A document released this Friday (16 October) by the World Health Organisation (WHO) ruled out testing for viruses in the waters of Guanabara Bay. Recommendations made to the Rio 2016 Organising Committee and the International Olympic Committee (IOC) are to step up the frequency of testing for bacteria.

“Tests for viruses will not be conducted because the WHO does not see the need,” said Mario Andrada, Rio 2016’s executive director of communication.

The WHO confirmed that it does not recommend virus testing as routine monitoring because there are no standardised methods for it, making the interpretation of results difficult.

Viral tests, according to the document, are conducted only in “specific exceptional circumstances”, such as an outbreak of a disease that may have a viral cause, or as part of a research protocol. “Outside these circumstances viral testing is not recommended in the current international guidelines.”

Guanabara Bay will host the Olympic and Paralympic sailing events (Photo: Matthew Rockman/Getty Images)

“The guidelines of the WHO are for tests to focus on two types of bacteria – enterococci and E.coli”, said Andrada, explaining that tests were carried out weekly, or every three days, and eventually on a daily basis.

The recommendation for the frequency to be stepped up will be followed, confirmed Andrada, although the WHO has not established an ideal number relating to tests to be carried out.

The document was published on the WHO website in response to questions about health risks for athletes competing in Rio’s open waters for the sailing, rowing, canoe and swimming events.

The WHO asks the authorities to follow its guidance for recreational activities in the water, like a continuous programme of microbiological tests for bacteria, as well as sanitary inspections to identify sources of health risks to bathers due to pollution.

The tests related to bacteria use standard indicators, based on international water monitoring guidelines in the context of public health.

According to the document, evidence suggests that in most cases health problems are related to contaminated faeces in the water, and, if ingested, are limited to short-term gastroenteritis.