Zika Virus

Doctors at the Spallanzani Institute for Infectious Diseases in Rome said it pointed to the possibility that the virus was reproducing itself in the male genital tract.

The infection is suspected of leading to thousands of babies being born with underdeveloped brains.

Zika is spread by mosquitos.

The outbreak was declared a global public health emergency by the World Health Organisation in February.

Brazilian researchers from Recife, the city at the centre of the Zika epidemic, describe seven suspect cases in the journal The BMJ.

The virus, which has been spreading across much of the Americas and has deterred some people from visiting the Olympic host country, is already known to cause a serious baby brain defect.

Mothers-to-be are urged to be vigilant.

Scientists found all three offered protection in tests on rhesus monkeys.

Zika has been deemed a public health emergency, because it can cause serious birth defects.

Teams around the world are working to design a vaccine that can be given to people, but it is likely to be years before any is ready for widespread use.

More than 60 countries and territories now have continuing transmission of Zika, which is carried by mosquitoes.

So far, cases outside of Latin America and the Caribbean, where the virus is prevalent, have been spread by travel to that region or sexual transmission.

The four Florida cases mean US mosquitoes may be carrying the virus.

Zika causes only a mild illness in most people but the virus has been linked to severe brain defects in newborns.

The Florida department of health said "a high likelihood exists that four cases are the result of local transmission", centred on one small area just north of downtown Miami.

 Researchers collected 500 mosquitoes and found the virus in three pools of mosquitoes. Each pool contains between one and ten mosquitoes. The presence of the virus in these mosquitoes does not mean they can transmit the virus.

Bailey-Cole, the Commonwealth 100 metres champion, told the Gleaner newspaper he discovered he had contracted the disease by chance.

"I didn't know I had it (Zika) until I went to get a haircut. After cleaning up, my girlfriend realised a bump was on my neck, which was a lymph node," Bailey-Cole said.

"I was experiencing back pains and muscle soreness, but I thought it was just soreness from the exercises I was doing. It is very disappointing."

Rutherford's partner Susie Verrill told Standard Issue magazine that they harbour serious concerns over the virus, which experts say is to blame for a surge of cases in Latin America of microcephaly - a serious birth defect in which babies are born with unusually small heads and brains.

The pair, who want to have more children, are as a result taking precautions ahead of Rutherford's defence of his long jump gold medal.

Several experts have called for the Games to be postponed or moved over fears it could speed up the spread of the virus around the world.

The WHO has rejected these calls, however, claiming it would "not significantly alter" the outbreak.

They have now called an emergency meeting for later this month to re-evaluate the situation.

"The emergency Committee meeting will consider the situation in Brazil, including the question of the Olympics," said Nyka Alexander, a spokeswoman for the WHO.

Leading American cyclist Tejay van Garderen today withdrew his name from consideration for the Olympics due to concerns he may contract the disease and pass it to his pregnant wife.

Van Garderen, a member of the 2012 Olympic team, who finished fifth at the 2014 Tour de France, was set to form part of the US team for the road race.

Dr David Hughes' claim comes less than two weeks after scientists in Brazil warned that the mosquito-borne virus could be even more dangerous than first thought.

Experts believe it could be behind several damaging neurological conditions - in addition to microcephaly - where babies are born with abnormally small heads because of restricted brain development - and Guillain-Barré syndrome, a neurological disorder which causes muscle weakness.

But Hughes is of the opinion that the risk to AOT team members will be minimal if individuals take the necessary precautions.