As the Olympics open this week in Rio de Janeiro, Latin America is still reeling from Zika, the mosquito-borne virus blamed for causing brain damage in babies.

Here is a traveler's round-up on the disease, which can also be transmitted sexually.

- WHO calls for 'vigilance' -

The arrival of winter has reduced the threat in Brazil, the country hit hardest by Zika. But the epidemic isn't over.

Tens of thousands of babies may be born with microcephaly -- abnormally small heads -- or related conditions in the course of the outbreak, researchers warn.

"Although a decline in cases of Zika infection has been reported in some countries, or in some parts of countries, vigilance needs to remain high," the World Health Organization said last week.

"At this stage, based on the evidence available, there is no overall decline in the outbreak."

The virus has been detected in 64 countries and territories, mostly in Latin America and the Caribbean.

There is no vaccine or cure for Zika, which causes flu-like symptoms and a rash.

Besides microcephaly in babies, the virus is also blamed for causing a neurological disorder called Guillain-Barre syndrome. Both conditions are potentially fatal.

- Brazil hardest hit -

Brazil has registered nearly 1.5 million confirmed Zika cases and more than 1,700 babies born with microcephaly linked to the virus -- 50 of whom died.

Cases have declined 87 percent since February, to 2,000 in early May.

But Zika fears have kept a number of athletes home from the Olympics, including big-name golf stars and some tennis players.

Downplaying the risk, Brazilian authorities predicted "less than one infection" among the half-million tourists expected for the Games.

- Colombia turns corner -

Colombia, the second-most affected country, declared its Zika epidemic over last week.

In 10 months, the disease infected at least 100,000 people and was linked to at least 21 cases of microcephaly, according to Colombian authorities.

They warned infections would continue on a smaller scale -- 600 to 700 a week.

- Tropics on alert -

Zika is spreading rapidly in Central America and the Caribbean.

Honduras announced its sixth death linked to Guillain-Barre and 10 cases of microcephaly Tuesday.

El Salvador has reported two babies born with microcephaly linked to Zika, and Guatemala 16 suspected cases.

Puerto Rico has also been hit hard: 5,582 Zika cases confirmed, including 672 pregnant women, according to US health officials.

Source: AFP