2004/2005 618 0 252 1(0.4%)
2005/2006 429 4 (0.9%) 163 0
Total 2227 7 (0.32%) 586 1 (0.17%)
These preliminary findings indicate that a low frequency of oseltamivir resistance was present in community isolates during influenza seasons in which there had been substantial oseltamivir use in Japan. Low frequencies of oseltamivir resistance in influenza A viruses (<0.5%) were also detected in isolates collected through the WHO Global Influenza Surveillance Network during the first 3 years (1999?002) after the introduction of the neuraminidase inhibitors into clinical use.
Resistance to H5N1 avian virus
The possible development of anti-viral resistance is of concern for pandemic planning and preparedness. However, to date, there have only been three documented cases of Tamiflu resistance to avian influenza H5N1. 3,4 In one case, the prophylactic dose (75 mg daily) rather than the treatment dose (75 mg twice daily) was given to a patient already exhibiting clinical symptoms, thus under-dosing the patient and increasing the risk of resistance.3 Once the twice daily treatment dose was provided, the patient recovered from her illness. Again this resistant virus was shown to cause less severe infection and was less capable of transmission. In the other two cases, the recommended dose and duration of oseltamivir was followed.4 However, while one patient received treatment on the second day of illness, the other patient started treatment late, on the sixth day of illness. Two further possible cases of resistance of H5N1 to Tamiflu in Egypt have been identified and are currently under investigation.
Roche’s efforts to support government pandemic stockpiling
Recently, the World Health Organization (WHO) reconfirmed the need for world governments to be vigilant in their plans to protect against a potential pandemic outbreak. WHO also reconfirmed that stockpiling antivirals - in particular o