Zika virus is a mosquito-borne virus that prior to 2015 occurred in Africa, Southeast Asia, and the Pacific Islands. However, in May 2015, the Pan American Health Organization (PAHO) issued an alert about the first confirmed Zika virus infections in Brazil. Since then Zika virus has been identified in several countries throughout South America, Central America, and the Caribbean, as well as states in Mexico. In the U.S., limited local transmission has been reported in Florida, and Texas. The U.S. territory of Puerto Rico has been significantly impacted. No locally-acquired cases of mosquito-transmitted Zika virus infection have been reported in San Diego County. All Zika cases reported locally have been travelers returning to San Diego from Zika-affected areas; this includes several sexually-transmitted cases and pregnancies reported to the U.S. Zika Pregnancy Registry.
For updated information on Zika activity in San Diego and
California, please see:
LOCAL ZIKA ACTIVITY AND STATISTICS
HOW IS IT SPREAD?
Zika virus is spread by the bite of an infected Aedes species mosquito, which actively bite humans during the daytime. These are the same mosquitoes that spread dengue, chikungunya, and yellow fever viruses. Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites. Zika virus is rarely spread from person to person; there have been rare instances of sexual and perinatal (mother-to-child) transmission as well as through blood transfusion.
The Zika virus can be transmitted from a pregnant woman to her unborn child. If Zika infection occurs during pregnancy, it could lead to microcephaly, a birth defect where a baby’s head and brain are smaller than expected, as well as other severe birth defects. More information about Zika and pregnant women.
WHAT ARE THE SYMPTOMS?
Symptoms begin between 2 and 12 days (most commonly 3-7 days) after exposure to the virus. Although most people who become infected with Zika virus have no symptoms, approximately 20% may develop acute onset of fever with rash, joint pain, or conjunctivitis (red eyes). Other commonly reported symptoms include muscle aches and headache that may last for several days to a week. Severe disease requiring hospitalization is uncommon and deaths from the disease are rare. However, there have been cases of Guillain-Barré syndrome reported in patients following suspected Zika virus infection. Some babies with microcephaly (abnormal brain and small heads) have been reported among mothers who were infected with Zika virus while pregnant. In April 2016, CDC scientists announced that enough evidence has accumulated to conclude that Zika virus infection during pregnancy is a cause of microcephaly and other severe fetal brain defects, as well as pregnancy loss, eye defects, hearing loss, and impaired growth in infants.
WHAT CAN YOU DO?
The public should continue to remember the “Prevent, Protect, Report” slogan that has guided the County’s fight against West Nile virus.
Prevent mosquito breeding sites. Every week, dump out and clean containers that hold water inside and outside homes. Fill plant saucers with sand or fine gravel so water won’t form pools where mosquitoes can breed.
Protect yourself from mosquito bites. Wear long sleeves and pants when outdoors. Use insect repellent, preferably one containing DEET. Make sure the screens on your windows and doors are in good condition, do not have holes or tears, and are secured to keep insects out.
you are being bitten by mosquitoes during daylight hours, or if you
find mosquitoes that match the description of the yellow-fever
mosquito or Asian tiger mosquito.
WHAT IS THE COUNTY DOING?
San Diego County is on the front line to stop the spread of the Zika virus. County public health and vector control officials continue to work with medical providers and residents, respectively, to investigate potential Zika cases and take necessary precautions to minimize the chance of local transmission. To date, 10 hand-held sprayings have been conducted across the county.
- County Public Health Lab Busy Watching for Zika
- VIDEO: County on Front Lines to Stop Zika Spread
- VIDEO: Mosquitoes, Mosquitoes; Protect Your Family (English)
VIDEO: Mosquitoes, Mosquitoes; Protect Your Family
Mexican health officials have reported that mosquitoes carrying Zika virus have been found in different regions of Mexico. These mosquitos can infect people with Zika who travel south of the border. Mosquitos that spread Zika have been reported as close as Ensenada, Baja California, about 80 miles south of San Diego.
Because Zika virus is primarily spread by mosquitoes, the CDC recommends that all travelers to Mexico protect themselves from mosquito bites, especially those who commute cross the border on a regular basis. It is important for travelers to protect themselves from mosquito bites after returning to the U.S. because, if a mosquito bites an infected person who is still contagious, it can spread the virus to another person.
LATEST UPDATE ON THE ZIKA VIRUS
For the latest, updated information on the Zika Virus, please see
Frequently Asked Questions – Zika Virus and Mosquitoes
San Diego County – May 2017
The websites and resources below provide additional information to community members and medical providers regarding Zika virus.
Information for the Public
County of San Diego
Pregnant Women: Protect Yourself from Mosquitoes
- VIDEO: Pregnant Women: Protect Yourself from Mosquitoes (Spanish)
- Eight Tips to Prevent Zika When Traveling
- Protecting Yourself, Your Family and Community From Mosquitoes
- San Diego County Vector Control Program
- Information about Aedes mosquitoes in San Diego County
- CDC - General Information About Zika Virus
- CDC - Up-to-Date List of Locations of Zika-Affected Countries
- CDC - Traveler’s Health Website
- Information For Parents
- Information For Pregnant Women
- Zap Zika: Use A Condom (CDC video)
CDC INFORMATION ABOUT OTHER DISEASES CARRIED BY AEDES MOSQUITOES
For more information, contact the Epidemiology Program 619-692-8499 or send us an e-mail.