Thursday, June 23, 2005

China syndrome

Word now is that Chinese authorities will allow the independent scientists from WHO and FAO to visit the Xinjiang autonomous region, where the lastest outbreak of avian flu in domestic geese has been confirmed in Tacheng, while additional reports of ducks and geese die-offs come from Xinjiang's capital, Urumqi (International Herald Tribune). Whether they will be able to confirm or disconfirm additional reports of numerous patients being admitted to the hospital with pneumonia is unknown.

Meanwhile the brouhaha over use by Chinese farmers of adamantine in poultry farm drinking water continues. The Chinese Ministry of Agriculture has denied any official or unofficial part in this practice, which some believe might have contributed to drug resistance of H5N1, although this is far from clear at the moment. However, it is a plausible consequence and the practice should never have been allowed.
WHO spokesman Dick Thompson said the issue of oseltamivir was raised when Henk Bekedam, the agency's chief representative in China, met earlier this week with senior Ministry of Health officials to express concern about agricultural use of the precious few antiviral drugs that combat flu in humans.

"He specifically brought up the issue of Tamiflu - oseltamivir - in agriculture....We wanted to clarify whether or not it had been used. Or was being used," Thompson said from Geneva.

"It's clear to us that the Ministry of Health shares our concerns about this and they understand the importance of ... the possible use of this antiviral in agriculture, that it might force or speed (development of) a resistant strain. (Helen Branswell, Canadian Press)
It is not clear whether this question was prompted by an abundance of caution or whether it was based on evidence (hard or soft) that use of oseltamivir or oseltamivir-like drugs was occurring in agricultural practice. While the drug is too expensive and scarce for that purpose (unless diverted in the black market) and although one starting point is a plant product (Chinese Star Anise), its manufacturer, Roche, says that there is a complex and time-consuming series of steps required to turn it into Tamiflu (trade name for oseltamivir). Roche spokesperson doubted it could be done as "knock-off," unlike adamantine.

Dr. Frederick Hayden, an antiviral expert at the University of Virginia, isn't so sure, as reported by Helen Branswell (Canadian Press, link above):
Hayden recalls a chilling conversation he had with a Chinese physician at a WHO meeting in Hanoi awhile back. She told him of the rumours of amantadine use in poultry operations. He asked if oseltamivir was used much in China. Too expensive, she replied, but noted a Chinese company made an oseltamivir-like drug.

He admitted he can't vouch for the accuracy of the information but remains worried nonetheless that inappropriate use of a drug similar to oseltamivir might have serious consequences for the future usefulness of the drug.
Well, maybe. Not enough information to go on here. But the practice of prophylactic feeding antimicrobials of any kind to farm animals should stop. It is not just a Chinese problem, or even mainly a Chinese problem. It is done my many countries, including the US. The same antibiotics used to fatten farm animals might be the ones we will need to treat a secondary infections in an influenza pandemic (not to mention a routine surgical wound infection).

Meanwhile, let's find out what's happening on the ground in western China.