Earlier this week, US Customs and Border Protection (CPB) officers seized 250 parcels of counterfeit Tamiflu being shipped into New York City - the biggest interception of the counterfeit flu drug to date.
The fake Tamiflu parcels came from Mauritius and it is believed that the fake drugs were intended for American consumers fearful of a possible flu outbreak, who purchased the drugs via the internet.
Fake Tamiflu has also recently surfaced in Chicago, and in San Francisco, where CBP officers seized 51 shipments of the counterfeit anti-bird flu drug that had been shipped to an airmail facility from Asia, less than a month ago.
US CBP officers are continually on the look out for suspect packages, expecting to intercept even bigger shipments of the counterfeit tamiflu in the coming months. "We believe the seizures will continue to go up dramatically," said William Heffelfinger, CBP.
In the past, counterfeit shipments of the drug have contained no more than trace elements of Tamiflu's active ingredient, oseltamivir, mixed with other harmless ingredients.
However, experts are worried about fake Tamiflu because if a flu outbreak should occur, people might take the fake drugs and consider themselves protected, when this would not necessarily be the case.
The World Health Organization has recorded 76 human deaths from H5N1 strain of bird flu since 2003. Until recently the virus has been contained in Asia but there have now been several confirmed cases in Turkey in recent weeks and there are fears that the virus is now knocking on the door of Western Europe.
The virus does not pass from person to person easily, but experts fear the virus could soon mutate into a form that could be passed on among humans and cause a flu pandemic.
The UK Department of Health estimates that if a pandamic reaches Britain, there could be 600,000 deaths if the virus was not contained, and 50,000 if the virus was contained.
Tamiflu reduces the severity and spread of traditional flu and is the most effective antiviral drug currently available for countering an avian influenza pandemic.
However, There is a global shortage of Tamiflu, as the manufacturer, Roche, cannot keep up with worldwide demand, which has increased ten fold this year, as countries gather stockpiles of the drug amid fears of a possible avian flu epidemic.
Roche is now working to address the supply problem, after bowing to pressure to outsource manufacturing of the drug to help boost supplies.
In December Roche announced that it has identified 12 potential manufacturing partners that it is now in negotiations with.
Meanwhile, Roche and Shanghai Pharmaceutical Group have signed the first sub-licensing agreement for the overall production of oseltamivir for pandemic use in China.
"As yet we have not identified anyone who could significantly speed up the agreed delivery timelines for the first half of 2006, but we have been able to identify partners to insure against breakdowns in supply and partners to broaden geographic coverage," said William Burns, CEO Roche Pharma Division.
"Based on the current orders we have received from governments around the world our capacity to produce 300 million treatments by 2007 is significantly ahead of demand," he added.