The power of smell can be powerful motivator. Freshly baked cookies might make someone want to go to the kitchen. A musky scent may tempt a woman to take a date. A new study has shown that a mosquito universe is characterized by irresistible smells. This is because two viruses have hijacked a person’s body to produce it.
Researchers discovered that the viruses that cause Zika fever and dengue fever alter the way their hosts smell. This makes them more susceptible to being bitten by mosquitoes. This discovery was made through experiments on mice and humans.
Scientists also discovered a way to stop this smell and prevent the spread of the disease using an existing medication known to those with acne, which is also known as Accutane.
Penghua Wang (assistant professor at UConn Health), the University of Connecticut’s medical center and school of medicine, said that “in some countries, these mosquito–transmitted diseases are very prevalent.” “If this medication works, people might be able to reduce or prevent this burden.
Acetophenone, a compound that can attract mosquitoes to your skin, is responsible for the smell. It is produced by bacteria that grows on the skin. However, normal skin produces a protein to stop it from growing. This study shows that Zika and dengue may suppress the production this protein, which allows the bacteria to grow faster, and more acetophenone can be produced.
This creates a strong scent that attracts mosquitoes, which in turn propels the cycle forward. Although people living in subtropical and tropical areas are more likely to be bitten by mosquitoes, the scent can increase the likelihood that they are biting those infected.
Vectors like mosquitoes help viruses survive. An infected mosquito can transmit the virus to a healthy person if it bites another human. Infected mosquitoes can transmit the virus to healthy mosquitoes. Infected mosquitoes may spread the virus to others.
Researchers have previously found that malaria can alter the odour of its host, which attracts mosquitoes. The new researchers thought it would be worth looking into whether this was also true for Zika or dengue.
The four closely related viruses that cause dengue are the causes of the viral infection. These viruses are spread by the bites of two types mosquitoes. According to the World Health Organization, while dengue is a risk factor for half the world’s population, more than 80% of cases are mild and not symptomatic. It can also be much more severe. Although scientists believe dengue cases are undercounted due to Covid-19, it is estimated that around 20,000 people die each year.
Zika is part of the same virus family as dengue, and can be transmitted by the same mosquitoes. Zika is not a serious illness. However, most people who have it do not experience symptoms. Those who do develop symptoms can experience neurological complications such as conjunctivitis, fever and conjunctivitis. Microcephaly, which is a birth defect caused by Zika virus infection in pregnancy, can also be caused by the virus.
There is no vaccine or medicine that can be used to prevent the Zika virus. The Zika vaccine is not recommended for children aged 9-16 who have been infected. This is because the goal is to prevent further dengue attacks.
A new study has revealed a previously undiscovered step in dengue and Zika spread. These infections can alter the person’s sense of smell, making them more attractive to mosquitoes. This makes them more likely to get bitten. Wang stated that it is not clear if this is an evolution-related process or a chance phenomenon.
To test the relationship between smell and mosquitoes, the study team infected mice using Zika and dengue. The team then created three interconnected cages to divide healthy mice, infected and mosquitoes. Each virus group was tested separately. The results were similar, however: 70% of mosquitoes preferred to be in the trapping room with infected mice.
Researchers also recruited patients with dengue fever from a Chinese hospital and healthy volunteers. The scientists collected the odors of the volunteers using armpit swabs. They then extracted the compounds responsible for those smells and transferred them to a piece filter paper. Next, a strange experiment was started: Volunteers were given a piece of paper that contained the odors of infected or healthy people. The other hand was given an unscented paper. Each hand was exposed to mosquitoes for 30 minutes.
Surprisingly, mosquitoes were attracted to the dengue-suffering hands more than any other option.
The researchers found that dengue patients emitted a higher amount of acetophenone when they compared their skin to the rest of the participants. The researchers also found that mice infected by Zika virus or dengue produced 10 times as much acetophenone as healthy mice. Even after scientists adjusted for other attractants like body heat or carbon dioxide, the main driver of mosquito bites was still scent.
The scientists discovered that dengue-infected mice produced less of the protein needed to kill acetophenone-producing bacteria. They set out to find a way to fix this problem. The mice were fed isotretinoin (a vitamin A derivative and a well-known acne medication). The mice’s skin was altered by the bacteria and acetophenone levels were reduced. The mosquitoes became less interested in eating the mice treated.
The team wants to test whether the same treatment works for humans because mouse skin is very different from human skin. The team also wants to expand the study and assess more Zika- and dengue-infected people. This study was limited to 10 patients. A large number of Malaysians are being surveyed in an effort to replicate the study.
Wang stated that the overall goal was to lower the disease burden and virus prevalence. This will take time. Although it won’t kill mosquitoes but may reduce their transmission, this treatment could be used.
Wang stated that these results may inspire genetic editing of mosquitoes in the near future. CRISPR is being used by other scientists to create a mutation that stops female reproduction. CRISPR could be used by scientists to stop the process of scent.
