A leading Brazilian health research institute says it has discovered the presence of active Zika virus in urine and saliva samples.

Paulo Gadelha, president of the Fiocruz institute, said scientists are trying to determine if the body fluids can spread Zika to new patients, and the discovery calls for special precautions for pregnant women.

Mr Gadelha, speaking at a press conference in Rio de Janeiro, suggested pregnant women avoid kissing people other than a regular partner or sharing cutlery, glasses or plates with people who have symptoms of the virus.

Brazilian researchers have pointed to a suspected link between pregnant women's infection with the virus and a rare birth defect in babies.

But Mr Gadelha added: "This is not a generalised public health measure, for the love of God."