Zika is a disease caused by a virus that has been spread through mosquitoes primarily in South America since May 2015. The first local transmissions in the United States were reported at the end of July. Here is what you should know about the virus:

How could I get Zika?

Zika is spread through infected Aedes mosquitoes, a species that also transmits dengue and Chikungunya viruses. People contract the virus when they are bitten by an infected mosquito, and mosquitoes can become infected if they bite a person who has the virus.

Zika can also be sexually transmitted. Until July 15, 2016, all sexually transmitted cases were spread from men to their partners, the CDC said. The first female-to-male transmission of the virus was reported in New York City.

What are the symptoms?

Fever, rash, joint pain and red eyes are the most common symptoms of Zika, according to the CDC. It can also cause muscle pain and headaches. Symptoms typically lasts a few days to a week, and it is uncommon for it to be severe enough to require hospitalization.

Does the Zika virus cause birth defects when a pregnant woman is infected?

The CDC said if a woman gets Zika while she is pregnant, the virus can cause a birth defect called microcephaly, which causes a baby’s head to be smaller than expected. Additionally, other birth defects, including eye defects, hearing loss and impaired growth, can be caused by Zika.

The CDC said the virus should not pose a risk for future pregnancies after the virus has been cleared.

NYC health officials announced on July 22, 2016, that the city’s first baby with Zika-related microcephaly was born. The mother was infected with the virus while traveling, the health department said.

How do I treat Zika?

There are no vaccines or medications for Zika. The CDC recommends drinking fluids, getting rest and taking acetaminophen medicines, such as Tylenol, to relieve your fever and pain. You should not take aspirin, ibuprofen or other nonsteroidal anti-inflammatory drugs until you are certain you don’t have dengue, another disease spread through the same mosquitoes. The NSAIDs could cause excessive bleeding if you have dengue.

Where are the infected mosquitoes?

The Pan American Health Organization reported the first confirmed Zika virus in Brazil in May 2015. Before that, the infected mosquitoes were found in Africa, Southeast Asia and the Pacific Islands. Since the outbreak in Brazil, the virus has spread to multiple countries in South America, Central America, the Caribbean, Mexico and now the United States.

The first locally transmitted cases in the United States were confirmed in Florida. As of Sept. 1, there were at least 49 cases in Florida that have likely been contracted from local mosquitoes, according to the state's health department. The most recent local transmissions have occurred in Miami Beach, health officials said. 

On Sept. 1, Florida officials announced they had trapped the first mosquitoes to test positive for Zika, confirming suspicions that many of the Florida cases were from local mosquitoes. Three mosquito samples tested positive from a small area in Miami Beach, officials said.  

The CDC released maps that show where this type of mosquito could be in the United States. The maps include nearly all Southern states, some parts of the Southwest and some Midwestern and Northeastern states. The CDC specifies, though, that just because the mosquitoes are present, that does not mean they are infected with the virus. The maps also do not show how many mosquitoes are present.

How many people in the United States have the virus?

The cases in the United States are primarily among travelers returning with the virus. The cases that are believed to be locally transmitted in Florida are the only local cases so far. There have been at least 2,686 travel-related cases of Zika, according to the CDC. There have been at least 463 travel-related cases reported in New York City, according to the city’s health department.

What should I do if I’m traveling to an affected area?

There is no vaccine to prevent the virus. If you are traveling to an area with infected mosquitoes, you should try to prevent being bitten by mosquitoes. The CDC advises travelers to wear long-sleeved shirts and long pants, use insect repellents, use mosquito bed nets, stay inside as much as possible and use permethrin, a synthetic chemical, on your clothes and gear. If you are pregnant or expecting to get pregnant, the CDC recommends postponing travel to any of the areas with infected mosquitoes to prevent the risk of the virus causing microcephaly.

What should I do if I’m pregnant and just returned from an area where outbreaks have occurred?

The CDC says all pregnant women who have traveled to Latin America recently should see their doctor and get tested for the Zika virus.