Mosquitoes have been causing trouble for humans for centuries. These small, seemingly harmless insects not only cause irritating bites but also can be a carrier of some of the deadliest human diseases.
Research shows that mosquitoes can transmit diseases such as Zika virus, West Nile virus, malaria, chikungunya virus, and dengue fever. According to the World Health Organisation (WHO), over 700 million people contract mosquito-borne illnesses every year, with over 1 million resulting in death.
But what makes us so vulnerable to mosquito-borne diseases? How do mosquitoes identify their next human target? Let us delve deeper into the world of mosquitoes to understand how they smell us, and how that knowledge could help us save lives.
How do mosquitoes find us?
Mosquitoes have an odour-detecting organ called antennae. The antenna has tiny hairs that contain odour receptors, allowing the mosquito to identify human body odour and carbon dioxide from a distance. Mosquitoes are attracted to carbon dioxide because it signals the presence of a potential host.
Researchers have discovered that mosquitoes can detect the presence of carbon dioxide from up to 50 meters away. They do this by following the plume of carbon dioxide that is carried by the wind. Some studies have also found that mosquitoes are attracted to lactic acid, uric acid, and ammonia – all of which are present in human sweat.
Once the mosquito has identified the presence of a human, it uses other senses such as heat sensors to locate the exact location of its next meal. Studies have found that mosquitoes can detect temperature differences as minute as 0.1 degrees Celsius, meaning they can easily locate the heat signature of a human body.
Why are mosquitoes attracted to certain people?
Have you ever wondered why some people get bitten by mosquitoes more frequently than others? Research suggests that genetics play a significant role in mosquito attraction. Mosquitoes seem to be attracted to people with certain blood types, such as Type O. People who regularly exercise also tend to attract mosquitoes as they produce more carbon dioxide and lactic acid.
Apart from genetics, other factors that attract mosquitoes include wearing dark clothing, wearing strong perfumes, and consuming alcohol. According to studies, mosquitoes are also more attracted to pregnant women. This can be dangerous as some mosquito-borne diseases, such as Zika, can cause birth defects in infants.
What happens when a mosquito bites us?
When a mosquito lands on our skin, it pierces the skin with its proboscis to locate a blood vessel. The mosquito then secretes saliva into the wound, which contains anticoagulants, enzymes, and proteins. The saliva prevents our blood from clotting, making it easier for the mosquito to feed.
It is the saliva that causes the itchy bump that we associate with mosquito bites. The immune system recognises the proteins in the mosquito saliva as harmful and releases histamines to counteract them. This causes inflammation, redness, and itching.
Mosquitoes can also transmit diseases through their saliva. When a mosquito feeds on an infected individual, it ingests the virus or parasite that causes the disease. The mosquito then passes on the virus or parasite to the next human it bites, leading to the spread of disease.
How can we protect ourselves from mosquito-borne diseases?
The most straightforward way to protect ourselves from mosquito-borne diseases is to prevent mosquito bites. This can be done by using mosquito repellents, wearing long-sleeved clothes and pants, and using mosquito nets when sleeping at night.
Eliminating mosquito breeding grounds is also critical in preventing the spread of mosquito-borne diseases. Mosquitoes lay their eggs in stagnant water, such as in flower pots, gutters, or even small puddles. By eliminating standing water, we can reduce the mosquito population and the likelihood of them breeding in our surroundings.
Understanding how mosquitoes smell us could also help us develop better prevention strategies. For instance, researchers are working to develop mosquito traps that mimic human body odour and carbon dioxide, luring mosquitoes towards them. This could be particularly useful in areas that are prone to mosquito-borne diseases, such as malaria.
Mosquitoes have been a significant threat to human health for centuries. They are responsible for transmitting some of the deadliest diseases to humans, causing countless deaths every year. Understanding how mosquitoes locate and identify humans could help us develop better strategies to protect ourselves from mosquito-borne diseases.
By being mindful of our behaviour, such as wearing long-sleeved clothes and pants, using mosquito repellent, and eliminating standing water, we can reduce our exposure to mosquitoes. Scientists are also working towards developing more effective prevention strategies, such as mosquito traps that mimic human odour.
As we continue to learn about mosquitoes and their interactions with humans, we can take steps towards creating a safer and healthier world for all of us.