First case of female-to-male Zika virus transmission reported in New York

US health authorities have announced the first known case of Zika virus spreading from a woman to a man during unprotected sex.  

The US Centre for Disease Control and Prevention said a 20-year-old woman had recently returned to New York from a country where Zika was circulating.

Shortly after, the woman began showing the tell-tale signs of the virus, including rash, fatigue, and a tingling sensation in fingers and toes.

Seven days later, her male partner suffered the same symptoms.

The pair tested positive for the disease after a blood and urine test was conducted in a New York City health department.

"The timing and sequence of events support female-to-male Zika virus transmission through condomless vaginal intercourse," the centre’s report concluded.

The health body did not specify where the woman may have been infected.

The case findings have prompted the centre to draft changes to its guidelines for sexually active people who have returned from countries where Zika is present.

Zika can cause birth defects, including the brain and skull deformity known as microcephaly.

No vaccine is currently available for the Zika virus.

Earlier today, Wimbledon finalist Milos Raonic and Romanian player Simona Halep announced their withdrawal from the tennis competition at the Rio Olympics.

"After much deliberation with my family and coaches, I am making this decision for a variety of health concerns including the uncertainty around the Zika virus,” Raonic said.  

Wimbledon winner Andy Murray was the first tennis player to withdraw from the impending Olympic Games, set to open on August 5.