Here’s Why Mosquitoes Are the Most Dangerous Animal in the World

Most of us are familiar with the buzzing of a mosquito. While typically just a nuisance, these little insects can also be quite dangerous. In fact, mosquitos are one of the deadliest animals in the world. This is due to the diseases, primarily viruses and parasites, that they can carry and pass to humans when they bite. While most cases are mild and resolve on their own or with treatment, some mosquito-borne diseases can be dangerous or lead to more serious complications.

Why Are Mosquitos Dangerous?

According to the Centers for Disease Control, CDC, mosquitos kill more people than any other animal in the entire world. But it’s not their venomous bite or poisonous body that does people in. The reason why these little insects are so dangerous comes down to diseases. Mosquitos carry diseases they can pass along to people. Many diseases carried by mosquitos are fatal when not immediately treated.

When a mosquito bites, it extends a long proboscis, pierces the skin, and sucks out blood. When they do this, their saliva also goes into your body. The proteins in mosquito saliva cause the characteristic itching and redness that people associate with mosquito bites. This is often the most tell-tale sign that you’ve been bitten since the actual bite doesn’t hurt much, if at all. Many people don’t even know that they’ve been bitten until they start to develop an itchy welt.

The danger from mosquitos comes from what else is in their saliva. In addition to the proteins that cause itchiness (which is generally annoying and uncomfortable but not dangerous), mosquitos can transfer disease-causing organisms like viruses to you when they bite.

Mosquitos aren’t all bad, however. They are an important food source for many other insects and animals around the world. There are around 3,500 species of mosquitos and they live all over the globe. Animals like fish, birds, and larger insects feast on mosquitos. Without them, the delicate balance of the ecosystem would be negatively impacted.

What Diseases Can Mosquitos Carry?

Mosquitos can carry parasites, viruses, and other organisms that cause disease. Some of the most dangerous diseases include malaria, chikungunya, West Nile, yellow fever, and Zika.

Malaria

This dangerous disease is only carried by one specific type of mosquito, the Anopheles mosquito. Malaria is caused by a parasite that these mosquitos get when they bite an infected person. These parasites then travel via the mosquito to the next person that they bite. There is a vaccine that can prevent malaria, which is recommended for anyone traveling to or living in an area known to be high-risk for malaria transmission. The CDC closely monitors malaria cases and publishes data about malaria outbreaks to inform the public.

Chikungunya

This disease is caused by a virus, which can be transmitted through mosquito bites. The CDC recommends taking steps to prevent mosquito bites as the best way to protect against chikungunya, especially if you are traveling to a high-risk area. These include wearing mosquito repellant, wearing long sleeves and pants, and using screens when indoors to prevent mosquitos and other insects from coming inside. A vaccine is being developed but is not widely available yet. Chikungunya can cause fever, pain, swelling, and a rash, although it is not typically fatal and resolves within a few weeks.

West Nile

West Nile virus is one of the most common mosquito-borne diseases in the U.S., according to the CDC. Fever is the most common symptom but others can include aches and pain, rash, and vomiting or diarrhea. However many people who contract West Nile virus don’t experience any symptoms at all. In most cases, West Nile resolves on its own with few complications. What makes it so dangerous, however, is that there is no vaccine or treatment available if you do contract West Nile virus. For those with complications, it can be very dangerous. It can cause inflammation and swelling in the central nervous system, including the brain and spinal cord. While this is rare, it can be very dangerous.

Yellow Fever

Another illness related to West Nile, yellow fever is spread through a virus and the Aedes and Haemagogus species of mosquitos. According to the CDC, yellow fever is primarily an issue in South America and Africa, especially in the tropical and subtropical regions. If you are traveling to or live in these areas, you are at higher risk of contracting yellow fever from an infected mosquito. Mild cases cause fever, aches and pains, and fatigue. More serious cases can harm the liver. While most people recover within a week or two, it’s still important to take steps to prevent yellow fever infections since there aren’t any treatments available after you have been infected. A vaccine is the best option and recommended for those traveling to or living in an area with known yellow fever risk.

Zika

The Aedes mosquito can also be a carrier of the Zika virus. Most adults who contract Zika are asymptomatic. Some have mild symptoms, such as fever, headache, or fatigue, that go away within a week without any treatment necessary. The danger from Zika is for pregnant women and their unborn babies. Pregnant women who contract Zika are at higher risk for miscarriage and their babies are also at higher risk for issues like microcephaly and other developmental defects. For this reason, the CDC declared Zika a Public Health Emergency of International Concern in February 2016 and recommended that pregnant women avoid places with known Zika outbreaks. Outbreaks declined and the emergency was lifted at the end of 2016, although Zika remains a concern in some areas.

Is a Mosquito Bite Deadly?

When a mosquito bites you, you’re not likely to experience more than some localized irritation and itching. Some people are more sensitive than others to the insect’s saliva. This is known as Skeeter syndrome. While it typically isn’t fatal, people with this sensitivities react to mosquito bites more. They can have swelling, irritation, and redness around the bite. Extreme cases can also have fever and blistering, as well as pain.

Skeeter syndrome can develop even if you have not had an allergic reaction to mosquito bites in the past. There are different species of mosquito, which means slightly different types of saliva. If you are traveling and have a stronger-than-normal reaction to a mosquito bite, you may be more sensitive to the species of mosquito at your travel destination. You might also have built up an immunity or tolerance for mosquitos that you come into contact with often, resulting in a stronger reaction when you come across a new species.

Most of the time, Skeeter syndrome symptoms go away within a few days. If you scratch excessively, however, you can be at risk for infections or other issues. This is especially true for babies or young children who may not understand that they can’t scratch at the bite.

Preventing Mosquito-Borne Illnesses

One of the best things that you can do to prevent mosquito bites and illness is to use a repellant topical product. Sprays are the most common and easiest to use, although there are also some lotion or band options as well. You can also wear long pants and long sleeves to provide less access to your skin (and blood).

If you are traveling to an area with a known outbreak or high risk for certain diseases, look into getting vaccinated ahead of time. This will ensure that you do not contract or develop severe symptoms. Not all mosquito-borne illnesses have a vaccine, however.