The Rio de Janeiro authorities have announced plans to prevent the spread of the Zika virus during the Olympic Games later this year.

An outbreak of the mosquito-borne disease - which is being linked to severe birth defects - has caused growing concern in Brazil and abroad.

Inspections of Olympic facilities will begin four months before the Games to get rid of mosquito breeding grounds.

Daily sweeps will also take place during the Games.

But fumigation would only be an option on a case-by-case basis because of concerns for the health of the athletes and visitors.

Rio de Janeiro's first Carnival street parades this year call for prevention against the Zika virus under the theme "Rio: The Olympics are here". Photo: AFP

The Brazilian health ministry says it is also banking on the fact that the Games are taking place in the cooler, drier month of August when mosquitoes are far less evident and there are considerably less cases of mosquito-borne virus.

What is Zika virus?

--It is spread by the Aedes aegypti mosquito, which also carries dengue fever and yellow fever

--It was first discovered in Africa in the 1940s but is now spreading in Latin America

--Scientists say there is growing evidence of a link to microcephaly, that leads to babies being born with small heads

--While Zika virus can lead to fever and a rash, most people show no symptoms, and there is no known cure

--The only way to fight Zika is to clear stagnant water where mosquitoes breed, and to protect against mosquito bites

The announcement by the Rio authorities comes amidst growing attention around the world over the large number of cases of Zika in the Americas.

Brazil has the largest-known outbreak of the virus which has been linked to a spike in birth defects in new-born babies whose mothers were bitten by the mosquito during pregnancy.

The US, Canada and EU health agencies have issued warnings saying pregnant women should avoid travelling to Brazil and other countries in the Americas which have registered cases of Zika.