Planning for the 2009 H1N1 Influenza Pandemic — Are Our Hospitals Ready?

Abstract & Commentary

By Rahul Gupta, MD, MPH, FACP, Clinical Assistant Professor, West Virginia University School of Medicine, Charleston, WV. Dr. Gupta reports no financial relationship to this field of study

Synopsis: Data from Australia and New Zealand show that the 2009 H1N1 influenza pandemic may pose a substantial burden on our health care systems, one we may have never endured in recent history.

Source: Webb SA, et al. Critical care services and 2009 H1N1 influenza in Australia and New Zealand. N Engl J Med 2009;361:1925-1934.

In april 2009, a novel h1n1 influenza virus, also known as swine flu, was first detected in the United States. This virus is spreading from person to person worldwide, probably in much the same way that regular seasonal influenza viruses spread. On June 11, 2009, the World Health Organization (WHO) declared it a global pandemic. In the United States, a national emergency was declared by President Obama on October 23, 2009, to deal with the rapid increase in the number of cases from the 2009 H1N1 influenza.1

In a recent paper, authors from the Centers for Disease Control and Prevention (CDC) and Harvard Medical School concluded that the initial reported laboratory-confirmed cases may have been a substantial underestimate of the true number and therefore a recent estimate predicts that in the United States, between April and July, a total of 1.8-5.7 million cases of this 2009 H1N1 influenza A virus may have actually occurred, including 9000-21,000 hospitalizations.2

In the current study, authors from Australia and New Zealand conducted a cohort study in all of their hospitals' intensive care units (ICUs) during the winter of 2009 in the southern hemisphere. All patients admitted to the ICU with confirmed infection by the 2009 pandemic influenza A (H1N1) virus were identified. A total of 722 patients (28.7 cases per million inhabitants) were admitted to an ICU and were confirmed to have infection with 2009 pandemic influenza A (H1N1) virus. Of these 722 patients, 669 (92.7%) were younger than 65 years of age and 66 (9.1%) were pregnant women. The highest age-specific incidence of ICU admission was among infants, whereas the highest number of ICU admissions was among patients 25-49 years of age. The median duration of treatment in the ICU was 7.0 days and about 65% (of those with available data) underwent mechanical ventilation for a median of 8 days. The maximum daily occupancy of the ICU was 7.4 beds per million inhabitants. As of Sept. 7, 2009, a total of 103 of the 722 patients (14.3%) had died, and 114 (15.8%) remained in the hospital.

The authors concluded that as a result of the study, the 2009 H1N1 virus had a considerable effect on ICUs during the winter months in Australia and New Zealand and suggest that these data can assist planning for the treatment of patients during the winter months in countries in the northern hemisphere such as the United States.

Commentary

Some recent estimates by the CDC place the number of 2009 H1N1 cases occurring from April to October 17, 2009 at between 14 million and 34 million.3 Furthermore, the CDC estimates that between about 63,000 and 153,000 of the 2009 H1N1-related hospitalizations occurred between April and Oct. 17, 2009, including between 2500 and 6000 deaths.

According to data from the American Hospital Association (AHA) Annual Survey, there were 59,400 ICU beds in the entire United States in 2000. In a similar survey in 2007, lack of staffed critical care beds was cited as the most common reason contributing to ambulance diversions. Additionally, concerns are being raised that there could be a shortage of hospital beds in 15 states if 35% of Americans become ill from the pandemic and 12 other states could reach or exceed 75% of their hospital bed capacity.4 However, it is important to take these estimates in context and not to jump to advocate a need for more hospital beds. Rather, we should be taking advantage of this opportunity to modernize core public health functions like risk communications as well as identifying surge capacities in our communities. This is also the most opportune time for conducting sound mass vaccination campaigns and reinforcing strong public health messages about ways to practice good hygiene. If anything, the data should reinforce the initial focus for vaccination of the target populations as identified by the CDC and WHO, including pregnant women who may suffer from a significantly higher morbidity and mortality if not vaccinated in a timely manner.

References

1. CNNHealth. Obama declares H1N1 emergency. Available at: www.cnn.com/2009/HEALTH/10/24/h1n1.obama/index.html. Accessed Nov. 22, 2009.

2. Centers for Disease Control and Prevention. Available at: www.cdc.gov/eid/content/15/12/pdfs/09-1413.pdf. Accessed Nov. 22, 2009.

3. Reed C, et al. Estimates of the prevalence of pandemic (H1N1) 2009, United States, April-July 2009. Emerg Infect Dis 2009 Dec; Epub ahead of print. Available at: www.cdc.gov/h1n1flu/estimates_2009_h1n1.htm. Accessed Nov. 23, 2009.

4. Trust for America's Health. H1N1 Challenges Ahead. Washington, DC: October 2009. Available at: http://healthyamericans.org/reports/h1n1. Accessed Nov. 23, 2009.