Tamiflu is entering rivers downstream of sewage treatment facilities. Researchers are concerned that if birds pick it up, they could develop and spread an even stronger, drug-resistant strain of influenza than H1N1 (swine flu), which Tamiflu currently treats.
Led by Gopal Ghosh, a team of Japanese researchers tested three rivers in Japan throughout last year’s flu season and found they were contaminated with oseltamivir carboxylate (OC), the active ingredient in Tamiflu. It was excreted by people through their urine and discharged from sewage plants. Science News reports that, according to environmental chemist Jerker Fick of Sweden, most sewage treatment technologies can’t remove OC, and nearly all Tamiflu will wind up in the environment in its active form of OC. Fick told Science News that, compared to Japan, U.S. policy toward Tamiflu is more conservative, with federal guidelines recommending that Tamiflu be reserved only for the very sick and those with compromised immune systems, so there may be less OC in U.S. rivers.
The researchers’ report was published Sept. 28 online in Environmental Health Perspectives.