Was the public health response to swine flu alarmist?

The public health measures taken in response to swine flu may be seen as alarmist, overly restrictive, or even unjustified, says a US expert in a paper published on bmj.com today. Peter Doshi, a doctoral student at the Massachusetts Institute of Technology, argues that our plans for pandemics need to take into account more than the worst case scenarios, and calls for a new framework for thinking about epidemic disease.

Over the past four years, pandemic preparations have focused on responding to worst case scenarios. As a result, we responded to the H1N1 outbreak as an unfolding disaster. Some countries erected port of entry quarantines. Others advised against non-essential travel to affected areas and some closed schools and businesses.

Pandemic A/H1N1 is significantly different than the pandemic that was predicted, says Doshi. Pandemic A/H1N1 virus is not a new subtype but the same subtype as seasonal H1N1 that has been circulating since 1977. Furthermore, a substantial portion of the population may have immunity.

Actions in response to the early H1N1 outbreak were taken in an environment of high public attention and low scientific certainty, he argues. The sudden emphasis on laboratory testing for H1N1 in the first weeks of the outbreak helped to amplify the perceived risk.

He also points out that, since the emergence of A/H1N1, the World Health Organisation has revised its definition of pandemic flu.

The wisdom of many of these responses to pandemic A/H1N1 will undoubtedly be debated in the future, he writes. What the early response to the pandemic has shown, however, is that the public health response to, as well as impact and social experience of a pandemic, is heavily influenced by longstanding planning assumptions about the nature of pandemics as disaster scenarios.

If the 2009 influenza pandemic turns severe, early and enhanced surveillance may prove to have bought critical time to prepare a vaccine that could reduce morbidity and mortality, says Doshi. But if this pandemic does not increase in severity, it may signal the need to reassess both the risk assessment and risk management strategies towards emerging infectious diseases.

He suggests that future responses to infectious diseases may benefit from a risk assessment that broadly conceives of four types of threat based on the disease's distribution and clinical severity.

For example, the 1918 pandemic was a type 1 epidemic (severe disease affecting many people), while SARS was a type 2 epidemic (infecting few, mostly severe disease), and the H1N1 pandemic may prove to be type 3 (affecting many, mostly mild).

Public health responses not calibrated to the threat may be perceived as alarmist, eroding the public trust and resulting in the public ignoring important warnings when serious epidemics do occur, he warns.

The success of public health strategies today depends as much on technical expertise as it does on media relations and communications. Strategies that anticipate only type 1 epidemics carry the risk of doing more harm than they prevent when epidemiologically limited or clinically mild epidemics or pandemics occur, he concludes.

Source: BMJ-British Medical Journal