Sometimes it seems that mosquitoes annoy certain people particularly often.
Researchers have discovered what the animals are attracted to.
Kassel - Although some home remedies drive away mosquitoes and one remedy relieves the itching after bites: the pests can get on your last nerve in summer.
Researchers have now discovered what particularly attracts the small animals.
Scientists at the University of Connecticut have researched the connection between certain viral diseases and mosquitoes.
Their work built on the previous finding that insects are attracted to smells.
What was also known: Mice suffering from malaria have a different scent profile compared to healthy mice.
Mosquitoes frequently moved to infected mice
In the new investigations, the researchers released mosquitoes on mice with and without dengue and circa viruses.
The result: the mosquitoes moved conspicuously often to the infected rodents.
The scientists observed a similar result in studies with human subjects.
The scent marks of a person suffering from dengue fever and a healthy person were placed on the hands of a test person.
The mosquitoes constantly preferred the hand with the sick smell.
During the tests, the research team found that the gaseous chemical compound acetophenone was found in particularly high concentrations in infected test subjects.
This fabric was particularly attractive to mosquitoes.
For this, acetophenone had to be sent through the skin.
Mosquitoes pass on viruses
In a comparison between infected and healthy mice, the researchers found an unusually high number of Bacillus bacteria in the sick animals.
These in turn are among the main acetophenone producers.
The scientists concluded from this: Viruses change the scent of the host body by changing the microbiome of the skin.
Normally, healthy skin produces high levels of a molecule that has an antimicrobial effect.
Only very small amounts of this molecule were found in sick mice.
The experts suspect that this was caused by the virus infection and that the Bacillus bacteria spread unchecked as a result.
This led to high acetophenone production, which attracted mosquitoes.
The mosquitoes then suck up the virus in the blood and pass it on.
In this way, the pathogen takes an active part in its spread.
The investigations mainly focused on dengue and Zika virus infections.
It is therefore unclear whether other viruses can also cause similar effects.
(Jan Wendt)