Mosquito Bites: How Deadly Are They?

There’s nothing more annoying than the moment you wake up in bed and hear the unmistakable buzz of a mosquito near your ear — except maybe when you’re in the middle of a titillating conversation and notice a mosquito that has oh-so-stealthily landed on your leg. And no matter how many times you slap at it, it escapes your wrath. 

Mosquitoes are more than annoying pests, however. Causing over one million deaths globally each year, they’re silent and lethal assassins. It’s challenging to wrap your mind around how an insect so small can cause such devastation around the world. Join us as we discuss six of the deadliest diseases mosquitoes carry and review what you can do to protect yourself from mosquito bites in the future. 

Why Mosquitoes Bite Us: What Gives? 

Think of mosquitoes as little vampires — except, unlike their blood-sucking cousins, they roam for prey during the day and usually disappear by dusk. But why is blood so important to their diet? And what do mosquitoes eat besides blood? 

Only female mosquitoes dine on your blood, and they do so because they require the nutrients in your blood to produce their eggs. Once they’ve homed in on a victim, they strike with the help of their needle-like mouthpart, called a proboscis, which pierces the skin and sucks out the blood. They use their saliva to lubricate the opening of the wound, which is what often creates the stinging or itching sensation you feel during or after a bite. Males, on the other hand, prefer vegetarian meals and only opt for flower nectar for sustenance. 

3 Deadly Diseases Mosquitos Carry 

As female mosquitoes move from host to blood-filled host, they sometimes pick up disease-causing microorganisms from infected victims. Once ingested, they can then transmit those pathogens to other innocent people or animals. Some of the most common and deadly diseases they spread include:  

West Nile Virus 

West Nile Virus (WNV) is transmitted to humans through mosquitoes that have bitten an infected bird with the disease. Approximately 80% of people who get WNV experience no symptoms, and those who do usually notice symptoms such as fever, headache, stiffness in the neck, tremors and muscle weakness. This disease is most dangerous to those who are immunocompromised, have certain medical conditions or are 60 and older. 


Malaria is spread by female Anopheles mosquitoes (one of more than 3,000 species). Symptoms usually begin about 10 to 15 days after a mosquito has bitten a victim and include fever, headache and chills. While malaria is treatable, some of the parasites that cause the disease have adapted against anti-malarial medications, which has left some strains of the disease completely drug resistant. 


The Zika virus is often passed through the bite of Aedes mosquitoes. Once a person is infected, there’s a large chance they’ll be asymptomatic. Those with symptoms often experience muscle and joint pain, fever, rash and conjunctivitis (pink eye). Surprisingly, mosquitoes aren’t the only culprits of spreading Zika. Infected humans can also spread the disease through sexual contact as the virus can survive in sexual organs, often with the transmitter not experiencing any symptoms. 

In addition, pregnant mothers with Zika can also transmit the disease to their unborn babies. An Zika infection during pregnancy can cause the baby to be born with microcephaly, a birth defect that causes the baby’s head to be smaller than normal. The disease also can lead to other severe birth defects. 

How to Prevent Mosquito Bites 

While mosquito bites are usually no more than an annoying nuisance to unwilling victims for a day or so, you never know when a disease-infected mosquito might buzz its way to your skin looking for a taste of your blood. Thankfully, there are precautions you can take to prevent mosquito bites. And while there’s no guarantee that one or two won’t slip past your defenses, it’s better to play it safe than sorry with the following tips: 

  • Use an Environmental Protection Agency (EPA)-registered insect repellent with an active ingredient, such as DEET, picaridin or oil of lemon eucalyptus (OLE). 
  • Cover your little one’s stroller or baby carrier with mosquito netting. 
  • Wear long shirts and pants if you plan on being in an environment with a mosquito-dense population. 
  • Don’t allow any accumulation of water in areas near your home, as mosquitoes breed in humid environments like stagnant puddles and buckets of water. 
  • If you have a small child pool or birdbath in your yard, drain it and change the water frequently. 
  • Keep your windows closed (unless you have a window screen) to avoid letting any unwanted mosquitoes into your home. 

Take a Bite out of the Competition with a Graduate Credential  

With the University of Florida’s online Master’s Degree in Entomology with a Specialization in Medical Entomology or  Graduate Certificate in Medical Entomology, you’ll learn everything you need to start the next chapter in your entomology career, whether you’re pursuing a role as a mosquito control technician, vector control specialist or another critical role in public health. Our programs features entirely online courses, where you’ll learn how to identify biting arthropods, discuss the biology of mosquitoes and arthropod-borne diseases and develop management options for mosquitoes and their diseases. 

Students are accepted year-round, and there’s no GRE requirement. You can complete your online coursework at a pace you’re comfortable with. Learn more about UF’s online entomology graduate certificate programs today. 


Learn More About the Program

Click for details about the Entomology and Nematology program.