Zika virus
Zika virusReuters

US health officials announced Tuesday that they are investigating 14 new cases of Zika virus possibly transmitted through sexual intercourse. Centre for Disease Control and Prevention(CDC), which had earlier published recommendations for protecting people against sexual transmission of Zika, confirmed that the virus was found in the blood samples of two women.

These women, in recent times, have not travelled to places affected by the Zika virus, but have contracted it from their male partners who returned from such places and had Zika like symptoms.

"Of the 14 new cases, several cases involve pregnant women," CDC said in an official statement.

As of Feb.17, the U.S. reported 79 cases of laboratory confirmed Zika virus. The CDC issued an advisory to the state and local officials, public health practitioners, laboratories, and clinicians about the need to follow interim guidance on avoiding sexual transmission of the virus.

"Although Zika virus primarily spreads through the mosquito bites, the new cases being reported suggest sexual transmission may be a more likely means of transmission than previously thought," the CDC said.

Following the confirmation of the virus in a Texas resident, who was infected through sexual relations, the CDC issued an advisory cautioning people against the spread of Zika through sex.

In early February, the Dallas County Department of Health and Human Services announced an occurrence of sexually transmitted Zika infection.

"We expect more cases of sexual transmission in next few months, as doctors become aware of the sexual transmission risk," Jennifer McQuiston, deputy incident manager for the CDC's Zika response, told National Public Radio.

The presence of Zika virus in pregnant women has raised concerns because of its possible links with microcephally, a congenital disorder that affects babies.

The CDC in its health advisory has urged men, who live in or have visited an area of active Zika transmission, and their pregnant partners to use a condom or practice abstinence for the duration of the pregnancy. It noted that the virus may persist in semen when it is no longer detectable in blood. 

The CDC  has also added the Marshall Islands in the Pacific Ocean and the Caribbean nation of Trinidad and Tobago to its list of countries and territories that pregnant women should avoid visiting. The region affected by Zika covers most of Latin American and the Caribbean countries.