Jaques Wagner, Brazilian President Dilma Rousseff's chief of staff, says it must be explained to athletes and spectators coming to Brazil for the Rio 2016 Olympic Games that there is "zero risk" from the Zika virus if they are not a pregnant woman.

Wagner was quoted by Reuters after the World Health Organization (WHO) declared that the virus constitutes a public health emergency.

Cases of the virus, which is spread by mosquitoes, have been rising in the country and the rest of the Americas ahead of Rio 2016.

Pregnant women have been advised not to travel to impacted areas due to a link between the virus and microcephaly - a condition which can lead to babies being born with small heads and under-developed brains.

Other symptoms include fevers, rashes, joint pain and conjunctivitis.

"We have to explain to those coming to Brazil, the athletes, that there is zero risk if you are not a pregnant woman," said Wagner.

Despite the WHO's declaration, International Olympic Committee (IOC) President Thomas Bach remains confident athletes will feel safe travelling to Brazil for the Games.

"We welcome this decision by the World Health Organization because it helps raise even more awareness and to provide even more resources to fight the virus," Bach told reporters at the University of California after meeting with members of Los Angeles' Bid Committee for the 2024 Olympics and Paralympics.

"We are in close contact with the WHO and we see also that so far there is no travel ban being pronounced by the WHO.

"We also see that the Olympic Games will be taking place in the winter time which is not the preferred breeding time for the mosquitoes."

Last week, Brazil’s Health Minister Marcelo Castro announced that 200,000 soldiers would be deployed to go house-to-house as part of a mosquito control campaign, and that insect repellent will be handed out to at least 400,000 pregnant women.

The Health Ministry says about 25 per cent of the country's 49 million homes have so far been inspected.

Rousseff said at a recent regional summit in Ecuador that Brazil would place "extreme emphasis" on wiping out mosquito breeding grounds, especially stagnant waters, and has authorised health and sanitary inspectors to use force if necessary to gain access to private buildings.

WHO director general Margaret Chan added that increased numbers of microcephaly cases represented an "extraordinary" event that required a co-ordinated response.

"I am now declaring that the recent cluster of microcephaly and other neurological abnormalities reported in Latin America following a similar cluster in French Polynesia in 2014 constitutes a public health emergency of international concern," she said.

The Zika virus is considered to be in the same category as Ebola, which killed over 10,000 people in Africa between 2013 and this year, meaning research and aid will be fast-tracked to tackle the infection.

Almost 4,000 cases of microcephaly have been reported in Brazil since October in comparison with fewer than 150 in 2014.

The United States National Institutes of Health (NIH) claims to have two potential Zika vaccines in development, one of which is based on an experimental West Nile vaccine that could be repurposed for Zika and, according to NIH, enter clinical trials by the end of this year.

The only way to avoid contracting it is to avoid being bitten by the Aedes mosquitoes that transmit the infection.

World number one women’s golfer Lydia Ko of New Zealand is said to be closely monitoring news surrounding the Zika virus.

Women's golf will debut at the Olympics this year, while the men's event returns for the first time since 1904.

"First of all we are more thinking about the people there, the people who are affected by it rather than what is going to happen [with the Olympics]," Ko said.

"Obviously I'm just hoping that everybody there is safe.

"There are some things that we can't control and that it is out of hands.

"We still have eight months until the Olympics, it's something we have got to keep looking at and monitor but for now, I guess that is all we can do."

The IOC has stated its belief that authorities in Brazil are taking "significant steps" to combat the Zika virus in the run-up to this summer's Games, which are 185 days away.

Meanwhile, the Trinidad and Tobago Olympic Committee (TTOC) has sent secretary general Annette Knott and Chef de Mission Ian Hypolite to Brazil, where they’re meeting with officials of the Rio 2016 Organising Committee regarding the Zika virus among other things.

TTOC President Brian Lewis told Trinidad and Tobago's Newsday he could not comment on possible effects the threat of the virus could have on the running of the Games until reports from Knott and Hypolite have been reviewed on their expected return later this week.

"At this point in time, it would be a bit premature for me to speculate on that; I await the return of secretary general Knott and Chef de Mission Hypolite and their reports, and then certainly we would be issuing the appropriate statements," he said.

"Most certainly, athlete welfare remains a priority to the TTOC.

"Based on the information we would also discuss it with our chief medical officer, which is Dr Terry Ali."