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Mosquitoes and Disease

Mosquitoes

Mosquitoes are small flying insects that feed on the blood of humans and animals, with only females biting to help their eggs grow. While most mosquitoes don’t spread diseases, some can carry harmful infections that affect both people and animals. 

Mosquitoes lay their eggs in standing water, where the larvae grow into adults. Mosquito eggs can hatch in as little as a bottle-cap full of water. Emptying all sources of standing water is one way to reduce mosquito populations in a yard or neighborhood.

Mosquitoes are most active in warm, humid weather, especially around dusk and dawn, but some will bite at any time of day. In places with warm weather all year round, mosquitoes can be a constant problem, so it’s important to protect yourself from their bites. 

Need to report standing water?

To report swimming pools that are not maintained, and other standing water, call the ECDOH at (716) 961-6800. 

Did you know?

While illnesses like Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) are rare in Western New York, they are not unheard of. In 2024, Erie County had zero reported cases of WNV and zero reported cases of EEE. However, there was one travel-related case of Chikungunya, one travel-related case of malaria, and four cases of Dengue fever. Statewide, New York reported 100 cases of WNV and two cases of EEE in 2024. Travelers to warmer regions are at a higher risk and should take precautions. 

Prevent Mosquito Bites

The best way to prevent mosquito-borne diseases is to protect yourself from mosquito bites. 

  • Use EPA-registered insect repellent; avoid spraying in eyes and follow product instructions for use
  • Wear long-sleeved shirts and pants
  • Treat clothing and gear with permethrin
  • Stay inside at dusk and dawn, when mosquitoes are most active
  • Repair windows, window screens and doorways to fix any gaps that could let mosquitoes in
  • Take steps to control mosquitoes indoors and outdoors 

How to Reduce Mosquitoes? 

  • Dispose of water-holding containers, used tires, and yard waste properly.
  • Ensure outdoor recycling bins drain, clean gutters, and eliminate standing water by draining or filling low areas.
  • Turn over wading pools and wheelbarrows when not in use.
  • Change birdbath water twice a week.
  • Maintain pools, hot tubs, and fountains with cleaning and chlorine. 

Mosquito Fact Sheet (PDF)

Do Mosquitoes Love Your Home and Yard?

Flyer: Fight Mosquitoes One Yard at at Time 

West Nile Virus (WNV) and Mosquitoes 

West Nile virus (WNV) is spread to people through the bite of an infected mosquito. Mosquitoes bite during the day and night. There is no vaccine to prevent WNV infection. The best way to prevent ­­­West Nile is to protect yourself from mosquito bites by using insect repellent, wearing long-sleeved shirts and pants, treating clothing and gear, and taking steps to control mosquitoes indoors and outdoors. 

West Nile Virus Symptoms

West Nile virus causes no symptoms in most people; 8 out of 10 people infected with West Nile virus do not develop any symptoms. 

If symptoms do occur, they may include: 

  • Febrile illness (fever) in some people
  • Serious symptoms in a few people such as high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. 

Learn more about WNV symptoms (CDC)

How West Nile Virus is Diagnosed

Healthcare providers diagnose West Nile virus infection based on: 

  • Signs and symptoms
  • History of possible exposure to mosquitoes that can carry West Nile virus
  • Laboratory testing of blood or spinal fluid 

If you think you or a family member might have West Nile, talk with your health care provider. 

Learn more about WNV testing 

West Nile Virus Treatment 

There are no specific medicines available to treat West Nile. Antibiotics do not treat viruses. 

Rest, fluids, and over-the-counter pain medications may relieve some symptoms. 

In severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care. 

Learn more about WNV treatment

Eastern Equine Encephalitis (EEE, "Triple E") and Mosquitoes

Eastern Equine Encephalitis (EEE) is a rare but serious disease that can affect people, horses, and some other animals. The virus is spread by mosquitoes, and although only about 10 human cases are reported annually in the U.S., it can be deadly. 

EEE Symptoms

Symptoms usually appear 4-10 days after being bitten by an infected mosquito. 

Symptoms include: 

  • High fever
  • Headache
  • Chills
  • Vomiting
  • As the disease progresses, people may become disoriented, have seizures, or fall into a coma. 

EEE is fatal in about 30% of cases, and many survivors face long-term health complications.  

Learn more about EEE symptoms 

When is Risk High for EEE? 

The risk is highest between late July and September, and people under 15 or over 50 are most at risk for severe illness.  

How EEE is Diagnosed  

Healthcare providers diagnose the EEE virus infection based on: 

  • Signs and symptoms
  • History of possible exposure to mosquitoes that can carry West Nile virus
  • Laboratory testing of blood or spinal fluid 

If you think you or a family member might have EEE, talk with your health care provider. 

Learn more about EEE testing 

How EEE is Treated

There are no specific medicines available to treat EEE. Antibiotics do not treat viruses. 

Rest, fluids, and over-the-counter pain medications may relieve some symptoms. 

In severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care. 

Learn more about EEE treatment 

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