Science News takes a long whiff of a chemical that smells like oranges and flowers that’s given off by people (and other mammals) infected with dengue and Zika. The chemical seems to be given off by a skin bacteria that flourishes on people with those infections – and it appears to attract more mosquitoes to bite the infected person:
Previous studies showed that other mosquito species prefer to feed on animals carrying the parasite that causes malaria. But it was unknown whether the same was true for viruses such as dengue or Zika, says Gong Cheng, a microbiologist at Tsinghua University in Beijing.
The chemical acetophenone — which to humans smells like orange blossom — may be that lure. Mice infected with dengue or Zika viruses give off approximately 10 times more acetophenone and attract more mosquitoes than uninfected animals, Cheng and colleagues found. People infected with dengue similarly release more of the chemical than healthy people. Samples of odors taken from the armpits of infected people also created potent mosquito magnets when smeared on filter paper attached to a volunteer’s palm.
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An infection stops mice from making an antimicrobial protein called RELMα, allowing the acetophenone-emitting microbes to flourish.
But a component of some acne medications can bring back RELMα in mice, the team found. Infected animals fed a derivative of vitamin A called isotretinoin produced less acetophenone and become less attractive mosquito targets.
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You can read more about Cheng’s research – and the possibility of using RELMα-boosting medicine to hide dengue sufferers from insects – here, in Cell.