Health officials have warned pregnant women to think twice about the lips they kiss and called on men to use condoms with pregnant partners if they have visited countries where Zika is present.
An Australian child has become the second person in Queensland to be infected with Zika, after a family trip to Samoa.
UN officials also called on many Catholic-majority countries in Latin America to allow women to terminate pregnancies if they fear the fetus may be at risk for a rare birth defect that causes brain damage and an abnormally small head.
In Brazil, Paulo Gadelha, president of the Fiocruz research institute, said scientists have found live virus in saliva and urine samples and the possibility it could be spread by the fluids requires further study.
He suggested pregnant women avoid kissing people other than a regular partner or sharing cutlery, glasses and plates with people who have symptoms of the virus.
The announcement coincided with the start of Carnival, a five-day bacchanalia in which millions of people take part in alcohol-fuelled parties where kissing as many people as possible is a top pastime. Gadelha underscored that the discovery needn't alter Carnival plans for anyone but pregnant women.
He also stressed that the Aedes aegpyti mosquito, which spreads dengue, chikungunya and yellow fever as well as Zika, remains the virus' main vector and said the fight against the mosquito should be a top priority.
Myrna Bonaldo, who headed the Fiocruz team behind the discovery of the virus in body fluids, said she was particularly surprised the virus was found in urine because Zika is generally thought not to thrive in acidic mediums.
"Each discovery is a surprise and a new find for us," she said. "For us scientists, it's extremely challenging to understand Zika virus."
Meanwhile, in Geneva, spokeswoman Cecile Pouilly said the UN High Commissioner for Human Rights was asking governments in Zika-affected countries in Latin America and the Caribbean to repeal any policies that restrict access to sexual and reproductive health services, including abortion.
The National Conference of Bishops in Brazil, however, said that the World Health Organisation's declaration this week that Zika was an international emergency didn't justify abortion.
Meanwhile, after the discovery of a sexually transmitted case of Zika, US health officials said men who have visited an area with Zika should use condoms if they have sex with a pregnant woman.
- AP, AAP