improve malaria control.

The study is published in PLOS Pathogens.