Tamiflu-resistant H1N1 virus casts shadow over India’s oseltamivir-only swine flu drug stock pile

H1N1 strains immune to Tamiflu is spotted in least three regions of the world. India’s swine flu medicine chest has only oseltamivir.

India’s all-out preparatory measures to tackle a possible swine flu outbreak by stockpiling millions of Tamiflu doses faces a serious setback as threat Tamiflu-resistant H1N1 strain of the virus looms large worldwide.

H1N1 strains immune to Roche Holding AG’s antiviral drug Tamiflu has been detected in at least three world regions. This has added to the panic level that H1n1 virus could be turning resistant to the very available medicines to fight the virus.

The World Health Organization reported it had detected  three incidents of H1N1 virus resistant to the Tamiflu (oseltamivir). The cases were reported in Denmark, Japan and Hong Kong and confirmed in laboratory testing.

WHO said that of nearly 1,000 samples of the H1N1 virus tested, these were the first to be resistant to Tamiflu.

India, as with the case of several developing nations, stockpiled only anti- swine flu pill Tamiflu (oseltamivir) pills to use in case of an emergency situation resulting from  a massive outbreak of the H1N1 virus.

Some health experts has been advocating the combined use of available anti-flu medicines, instead of depending on a single drug like oseltamivir because the chances of the virus getting resistant to a single drug is rather high in case of epdemic situation. In such a situation, the health authorities would soon be run out options if the emergent strain get immune to the therapy, they warned.

Sensing the eventuality, countries including Australia has stockpiled GlaxoSmithKline’s  Relenza ( zanamivir) – the only other alternative to tackle swine flu available–too in their stockpile.

Tamiflu was widely used in 2005 to combat the H5N1 bird flu in Southeast Asia.

Roche’s Tamiflu comes in an aeasy-to-use pill form, whwereas GlaxoSmithKline Plc’s flu drug Relenza is an inhaled powder formulation. Both the drugs claim to reduce the severity and the duration of influenza symptoms by 24 to 30 hours if treatment is started within the first two days of illness.

Tamiflu pills sales peaked  2.6 billion Swiss francs ($2.4 billion) in 2006 and 2.1 billion francs in 2007 as fears of a global influenza outbreak prompted governments, mostly in developed countries, to store millions of courses of Tamiflu that could be used to prevent infection in health-care workers and others performing critical job functions. This has drive the sales of both the drugs.

“The possibility of an anti-viral resistant strain emerging is a serious consideration,” noted U.S. Health and Human Services Secretary Kathleen Sebelius in a conference.

Over 160 cases of  swine flu cases were reported in India so far.

“So far, 1,007 people have been tested, of whom 158 have tested positive for Influenza A(H1N1),” a statement issued by the health authorities said.

Of  the  nearly 1,010 people tested for swine flu, 303 were identified through entry screening at the 22 international airports. “Of the 158 positive cases, 113 have been discharged,” the officials added.

The World Health Organization (WHO) said there were 94,512 laboratory confirmed cases of influenza A (H1N1) infection in 135 countries since the outbreak of the virus. There have been 429 deaths globally, a majority of them from Mexico and US

Swine flu has infected more than 1 million people in the U.S., according to the CDC. About 98,000 cases have been confirmed by laboratory tests worldwide, the World Health Organization reported on its Web site.

Asthma is the leading single underlying diagnosis with H1N1, present in a third of hospitalizations.

India has set its stockpile of the antiviral oseltamivir target to 10 million doses as it joined a host of Asian nations in stepping up surveillance to check the spread of the H1N1 flu in the region.

Recently, Roche India has been issued a customs duty waiver for importing one million capsules of the swine flu drug oseltmavir by the government of India. Roche India, the Indian arm of the Swiss drug giant, said it would maintain the oseltamivir drug stock as a buffer to supply to the government in case of an emergency situation arising out of a swine flu out break.