Blood-sucking mosquitoes as disease surveillance tools?

Since mosquitoes collect blood, could they be tools for monitoring the spread of disease? University of Auckland researchers are investigating just that.

Led by Professor Jacqueline Beggs, the project seizes on advances in gene technology which let scientists amplify difficult-to-identify traces of pathogens in small and complex blood samples.

If the technique can be scaled up from proof-of-concept, it could be used to monitor for disease outbreaks in wild animals, taonga species, and livestock.

In the research, scientists will catch mosquitoes that have fed on animals and analyse the mosquitoes’ blood.

“Mosquitoes are flying syringes, very inexpensive collectors of blood samples,” says Beggs. “There’s a big opportunity here to add a cost-effective surveillance tool to the country’s biosecurity toolkit.”

Scientists will be supported by researchers from Northland Māori iwi (tribe) Ngāti Kuri, and the blood wll be collected from mosquitoes in the Far North and at a research farm in the Waikato.

Mosquitoes caught in traps above water sources will be frozen and brought back to the lab for molecular analysis. In an individual case, hundreds may be needed to get enough blood.

Dr Richard O’Rorke will use advanced DNA and RNA technologies to reduce the large amount of “noise” in blood samples from genetic information irrelevant to detecting pathogens.

The analysis will disclose which animal species the mosquitoes have been feeding on.

Pilot work has focused on blood parasites which cause avian malaria, which is sometimes fatal in native and introduced birds in New Zealand and is a problem around the world.

New Zealand’s native wildlife is vulnerable to incursions of global pathogens because of the loss of genetic diversity in many species, such as the critically endangered kākāpō.

O’Rorke will travel to a lab in Spain with expertise in West Nile virus research to test his methods. That’s the world’s most widespread mosquito-borne virus, posing a growing threat to human and animal health across continents, but yet to reach New Zealand.

Climate change is increasing the threat from pathogens by altering the global distribution of disease-spreading insects.

The research is funded by a Government `Smart Ideas' fund.