Could a Chicken-based Mosquito Repellent Protect Humans from Malaria?
Researchers from Sweden appears to imply that mosquitoes—and malaria mosquitoes, in particular—are not a big fan of poultry. The researchers conducted several experiments in Western Ethiopia involving the collection and analysis of blood-feeding patterns of the female of the Anopheles arabiensis mosquitoes, which is one of the more dominant causes of malaria in the sub-Saharan region of Africa.
Through this study, they found an odd trend. Across three villages where humans and livestock regularly interact, mosquitoes bit organisms more or less based on whether they were inside or outside. Obviously, humans were more likely to be bit indoors, but cows were more likely to be bit outdoors.
However, they noticed that regardless of the presence of chickens, the mosquitoes did not appear to like them at all.
Corresponding study author Professor Richard Ignell—from the Swedish University of Agricultural Sciences—explains, “Previous studies has shown that mosquitoes are able to discriminate among humans based on differences in specific odorants emitted. However, before our study there had been none that looked at odors from non-preferred blood hosts of mosquitoes.”
Now, it is important to note that the researchers only looked at this one particular species of mosquito. So, it could be that the result may be true for other mosquitoes too (and it could be that it is only true of this species). Regardless of the implications, though, Ignell goes on to say, “Considering that mosquitoes often display some type of preference for their blood hosts — not all mosquitoes bite humans for example, and that they heavily rely on their sense of smell for finding their hosts and discriminate against others, it is very likely there are other similar repellents to be found elsewhere.”
The researchers theorize that perhaps the reason mosquitoes avoid chickens is that ruffled feathers—like those of a chicken—act as impediment. Of course, chickens readily eat insects—like mosquitoes—so maybe the insects have just learned to be wary of poultry. Some also suggest that maybe mosquitoes just don’t like the blood of chickens and, as such, chickens have evolved over millions of years to adapt an ingrained scent that deters mosquitoes.
As such, Ignell notes that this could lead to chemical repellent we could use to deter malaria-bearing mosquitoes from biting humans. He says, “The repellents we identify seem to work as spatial repellents, i.e. they act over a rather long distance, which is in contrast to commercial mosquito repellents using DEET (considered the gold standard) that only are active at close range. The chicken-based repellents are not toxic so they cannot be compared with pesticides which have a special role not least in sub-Saharan Africa to keep the populations of malaria mosquitoes down.”