What to Know Many people infected with Zika virus won’t have symptoms or will only have mild symptoms.

A blood or urine test can confirm Zika infection diagnosis.

There is no specific medicine for Zika.

San Diego County officials will be spraying a two-block area of South Park after discovering the larvae from a mosquito known to be a carrier of the Zika virus, NBC 7 has learned.

County vector officials went door to door Thursday notifying residents that the spraying will take place Friday morning. The area in question is between 31st and 32nd streets and Grape and Elm streets.

The county sprayed the South Park neighborhood less than 24 hours after notifying residents, leaving some of them upset. Now they know why the county acted so quickly. NBC 7’s Artie Ojeda has more.

The action comes as county officials are investigating a possible case of mosquito-borne illness, possibly Zika, in South Park.

NBC 7 has learned that a person who lives in South Park recently traveled abroad and did not contract the mosquito borne illness in San Diego. A county spokesperson says the case in South Park could turn out to be any number of mosquito borne illnesses, but suspect Zika or Dengue virus, because of the discovery of the Aedes larvae.

County officials want to make it clear, the Aedes larvae did not test positive for any disease, nor were any adult mosquitoes trapped nearby.

A county spokesperson says vector officials look for Aedes larvae and adult mosquitoes each time a suspected case is identified. This is the first time the county has found Aedes larvae close to a suspected case.

On Thursday morning, county vector officials began placing door hangers on about 100 homes, advising residents of plans to begin spraying some time during the day on Friday.

The spraying will be done by hand, by several teams, rather than any night time air-spraying as we’ve seen in the past.

Zika Virus in California

As of Wednesday, there have been 137 cases of the Zika virus reported in the state of California. The only U.S. states reporting more cases are Florida and New York.

The California cases are not local mosquito-borne transmissions, according to the California Department of Health. They have only involved people who contracted the virus while traveling outside the U.S. or through sexual contact with someone who had.

Aedes aegypti (or yellow fever mosquitoes) and Aedes albopictus (or Asian tiger mosquitoes) are known to transmit the virus. These are not native to California.

As of the beginning of August, mosquitoes that can carry the virus have been found in 12 California counties.

"Still, there is no evidence these mosquitoes are transmitting Zika in the state at this time," according to the California Department of Public Health website.

The CDC has developed a map of countries with active virus transmissions of Zika virus.

CDC

What You Need to Know

The state of California reported on August 4 that two babies with Zika-related microcephaly have been born in California. In both cases, the women spent time during their pregnancies in countries where the virus is endemic, officials said.

Fever, rash, joint pain and conjunctivitis are the most common symptoms of Zika. Other symptoms may include muscle pain and headache, according to the Centers for Disease Control and Prevention.

It is common for a patient to not realize they are infected since the virus is usually mild with symptoms lasting for several days to a week. The CDC also said the virus rarely results in death.

The Zika virus usually remains in the blood of an infected person for about a week. The Food and Drug Administration approved the first commercial U.S. test to diagnose the Zika virus in April.

Steps You Can Take

Anyone living or traveling an area known to have the Zika virus should take steps to prevent mosquito bites. Suggestions include wearing long-sleeved shirts and long pants and using insect repellents that are registered with the EPA. Stay and sleep in screened-in or air-conditioned rooms. And of course, take steps to control mosquitoes in and around your home.