WASHINGTON — The Virginia Department of Health reports that as of May 26, there are 18 known cases of the Zika virus in the state.

Half of those infected live in the northern region of the state.

The Centers for Disease Control and Prevention said it knows of four people carrying the virus in D.C. and 17 in Maryland.

While most people may not know they carry the virus, if bitten by a mosquito, that mosquito becomes dangerous to pregnant mothers whose children could be harmed if the virus is transmitted.

Threats to unborn children include microcephaly and other neurological disorders.

The CDC suggests expectant mothers cover their skin and use insect repellent for protection.

Symptoms of the Zika virus include rash, fever, achy joints and headaches and can last up to a week.