"There are many things we don't know about Zika", he said.

Scott signed the order to cover Miami-Dade, Lee, Hillsborough and Santa Rosa counties.

Earlier this week, the World Health Organization (WHO) declared the Zika virus outbreak a public health emergency. "The Pan American Health Organisation (PAHO) estimates there will be 4 million additional cases of infection from the Zika virus in the Americas region by the end of 2016".

The mosquito-borne virus, which is rapidly spreading in the Americas, has been linked to a spike in birth defects in thousands of babies in Brazil. Zika had been thought to be spread by the bite of mosquitoes of the Aedes genus, so sexual contact as a mode of transmission would be a potentially alarming development.

A case of Zika virus infection transmitted through sexual intercourse has been discovered in Texas.

Doctors fear the mosquito-born illness is causing the birth defect that results in abnormally small heads and brains in infants. However, the virus is a threat to pregnant women.

Montana Department of Health and Human Services officials say the virus was discovered in the late 1940's but it wasn't until 2014 that these new symptoms showed up in South America.

It also directs the Florida Department of Health to determine further resources and information needed in the state from the CDC to combat the spread of the Zika virus.

The Zika virus has been found in 28 countries, with a majority of the cases being reported in Brazil. Unemployed and five months pregnant, 21-year-old Lourenco lives in a slum at the epicenter of Brazil’s tandem Zika and microcephaly outbreaks, the state of Pernambuco. However, a case in Texas had been linked to sexual transmission.

"Education and awareness is crucial in preventing Zika virus", said Dr. Christopher Perkins, DCHHS medical director/health authority. Illness is often mild and typically resolves within a week. Travelers with fever, rash, joint pain and pink eye will want to protect against bites for one to two weeks after returning.