|Photo: Renjith Krishnan|
“If you find antibiotic-resistant bacteria in an ecosystem, it’s hard to know where they’re coming from,” said study co-author Andrew Juhl, a microbiologist at Columbia University’s Lamont-Doherty Earth Observatory. “In the Hudson, we have a strong case to make that it’s coming from untreated sewage.”
On repeated visits to 10 locations on the Hudson, the researchers found microbes resistant to ampicillin 84 percent of the time, and resistant to tetracycline 38 percent of the time. The stretches harboring the most sewage-indicator bacteria also generally contained the most antibiotic-resistant ones. These were led by Flushing Bay, near LaGuardia Airport, followed by Newtown Creek, on the border of Brooklyn and Queens; and sewage outfall pipes near Piermont Pier in Rockland County, N.Y.; West 125th Street in Manhattan; and Yonkers, in Westchester County, N.Y.. The antibiotic-resistant bacteria found include potentially pathogenic strains of the genera Pseudomonas, Acinetobacter, Proteus and Escherichia.
“They could be difficult to treat in people with compromised immune systems,” said Dr. Stephen Morse, an infectious disease epidemiologist at Columbia’s Mailman School of Public Health, who was not involved in the study. “If I were inclined to swim in the Hudson, quite truthfully I’d look to this paper for the places to stay away from.”
Though people routinely catch infections while swimming, only severe illnesses are typically treated with antibiotics. And an antibiotic-resistant infection would be noted only if the illness failed to respond to treatment--a scenario that probably happens, but is not well documented or reported, said Morse. One exception was an outbreak on the Indonesian island of Borneo in 2000 when 32 athletes competing in a swimming event in the Segama River came down with leptospirosis. Transmitted by animal urine, the infection is marked by fever, chills and pink eye.
Previous studies in the Hudson have shown that microbe counts go up after heavy rains, when raw sewage is commonly diverted into the river. Some 27 billion gallons of raw sewage and rainwater are released into the Hudson each year by wastewater treatment plants.
Antibiotic resistance has become a public health crisis. About 100,000 people die each year from hospital-acquired infections, most of which are due to antibiotic-resistant pathogens, according to the Infectious Diseases Society of America. Superbugs resistant to methicillin kill about 19,000 people each year, more than HIV/AIDS. The development of resistance has been linked to overuse of antibiotics to treat minor infections in humans, and to industrial feedlots, where low levels of antibiotics are fed to chicken, cattle and pigs to promote growth and prevent infection. The Natural Resources Defense Council estimates that 80 percent of antibiotics in the U.S. are fed to livestock.