Prevent. Promote. Protect. Mosquitoes and disease

Mosquitoes and disease

There are many diseases that are transmitted by the bites of infected mosquitos.  These include, but are not limited to West Nile Virus, La Crosse Virus, St. Louis Encephalitis, Dengue, Chikungunya, and Zika.  In 2015, there were 34 confirmed cases of West Nile Virus with 2 deaths, and 15 cases of La Crosse Virus in Ohio.

Because the viruses are widespread, infections are likely to continue.  For more information on specific mosquito related diseases, please refer to the Ohio Department of Health by clicking here.

A Culex pipiens mosquito. This species of mosquito is important in the West Nile Virus transmission cycle. 


Controlling mosquitos is more of a continual effort rather than a single action.  Mosquitos breed and develop in standing water.  Cooperate with your neighbors to empty items that hold water and turn them over or store inside.  Examples are tires, buckets, planters, toys, pools, and birdbaths.

Water standing in detention ponds, ditches, catch basins, and natural bodies of water may or may not be breeding grounds for mosquitos as they may contain other wildlife that are predators of mosquitos. The only way to know if a body of water is a mosquito habitat is by dipping.  Dipping is a process whereby water is skimmed from the surface and examined for mosquito larvae.  Contact the Clark County Combined Health District to request inspection of specific areas you believe to be mosquito breeding grounds.  We may be contacted by email at or by telephone at 937-390-5600.

If larvae are present then the next course of action is to determine how to best control the larval activity.  Reducing or eliminating the standing water and other natural methods are preferred over using chemicals called larvicide.

Using fogging chemical is intended for adult mosquitos as a last line of defense and should not be performed as the only activity to control mosquitos.  These chemicals less effective than comprehensive efforts to reduce the source of the problem and may endanger beneficial wildlife such as honey bees.

There are other actions to take to protect yourself and family.

  • Use approved repellents according to the label.
  • Use hands to apply repellents to children and never apply repellents to their mouths, noses, hands, or eyes.
  • Wear lighter color clothing that covers the arms and legs.
  • Use screens on windows and doors.  Repair holes in screens.
  • Stay indoors during periods of increased mosquito activity.
  • Use air conditioning when possible.
  • Keep rain gutters and down spouts clear to avoid pooling water.
  • Add mosquito fish to livestock watering troughs.  For more information related to agricultural mosquito control visit
  • Keep ditches and other low lying areas mowed.
  • Use condoms when having sexual contact with a person who has traveled to an area under a travel advisory.

Zika Virus:

Areas with active mosquito-borne transmission of Zika virus

  • Prior to 2015, Zika virus outbreaks occurred in areas of Africa, Southeast Asia, and the Pacific Islands.
  • In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infections in Brazil.
  • Currently, outbreaks are occurring in many countries and territories.
  • Zika virus will continue to spread and it will be difficult to determine how and where the virus will spread over time.

US Territories*

  • Local mosquito-borne transmission of Zika virus has been reported in the Commonwealth of Puerto Rico, the US Virgin Islands, and American Samoa.

*Territories of the United States are sub-national administrative divisions overseen by the US federal government.

US States

  • No local mosquito-borne Zika virus disease cases have been reported in US states, but lab tests have confirmed Zika virus in travelers returning to the United States. These travelers have gotten the virus from mosquito bites and some non-travelers got Zika through sex with a traveler.
  • With the recent outbreaks, the number of Zika cases among travelers visiting or returning to the United States will likely increase.
  • These imported cases could result in local spread of the virus in some areas of the United States.

Specific areas where Zika is spreading are often difficult to determine and are likely to change over time. If traveling, please visit the CDC Travelers’ Health site for the most updated travel information.

What we know:

  • No vaccine exists to prevent Zika virus disease (Zika).
  • Zika virus is mostly spread through the bite of an infected mosquito. Prevent Zika by avoiding mosquito bites (see below).
  • Mosquitoes that spread Zika virus bite mostly during the daytime.
  • Mosquitoes that spread Zika virus also spread dengue and chikungunya viruses.
  • Zika virus can be spread during sex by a man infected with Zika to his sex partners.

Are you pregnant? Here’s what you can do to protect yourself if you don’t currently live in an area with Zika.

