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Mosquitoes and Personal Protection

Photo of Mosquito

Mosquitoes are flying insects that feed on human and animal blood. Female mosquitoes feed on blood for egg development. The bite of a mosquito typically results in an itchy welt, but can occasionally transmit pathogens (germs) such as West Nile virus and Eastern Equine Encephalitis virus. There are about 50 different species of mosquitoes in Suffolk County, but only some transmit disease.

Photo of pail dumping water

Several types of mosquitoes lay their eggs in containers around the home such as flower pots, children’s toys, discarded tires, clogged gutters, ornamental ponds without fish, non-maintained pools or puddles on pool covers. Some types of mosquitoes lay eggs that float on the surface of the water, while others lay eggs that adhere to the sides of the container. After time, the eggs will hatch into larvae, develop into pupae and emerge as adults. Dumping standing water around the home can help reduce their numbers.


How can I reduce mosquitoes around my home?

To remove mosquito breeding areas around the home, check for containers that may have been filled by rain or sprinkler systems. Remove or discard containers that you don’t want. Empty and scrub items that you wish to keep, such as bird baths. Scrubbing removes eggs laid on the side of the container.

Areas where water can collect:

  • Old tires
  • Tarps and buckets
  • Unused plastic swimming pools & toys
  • Bases of flowerpots
  • Bird baths
  • Watering cans
  • Pet dishes
  • Clogged rain gutters
  • Standing water on flat roofs
  • Around faucets and air conditioning units
  • Boats and cargo trailers

Mosquito Life Cycle:

Photo of Mosquito Life Cycle

Mosquitoes bite during the day and night, and can be active from spring until late fall. Preventive measures should be used whenever mosquito bites are likely. The most effective way to avoid getting sick from germs spread by mosquitoes is to prevent mosquito bites.

CDC Mosquito-Borne Diseases Information

How can I avoid being bitten by a mosquito?

If you are outdoors, it is important to take proper precautions against mosquito bites. Such precautions include wearing long-sleeved shirts and long pants, using repellents as directed, considering staying indoors when mosquitoes are actively biting, placing mosquito netting over infant carriers, fans/citronella candles, and installing or repairing window and door screens so that mosquitoes cannot get indoors. Help reduce the number of mosquitoes around your home by regularly emptying sources of standing water that mosquitoes may use for breeding, such as flower pots, pet bowls, clogged gutters, etc. Bird baths should be scrubbed clean to remove laid eggs and refilled weekly.

Should I use mosquito repellents?

Consider using repellents that are EPA registered to repel mosquitoes. Always read and follow all label directions carefully. CDC recommends repellents containing DEET, oil of lemon eucalyptus, picaridin and IR3535, among others, that may be applied to the skin and clothing. Lower concentrations of DEET are preferable, especially for children. Repellents containing permethrin may be applied to clothing only.

Mosquitoes and the Disease They Cause

Mosquitoes can transmit disease through their bites, including West Nile, Eastern equine encephalitis, Chikungunya, Dengue, Zika and malaria. The most effective way to avoid getting sick from germs spread by mosquitoes is to prevent mosquito bites.

West Nile Virus (WNV) Disease is the most common mosquito-borne disease in the U.S. and is spread primarily by Culex mosquitoes, which are common in Suffolk County. Culex mosquitoes breed in water-filled containers, such as flower pots, pet bowls, clogged gutters, etc. Help reduce the number of mosquitoes around your home by regularly emptying these sources of standing water.

Most people infected with WNV do not feel sick. Mild cases of WNV infection (West Nile fever) may include a slight fever and head and body aches. Severe infections (West Nile encephalitis) may also include muscle weakness and may progress to encephalitis or meningitis.

WNV disease symptoms usually occur three to 14 days after exposure. Individuals who are most at risk for severe infection include those over 50 years of age and those with chronic illness or compromised immune systems. Healthy children and adults are at low risk for serious illness from West Nile virus. Horses are susceptible to WNV infection and should be vaccinated.

CDC West Nile Virus Information

Eastern Equine Encephalitis (EEE) is a rare mosquito-borne illness in humans, and only a few cases are reported in the United States each year. EEE virus is typically spread by a variety of mosquitoes from wooded, swampy regions. In Suffolk County, this virus has been found sporadically in mosquitoes but there has never been a human infection.

Most persons infected with EEE have no apparent illness. Severe cases (involving encephalitis, an inflammation of the brain) begin with the sudden onset of headache, high fever, chills and vomiting. The illness may then progress into disorientation, seizures, or coma. EEE is one of the most severe mosquito-transmitted diseases in the United States with approximately 33 percent mortality and significant brain damage in most survivors. Horses are susceptible to EEEV infection and should be vaccinated.

CDC Eastern Equine Encephalitis Information

Chikungunya, Dengue and Zika Viruses are spread primarily by Aedes mosquitoes. Aedes mosquitoes will bite anytime during the day or night. The vast majority of these infections are acquired while traveling to other countries. Outbreaks have occurred in other regions of the world such as parts of Africa, Asia, Europe, South and Central America, Mexico and the Caribbean. Precautions should be taken when traveling to places where these viruses are circulating. Visit the CDC’s website for current information on at risk travel destinations.

In addition to the bite of an infected mosquito, Zika virus can also be spread through sexual contact or blood transfusions. It can also be passed from mother to fetus during pregnancy. Infection during pregnancy can cause certain birth defects.

CDC Chikungunya Virus Information

CDC Dengue Virus Information

Malaria is a mosquito-borne disease caused by a parasite (Plasmodium). People with malaria often experience fever, chills, and flu-like illness. The vast majority of cases in the United States are in travelers and immigrants returning from countries where malaria transmission occurs, many from sub-Saharan Africa and South Asia.

