What Diseases Do Mosquitos Carry?

Mosquitos can carry many diseases, including Zika, West Nile Virus, and Malaria. Many of these illnesses run rampant in Africa and other oversea continents.

Sep 17, 2023By Colt Dodd
what diseases do mosquitos carry

While mosquitos play an important role in the food chain, these buggers can carry harmful diseases, including Malaria and West Nile Virus. Pfizer reports that these six-legged bloodsuckers cause more than 700,000 deaths worldwide annually, with many of the deaths coming from Africa and affecting children under five years old.

Prevention is key to protecting oneself against the diseases that mosquitos carry. Yet, it helps to know what diseases these critters carry in the first place. Lovers of the outdoors can learn about protecting themselves here.

How Do Mosquitos Transmit Disease?

mosquito engorged with blood
Image Credit: Wikimedia Commons

Female mosquitos need blood to produce eggs. And, like all living things, mosquitos can get infected with viruses. With those two things in mind, here’s how a mosquito would transmit a disease to a person:

  • A female mosquito develops a virus. Let’s say Malaria.
  • The virus multiplies inside the mosquito.
  • The mosquito bites a human, transmitting Malaria through its saliva.
  • The person develops Malaria symptoms within six to 30 days.

And what of the female mosquito? Does she just carry on with her life like nothing happened? According to Science, nature has a way of delivering poetic justice. The female mosquito will succumb to the virus, just as a severely infected person would. There are no winners here.


symptoms of malaria diagram
Image Credit: 1Wikimedia Commons

When people think of diseases that mosquitos cause, their first thought goes to Malaria. That’s because in 2021 alone, this parasitic disease caused more than 240 million cases worldwide. The Centers for Disease Control and Prevention (CDC) notes that Malaria can result in flu-like symptoms, such as:

  • Chills
  • Headaches
  • Muscle pain
  • Chronic fatigue
  • Vomiting
  • Nausea
  • Diarrhea

If left untreated, Malaria can result in jaundice, anemia, and blood cell death. Malaria is relatively rare in the United States; only about 2,000 cases are reported each year, and many of those people had returned from overseas. If one suspects they have Malaria after traveling abroad, they should consult a medical professional.


symptoms of zika mosquito borne
Image Credit: Wikimedia Commons

Unlike many diseases mosquitos transmit, there is no cure or medication for Zika. While this illness mostly results in minor symptoms (such as fevers and rashes), it can spell trouble for pregnant women. If a mother passes Zika to her fetus, the child can suffer from:

  • Microcephaly. Per the CDC, this is a birth defect where a newborn’s head is smaller than the average size for its weight, age, and sex. This can result in smaller brains and decreased cognitive function.
  • Malformed limbs. Zika can affect how a baby develops in the womb. It can even affect the growth of limbs, resulting in clubfeet and other deformities.
  • Poor vision. Zika can cause scarring and pigment changes to the back of the eyeball. As the child develops, they may need disability-accessible accommodations to navigate the world around them.

If a mother contracted Zika during her pregnancy, she should share that information with her child’s healthcare provider. Even if the baby seems externally fine, some symptoms don’t outrightly manifest.

West Nile Virus (WNV)

west nile virus up close
Image Credit: Wikimedia Commons

Here’s some good news from the CDC; even though WNV is among the most common mosquito-borne illnesses in the U.S., it’s usually not fatal. In fact, only one out of every five infected people develop fevers and other symptoms that call for medical attention.

One can prevent contracting WNV by:

  • Wearing long-sleeved shirts and pants when going outdoors
  • Using bug spray
  • Checking with local health advisories for breakouts
  • Limiting outdoor exposure from summer to fall

Like many of the mosquito-transmitted diseases on this list, WNV generally presents flu-like symptoms, ranging from fevers to joint pain. The CDC notes that there’s no set-in-stone treatment for WNV. It usually includes addressing the patient’s symptoms and waiting the virus out.

Dengue Fever

dengue fever symptoms after mosquito
Image Credit: Wikimedia Commons

Dengue is a tropical disease, as it affects those who live in humid climates. The CDC notes that more than half of the world’s population lives in areas where they could contract Dengue. But just what is this?

Dengue is a virus that affects more than 400 million people each year. The symptoms can range from mild to severe, with many treatable using over-the-counter medications. Symptoms generally last anywhere from two to seven days, and they include:

  • Rashes
  • Joint pain
  • Gastrointestinal discomfort
  • Muscle pain
  • Headaches
  • Fatigue
  • Eye pain
  • Fevers

Lesser-Known Mosquito Diseases

mosquito on someone_s skin
Image Credit: Wikimedia Commons

Diseases like Malaria and Zika are household names. Yet, some may be surprised to learn that mosquitos can also transmit these illnesses:

  • Yellow fever. Yellow fever claims the lives of 30,000 people each year––with many of those deaths happening in Africa. The CDC notes that if someone wants to travel to Africa, they should get vaccinated first.
  • Japanese encephalitis. While there are less than 1,000 cases each year, this is not a condition to be trifled with. Japanese encephalitis can cause brain swelling, fevers, and disorientation. There’s a vaccine for this illness, too.
  • Rift Valley fever. The Rift Valley refers to an area in sub-Saharan Africa where people raise livestock. This illness generally results in mild symptoms that resolve themselves. Yet, a small number of patients can develop eye disease and brain swelling.
  • Filariasis. Even though this is relatively rare (affecting less than 1,000 people worldwide annually), this virus can travel to the lymph nodes and cause swelling in the legs, arms, and genitals.

Do Mosquitos Have Any Benefits?

a mosquito on a white wall
Image Credit: Wikimedia Commons

With all this talk about disease, it may seem as though mosquitos have no right to exist on Planet Earth. Yet, as noted, they play a critical role in the food chain. For instance, mosquito larvae are a great food source for fish and frogs. Mosquitos themselves make tasty snacks for lizards, birds, and bats.

So, the next time one scratches at a mosquito bite, remember prevention is key to avoiding mosquito-borne illnesses. Also, without these insects, the food chain would collapse.

Colt Dodd
By Colt Dodd

Colt Dodd is a sighthound enthusiast with three years of freelance writing experience. He has an Italian greyhound/Shetland sheepdog mix named Homer. In his spare time, he enjoys going to dog parks and writing fiction.