Military and Nebraska Medical Experts Weigh In on Containment Needed for Ebola/ Annals of Internal Medicine online

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Ideas and Opinions |

Mark G. Kortepeter, MD, MPH; Philip W. Smith, MD; Angela Hewlett, MD; and Theodore J. Cieslak, MD
The largest outbreak of Ebola virus continues unabated in West Africa. With the recent death of a patient with Ebola virus disease at a hospital in Dallas, Texas, and the sobering reality that nosocomial spread has occurred in a U.S. facility, U.S. medical centers are coming to grips with the need to prepare for care of patients with this devastating disease. The Centers for Disease Control and Prevention has developed a hospital preparedness checklist, and the latest guidelines continue to express confidence that patients with Ebola can be cared for safely in a conventional medical facility by using barrier methods (standard, contact, and droplet precautions) as the primary means of protecting medical staff (12). Recent experience with several Ebola-infected patients in the United States provides validation that such patients can be cared for safely in a facility that is adequately prepared.
Since the first reported outbreaks of Marburg (1967) and Ebola (1976), there has been an evolution in our thinking about the optimal personal protective measures for medical staff caring for patients infected with these viruses. From 1972 to 2010, a high-level containment care (HLCC) unit at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), often called “the slammer,” was considered the gold standard for such care. The unit’s engineering controls were modeled after a biosafety level–4 (BSL-4) laboratory, with positive-pressure “space” suits, compressed in-line air, HEPA filtration, a decontamination shower, ultraviolet light pass boxes, an airlock, and antiseptic dunk tanks for movement of items in and out of the containment area. Toilet waste was discharged into the laboratory sewer system, and the facility possessed its own autoclave, operating room, and bedside laboratory. These built-in capabilities significantly reduced logistics challenges and provided reassurance that nosocomial spread could be reduced to near zero. Given the relatively high percentage of caregivers who have died of filoviral and other BSL-4 virus infections in the field, and the prior uncertainty in whether such high infection rates might be caused by droplet or airborne spread, utilization of such a containment facility seemed reasonable. Although used on occasion to quarantine field workers potentially exposed to highly hazardous viruses, the unit was used primarily for isolating individuals exposed to a BSL-4 virus in the laboratory. During the unit’s 38 years of operation, 21 patients were quarantined after potential exposures—and none became ill (3).


Over time, we learned that the spread of filoviruses occurs primarily by direct contact with blood and body fluids (1). Thus, it was determined that a patient care facility with the full panoply of BSL-4 laboratory–like features was no longer needed. The facility was decommissioned and refurbished as a training facility for scientists working in the institute’s containment laboratories.


If the USAMRIID HLCC is no longer needed because patients with filoviruses may be managed safely using barrier methods, one might ask whether any HLCC or biocontainment patient facilities are needed at all (4). Currently, 4 such facilities exist in the United States, operating at a higher level of containment (and possessing more sophisticated engineering controls) than a conventional hospital isolation room and yet lack some BSL-4 features present in the USAMRIID HLCC: Emory University Hospital, Atlanta, Georgia; University of Nebraska Medical Center, Omaha, Nebraska; Saint Patrick’s Hospital, Missoula, Montana; and the National Institutes of Health Clinical Center, Bethesda, Maryland. All except the University of Nebraska serve as referral centers for laboratories that work with BSL-4 viruses. Although patients infected with such diseases as Lassa and Marburg have been safely managed in conventional settings, the serious nature of filoviral and arenaviral infections, their rarity and unfamiliarity to clinicians in developed settings, the lack of effective treatments and vaccines, their propensity to infect health care staff, and the infection control challenges they present argue for, in our opinion, specialized containment and treatment facilities…

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