Concerns Zika virus could spread

The WHO says the new revelation that the Zika virus can be sexually transmitted must be closely monitored.

A worker of the Salvadorean Ministry of Health fumigates a house in Soyapango as part of a campaign of fumigation to reduce the presence of the mosquito that transmits the Zika virus. Picture: EPA/Oscar Rivera.

JOHANNESBURG - There are concerns that the Zika virus will now spread after the US recorded its first case of infection through sexual contact.

The World Health Organisation (WHO) says the majority of infections are still through mosquito bites.

The WHO has told Eyewitness News that the new revelation that the Zika virus can be sexually transmitted must be closely monitored.

The organisation's Sarah Barber say people who have been infected must be extra careful.

"Take care in terms of wearing protection when having sexual intercourse."

Barber says sexually transmitted cases are not very common at this stage but urgent research will have to be conducted.

In Brazil, more than 4,000 babies are suspected to have microcephaly, a birth defect where a baby's head is smaller than usual possibly because their mothers contracted the Zika virus.

Brazilian health officials have also confirmed that the Zika virus was transmitted through two blood transfusions last year.

Experts say it's a race against time to urgently come up with comprehensive answers regarding the virus and whether it is definitely linked to birth defects.

The WHO says South Africans can be assured that there won't be a widespread outbreak of the Zika virus.

Barber says there is evidence that the virus can be sexually transmitted but only research will determine how long the virus is contagious.

"There is evidence Zika was evident in human semen."

She says more evidence says the research on microcephaly could take some time.

"Find the case first, confirm the case and the exposure and then determine the cause."

South Africans have been warned not to travel to the areas where the Zika virus has been detected.