Fears over role of hospital sewage in the spread of superbugs

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SewageSuitEvery day Southern California hospitals unleash millions of gallons of raw sewage into municipal sewers. The Los Angeles Times reports that the malodorous muck flows miles to one of the region's sewage plants, where it is treated with the rest of the area's waste and then released as clear water into a stream or directly to the Pacific.

The scientists at the Environmental Protection Agency recently announced they had discovered a lethal superbug – the same one that caused outbreaks at UCLA and two other Los Angeles-area hospitals – in sewage at one of those plants. They declined to name the facility. But, the report says, EPA scientists did not test treated wastewater flowing out of the plant to determine whether it still contained CRE, or carbapenem-resistant enterobacteriaceae.

The report says  Instead the facilities serve as "a luxury hotel" for drug-resistant bacteria, a place where they thrive and grow stronger, said Pedro Alvarez, a professor of environmental engineering at Rice University, one of the scientists studying the problem.

Alvarez and other researchers say the failure of sewage plants to eliminate the dangerous bacteria is one way they may be spreading from hospitals to the environment. "Chlorine is just not doing it," Alvarez said of the treatment used by most plants.

The report says the fear is that healthy people otherwise not at risk from the bacteria – including swimmers at the beach – could be infected. Already officials are worried about the surprising number of people sickened with CRE who have not recently visited a medical facility: 8%, according to an October study.

The report says hospitals are not breaking laws by releasing the sewage. Laws regulate the overall level of disease-causing bacteria in the nation's surface waters, but there is no specific regulation of bacteria resistant to antibiotics.

Deemed the "nightmare bacteria" by federal officials, CRE survives nearly all antibiotics. It kills as many as half its victims. Government officials, including those at the US Centres for Disease Control and Prevention, say they are monitoring the wastewater studies but have so far made no recommendations to hospitals about the treatment of sewage that may harbour CRE. "The prevention and control of CRE is an evolving process," said Melissa Brower, an agency spokesperson. "CDC will continue to assess the appropriateness of this as new information becomes available."

The report says researchers have tried for years to raise the alarm about hospital sewage. The sludge includes not just waste from patients suffering from drug-resistant infections but also high levels of antibiotics prescribed to treat them.

As the sewage mixes, the antibiotics kill off weaker bacteria, leaving the more lethal ones to thrive. The bugs reproduce rapidly, and different species can swap genes, transferring their ability to withstand the drugs.

"The idea of CRE flowing down our sewer pipes gets me nervous," said Dr. James McKinnell, an infectious disease expert at the Los Angeles Biomedical Research Institute, who has been working to stop superbugs from spreading. "We should be testing our runoff." CRE thrives in water – hospitals have found it living in sink drains and the bacteria are happy in patients' intestines and it passes through in urine and waste.

The report says some surf spots — like the Santa Ana River jetties in Orange County – have become known as places with great waves that can make you sick. "Just check yourself for cuts prior to entering," the surfing magazine Stab recently warned about the site on the northern border of Newport Beach. "Oh, and keep your mouth shut."

California officials don't know what bacteria is in the seawater, the report says. They monitor the ocean water for what they call faecal indicator bacteria – a sign of raw sewage. But they rarely test for specific bacteria, including those that are drug-resistant.

A 2010 study estimated that 689,000 to 4 million people are struck by gastrointestinal illnesses caught from Southern California beaches each year. An additional 693,000 are sickened with respiratory problems.

Full report in The Los Angeles Times

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