Malaria: Severity of infection varies depending on time of mosquito bite, study finds

Mosquito-borne diseases: a threat that varies depending on the time of the bite

A study by McGill University in Montreal reveals that the severity of infection by the malaria parasite could vary significantly depending on the time of day when the mosquito bite occurs. A discovery that would have considerable implications in the fight against other parasitic diseases.

Malaria is a mosquito-borne disease that affects hundreds of millions of people worldwide and claims more than half a million victims each year, the majority of whom are children. While prevention involves fighting mosquito bites (mosquito nets, long clothing, mosquito repellents, etc.) and taking antimalarial medications – on prescription – a Canadian study offers a new angle of attack.

The Circadian Rhythm at Play

Researchers at McGill University have observed that mice infected at night had less severe symptoms and more limited parasite proliferation than those infected during the day.

At the heart of this discovery are circadian rhythms, the approximately 24-hour biological cycles that govern many physiological functions in almost all living organisms.

“The differences observed in the host’s response to infection depending on the time of day suggest that circadian rhythms influence disease progression," explains Nicolas Cermakian, Director of the Molecular Chronobiology Laboratory and lead author of this work.

Leishmaniasis also concerned

This scientific advance could have considerable implications in the fight against malaria and other parasitic diseases. Previous work by the same team has shown that leishmaniasis, another serious parasitic disease, is also influenced by the biological clocks of the host.

For the authors, “these results could lead to new prevention and treatment strategies, taking into account the circadian rhythms of both parasites and their human hosts.”