Scent can be a powerful motivator. The scent of freshly baked cookies can force anyone to come to the kitchen, while a musk -like perfume can seduce a date. In the mosquito universe, an irresistible scent is produced by two dangerous viruses after hijacking a human body, A new study found it.
The viruses that cause Zika and dug fever, change the scent of their hosts, giving them more likely to be bitten by mosquitoes, according to researchers. The discovery was announced on Wednesday in the magazine Cell and is the result of experiments on both mice and people.
The scientists also identified a possible way to block this scent and to stop the spread of the disease, using a medicine that is already known in people who struggle with acne, IsotretinoinAlso known under the trade name Battery†
“In some countries, these diseases transmitted by mosquitoes are very prominent,” said Co-author Penghua cheek, an assistant professor at Uconn Health, the Medical Faculty and the Medical Center of the University of Connecticut. “If this drug really works in the long term, people may have a way to prevent or at least reduce this burden.”
The scent is linked to high levels of a connection called Acetofenon, described by the authors of the research as a “powerful bait” for mosquitoes. It is made by a bacterium that grows on the skin, but normally the skin separates a protein that stops it. However, this study suggests that Zika and Dengue suppress the production of this crucial protein, so that the bacteria can grow faster and there is more acetophenone.
This results in a scent that attracts mosquitoes and pushes the infection cycle. While people in tropical and subtropical areas – where these viruses are thriving and an important problem for public health – are generally bitten by mosquitoes, this scent increases the chance that mosquitoes bite infected individuals.
Vectors such as mosquitoes help to survive viruses. When an infected mosquito stabs a healthy person, he can transfer a virus. In the meantime, an infected person can spread the virus to a healthy mosquito. Only infected mosquitoes can cause more damage.
Researchers earlier discovers That malaria can change the smell of his host, which in turn attracts mosquitoes. This suggested the new authors of the research that it was worth investigating whether the same applied to Zika and Dengue.
Dengue is a viral infection caused by: Four closely related viruses† These viruses spread through the bites of two Types of mosquitoes† While half of the world’s population runs the risk of developing dengue, 80% Of the cases are generally mild and asymptomatic, according to the World Health Organization. However, it can be more serious. While scientists report Dengue cases can be underestimated because of COVID-19, which is known to cause on average 20,000 dead every year.
Zika belongs to the the same family of viruses As a dengue and is transmitted by the same types of mosquitoes. Most people with a ZIKA infection do not develop symptoms, and those who do suffer from disorders such as fever, conjunctivitis and neurological complications. A Zika virus infection during pregnancy can also lead to a birth defect called microcephaly†
There is No specific vaccine Or medicine against the Zika virus. The dengue vaccine is only recommended for children between 9 and 16 who: already infected – The goal is to prevent serious dengue in the future.
The new study discovered a previously unknown step in the spread of Zika and Dengue. These infections can change the way a person smells, and this scent makes them more attractive for mosquitoes, which means that they are more likely to be bitten. For now it is unclear whether this process is the result of evolution or coincidence, Wang said.
The research team infected mice with Zika and Dengue to investigate the connection between odor and mosquitoes. They then set up three interconnected cages, in which healthy mice, infected mice and mosquitoes were distributed. Each virus group was assessed separately. However, the results were very similar: about 70% of the mosquitoes chose to be in the catching room with infected mice.
The scientists also recruited Knokkelkoort patients from a hospital in China and healthy volunteers. They collected the scents of the volunteers through armpit swabbers and extras and transferred the connections that caused those smells to a piece of filter paper. Then a new seemingly unpleasant experiment began: a paper with the smell of a healthy or infected person was confirmed on the basis of a volunteer, while an odorless paper was attached to their other hand. Both hands were exposed to mosquitoes for 30 minutes.
Overwhelming, the hands were covered with the scent of dengue patients more attractive for mosquitoes than the other options.
When the researchers evaluated the skin of the study participants, they discovered that the dengue patients showed a much higher emission of acetophenon than the other participants. In the meantime, mice contaminated with Zika or Dengue also produced 10 times more acetophenon than healthy mice. Fragrance remained the main cause of mosquito bites, even after scientists had control over other locomotives, such as body heat and levels of carbon dioxide.
After the scientists established that mice contaminated with Zika or Dengue produced less of the protein that the acetophenon-causing bacteria killed, they went looking for a solution. They led the mice isotretinoin, a derivative of vitamin A and a well -known medicine against acne. This changed the bacteria composition on the skin of the mice and reduced the acetophenon content. In turn, the mosquitoes were less interested in eating the treated mice.
Because mouse skin is different from human skin, the team now wants to see if the same treatment would also work for people. They also want to expand the study more generally and evaluate more human patients with dengue and Zika – this study only included 10 dengue patients. There is an attempt to make this study again with a major sample of people in Malaysia.
“In general, the goal is to reduce virus prevalence and the disease burden,” said Wang. “But this will take a while. This potential treatment will not kill mosquitoes, but it can reduce the transfer. ”
In the distant future, these results can also inspire the genetic adaptation of mosquitoes, Wang said. Other scientists are already experimenting with CRISPR to spread That female reproduction blocks. Scientists could also use CRISSPR to interrupt this process linked to odor.
“We could try to silence the mosquito’s oures,” said Wang. “Those mosquitoes could still reproduce, but they may react less to human signals. They may be less interested in biting people.”