Viral Outbreaks in an Age of Global Citizenship

In the previous decade, health care providers worldwide have wrestled with several viral diseases that posed potentially serious threats, including Middle Eastern Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), and the 2009 H1N1 influenza pandemic. To date there have been relatively small numbers of EVD, MERS, or SARS patients treated in the United States, but the H1N1 influenza pandemic taught us that viral diseases do not respect international boundaries. The Table illustrates how quickly diseases that originate elsewhere can affect the United States. It behooves us to pay attention to global health care problems and to be ready to respond. We are global citizens, and we cannot view illnesses as geographically distinct problems that don’t concern us.

Two imported cases of MERS, in health care providers who were infected while working in Saudi Arabia, were documented in the United States in May 2014.^3,4  These were the first reports of MERS in the United States, but MERS has received much less publicity than EVD. Unlike EVD, MERS did not spread to the health care workers who treated the 2 imported cases, and did not generate widespread concern among the public.

SARS caused a global outbreak in 2003, and although no deaths occurred in the United States, 29 states reported probable cases.^4,5  Breaches in the use of personal protective equipment were linked to infections in health care providers. SARS subsided as mysteriously as it began, and there have been no known cases of SARS anywhere in the world since 2004.

Our familiarity with seasonal influenza may make us less likely to think about pandemic influenza as a serious risk. However, the CDC estimated that the 2009 pandemic influenza outbreak involved approximately 60.8 million cases and more than 12000 deaths in the United States alone.⁶  In a review of the 2009 influenza pandemic, Fineberg stated, “In terms of persistence, versatility, potential severity, and speed of spread, however, few viruses rival influenza virus.”^7(p1335)

The first reported outbreak of Ebola occurred in 1976, and thus far all EVD outbreaks have originated in Africa.⁸  The 2014 West African outbreak is the largest ever reported, and it occurred concurrently with an unrelated Democratic Republic of Congo outbreak. At the end of October 2014, the World Health Organization reported more than 10000 probable, confirmed, and suspected cases in West Africa, with almost 5000 deaths, and the reported number of cases was doubling every 15 to 20 days in Liberia.⁹ 

In September 2014, the Centers for Disease Control and Prevention (CDC) published an Ebola Response modeling tool to estimate the potential number of future cases and how additional control measures might affect the number of cases.¹⁰  Extrapolating from existing data, they estimated that if no additional interventions to control the spread were instituted, Liberia and Sierra Leone would have approximately 550000 EVD cases (and an estimated 1.4 million cases when corrected for underreporting) by January 2015. Further modeling predicted that if 70% of EVD cases were treated under conditions that limited transmission (including safe burial of patients who succumb to EVD), the outbreak would be nearly over by the end of January 2015. These astonishing figures highlight the importance of interrupting transmission.

Because outbreaks involve novel pathogens, they challenge our thinking. Although experience serves as an initial rough guide for responses to outbreaks, novel pathogens are unpredictable and often defy conventional wisdom. Research is difficult to conduct during an outbreak. Resources are scarce, and the focus is appropriately on the urgent needs of reducing the spread of disease and providing supportive care to victims. Despite the difficulties, research to develop novel diagnostic strategies, therapies, and vaccines is crucial and offers broad potential benefit to future patients. Interestingly, all of the viral pathogens in Table 1 have zoonotic connections. Research that improves our understanding of animal sources and zoonotic transmission, as well as surveillance of viral pathogens in animals, is underdeveloped and underfunded, but it is vital to prevention of future outbreaks.

Outbreaks reinforce the importance of critical care knowledge, skill, and teamwork in uncertain situations. Prevention and supportive therapy, which seem simple, require high levels of infrastructure and of provider knowledge and skills. These elements are already part of the critical care tool kit, but outbreaks highlight the importance of the basics as a foundation for clinical practice. For example, infection control practices are one of the first skill sets that nurses and physicians learn, but they are also some of the most difficult skills to perform well and consistently.

Containing the spread of EVD, MERS, SARS, and influenza requires standard and contact precautions. Airborne infection isolation is recommended for MERS, SARS, and influenza; although EVD is not spread by airborne transmission, it can be spread by aerosolized secretions. In order to be effective, infection control measures must begin at the first point of contact with a potentially infected person. The recent Ebola outbreak reminds us that hand washing, personal protective equipment, and pristine technique are essential. Practice makes perfect. Safety requires both individual effort and exceptional teamwork, including taking accountability for helping each other adhere to infection control protocols.

The very nature of clinical care brings nurses, physicians, and other members of the health care team into close proximity with patients at the most infectious period of their illness. Today’s risks are mitigated by better understanding of pathogenesis and transmission, by the availability of personal protective equipment, and by the exceptional knowledge and skills of critical care providers. But caring for outbreak victims will never be completely free of risk. Our duty is to use all our knowledge and skills to protect ourselves, our patients, and the public, and to be ready for the next challenge. History has shown there will always be dedicated health care providers ready to take evidence-based practice and basic human compassion to the frontlines of these battles.