WHO still confident in Tamiflu

Recent cases of resistance to Tamiflu in Britain and America are unlikely to be a sign that the virus is becoming less susceptible to Roche's flu drug, also known as oseltamivir, according to Dr. Keiji Fukuda, the top flu expert at the World Health Organisation (WHO). Since the advent of the H1N1 swine flu virus, the WHO has registered 75 mostly isolated cases of resistance to Tamiflu worldwide. Last week, four cancer patients tested positive for a form of flu virus resistant to Tamiflu in North Carolina  and there has also been a cluster of resistance in five patients in Wales.

However, patients who resist Tamiflu are severely immunocompromised, and thus highly vulnerable to developing drug resistance if they are taking antivirals or antibiotics for chronic illnesses. Fukuda said that provided there is no sign the resistant viruses are moving from these patients to healthy people, the virus is unlikely to have changed.

'We don't know the full answer. But it is more likely that we are not seeing a change, a major shift in the epidemiology on the properties of these viruses with regard to oseltamivir resistance', said Fukuda. '[The Wales and North Carolina clusters probably] don't have big implications for the overall pattern of spread or the overall pattern of illness in the general community.' Fukuda added that Tamiflu was effective if used early and correctly.