Pregnant women are being warned to avoid a part of Miami where there have been fourteen cases of the zika virus.

U.S. health experts are also telling couples who have been there recently to put off having children for at least two months, after the number of people feared infected through mosquito bites in the U.S. climbed to 14.

In its highly unusual warning, the Centers for Disease Control and Prevention also says expectant mothers should get tested for the virus if they have visited the neighbourhood since mid-June.

All 14 cases are thought to have occurred in Miami’s Wynwood arts district, a trendy, fast-gentrifying neighbourhood of warehouses, art galleries, restaurants and boutiques.

CDC Director Doctor Tom Frieden told ABC’s Good Morning America today, the concern extends beyond Miami.

“All over the U.S., wherever the Aedes aegypti mosquito is present, which is 30 states generally in the south of the U.S., women who are pregnant really need to do everything they can to protect themselves from mosquito bites,” Frieden explained.

But Frieden tempered his statement by noting that the Aedes aegypti species of mosquito most capable of transmitting the virus typically does not travel more than 150 metres in its lifetime.

The Zika virus has been sweeping Latin America and the Caribbean in recent months. It can cause severe brain-related birth defects, including extremely small skulls.

The global outbreak has led to more than 18-hundred serious defects.