Although the risk of an Ebola outbreak in the United States remains low, recent confirmed infections in 2 Dallas health care workers have intensified preparedness activities. While investigators continue to probe how the transmissions occurred, US health systems are formalizing processes to identify and care for patients infected with Ebola virus—often referred to as “preparedness.”
As of October 15, 8973 cases and 4484 Ebola deaths had been reported in West Africa since the outbreak’s start last March. In recent weeks, US health professionals have seen 8 patients with Ebola virus infection: 7 US residents and 1 from Liberia; 5 of the US residents contracted the disease in West Africa where they were diagnosed before returning to the United States for treatment. On October 12, health officials confirmed Ebola infection in a nurse who cared for the Liberian patient at a Dallas hospital. A second nurse from the same hospital was diagnosed with Ebola infection 3 days later.
Basic preparedness activities include developing specific screening and triage questions, based on the Centers for Disease Control and Prevention (CDC) recommendations, in different health care settings, including emergency departments and outpatient and inpatient settings. Other components include ensuring that clinical areas have protective clothing and equipment, and all staff are instructed on proper use.
For example, the University of Michigan Health System is conducting an exercise for its adult and pediatric emergency departments to identify problem areas and strategies to address them. Performed with great caution, the exercise will involve clinicians, nurses, and other health system staff as well as “mock” patients being triaged to emergency departments. Emergency management and Infection Prevention & Epidemiology professionals will assess screening, escalation, isolation, personal protective equipment (PPE), and lab point of care testing.
Although health officials continue to stress the benefit of early diagnosis of Ebola virus disease (EVD), no point-of-care diagnostic tests are yet available. If the diagnosis is suspected or confirmed, treatment remains largely limited to supportive measures, such as intravenous fluids, medications to maintain blood pressure, and antibiotics to treat concurrent infections. To date, there are no effective treatments and no approved vaccine. A number of experimental vaccines and therapies are being developed, including ZMapp, a combination of 3 different monoclonal antibodies. Other agents being studied include whole blood and immune serum, and novel antivirals. There has also been interest in drugs such as statins that affect the inflammatory cascade, because acute inflammation appears to be common among patients who die. Most of the agents have yet to be evaluated in phase 1 human studies and all are in limited supply.
Despite the large numbers of patients affected in Africa, clinical evaluation and laboratory testing have been in short supply due to resource limitations. The clinical team at Emory University, led by Bruce Ribner, MD, made several key observations based on treatment of 2 patients with EVD. Ribner recently summarized the team’s observations for infectious diseases specialists at the IDWeek 2014 conference in Philadelphia.
Ribner noted that despite weight gains of 15 to 20 kilograms, both patients experienced profound fluid loss. Electrolyte losses also were significant and included dangerously low levels of sodium, potassium, and calcium, resulting in heart rhythm abnormalities. Ebola virus RNA was detected in blood, urine, vomitus, stool, endotracheal suctioning and semen and on skin. However, environmental testing in the patient rooms yielded no evidence of viral RNA, including several high-touch areas like bed rails and bathroom surfaces.
Ribner also discussed differences between guidance for laboratory testing from the CDC and the American Society for Microbiology. The Emory team considered what might happen if a specimen from an EVD-infected patient spilled in the main lab: the laboratory would be closed for hours and would adversely affect functions throughout the entire hospital. In addition, there was concern that laboratory technologists would not perform tests on blood from patients with EVD, prompting the Emory team to set up a “point-of-care” testing area next to the patient care unit. Lab testing was kept to a minimum in order to limit exposures.
Health care workers were trained to use PPE that included impermeable body protection (gown, leg, and shoe covers), face mask or N95 facepiece respirators, eye and face protection (goggles and face shield), and gloves. Practical considerations led the Emory team to use full body suits and powered air purifying respirators, a decision based in large part on the need to work for extended periods of time.
Even waste disposal raised unexpected challenges. Although the CDC guidance indicates that sanitary sewers are acceptable for patient waste, the local water authority in Atlanta disagreed. The Emory team disinfected all patient liquid waste with bleach or quaternary detergents for 5 minutes before it could be flushed. The hospital’s waste disposal contractor would only pick up materials that were certified as free of Ebola virus. As a consequence, the hospital dedicated an autoclave to process all materials used in clinical care so they would be accepted as regulated medical waste. By the end of the patients’ stay, the autoclaved and boxed materials filled several trailers—for just 2 patients.
The current Ebola epidemic illustrates the need for dedicated funding for infection prevention programs worldwide. Because Ebola transmission risk is highest during severe illness, transmission to caregivers has been a major feature of most prior Ebola outbreaks. A recent statement from the Society for Healthcare Epidemiology (SHEA) indicated that increased resources for infection prevention programs will improve the response not only to Ebola but to other infectious diseases. The statement also noted that the complexity of ensuring 100% adherence to infection control practices, particularly with PPE, points to the need for improved training of health care workers across all practice settings. “Dedicated funding at the hospital, state, and national levels for infection prevention programs helps protect patients and health care workers from both Ebola and other health care–associated infections,” said Daniel Diekema, MD, SHEA president.
Michael Edmond, MD, chief quality officer, University of Iowa Hospitals and Clinics, emphasized the need to rethink some of the rituals surrounding clinical care in the age of Ebola. “The progression of the Ebola epidemic, particularly the recent episodes of transmission to health care workers who wore appropriate personal protective equipment, raises interesting questions. . . . Ebola also pushes us to reconsider therapies that have a reasonably high probability of futility but increase risk to health care workers,” Edmond wrote on his website, http://haicontroversies.blogspot.com.
“In the case of the Dallas patient, who underwent endotracheal intubation and hemodialysis, we are left to question whether these procedures played some role in infection of the critical care nurse. Should [cardiopulmonary resuscitation], which would seem to involve a very high degree of risk to bedside providers, not be performed? The ethical issues associated with withholding these procedures typically associated with routine critical care need to be explored since the risk-benefit calculus is markedly shifted by the level of risk to health care workers,” he added.