RIO DE JANEIRO • Scientists have found dangerous drug-resistant "super bacteria" off beaches in Rio de Janeiro that will host Olympic swimming events, and in a lagoon where rowing and canoe athletes will compete when the Games start on Aug 5.
The findings from two unpublished academic studies concern Rio's most popular spots for tourists and greatly increase the areas known to be infected by the microbes normally found only in hospitals. They also heighten concerns that the Brazilian city's sewage-infested waterways are unsafe.
A study published in late 2014 had shown the presence of the super bacteria - classified by the US Centres for Disease Control and Prevention (CDC) as an urgent public health threat - off one of the beaches in Guanabara Bay, where sailing and wind-surfing events will be held during the Olympics.
The first of the two new studies, reviewed last September by scientists at the Interscience Conference on Antimicrobial Agents and Chemotherapy in San Diego, showed the presence of the microbes at five of Rio's showcase beaches, including the ocean- front Copacabana, where open-water and triathlon swimming will take place.
The other four were Ipanema, Leblon, Botafogo and Flamengo.
The super bacteria can cause hard-to-treat urinary, gastrointestinal, pulmonary and bloodstream infections, along with meningitis. The CDC says studies show that these bacteria contribute to death in up to half of patients infected.
The second new study, by the Brazilian federal government's Oswaldo Cruz Foundation lab, which will be published next month by the American Society for Microbiology, found the genes of super bacteria in the Rodrigo de Freitas lagoon, where rowing events will take place, in the heart of Rio and in a river that empties into Guanabara Bay.
Waste from countless hospitals as well as hundreds of thousands of households pours into storm drains, rivers and streams crisscrossing Rio, allowing the super bacteria to spread outside the city's hospitals in recent years.
Cleaning the city's waterways was meant to be one of the Games' greatest legacies and a high-profile promise in the official 2009 bid document Rio used to win the right to host South America's first Olympics.
That goal has instead turned into an embarrassing failure, with athletes lamenting the stench of sewage and complaining about debris that bangs into and clings to boats in Guanabara Bay.
While both studies used water samples that are from 2013 and 2014, experts said they had seen no advances in sewerage infrastructure in Rio to improve the situation.
The contamination has prompted Brazilian federal police and prosecutors to investigate whether Rio's water utility Cedae is committing environmental crimes by lying about how much sewage it treats. Investigators are also looking into where billions of dollars in funds went since the early 1990s, money earmarked to improve sewage services and clean up Guanabara Bay.