Friday, September 4, 2009

BMJ: Was the public health response to swine flu alarmist?

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 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.

Peter Doshi, Doctoral Student, Program in History, Anthropology, and Science, Technology and Society, Massachusetts Institute of Technology, Cambridge, MA, USA


My Comments:

  1. There is no doubt that there have been vigorous debates regarding this A/H1N1 flu pandemic, with many claiming that the overall official responses had been alarmist and over the top, starting with the WHO, and most national health authorities.
  2. However, it is clearly mainly due to "hindsight wisdom", that one finds this highly infectious disease, so much more benign than it was feared to be, thus far. At least this seems to be the case in most Western countries, where antiviral medications have been generously dished out to anyone having ILI (flu-like illness).
  3. That it is very contagious cannot be denied, but it is also becoming increasingly clear that most people exposed to this infection appear to have quite mild symptoms with some having none at all.
  4. The difficult question is who amongst us have such supposedly natural immunity or who would have very mild subclinical infections at all. According to some, the similarity of the viral genome to the 1987 flu pandemic might have given immunity to many people already previously exposed--thus the milder uptake.
  5. However, it cannot be denied that in other countries where flu outbreaks are less than perennial or seasonal in their occurrence, the outbreak has been experienced with greater ferocity of more severe ailments. Pneumonia and multi-organ breakdown appear to have afflicted more Malaysians than ever before... so this is certainly new.
  6. The number of cases still being admitted to ICUs for critical care and mechanical respiratory support, and even dying, attest to the more virulent nature among some of our patients who have contracted this disease.
  7. Thus, for Malaysia at least, we have much to learn about this enigmatic flu outbreak, but we do know that among the sickest patients, we have to marshal in even more appropriate and urgent life support care, so as to save more lives.
  8. My contention is still that what we have done is appropriate and necessary, and we did modify our stance repeatedly as we learn more about the ailment.
  9. One possible criticism may be that we had perhaps erred on the side of extreme caution and possibly some delay in dissemination of changing urgent decision pathways, including use of definitive treatment a little too late sometimes--but we have done as best can be under the circumstances.
  10. Our weaknesses and shortcomings have been exposed, and as someone cynically had said: "that this is a timely stress test for checking the capacity and effectiveness of our entire health care system!"

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