Scientific Evidence Supports WHO’s Action To Declare H1N1 Flu Pandemic As ‘Imminent’

Amidst criticism that the WHO stoked public fears over the H1N1 (swine) flu outbreak, a study released on Monday supports the swift action of the WHO to raise the pandemic threat level to reflect that a pandemic is imminent, the AP/Google.com reports (Schmid, AP/Google.com, 5/11).

Drawing from early data from the H1N1 flu outbreak in Mexico, the international spread of the virus and the genetic diversity of the virus, researchers from the Imperial College in London, WHO staff and Mexican scientists estimate that by April 23, nearly 23,000 people were infected with the swine flu, Time reports (Walsh, Time, 5/11). The study was published in an early release in the journal Science (Schmid, AP/Google.com, 5/11).

"Our early analysis would suggest this is going to be an outbreak comparable to that of 20th century pandemics regarding the extent of its spread – it's very difficult to quantify the human health impact at this stage, however," said Neil Ferguson of Imperial College, London, the lead author of the study (AP/Google.com, 5/11). He added, "It is likely to spread around the world in the next six to nine months and when it does so it will affect about one-third of the world's population." Ferguson sits on the WHO's emergency committee for the H1N1 flu outbreak, the BBC reports (BBC, 5/12).

The AP/Google.com writes, "While WHO is reporting about 4,800 confirmed cases [of H1N1] in 30 countries, the new analysis estimates there have been between 6,000 and 32,000 cases in Mexico alone" (AP/Google.com, 5/11). Anne Schuchat, interim deputy director for science and public health programs at the CDC, said on Monday that the large number of underreported cases of swine flu in Mexico is likely similar in the U.S. People who contract the virus, but fail to report symptoms fall under the radar, "the numbers we are reporting are a minority of the actual infections that are occurring in the country," Schuchat said (Gardner, HealthDay/U.S. News & World Report , 5/11).

The WHO on Tuesday reported that 30 countries have officially reported 5,251 cases of H1N1 infection. Laboratory cases have confirmed: 2,059 cases in Mexico, including 56 deaths; 2,600 cases in the U.S., including three deaths; 330 cases in Canada, including one death; and eight cases in Costa Rica, including one death.

The WHO writes, "The following countries have reported laboratory confirmed cases with no deaths - Argentina (1), Australia (1), Austria (1), Brazil (8), China (2, comprising 1 in China, Hong Kong Special Administrative Region, and 1 in mainland China), Colombia (3), Denmark (1), El Salvador (4), France (13), Germany (12), Guatemala (1), Ireland (1), Israel (7), Italy (9), Japan (4), Netherlands (3), New Zealand (7), Norway (2), Panama (16), Poland (1), Portugal (1), Republic of Korea (3), Spain (95), Sweden (2), Switzerland (1) and the United Kingdom (55)" (WHO Influenza A(H1N1) - update 26, 5/12).

The team of researchers used a variety of methods to assess how the virus is transmitted, concluding that each case of the flu resulted in between 1.4 and 1.6 infections to others (AP/Google.com, 5/11) – a transmission rate higher than the seasonal flu, Reuters reports. The study also pointed to the village of La Gloria in the state of Veracruz as the origin of the outbreak, "which had been the subject of intense speculation," Reuters writes (Fox, Reuters, 5/11).

The findings suggest the swine flu will be less deadly than the Spanish flu of 1918, which resulted in the deaths of an estimated 50 million people (BBC, 5/12). Rather the H1N1 virus appears as lethal as the virus behind the 1957 Asian flu pandemic, which killed an estimated 70,000, compared to the 36,000 people who typically die annually from the seasonal flu, according to HealthDay/U.S. News & World Report.

Infectious disease experts caution that the conclusions of the Science paper are based on infection rates, not the severity of the swine flu disease or fatalities. At this time, "[t]he most important unknown is the clinical severity of the illness, although the accumulating evidence is that the severity is no worse than that of the seasonal flu," said Christopher Crnich, assistant professor of medicine in the division of infectious disease at the University of Wisconsin School of Medicine and Public Health. However, "no mathematical model is going to be able to predict [severity]," Crnich added.

While the authors acknowledged that the data on the spread and strength of the illness remains incomplete, the study "supports the [WHO's] phase 5 decision, and indicates a certain level of person-to-person spread," HealthDay/U.S. News & World Report writes (HealthDay/U.S. News & World Report, 5/11) and may be able to help influence policymakers balancing cost of actions against the potential spread of H1N1 flu (AP/Google.com, 5/11).

"Professor Ferguson said his findings confirmed that decisions must be taken swiftly on vaccine production," according to the BBC. "We really need to be prepared, particularly for the autumn. At the moment, the virus is not spreading fast in the northern hemisphere, because we are outside the normal flu season, but come the autumn it is likely to cause a really major epidemic," Ferguson said (BBC, 5/12) 

The WHO will meet with vaccine makers, country regulators and health experts on Thursday to discuss the production of a swine flu vaccine (Kaiser Daily Global Health Policy Report, May 7). The WHO on Monday also announced it was creating a new index to gauge the severity of the threat posted by a potential pandemic flu virus to help assist national authorities in the implementation of preparedness measures, CNews.com reports (Branswell, CNews.com, 5/11).

The AP/Washington Post Examines Generic Production of Tamiflu

The AP/Washington Post examined criticism directed toward the WHO about the potential production of generic Tamiflu for developing countries facing the spread of H1N1.  The antiviral has been shown to reduce the transmission of flu virus and the severity of the disease when started within the first 48 hours after flu symptoms appear.

While representatives from the WHO argue they are doing their best to supply developing countries with stockpiles of antivirals, the AP/Washington Post reports critics are beginning to wonder why the organization "has not ordered up new batches of generic Tamiflu."

Though Roche, the maker of Tamiflu, sells batches of the antiviral for around $100 in the U.S., the company began selling the antiviral at a discounted price of $16 per treatment to poor nations in 2005. The following year, Roche gave two companies in China and one in India permission to produce generic versions of the drug. The Indian pharmaceutical company Cipla, which, according to the AP/Washington Post, "does not recognize Roche's patent," said they sell the generic Tamiflu for $12.

Last week, Cipla said it would only need a few weeks to produce 1.5 million doses of the generic Tamiflu, and could make millions more at the request of poor countries and international agencies like the WHO. "We could make a lot more, but there needs to be firm commitment from countries and international agencies like WHO," Yusuf Hamied, Cipra's chairman, said. "The ball is in their court."

Elil Renganathan, a WHO official working on antivirals, said the WHO is exploring options for generic production of Tamiflu, but cautioned that the WHO must ensure that generic medicines meet drug safety standards. The AP/Washington Post writes, "Some critics suspect WHO is reluctant to anger drug companies, which supply it with free stockpiles of drugs, by encouraging the use of generics. Given all they spend on research and development to produce new drugs, Western pharmaceuticals have long fought to keep generics out of the market in all circumstances" (Cheng, AP/Washington Post, 5/11).

Roche on Tuesday announced it is donating 5.65 million doses of Tamiflu to the WHO's stockpiles, the Wall Street Journal reports. Five million of the doses are to replenish those that WHO has already sent to developing countries for fighting H1N1 (Wall Street Journal, 5/12).