Public Release: 

Little or no evidence for some swine flu interventions

Direct communications from health agencies to doctors needed


The Lancet today publishes Online First an Editorial and a World Report, plus a Comment from Lancet Infectious Diseases Editor John McConnell, on the swine flu outbreak (now referred to as influenza A(H1N1)).

The Editorial says: "Panic has ensued in some regions: the culling of hundreds of thousands of pigs has been ordered in Egypt; pork trade has been restricted; facemasks have been widely distributed; airports are using thermal-based scanners to screen passengers. These measures have little, or no, evidence for their implementation. There is uncertainty regarding travel advisories; WHO does not advise restriction of regular travel or closure of borders, whereas recommendations in the USA, UK, Canada, and Australia are to avoid all non-essential travel to Mexico. Amidst this confusion, many Mexican travellers have been quarantined in China."

It praises the overall reaction in the UK, headed by an influenza awareness campaign, but criticises the UK Health Protection Agency, which, although it issued clear algorithms on what to do in suspected influenza A(H1N1) cases, did not provide timely advice on practical management, including which swabs to take, which culture medium to use, where to send samples, and how to obtain antiviral medication.

The Editorial concludes: "While it is reassuring that there is a global effort in the fight against influenza A(H1N1), more attention is needed at a national level to ensure that those on the front-line are kept abreast of accurate updates and practical advice. Direct, rapid communiqués from health agencies to health professionals, by email or text message alerts, would speed up dissemination of information. Consistent international recommendations about travel to or from affected countries are also needed. Pandemic preparedness relies on an effective communication strategy with timely implementation of evidence-based procedures. But an effective global response can only be ensured if the appropriate national responses are in place. Some of these national responses have been found wanting."

The Comment by John McConnell says if a pandemic is declared, an urgent issue will be whether to continue the practice of giving oseltamivir (tamiflu) prophylactically to contacts of confirmed cases. He says: "At four schools in the UK where pupils have confirmed infection, prophylactic oseltamivir has been issued to hundreds of fellow students. Although this policy follows Health Protection Agency advice, I wonder about sustainability. At a Lancet conference on pandemic influenza in 2006, Frederick Hayden (University of Virginia, USA) stated that for a group of 1000 people 16 times as much antiviral was needed to prevent influenza infection as to treat it. By this measure, the UK has stockpiles of oseltamivir sufficient to treat 30 million people (about half the population) but to prevent infection in only 1.9 million."

He concludes: "On May 17, The Lancet will be supporting a late-breaker session on influenza A (H1N1) at the European Conference on Clinical Microbiology and Infectious Diseases in Helsinki, Finland. We plan to make freely available from website a video recording of this session, plus additional content relevant to the current outbreak taken from the Lancet journals and others published by Elsevier."

The World Report, written by freelance journalist Anastasia Moloney, questions whether the local and international response to the outbreak was quick enough.

It says: "WHO issued its first public response about the influenza A outbreak on April 24, and held its first emergency meeting the next day. That was 18 days after Mexican health officials first raised the alarm locally. By then, the virus had spread across Mexico's borders to the USA. It was when the USA confirmed seven cases of influenza A (H1N1) on April 24 that international agencies started to respond quickly.

"Although it is difficult to reconstruct the hazy timeline of events, the Mexican experience has exposed delays and apparent flaws in procedures to detect disease outbreaks as set out in the International Health Regulations in 2007, which aimed to strengthen WHO's response capacity after the epidemic of Severe Acute Respiratory Syndrome."

The Pan American Health Organisation's (PAHO) spokesperson, Daniel Epstein, confirms that PAHO received alerts from Veratect (a US biosurveillance consultancy) on April 16, but defends criticisms that the agency was slow to act. "There was no time delay", he said, "a cluster of influenza cases in one country does not necessarily have international significance".

Mexico's response to the outbreak has also been criticised. Agenor Álvares da Silva, head of the Brazilian National Health Surveillance agency, has questioned the slow response of Mexican health authorities since, he says, alarm bells had been raised in March, but international health authorities were only informed about a potential epidemic in mid-April. However, government public awareness campaigns on the radio and television have been advising people with flu-like symptoms to stay at home and wash their hands well. This seems to be paying off. A local opinion poll said that 87% of Mexicans knew about the preventive measures implemented by the government, and that 84% believed the government has provided clear and sufficient information about the epidemic.

Experts think that the new H1N1 virus--a hybrid of avian, porcine, and human influenza--originated in Mexico. However, the Mexican Government, has been keen to stress that unusual cases of influenza had been detected around the same time in both the USA and Mexico from the end of March onwards.

The World Report concludes with a quote from Melvin Kramer, president of EHA Consulting Group, a public health consultancy in Maryland, who emphasises that the outbreak must be seen in context. "It's scary, it's bad but I think we've been hyped...35,000 to 37,000 people in the US die every single year from seasonal flu."


Lancet Press Office (for Editorial/Comment) T) +44 (0) 20 7424 4949 E)

Anastasia Moloney (for World Report) T) (currently in Colombia) + 57 310 349 4559 E)

For full Editorial, Comment, and World Report, see:

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