Written by Steven Lawrence, MD, MSc, associate professor in the Division of Infectious Disease at the School of Medicine
The emergence, rapid spread, and ongoing transmission of Ebola Virus Disease (EVD) in West Africa have taught us many lessons about this deadly disease that was virtually unknown in the developed world before 2014: EVD can cause very large, sustained epidemics. This outbreak, with 8000+ deaths and counting, is by far the worst in history for many reasons including introduction into a region unfamiliar with it, lack of healthcare infrastructure, simultaneous multi-national involvement and spread to more densely populated urban areas.
The impact in Sierra Leone, Liberia, and Guinea has been devastating. In addition to the human toll in terms of morbidity and mortality, substantial social and economic turmoil has ensued, threatening to disrupt what had been a promising decade of economic progress in these three developing countries. Despite the accelerated international response over the past several months, significant transmission continues in the region.
EVD is often characterized by a tri-phasic presentation. Symptoms start with a non-specific febrile illness resembling malaria (which can be a co-infection), followed by an often severe, cholera-like, gastroenteritis with massive GI fluid losses complicated by severe electrolyte disturbances and pre-renal azotemia. For those who do not recover after the GI phase, multi-organ failure and sepsis syndrome ensues. Severe hemorrhagic complications occur in a minority of patients.
Aggressive supportive care may dramatically reduce the case fatality rate. Advanced supportive measures, particularly intravenous hydration with careful monitoring and repletion of electrolytes, appears to improve survival from the overall case fatality rate of about 70% in West Africa, to less than 30% for patients treated in developed countries. It is unclear if the use of investigational drugs in these patients may have also contributed to improved survival.
Extensive training in infection prevention procedures is critical. Epidemiologic studies of EVD outbreaks implicate direct contact with infected body fluids as the primary source of person-to-person transmission. However, given the large volumes of infectious fluids generated by patients in later stages of illness, personal protective equipment (PPE) must be used with meticulous care. As most US healthcare workers (HCWs) are not accustomed to treating patients while wearing advanced PPE, training with demonstration of competency on correct PPE donning and doffing is paramount.
The first documented outbreak of EVD in West Africa has led to a devastating humanitarian crisis in the three involved countries. Ongoing transmission and an accelerated international response with volunteer HCWs means that exported cases from the region will likely continue to occur. We anticipate additional cases will either be evacuated to, or identified in, the United States. Preparedness for such an event is critical to mitigate the impact. Screening procedures focusing on recent travel history and symptoms is being undertaken at Washington University and Barnes-Jewish Hospital medical facilities similarly to most healthcare settings across the country. While sustained transmission in the US is highly unlikely because of our public health and medical infrastructure, we must remain vigilant in order to quickly identify and isolate suspected cases.
This article originally appeared in Washington University’s Infectious Diseases Division Newsletter, Volume 9, Issue 4, December 2014.