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."
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."
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