First case of Zika virus in SLO County reported

A northern San Luis Obispo County resident contracted the Zika virus while traveling to Mexico in late September, the county Public Health Department said Thursday.

It is the county’s first confirmed case of a Zika infection, public health officials said.

The individual developed symptoms within five days of returning home. No additional information about the person was released to protect patient privacy, health officials said.

In California, Zika virus infections have been documented only in people who were infected while traveling outside the United States or through sexual contact with an infected traveler.

County epidemiologist Ann McDowell said health officials presume this person contracted the infection from a mosquito bite.

“They went to an area where there is active mosquito transmission of the disease,” she said, adding, “At this time, we don’t see serious illness in this individual.”

Local residents should not be concerned, McDowell added, but the information is provided to the public so that people can be aware of what precautions they could take, as well as the risks associated with traveling to areas with the Zika virus.

Zika infection during pregnancy can cause a birth defect of the brain called microcephaly — a condition where a baby’s head is much smaller than average — and other severe fetal brain defects.

Many people infected with Zika virus won’t have symptoms or will only have mild symptoms, according to the Centers for Disease Control and Prevention. The most common symptoms of Zika are fever, rash, joint pain and conjunctivitis (red eyes). Other symptoms could include muscle pain and headache.

There have been 328 travel-associated Zika virus infections in the state as of Oct. 7, according to the California Department of Public Health.

San Luis Obispo County’s first Zika case brings the total number of California counties with at least one case to 31.

To date, there has been no mosquito-borne transmission of the Zika virus in California, local health officials said.

Zika virus is transmitted to humans primarily through the bite of an infected Aedes species mosquito. Aedes mosquitoes capable of transmitting Zika have not been detected in San Luis Obispo, Santa Barbara or Monterey counties, although they are present in 12 other California counties, including nearby Kern County.

San Luis Obispo County contracts with the North Salinas Vector Control District to conduct mosquito surveillance in the northern area of the county, and no evidence of an Aedes species has been detected to date.

This story was originally published October 13, 2016 at 1:33 PM with the headline "First case of Zika virus in SLO County reported."