TEMPO.CO, Jakarta - The World Health Organization (WHO) has rejected a call to move or postpone this summer's Rio Olympic Games over the Zika outbreak.

It said this would "not significantly alter" the spread of the virus, which is linked to serious birth defects.

In an open letter to the WHO, more than 100 leading scientists had said new findings about Zika made it "unethical" for the Games to go ahead.

They also said the global health body should revisit its Zika guidance.

The International Olympic Committee (IOC) has said it sees no reason to delay or move the Games because of the mosquito-borne disease.

The outbreak began in Brazil a year ago, but now more than 60 countries and territories have continuing transmission.

Between February and April 2016, Brazil's health ministry registered 91,387 likely cases of the Zika virus. The number of babies born with Zika-linked defects stood at 4,908 in April.

While Zika's symptoms are mild, in the letter the experts say it causes babies to be born with abnormally small heads and may also cause a rare and sometimes fatal neurological syndrome in adults.

The letter is signed by 150 international scientists, doctors and medical ethicists from such institutions as Oxford University and Harvard and Yale universities in the United States.

They cite the failure of a mosquito-eradication program in Brazil, and the country's "weakened" health system as reasons to postpone or move the Olympics in "the name of public health".

BBC | GHOIDA RAHMAH