According to the Centers for Disease Control and Prevention, mosquitoes can spread the following diseases to humans through their bites: the Zika virus, West Nile virus, Chikungunya virus, dengue, and malaria. The most severe cases can result in death.
But what if there was a way to prevent infected mosquitoes from spreading these viruses? Researchers at the MRC-University of Glasgow Centre for Virus Research found that mosquitoes that had fed on sugar prior to having an infected meal didn't contract viral infections from their food.
The study evaluated the Aedes aegypti species of mosquito, an arbovirus vector, and discovered that sugar feeding gave it enhanced immunity in its stomach. This in turn protected females of the species against infection.
“This study is important because we’ve been able to show that sugar feeding by these mosquitos blocks an initial infection of an arbovirus and lowers infection prevalence and intensity, thereby decreasing the potential of female mosquitoes to transmit these viruses further," Dr. Emilie Pondeville, Molecular Entomologist at the MRC-University of Glasgow Centre for Virus Research, said in a statement.
Where would these mosquitoes get the sugar? Both adult male and female mosquitoes eat plant nectar and sap to get carbohydrates for their energy reserves. However, mosquito females need a blood meal to be able to reproduce. In some natural settings, Aedes aegypti female mosquitoes almost exclusively feed on blood.
In these circumstances, the new findings suggest that a lack of sugar intake could be what is increasing the spread of mosquito-borne arboviral diseases. It also provides a possible explanation for the high susceptibility and transmission of arboviruses by this mosquito species.
The study is the first to examine the role that sugar plays in a mosquito's tendency to infect humans.
“In future, this could inform the development and application of vector control strategies such as sugar baits, aimed at reducing arbovirus transmission," concluded Pondeville. It should be noted that some mosquitoes have already been engineered to spread antimalaria genes. Could similar innovations lead to inhibiting the spread of arboviruses?