CDC Malaria Information

Diagnosis and Treatment

Be sure to seek medical attention if you become ill after a mosquito bite. Generally, an evaluation of symptoms and blood tests will be used in making a diagnosis. There is no specific treatment for viral infections, other than to treat the symptoms and provide supportive care. Antimalarial medications may be used to treat malaria. Prompt diagnosis and treatment improves outcome. Your medical provider will choose the care that is best for you.

Mosquito Pathogen Surveillance Program

In the early 1970s, Suffolk County Department of Health Services (SCDHS) established a mosquito pathogen surveillance program in response to finding Eastern equine encephalitis virus (EEEV) in several domesticated animals in Eastern Suffolk County. Since EEEV is spread through the bite of an infected mosquito, the SCDHS began conducting mosquito surveillance using mosquito traps to monitor for the presence of this virus at 12 locations in Suffolk County. EEEV remained the main pathogen of medical importance in Suffolk County until the 1999 discovery of West Nile virus (WNV). As a result, the Arthropod-Borne Disease Laboratory (ABDL) expanded the mosquito pathogen surveillance program to include WNV. The ABDL now monitors mosquitoes for EEEV and WNV at approximately 50 locations throughout Suffolk County. Mosquitoes are collected and tested weekly for the presence of these viruses and results are used by Suffolk County Vector Control in their efforts to reduce mosquito populations. Testing results are also released to the public to increase awareness and to stress the importance of personal protection against mosquito bites. Homeowners can assist by eliminating any standing water around their homes to prevent mosquito breeding. To view the latest Suffolk County press releases, including the latest on mosquito-borne disease, follow the below link, or follow us on social media @Suffolk County Health. Mosquito-related information is typically posted during the spring and summer months, when mosquitoes are active.

SC Dept of Health Services Press Releases


Here are two types of traps used to collect mosquitoes in Suffolk County:


Light Trap

Gravid Trap


Education & Outreach

Public Health Videos:

A two-part look at how mosquitoes are captured and tested for mosquito-borne diseases.

The Science
of Catching and
Testing Mosquitoes
Video (Part 1)
Mosquitoes for
West Nile
Virus Testing
Video (Part 2)

A look at how to reduce mosquitoes in your back yard.

How To Stop
Mosquitoes From
Breeding in
Your Back Yard
Video (Part 1)

Brochures on Mosquito-Borne Diseases:

Get the Buzz about
Mosquitoes in English
Get the Buzz about
Mosquitoes en Español

Public Health Information Line:

Residents are encouraged to report sightings of dead birds, such as crows, blue jays and hawks that may have been infected with the virus to the Department of Health Services Public Health Hotline

from 9 AM to 4:30 PM Monday through Friday. June 1st- September 1st.

Questions about Mosquitoes and Mosquito-Borne Diseases in Suffolk County
If you have questions about mosquitoes or mosquito-borne diseases, send them to:  Mosquito.Prevention

Mosquito Control

The Suffolk County Department of Public Works, Division of Vector Control, is responsible for controlling mosquito infestations that are of public health importance. For more information about mosquito spraying, or for an online mosquito complaint form, visit Vector (Mosquito) Control or to learn more about the "No Spray" Law
and how to

Spraying Notices

Vector (Mosquito)
Control and
Wetlands Management
Long-Term Plan

Division of Vector
Control 2023
Plan of Work

Reported Cases of Mosquito-Borne Disease in Suffolk County

West Nile Virus (WNV) in Suffolk County

* Number in parentheses indicates number of deaths
Year Mosquito Samples Testing Positive Humans Cases*
2023 99 5 (0)
2022 96 11 (0)
2021 111 8 (0)
2020 88 5 (0)
2019 86 3 (0)
2018 142 11 (0)
2017 119 6 (2)
2016 125 5 (0)
2015 200 5 (0)
2014 186 1 (0)
2013 178 5 (0)
2012 210 14 (0)
2011 81 4 (0)
2010 295 25 (3)
2009 17 1 (0)
2008 41 9 (0)
2007 12 0
2006 57 2 (0)
2005 76 9
2004 8 0
2003 40 10 (2)
2002 34 8 (2)
2001 68 1 (0)
2000 121 0

Eastern Equine Encephalitis Virus (EEEV) in Suffolk County

● Only years where EEEV has been found are shown
● EEEV has not been found in horses since 2003
● There has never been an identified EEEV human case in Suffolk County
● Equine vaccines for EEEV reduce horse cases
Year Mosquito Samples Testing Positive Humans Cases
2019 9 0
2017 4 0
2008 3 0
2003 1 0
1997 5 0
1996 26 0
1994 49 0
1993 6 0
1990 1 0
1978 1 0
1973 1 0


Agency (EPA)

This website contains information about pesticides, health and safety, environmental effects, controlling pests, regulation of pesticides, compliance and enforcement, grants and partnerships, science and policy and more. It also contains a section for kids.

Mosquito-borne Disease Information

Centers for
Disease Control
Topics Webpage
New York State
Department of
Health Information
Centers for
Disease Control
West Nile
Virus Webpage
Centers for Disease Control EEE Virus Webpage

Disease Transmission

CDC West Nile Virus
CDC Eastern Equine Encephalitis


Pesticide Poisoning

If you think you have been adversely affected by a pesticide product, contact your medical provider immediately.

For information on pesticide poisoning, call the NPIC - National
Pesticide Information
1 (800) 858-7378.

Pesticide Regulatory
Programs: New York State
Department of Environmental
Conservation (DEC)

Suffolk County Government

H. Lee Dennison Bldg

100 Veterans Memorial Hwy
P.O. Box 6100
Hauppauge, NY 11788

Riverhead County Center

County Road 51
Riverhead, NY 11901