Moderately Tamiflu-resistant bird flu in Egypt--WHO

GENEVA, Jan 19 (Reuters) Two people who died of bird flu in Egypt last month had a strain of the H5N1 virus which has shown ''moderate'' resistance to the frontline antiviral Tamiflu, the World Health Organisation (WHO) said.

Known as ''294S'', the mutated strain was first detected in 2005 in a teenage girl in Vietnam who survived, but this is the first evidence of it spreading beyond Asia, it said yesterday.

The United Nations agency said that the latest cases did not change its recommendation to treat bird flu patients with Tamiflu, known generically as oseltamivir. Made by Swiss-based Roche, the flu drug is being stockpiled by governments worldwide for use in the event of an influenza pandemic.

''What we've confirmed is that H5N1 viruses isolated from two patients in recent cases in Egypt both showed this so-called 294S change,'' Keiji Fukuda, coordinator for the WHO's global influenza programme, told Reuters.

He said that there was ''no clinical information'' upon which to base any change to the WHO's recommendations on treatment.

''But based on what we see from laboratory tests, we expect any reduction in sensitivity or increase in resistance is going to be on the moderate side,'' Fukuda said.

''We're not making any changes in recommendations for therapy because we don't have strong evidence this means oseltamivir should not be used.'' The mutated strain was found in a 26-year-old Egyptian factory worker and his teenage niece in the Nile Delta province of Gharbia, both of whom died in December along with another female relative, according to Fukuda.

The uncle and niece were given Tamiflu in the second hospital in which they were treated, after the disease was already more developed, he said.

Egypt, which announced on Wednesday it was treating another bird flu patient, has recorded 10 deaths among 19 confirmed human cases -- the largest toll outside Asia.

Worldwide, there have been 161 fatalities among 267 known cases since 2003, according to the Geneva-based WHO.

''LESS EFFICIENT'' Laboratory tests on the two Egyptians' samples showed the 294S mutation, known to have levels of resistance which make oseltamivir ''less efficient'' in such cases, Fukuda said.

More research was needed, but for now there are ''no wholesale recommendations on changes in treatment using oseltamivir,'' according to Fukuda, a US influenza expert.

Governments wordwide have been stockpiling Tamiflu in case the H5N1 virus mutates and becomes easily transmissible among humans, sparking a pandemic which could kill millions of people.

The WHO reaffirmed last May that patients should get Tamiflu as a frontline treatment, but said that in certain cases, doctors may consider using it along with amantadine, an older class of effective flu drugs.

Its recommendations, based on a consensus of international experts, also said that zanamivir -- which is marketed as Relenza by GlaxoSmithKline -- was a second choice.

Both Tamiflu and Relenza belong to a new drug class called neuraminidase inhibitors and can prevent the virus from infecting cells in the first place.

REUTERS SSC KP0935