The 2009 swine flu (influenza A H1N1) pandemic defied predictions that the next influenza outbreak was likely to be due to avian influenza arising from H5N1-endemic countries in Southeast Asia. As the world struggled to cope with the global financial meltdown, a new unexpected influenza challenge emerged from the Americas, but with the public health community better prepared than before. Although the avian influenza predictions have not occurred yet, the dire warnings were not misplaced, as the pandemic planning that ensued greatly helped decision makers and healthcare professionals around the planet to deal with the current A(H1N1) outbreak.

The numbers of A(H1N1) infections have increased rapidly. On 11 June 2009, after nearly 30 000 laboratory confirmed cases reported in 74 countries, the WHO declared the A(H1N1) outbreak the first pandemic of this century.1 Estimates of the reproduction number (defined as the “number of cases that one case generates on average over the course of their infectious period”) for A(H1N1) range from 1.4 to 1.6, which are higher than for the usual strains of seasonal influenza. However, compared to the 10% mortality rate seen with SARS, the case fatality ratio for A(H1N1) is lower and estimated to be from 0.2% to 0.4%.2 3

Although no official numbers have been specified, an early report gives the impression that the proportion of health care workers (HCWs) among cases is low. In the USA as at 13 May 2009, among the confirmed and probable cases in adults (18–64 years old) reported to the CDC, approximately 4% were among HCWs.4 This is a relatively low proportion in relation to the 9% of working adults employed in health care settings in the USA.4 The report also suggested that the risk to HCWs is likely to be higher in the outpatient setting.4 As data on additional cases become available, the risk for infection among HCWs may become clearer.

This finding is cause for cautious optimism for HCWs because A(H1N1) appears to be more contagious than seasonal influenza, and frontline HCWs are at high risk of exposure during infectious disease outbreaks. In stark contrast, during the SARS outbreak in 2003 which affected 8422 persons in 29 countries and caused 908 deaths, over a fifth (21%) of all SARS cases worldwide and over 40% of cases in Canada and Singapore were among HCWs.5 6

Why is the situation regarding risks to HCWs different now? One reason is that the state of infection control has progressed since the SARS outbreak in 2003. The emergence of another threat, avian or H5N1 influenza, against the backdrop of warnings of an “overdue” pandemic spurred the formulation of comprehensive pandemic readiness plans by healthcare decision makers in many countries.

The delay in containment of the 2003 SARS outbreak in Singapore was due to difficulty in identifying potentially exposed persons, as there were poor visitor records and excessive HCW movements and contacts. HCWs were not using full personal protective equipment (PPE) for most of the time during the period, and many did not understand that the various types of PPE offered differing levels of protection.7 8 In 2006, it was noted that most Asia-Pacific countries had political support for improving pandemic preparedness by means such as enhanced surveillance and prudent resource allocation, although some gaps remained.9 National pandemic readiness plans are in place in all European Union countries as well as at the level of the European Commission.10 In 2009, due to the implementation of pandemic readiness plans, hospitals and clinics are better prepared to deal with infectious disease outbreaks. More appropriately equipped and ventilated isolation wards have been built, and visitor-control policies and contact tracing networks have been improved and backed by enforcement measures. Not only were guidelines and protocols developed for the triage and management of suspected cases and contacts, drills were also conducted in various healthcare institutions to ensure that the protocols were understood by the healthcare staff in many countries, such as those in the Asia-Pacific region.11 The plans are also regularly revised and updated.

In the past few years, global surveillance and response has improved with the strengthening of systems such as WHO’s Global Outbreak Alert and Response Network (GOARN). In addition, the International Health Regulations (IHR), an international legal instrument that is binding on 194 countries across the globe, came into force on 15 June 2007. The IHR require countries to report certain disease outbreaks and public health events to WHO and strengthen their existing capacities for public health surveillance and response.12 Such collaborations have facilitated the early detection and reporting of the influenza A (H1N1) outbreak. Through this and extensive media coverage, HCWs were alerted and ready to receive and manage patients. Members of the general public were also more aware of the disease and able to appreciate the importance of providing a travel history and seeking treatment early if they developed flu-like symptoms. They were also more likely to wear masks and practice socially responsible behaviour when seeking treatment. This would help reduce the risk of HCWs contracting the infection from their patients at the workplace, especially in primary care settings.

Today’s HCWs are better prepared than ever before to face a pandemic. With improved containment, surveillance and mitigation measures as well as a better informed public, there is cause for optimism that HCWs will not bear the brunt of the disease burden, unlike the situation during the SARS outbreak. However, this needs to be balanced by caution, as experts warn that the A(H1N1) virus may become more virulent over the next few weeks and months.13 The challenge we face is to keep our HCWs adequately prepared at a level that is sustainable over the long term, and protected in the event the situation suddenly worsens. Another concern is that several countries are in transition, moving from the occurrence of travel-related cases to more established, community-type spread. If and when extensive population spread occurs, HCWs would also be at risk for community acquired infections. If significant numbers of infected HCWs are off work, it would be reasonable to expect the resulting health manpower shortage to place further burdens on HCWs remaining at work.