Malaria drug may be fueling antibiotic resistance
By Julie Steenhuysen
CHICAGO (Reuters) - Treatment with a common malaria drug may explain why people in remote villages in South America have high levels of resistance to a widely used class of antibiotics known as fluoroquinolones, despite never having taken the drugs, Canadian researchers said on Tuesday.
The surprising findings suggest that treating malaria with the cheap, widely used drug chloroquine -- a close cousin of fluoroquinolones -- may boost the risk of resistance to these antibiotics, they said.
Fluoroquinolones or quinolones are among the most commonly used antibiotics in North America and Europe, said Dr. Michael Silverman of Lakeridge Health Centre in Oshawa, Ontario. "Loss of these drugs would be a major blow to public health," said Silverman, whose study appears in the journal PLoS One.
He and colleagues studied people in extremely remote villages in the Guyanese rain forest during humanitarian medical visits between 2002 and 2005.
Silverman said this population had never been exposed to fluoroquinolones, and thus represented a unique population to study antibiotic resistance, which is thought to be linked with the overuse of antibiotics. He had expected to find none.
Instead, they found 4.8 percent of people studied had strains of E. coli that were resistant to the antibiotic ciprofloxacin, the generic name for Bayer AG's drug Cipro, and one of the most popular fluoroquinolones.
Silverman said a resistance rate of 4.8 percent is especially high considering that a 2003 study published in the Journal of the American Medical Association found a 4 percent resistance rate in intensive care units in North America, where the drug is widely used.
Tests of local water samples confirmed that no antibacterial agents were found in the drinking water, but chloroquine, used to fight malaria, was present. Continued...