Study: Deadly ‘superbug’ MRSA now being found at U.S. wastewater treatment plants
Using reclaimed water to irrigate lawns, parks, gardens, and various other types of landscaping is common in many communities across the U.S., particularly in areas prone to water shortages and drought. But a new study headed by researchers from the University of Maryland School of Public Health suggests that this practice may no longer be safe, as antibiotic-resistant “superbugs” like methicillin-resistant Staphylococcus aureus (MRSA) are now being detected in both influent and effluent water samples at wastewater treatment plants nationwide.
Study author Amy R. Sapkota, an assistant professor at the Maryland Institute for Applied Environmental Health, and her colleagues, some of whom came from the University of Nebraska Medical Center, collected wastewater samples from two mid-Atlantic and two Midwestern wastewater treatment plants (WWTPs) for their study, and analyzed them for the presence of superbugs like MRSA. The team drew samples of influent, which is the raw sewage directly fed into a treatment plant, as well as effluent, which is partially treated wastewater that is commonly recycled for irrigation purposes.
Shockingly, half of all the wastewater samples taken from each of the WWTPs tested positive for MRSA, while a similar pathogen known as methicillin-susceptible Staphylococcus aureus (MSSA) was detected in 55 percent of all the collected samples. As far as influent is concerned, the team detected MRSA in a staggering 83 percent of the samples taken from all plants, indicating a widespread problem of superbug contamination that is occurring in more places than just hospital rooms.
“MRSA infections acquired outside of hospital settings — known as community-acquired MRSA or CA-MRSA — are on the rise and can be just as severe as hospital-acquired MRSA,” said Sapkota in reference to her team’s findings. “However, we still do not fully understand the potential environmental sources of MRSA or how people in the community come in contact with this microorganism.”
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Has Norway Beaten MRSA? Is it true that Norway has eradicated the superbug¸ MRSA? How did this happen?
Answer (Published 3/15/2010)
MRSA stands for methicillin-resistant Staphlococcus aureus, known as a “superbug,” because the infections it causes resist treatment with our most powerful antibiotics. According to a recent study, MRSA is believed responsible for the deaths of nearly 19,000 hospital and nursing home patients in 2005 (the last year for which we have complete figures), exceeding deaths due to HIV-AIDS, Parkinson’s disease, emphysema, or homicide for each year since 2005.
According to the World Health Organization, antibiotic resistance associated with MRSA is a leading public health threat, even in the best hospitals in the most advanced nations. But not in Norway, where the public health system recognized the problem in the 1980s and tackled it with some simple measures that have virtually eliminated MRSA (although a few cases are brought in every year by travelers from abroad).
Norway’s aggressive campaign started with a decision to cut back dramatically on the use of antibiotics, thereby slowing the development of resistance to these drugs. Today, some of the newest and most costly antibiotics available aren’t even registered for use in Norway.
Other elements of Norway’s strategy include isolating patients who test positive for MRSA and requiring medical personnel who test positive to stay home. In addition, doctors track each case of MRSA they find by its individual strain and test everyone who has been in contact with an infected patient. To further reduce the chance of infection, all workers in Norway are paid for days they or their children stay home sick. And drug manufacturers are prohibited from advertising, thus reducing patient demands for prescription drugs.
The Norway model has been tested successfully elsewhere, including a hospital in England, one in Billings, Montana, and at Juntendo University Hospital in Tokyo. Testing everyone who came in the door for MRSA cut infection rates so dramatically in a study at a Veterans’ Administration (VA) Hospital in Pittsburgh that today all 155 VA medical centers in the U.S. do the same testing, and have cut MRSA infections by 50 percent.
Norway’s approach is simple and certainly less costly than it would be to treat thousands of MRSA patients annually. Bottom line: it works.
Andrew Weil, M.D.[/box]
Communities that recycle water for irrigation, drinking could be creating major public health hazard
But the issue gets even worse. According to the team’s findings, which were published recently in the journal Environmental Health Perspectives, MRSA, MSSA, and various other potentially-deadly superbugs can even persist beyond the initial treatment phases. Effluent samples collected at one of the WWTPs tested positive for MRSA, which means anywhere the partially-treated water ends up getting sprayed — recycled water is often sprayed on sports fields, grassy knolls, and other common areas frequented by families with children — is also being potentially doused with killer bacteria.
“Our findings raise potential public health concerns for wastewater treatment plant workers and individuals exposed to reclaimed wastewater,” added Rachel Rosenberg Goldstein, one of the study’s lead authors. “Because of increasing use of reclaimed wastewater, further research is needed to evaluate the risk of exposure to antibiotic-resistant bacteria in treated wastewater.”