1. Avoid travel to an area with Zika. – Until we know more, CDC recommends special precautions for pregnant women. Women who are pregnant should not travel to any area where Zika virus( is spreading.  If you must travel to one of these areas, talk to your doctor or other healthcare provider first and strictly follow steps to prevent mosquito bites during your trip.

2. Take steps to prevent mosquito bites. – a) Wear long-sleeved shirts and long pants. b) Stay in places with air conditioning and window and door screens to keep mosquitoes outside. c) Use Environmental Protection Agency (EPA)-registered insect repellents. When used as directed, these insect repellents are proven safe and effective even for pregnant and breastfeeding women. d)Remove or stay away from mosquito breeding sites, like containers with standing water.

***Entire Pregnancy – Couples should use a condom every time they have sex during the pregnancy if the male partner has or is at risk for Zika virus infection. ****


3. Take steps to prevent getting Zika through sex. – Until more is known, pregnant women with male sex partners who have lived in or traveled to an area with Zika virus should either use a condom every time they have sex or not have sex during the pregnancy. To be effective, condoms must be used correctly (warning: this link contains sexually graphic images) from start to finish, every time during sex. This includes vaginal, anal, or oral (mouth-to-penis) sex or do not have sex during the pregnancy.

If a pregnant woman is concerned that her male partner(s) may have or had Zika virus infection, she should talk to her doctor or other healthcare provider. She should tell her doctor or other healthcare provider about her male partner’s travel history, including how long he stayed, whether or not he took steps to prevent getting mosquito bites, and if she had sex with him without a condom since his return.

4. See a doctor or other healthcare provider – Pregnant women who have recently traveled to an area with Zika should talk to a doctor or other healthcare provider about their travel even if they don’t feel sick. It is especially important that pregnant women see a doctor or other healthcare provider if they develop a fever, rash, joint pain, or red eyes during their trip or within 2 weeks after traveling to an area where Zika has been reported. They should tell the doctor or other healthcare provider where they traveled.  CDC has guidance to help doctors decide what tests are needed for pregnant women who may have been exposed to Zika.


Prevent Bug Bites

Bugs (including mosquitoes, ticks, and some flies) can spread diseases (including Zika, dengue, and Lyme disease), many of which cannot be prevented or treated with a vaccine or medicine. Reduce your risk by taking steps to prevent bug bites. See below for special instructions to protect babies, children, and pregnant women.

Use Insect Repellent

Use EPA-registered insect repellents that contain at least 20% DEET (products include Cutter Backwoods and Off! Deep Woods) for protection against mosquitoes, ticks, and other bugs. Other repellents protect against mosquitoes but may not be effective against ticks or other bugs:

  • Picaridin (also known as KBR 3023, Bayrepel, and icaridin); products include Cutter Advanced, Skin So Soft Bug Guard Plus, and Autan
  • Oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD); products include Repel Lemon Eucalyptus
  • IR3535; products include Skin So Soft Bug Guard Plus Expedition and SkinSmart

Find the EPA-registered insect repellent that is right for you. The effectiveness of insect repellents that are not registered with the EPA, including some natural repellents, is not known.

When using insect repellent, follow the instructions on the package and reapply as directed:

  • In general, higher percentages of the active ingredient provide longer-lasting protection. However, this increase in protection time maximizes at about 50% DEET.
  • If you are also using sunscreen, apply it first, let it dry, and then apply repellent. Do not use products that contain both sunscreen and repellent.
  • Do not spray repellent on the skin under clothing.

Consider using clothing and gear (such as boots, pants, socks, and tents) that are treated with permethrin (an insecticide). You can buy pre-treated clothes or treat your own clothes. If treating items yourself, follow instructions carefully. Do not use permethrin directly on skin.

*Insect repellent brand names are provided for your information only. The Centers for Disease Control and Prevention and the US Department of Health and Human Services cannot recommend or endorse any name-brand products.

Cover Exposed Skin

As much as possible, wear long-sleeved shirts, long pants, socks, and a hat. Tuck your shirt into your pants, and tuck your pants into your socks for maximum protection. Some bugs, such as tsetse flies, can bite through thin fabric.

Avoid Bugs Where You Are Staying *Especially Important if traveling*

Choose hotel rooms or other accommodations that are air conditioned or have good window and door screens so bugs can’t get inside. If bugs can get into where you are sleeping, sleep under a permethrin-treated bed net that can be tucked under the mattress. When outdoors, use area repellents (such as mosquito coils) containing metofluthrin or allethrin.