Public release date: 2-Oct-2007

Swedish researchers have discovered that oseltamivir (Tamiflu); an antiviral drug used to prevent and mitigate influenza infections is not removed or degraded during normal sewage treatment. Consequently, in countries where Tamiflu is used at a high frequency, there is a risk that its concentration in natural waters can reach levels where influenza viruses in nature will develop resistance to it. Widespread resistance of viruses in nature to Tamiflu increases the risk that influenza viruses infecting humans will become resistant to one of the few medicines currently available for treating influenza

The Swedish research group demonstrated that oseltamivir, the active substance in Tamiflu, passes virtually unchanged through sewage treatment

Influenza viruses are common among waterfowl, especially dabbling ducks such as mallards. These ducks often forage for food in water near sewage outlets. Here they can potentially encounter oseltamivir in concentrations high enough to develop resistance in the viruses they carry.

“The biggest threat is that resistance will become common among low pathogenic influenza viruses carried by wild ducks.” adds Björn Olsen. These viruses could then recombinate with viruses that make humans sick to create new viruses that are resistant to the antiviral drugs currently available.

The Swedish researchers advise that this problem must be taken seriously so that humanity’s future health will not be endangered by too frequent and unnecessary prescription of the drug today.

Ralph’s Note – The irony being that in trying to prevent the low level threat of the Bird Flu. Could result in the mutations necessary to make it into the lethal virus that many fear.