Rio 2016: will there be health repercussions?

When Dr Margaret Chan, Director-General of WHO, stated that the health risks for both participants and spectators at the Rio Olympic games were “low and manageable” she was referring to possible exposure to Zika virus. But the other major health concern raised was the quality of the water, particularly for the one to two thousand athletes who competed in aquatic events.
Both the CDC and WHO provided advice on managing the risk of Zika virus infection whilst in Brazil, including use of insect repellent and wearing light clothing covering most of the body. Visitors were also urged to stay in air-conditioned accommodation so that open windows would not admit mosquitoes, and to avoid impoverished areas where lack of suitable sanitation encourages Zika vectors to breed. Abstention or the correct and consistent use of condoms was also advocated whilst in Brazil and for at least eight weeks after returning. Unfortunately we now know that the virus can persist in semen for much longer than eight weeks; two recent cases in men who contacted symptomatic Zika infection (and around 80% of cases are estimated to be asymptomatic) still had virus in their semen after 181 and 188 days respectively.
There was a rather bizarre occurrence during the games, when water in certain dedicated swimming pools turned from blue to green overnight. However the Fédération Internationale de Natation (FINA) Sports Medicine Committee confirmed that this resulted from “some of the chemicals used in the water treatment process running out”, causing the pH to be outside the normal range. FINA’s assurance that there was no risk to the health and safety of athletes was trusted; hopefully there was sufficient supporting evidence. However the potentially most serious health threat was the quality of the natural recreational water used for many aquatic events, water that is still significantly contaminated with untreated sewage. Athletes and visitors were urged to have vaccinations such as typhoid and Hepatitis A before travelling to Brazil, to avoid swallowing recreational water and to shower after being exposed to it.
But the risks to visiting athletes and participants were hopefully only transient compared with the enduring health hazards faced daily by the poorer citizens of Brazil. The best possible legacy of the Rio Olympic games would not be an increased interest in athletics but rather continued intensive Aedes mosquito control, widely disseminated information on sexual and vertical transmission of Zika virus, the sustained treatment of raw sewage and the provision of safe drinking water.