SYDNEY (AP) — A pregnant woman in Australia has tested positive for the Zika virus after traveling overseas — the second such case this week, health officials said Friday.

The woman, from Victoria state, was diagnosed with Zika after returning from a country where the mosquito-borne virus is prevalent, Victoria Health Minister Jill Hennessy said. She declined to release any other details about the case, including where the woman had traveled, citing patient privacy.

Earlier this week, a pregnant woman in Queensland state was also diagnosed with Zika after traveling abroad.

Experts say the risk of Zika spreading across Australia is extremely low. The type of mosquito that carries the virus only lives in the far northeast corner of the country, which is sparsely populated.

"My primary concern today is not about a public health risk, but a woman who is dealing with the anxiety of receiving news that is incredibly concerning," Hennessy told reporters.

The Zika virus has spread quickly through Latin America. Most people who contract it have either mild or no symptoms, but it is suspected of causing a birth defect that results in babies born with abnormally small heads.