Solano County health and social service officials announced Friday that a resident has the county's first case of the Zika virus.
But health officials said county residents are not at any risk of contracting the virus. The officials said transmission of the virus occurs mainly through two mosquitoes, which are not native to the Bay Area and are not established in the county.
County Health Officer Dr. Bela Matyas said residents cannot contract the virus through casual contact as they might catch the flu or measles.
He said for a while the virus is in an infected person's blood, so it could be passed from one person to another through a blood transfusion or organ donation.
It's also possible mosquitoes that transmit the virus could make their home in the county, which would then put residents at risk.
The Solano County Mosquito Abatement District could not immediately be reached for comment.
Solano County's Deputy Health Officer Dr. Michael Stacey said the most effective way to prevent the spread of the virus is to avoid traveling to places where the virus is being spread, which is mainly in Central and South America.
The resident who has the virus recently traveled to Central America, according to county officials.
The virus has been linked to a disease called microcephaly, which causes babies to be born with smaller heads. It's also been linked to pregnancy loss, poorly developed brains in fetuses and newborns and impaired growth in fetuses and infants.
The virus can be transmitted sexually, so health officials are encouraging men to use condoms correctly and consistently or abstain from sex.
Matyas said so far the transmission has occurred from men to women. He said it might be possible for women to transmit the virus to men during sex, but so far no such cases have occurred.