Cow urine scent halted malaria's progress

Mosquitoes drink fresh cow urine and are attracted by its scent. The nitrogen compounds in urine are used by mosquitoes as a kind of energy drink: to reproduce, live longer and fly far. Researchers have determined which chemical substances in cow urine the mosquitoes are attracted to, and why. The traps placed in Magge contained these substances, which smell like fresh cow urine, but with the difference that the synthetic smell lasts for at least a month.

– We want to develop simple traps that can be used to cost-effectively combat malaria. We could see that one of the benefits of attracting mosquitoes with this particular scent is that it attracts mosquitoes at all stages of life. The scent attracts both males and females, those that will suck blood, those that have just sucked blood and those that will lay eggs, says Rickard Ignell, professor at SLU.

To compare and ensure that the results were indeed due to the traps, the researchers conducted tests in two Ethiopian villages, one where the traps were used and another where the traps were not used. The researchers from the Department of Plant Protection Biology at SLU collaborated with Addis Ababa University and the local village teams.

The increased emergence of insect-resistant populations of malaria vectors, along with many other factors, has caused increased malaria cases in recent years in Ethiopia.

– In the study, we have indications that mass trapping of mosquitoes using this type of scent trap can be the next generation tool to counteract the spread of malaria. Now more control studies are needed to see if the method can be used in other places and contexts, says Yared Desta, PhD student at Addis Ababa University.

The study was financed by the Swedish Research Council's funds for development research. This type of research grant, which was previously possible to apply for, has a focus on research that is important for poverty reduction and sustainable development in low-income countries.

– Funding for development research has been extremely important in generating new knowledge on global issues. Our results are promising but we would now need to carry out more field trials to ensure that the scent attracts malaria mosquitoes also in other places in Africa, concludes Rickard Ignell.