Why do some people attract more mosquitoes than others?

While some people can go unnoticed by the onslaught of mosquitoes, it is common for others to be more prone to being bitten — and not just from the nuisance mosquito, but also from flies, bees, and even moths.

Whether outdoors or indoors, there are numerous reasons that affect the attraction of mosquitoes by certain people, from alcohol consumption to the gestation. Most are related to one factor: the odors expelled by the skin.

“Both perspiration and body temperature can attract or inhibit the arrival of insects on the skin. Some substances expelled in perspiration, such as lactic acid, uric acid and ammonia are attractive to mosquitoes”, explains dermatologist Simone Neri.

Does “Sweet Blood” attract more mosquitoes?

The answer is not. Although many people believe in the belief that the taste of blood can attract the attention of mosquitoes, this attraction is related to the substances exhaled by the human body, as pointed out by Simone.

Insects that feed on blood, called hematophagous, have sensory organs dedicated to detecting chemicals, such as lactic acid, present in human sweat — especially after physical activity.

Another substance that can also trigger hematophagous antennae is carbon dioxide (CO2), a gas that is released during breathing and which, in a large amount, increases the possibility of receiving a mosquito bite.

In this context, learn about some factors that increase the risk of being targeted by mosquitoes and how to properly protect yourself from them, according to experts consulted by Minha Vida.

1. pregnancy

Due to the hormonal changes that occur during pregnancy, it is common for pregnant women to exhale more carbon dioxide and present an increase in body temperature, being more exposed to the attack of mosquitoes.

This was pointed out in a study carried out in 2016 by the University of Durham in the United Kingdom. According to the researchers, pregnant women are twice as vulnerable to mosquitoes.

“The conclusion is that this was due to the accelerated metabolism resulting from the pregnancy. Pregnant women exhale 21% more carbon dioxide than other people, which can attract more insects”, points out Simone.

The other hypothesis is that, when pregnant, a woman experiences an increase in body temperature of about 0.7°C, which leads her to exhale more substances such as lactic acid, uric acid and ammonia, which are attractive to mosquitoes.

Also read: Best repellents for pregnant women: find out which ones to use

2. Blood type

People with blood type “O” attract twice as many mosquitoes as people with other blood types, whether positive or negative, according to Camila Hoffman, a dermatologist at the Alemão Oswaldo Cruz hospital. This factor was studied in a study published in Journal of Medical Entomology.

According to the researchers, this behavior is related to the secretions produced by the human body, which help insects identify our blood type. However, it is noteworthy that the case requires more scientific studies for the thesis to be validated.

3. Physical activities

When exercising, the body produces lactic acid to generate more energy for the muscles. When expelled in sweat, the substance is easily detected by the antennae of mosquitoes, making the person more vulnerable to the bite. In addition, as Simone Neri explains, the increase in body temperature during physical exercise can also attract more mosquitoes.

4. Consumption of alcoholic beverages

The consumption of alcoholic beverages increases human attractiveness to mosquitoes, especially malaria vectors, as pointed out by a study by Lefevre et al. According to the researchers, the ethanol present in alcohol (and which is expelled through sweat) can make people more prone to the bite of these insects.

The research also indicated that other forms of alcohol found in nature can also attract mosquitoes, such as fructose and nectar produced by flowers.

In addition to this, other studies have already pointed out the possible relationship between alcohol and the attractiveness of this type of insect. But, like the blood factor, more research is still needed for the thesis to be validated in the scientific community.

5. Genetic factors

Genetic factors may be related to the attractiveness of mosquitoes. The reason for this is not yet known, but it is understood that while some people emit compounds that repel insects, others carry out the opposite process, according to research by the London School of Hygiene and Tropical Medicine.

During the experiments, it was observed that two identical twins did not show differences in the level of attraction of the mosquitoes — while, when the twins were different, it was noticed that one of them attracted the attention of the insects more than the other.

How to protect yourself from mosquitoes?

Mosquitoes, in addition to causing wounds and allergies, can be vectors of dangerous diseases such as dengue, yellow fever and malaria. As a result, it is essential to maintain updated vaccination card and adopt some protective habits — especially for groups considered at risk, such as pregnant women.

Camilla explains that use of repellent it is essential to protect against mosquitoes and should be adopted from childhood. “There is a specific repellent for babies, for example. The recommendation is to use it from six months and, from two years old, you can use adult repellent”.

For people who have allergies or skin irritations to this type of product, Simone points out that there are repellents based on citronella, a natural and biodegradable compound that poses no health risks.

Finally, one method that can help keep mosquitoes out of your home is Install screens on doors and windows. Remember not to leave them open at sunrise and sunset, as these are periods when mosquitoes are most active.

Also read: Vaccines: answer eight questions that arise when updating your card