It turns out that the virus changes the host's body odor into a 'mosquito-attracting odor' that makes it easier to be bitten by mosquitoes
malaria , dengue fever and Zika fever , andmore than 1 million people worldwide die annually from the effects of mosquito-borne diseases. It has been with. Regarding mosquitoes, which are said to be ' the animals that killed the most humans, ' research results have been reported that a specific virus changes the host's body odor into a 'mosquito-attracting odor', making the host more susceptible to mosquito bites. I did.
Mosquitoes not only cause itching in the sting area, but also transmit various diseases such as
A volatile from the skin microbiota of flavivirus-infected hosts promotes mosquito attractiveness --ScienceDirect
Viruses can change your scent to make you more attractive to mosquitoes, new research in mice finds
When a mosquito sucks the blood of an animal infected with a specific virus or pathogen, it becomes a carrier of the virus or pathogen and then spreads the virus or pathogen to the animal that sucked the blood. Therefore, how mosquitoes find target animals is an important factor in the circulation of the virus in nature and helps to devise new strategies to prevent mosquito-borne diseases.
It has long been known that mosquitoes use a variety of sensory cues, such as animal body temperature and carbon dioxide released by respiration, to find targets. A 2014 study also found that malaria-infected mice changed their body odor and attracted more mosquitoes. With this in mind, research teams in China and the United States have studied whether viruses such as dengue virus that causes dengue fever and Zika virus that cause Zika fever also change the odor of the host, and whether there is a way to prevent the change in body odor. ..
acetophenone ' attracted more mosquitoes.
First, the research team put 'Dengue virus-infected mice,' 'Zika virus-infected mice,' and 'virus-infecting mice' in different glass cases to create an air flow and move the mice in the direction of mosquitoes. I smelled it. It was confirmed that mosquitoes were more strongly attracted to mice infected with dengue virus and Zika virus than to mice not infected with the virus.
Mice infected with Zika virus emit less carbon dioxide than non-infected mice, and mice infected with dengue virus also emit the same amount of carbon dioxide, so 'carbon dioxide' is excluded as the reason why mosquitoes are attracted to mice. it was done. In addition, because the glass case made it impossible for mosquitoes to distinguish between mice whose body temperature had risen due to illness and mice with normal temperature, 'body temperature' was also excluded from the factors. However, when the glass case was filtered to prevent the mosquitoes from reaching the odor, the number of mosquitoes attracted to the virus-infected and non-infected mice became about the same, so the 'body odor' of the mice became The research team says it was confirmed to be attracting mosquitoes.
The research team then isolated 20 gaseous compounds from body odor released by virus-infected mice and identified three compounds that had a significant response to mosquitoes. When we applied these compounds to the skin of mice and humans and investigated how much mosquitoes were attracted, we found that only an organic compound called '
Mice infected with dengue or Zika virus produce 10 times more acetophenone than uninfected mice, and body odor samples taken from the armpits of humans with dengue contain more acetophenone than healthy humans. I also found out that. It was also confirmed that when a dengue patient's body odor sample and a healthy human body odor sample were applied to the volunteer's skin, the mosquitoes were consistently attracted to the dengue patient's body odor.
genus Bacillus , which is a common gram-positive bacillus, were significantly increased in the virus-infected mouse. did.
These findings suggest that dengue and Zika viruses can increase the amount of acetophenone produced and released by the host, thereby attracting more mosquitoes. The research team also investigated the question, 'Why does infection with dengue virus or Zika virus increase the amount of acetophenone released?'
Because acetophenone is a metabolic by-product produced by bacteria that inhabit human and mouse skin, the researchers said, 'The virus does not change the type of bacteria that inhabit the skin, resulting in increased production of acetophenone. I thought. To test this idea, we conducted experiments to remove more gut bacteria from dengue and Zika virus-infected mice, or to remove skin bacteria and expose them to mosquitoes. As a result, the amount of mosquitoes attracted was significantly lower in the mice from which the skin bacteria were removed, suggesting that the skin bacteria are the source of acetophenone. Then, when the skin bacterial composition of the virus-infected mouse and the non-infected mouse was compared, it was found that the bacteria of the
Finally, the research team researched ways to prevent the virus from increasing acetophenone production and prevent changes in body odor. Focusing on the fact that virus-infected mice have a reduced amount of resistin-like molecule α (RELMα) that fights microorganisms in the skin, the research team focused on the virus-infected mouse with a derivative of vitamin A that increases the production of RELMα. After measuring the amount of RELMα and bacteria of the genus Basilus present in the skin, an experiment was conducted in which the virus was exposed to mosquitoes.
As a result, it was found that the amount of RELMα in infected mice treated with a vitamin A derivative was similar to that in non-infected mice, and the amount of Bacillus bacteria on the skin was reduced. We also found that virus-infected mice treated with vitamin A derivatives did not change the amount of mosquitoes attracted compared to non-infected mice.
The research team aims to reproduce these results in humans as the next step. Vitamin A deficiency is a common disease in many developing countries, including Southeast Asia and sub-Saharan Africa, where mosquito-borne virus transmission is severe. Therefore, by increasing the amount of vitamin A or vitamin A derivative to be inoculated orally, it is possible to reduce the virus transmission by mosquitoes and suppress the long-term epidemic of dengue fever and Zika fever.