RIO DE JANEIRO (AFP) - Mosquito-borne viruses including Zika, which is feared to cause brain damage in babies, have driven a surge in sales of insect repellent in Brazil, manufacturers say.

The Brazilian insect repellent sector saw sales rise to a record US$54 million (S$76 million) in 2015 up from US$36 million a year earlier, newspaper O Globo said on Sunday (Feb 7), citing a study by the Nielsen consumer research firm.

One manufacturer, Osler, told AFP sales increased 800 percent in the December 2015 to January 2016 period, year-on-year.

Pharmacies meanwhile said they were starting to sell out of some repellents.

Brazil is the country worst affected by the outbreak of Zika, with 1.5 million cases reported last year.

Scientists have linked it to babies born with microcephaly, a condition which causes them to have abnormally small heads.

It has also been linked to Guillain-Barre syndrome, a neurological disease that can cause paralysis in humans.

There is currently no cure or vaccine for Zika, which usually causes little more than a fever and rash in adults.

Instead authorities are focusing on preventive measures, cleaning up potential mosquito breeding grounds and recommending that people use repellent.

Brazil has also suffered from a rise in cases of dengue, another mosquito-borne disease.

Dengue killed 863 people in Brazil in 2015, an increase of more than 82 per cent on the previous year, the government said.