Have you ever noticed that mosquitoes seem to bite some people more than others, even when they are all in the same place with the same amount of exposed skin at the same time?
Because mosquitoes can spread diseases like malaria, zika, and dengue fever, scientists have studied the various factors that can make some people more attractive to mosquitoes. One of these factors is blood type.
In this article, we examine the relationship between mosquito bites and blood type, and also examine other factors that mosquitoes attract.
People with different blood types have different sets of specific proteins (antigens) on the surface of their red blood cells. You inherit your blood type from your parents. There are four different blood types:
- ONE: just an antigen on the surface of the red blood cells
- B: only B antigen on the surface of the red blood cells
- FROM: both A and B antigen on the surface of red blood cells
- THE: no A or B antigen on the surface of the red blood cells
Some people can also have these antigens in body fluids such as saliva or tears. These people are called secretaries. For example, someone with blood type A would be a type A secretor. Those with blood type O secrete H antigen, a precursor to the A and B antigens.
What does all this mean for your attractiveness for mosquitoes?
In general, mosquitos seem to be more attracted to people with blood type O than other blood types. We’ll dig deeper into the research on this topic below.
An older 1974 study recruited 102 participants to examine various individual factors that might attract mosquitoes. When the researchers analyzed the results, they found that mosquitoes preferred to feed people with type O blood.
Recently, a 2019 study also looked at the blood type preference in mosquitoes. They did this by providing samples of different blood types in separate feeders. It was observed that mosquitoes preferred to feed on the type O feed than on the other feeds.
A 2004 study examined the preference of mosquitoes for blood group and secretor status. The overall results were as follows:
- More mosquitoes landed on people with blood group O. However, this result was only statistically significant in comparison to blood group A and not to the other blood groups.
- Mosquitoes landed on type O secretors significantly more frequently than type A secretors.
- When blood group antigens were applied to the arms of the study participants, mosquitoes were significantly more attracted to people with H (type O) antigen than they were to A antigen. Meanwhile, A antigen was significantly more attractive than B antigen.
Because blood type antigens can be found in saliva and in the tears of secretors, mosquitoes may be able to recognize these antigens when approaching a person. However, no research has yet been done to support this idea.
Also keep in mind that while the 2004 study found a preference for blood type O over type A, this did not apply to the other blood types. Obviously, other individual factors can influence who mosquitoes bite.
The available research shows that mosquitoes prefer people with type O blood. However, it is likely that many other additional factors also play a role in a person’s attractiveness to mosquitoes.
Let’s take a closer look at some of the other single factors that mosquitoes can attract.
They release carbon dioxide when you exhale, leaving a trail of carbon dioxide that a mosquito can follow.
An increase in carbon dioxide in the air can alert a mosquito that a possible host is nearby. The mosquito then moves towards the source of carbon dioxide.
If you find that mosquitos bite you more than other people, you may just smell extra good to them. Several factors can affect how you smell like a mosquito, such as:
- Connections on your skin. Researchers have found several compounds on the skin that make some people more attractive to mosquitoes. Examples are ammonia and lactic acid.
- Bacteria. The bacteria on your skin can also affect your body odor. According to a 2011 study, people with a higher frequency but lower bacterial diversity on their skin were more attractive to mosquitoes.
- Genetics. It has been found that mosquitoes are more attracted to smells on identical twins than they are on fraternal (non-identical) twins.
In addition to carbon dioxide and odors, our body also gives off heat. Research from 2017 showed that female mosquitoes move towards heat sources regardless of their size.
While it’s not clear why, research from 2018 showed that mosquitoes are more attracted to black objects. Because of this, you may find that you get more mosquito bites when you wear darker colors.
A small study from 2002 found that mosquitoes may be more attracted to people who have been drinking.
In the study, mosquitoes landed on participants more often after consuming a small amount of beer.
A 2004 study found that pregnant women attracted higher numbers of mosquitos compared to non-pregnant women.
This may be because pregnant women release more carbon dioxide and have a higher body temperature.
Mosquito repellants that have been classified as safe and effective by the Environmental Protection Agency (EPA) include the following active ingredients:
- DEET (marketed as Repel, Off! Deep Woods, and other brands)
- Picaridin (marketed as Natrapel and Sawyer)
- 2-undecanone (this repellant is found naturally in cloves and is marketed as the Bite Blocker BioUD)
- IR3535 (distributed by Merck)
- Lemon Eucalyptus Oil (OLE)
Studies from 2015 and 2017 comparing various commercially available mosquito repellants found that those containing DEET were the most effective against mosquitoes overall.
In addition to the repellants listed above, some natural products can also repel mosquitoes. Some examples include, but are not limited to:
Safety tips for using mosquito repellants
- Always follow the application instructions on the product label.
- Some repellants shouldn’t be used on children under a certain age. Do not use DEET in babies younger than 2 months. Avoid using OLE in children under 3 years of age.
- Avoid getting the repellant near your eyes or mouth.
- Apply the repellant only to exposed skin and not under clothing.
- Keep repellants away from cuts, burns, or rashes.
- When you go back inside, wash the repellent off your skin with soap and warm water.
In addition to using a mosquito repellent, here are some steps you can take to prevent a bite:
- Avoid active times. Mosquitoes are most active in the morning and evening light. Avoid outdoor activities during this time.
- Avoid dark clothes. Try to wear light-colored clothing that covers your arms and legs. Clothing can also be treated with a repellent called permethrin.
- Prevent entry. Make sure your window and door panes are not cracked to keep mosquitoes from getting into your home.
- Use a mosquito net. If you sleep outside or in a place where mosquitoes can get inside, consider using a mosquito net.
- Eliminate standing water. Mosquitoes need standing water in order to reproduce. Try to limit standing water by draining it from empty flower pots and paddling pools.
Mosquito bites usually resolve on their own after a few days. In the meantime, however, there are a few things you can do to relieve itching and discomfort:
- Apply a cold compress. Gently placing a cool compress or ice pack over the bite for a few minutes can relieve itching and swelling.
- Try a baking soda paste. To relieve the itching, mix 1 tablespoon of baking soda with water to make a paste and apply it to the mosquito bite.
- Use OTC (over-the-counter) products: Various over-the-counter anti-itch creams and oral antihistamines have been developed to help relieve itching.
While it can be very tempting, resist the urge to scratch a mosquito bite. This can increase the risk of skin infection.
Female mosquitoes suck blood from humans and other animals in order to reproduce. Although mostly annoying, a mosquito bite can lead to diseases such as malaria in some parts of the world.
Research has found that mosquitoes may prefer to bite people with Type O blood. However, additional research is needed to further determine the relationship between blood type and mosquito attraction.
In addition to blood type, other factors such as carbon dioxide, body odor, heat, and dark clothing can also attract mosquitos.
You can reduce the risk of mosquito bites by using mosquito repellants, avoiding outdoor activities when the mosquitoes are most active, and eliminating stagnant water in your yard.