Risks
Most mosquitoes in the United States are harmless. These "nuisance mosquitoes" can still cause uncomfortable bites and prevent outdoor activities. Mosquitoes have been known to carry disease in the United States and you should avoid mosquito bites as much as possible.
In other parts of the world, mosquitoes are responsible for hundreds of thousands of deaths each year. Africa, Central America, South America and Asia are most impacted by the deadliest animal on earth.
If you are traveling out of the United States, talk with your healthcare provider about precautions you can take. Malaria pills or yellow fever vaccination might be recommended. Visit your healthcare provider at least 6 weeks before your trip.
Local transmission of a disease happens when a mosquito bites someone who is sick and then bites a healthy person. Avoiding all mosquito bites is the best prevention against disease from mosquitoes.
If you are traveling out of the United States, talk with your healthcare provider about precautions you can take. Malaria pills or yellow fever vaccination might be recommended. Visit your healthcare provider at least 6 weeks before your trip.
Local transmission of a disease happens when a mosquito bites someone who is sick and then bites a healthy person. Avoiding all mosquito bites is the best prevention against disease from mosquitoes.
West Nile Virus
West Nile virus (WNV) is the most common disease from a mosquito in the continental United States. Many people do not show symptoms or get mild symptoms. Rarely, WNV can causes severe symptoms that require hospitalization and can be fatal.
There is no preventive medication or treatment specifically for WNV. Preventing mosquito bites in general is the best protection. WNV can infect people and animals (mainly horses). Getting WNV does provide some immunity against getting sick again. However, it is uncertain how long this immunity lasts.
2012 was the deadliest year for WNV in the United States. 286 people died and over 5,600 human cases were reported. Many people who get sick with WNV have mild symptoms and may not seek medical care so it is unclear how many people were actually infected in 2012. WNV can be found in other places including Australia, Africa and Europe.
There is no preventive medication or treatment specifically for WNV. Preventing mosquito bites in general is the best protection. WNV can infect people and animals (mainly horses). Getting WNV does provide some immunity against getting sick again. However, it is uncertain how long this immunity lasts.
2012 was the deadliest year for WNV in the United States. 286 people died and over 5,600 human cases were reported. Many people who get sick with WNV have mild symptoms and may not seek medical care so it is unclear how many people were actually infected in 2012. WNV can be found in other places including Australia, Africa and Europe.
Zika
Zika is a viral infection that can cause significant birth defects if a mother is infected during pregnancy. If you are traveling to a country where Zika is prevalent, speak to your healthcare provider about precautions to take before, during and after your trip.
Zika is not very dangerous to the average adult but can cause uncomfortable symptoms such as headaches, fever or a rash. Since Zika often does not cause symptoms or has mild symptoms, you may not know you are infected. Zika can be spread through sexual intercourse so it is important to take extra precautions if you are or are planning to become pregnant and may have been exposed to Zika.
There has not been a reported case of local transmission of Zika in the continental United States since 2018. You can become infected if you travel to an area where Zika is common including South America, Central America and South East Asia.
Zika is not very dangerous to the average adult but can cause uncomfortable symptoms such as headaches, fever or a rash. Since Zika often does not cause symptoms or has mild symptoms, you may not know you are infected. Zika can be spread through sexual intercourse so it is important to take extra precautions if you are or are planning to become pregnant and may have been exposed to Zika.
There has not been a reported case of local transmission of Zika in the continental United States since 2018. You can become infected if you travel to an area where Zika is common including South America, Central America and South East Asia.
Malaria
More than 600,000 people die from malaria each year and is caused by a parasite that enters the bloodstream. Malaria is treatable but can be fatal is treatment is delayed or does not happen.
Even if you had malaria once, you could get it again. Preventing mosquito bites is very important if you are in an area where malaria is common. Malaria is most often found in Africa and can also be found in South America and Asia.
If you are traveling out of the country, talk to your healthcare provider about preventive medication you can take.
Each year about 2,000 people from the United States get sick with malaria. Most often, people who get sick were infected while traveling in an area where malaria is common.
Even if you had malaria once, you could get it again. Preventing mosquito bites is very important if you are in an area where malaria is common. Malaria is most often found in Africa and can also be found in South America and Asia.
If you are traveling out of the country, talk to your healthcare provider about preventive medication you can take.
Each year about 2,000 people from the United States get sick with malaria. Most often, people who get sick were infected while traveling in an area where malaria is common.
Dengue
Dengue is rarely fatal but might require hospitalization for severe illness. Dengue kills up to 40,000 people each year and millions of people get sick. Dengue can most often be found in Central and South America, Africa and Asia. There are 4 strains of the dengue virus. You can be infected with dengue multiple times.
Most people recover in about a week and there is no specific treatment.
In the United States, locally transmitted cases have most commonly been found in Puerto Rico, Florida and Texas. Most cases of dengue in the United States are in people who traveled to other countries.
Most people recover in about a week and there is no specific treatment.
In the United States, locally transmitted cases have most commonly been found in Puerto Rico, Florida and Texas. Most cases of dengue in the United States are in people who traveled to other countries.
Other diseases
You can learn more about viruses and parasites caused by mosquitoes here.
Prevention
You can prevent mosquito bites by using insect repellent, wearing long sleeved shirts and pants, eliminating standing water where mosquitoes can breed and using screens at home.
Before you travel out of the county, talk with your healthcare provider about your risks and precautions you should take. If you are traveling to other parts of the United States, be aware of any outbreaks.
Before you travel out of the county, talk with your healthcare provider about your risks and precautions you should take. If you are traveling to other parts of the United States, be aware of any outbreaks.