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Ebola in US triggers travel screening, advanced protocols for HCWs
In October, two health care workers from Texas Health Presbyterian Hospital in Dallas were confirmed to have contracted Ebola from Thomas Eric Duncan, the first patient diagnosed with the infection in the United States. Duncan died on Oct. 8.
The CDC confirmed the first health care worker case on Oct. 13. The nurse, Nina Pham, was later sent to the NIH Clinical Center and has since been declared free of Ebola and discharged. The second nurse case, Amber Vinson, was confirmed on Oct. 15. She was sent to Emory University Hospital for treatment and was released on Oct. 28.
Vinson’s case was not without incident: She reported air travel the evening before her symptoms developed, prompting the CDC to reach out to passengers on the flight. CDC Director Thomas Frieden, MD, MPH, said she had traveled to Ohio before Pham became ill. At the time of her flight back to Texas, however, Vinson was among the group with known exposure to Ebola and should not have traveled.
“This patient should not have been allowed to travel by plane or public transport by virtue of being in an exposed group,” Frieden said during a media briefing. “Although she did not report any symptoms or meet the fever threshold of 100.4, she did report that her temperature was 99.5. By both of those criteria, she should not have been on that plane. We will, from this moment forward, ensure that no other individual being monitored for exposure undergoes travel in any way other than controlled movement.”
Although the level of risk to people around her on the plane was extremely low, the CDC asked passengers on both of Vinson’s flights to contact the CDC. The flights were Frontier flight 1142 on Oct. 10 from Dallas to Cleveland, and Frontier flight 1143 on Oct. 13 from Cleveland to Dallas.
Health care worker safety
The cases of Ebola in the Dallas nurses brought to the forefront the issue of hospital preparedness for caring for patients with the infection.
Both nurses had been wearing personal protective equipment (PPE) while caring for Duncan. The CDC is investigating how the infections occurred, but Frieden said it may have resulted from variability in procedures observed in putting on and taking off protective equipment.
The two cases have prompted the CDC to expand contact investigations to include other health care workers with potential exposure. It identified 76 potential contacts, though none has shown symptoms of the disease.
None of Duncan’s 48 additional contacts under investigation by the CDC developed Ebola.
Shortly after the nurses’ infections were confirmed, the CDC announced new recommendations for any health care institution caring for a patient with Ebola. First and foremost, Frieden said, is that a site manager should be overseeing every aspect of infection control around the clock. Increased infection control training for health care workers and reducing the number of workers entering isolation units also were advised.
“Every hospital in the country needs to be ready to diagnose Ebola,” Frieden said. “That means that every doctor, every nurse, every staff person in the ED who cares for someone with fever or other signs of infection needs to ask, ‘Where have you been in the past month?’ ”
The CDC also has tightened guidance on PPE use, offering detailed steps on safely putting on and taking off the equipment. The guidance is focused on three principles: rigorous training, no skin exposure and supervision when putting on and taking off equipment.
Airport entry screening
Early in October, the CDC and the Department of Homeland Security’s Customs and Border Protection (CBP) implemented entry screening for Ebola at five airports that receive more than 94% of travelers from Guinea, Liberia and Sierra Leone. The five airports include New York’s JFK, Washington-Dulles, Newark, Chicago-O’Hare and Atlanta.
Later in the month, the Department of Homeland Security mandated all travelers from these countries be directed through one of those five airports.
“We work to continuously increase the safety of Americans,” Frieden said in a press release. “We believe these new measures will further protect the health of Americans, understanding that nothing we do will get us to absolute zero risk until we end the Ebola epidemic in West Africa.”
CDC staff have been dispatched to each airport and screening will begin when CBP officers review passports. Travelers from Guinea, Liberia and Sierra Leone will be escorted to a designated screening area, observed by CBP staff for illness and asked questions about their health and exposure. Medical staff also will take travelers’ temperatures.
Travelers with fever, symptoms or possible Ebola exposure will be evaluated by a CDC quarantine station public health officer. Those determined to require evaluation or monitoring will be referred to public health authorities. Travelers without symptoms, fever or a history of exposure will be asked to complete a daily temperature log and provide contact information.
“CBP personnel will continue to observe all travelers entering the United States for general overt signs of illnesses at all US ports of entry and these expanded screening measures will provide an additional layer of protection to help ensure the risk of Ebola in the United States is minimized,” Alejandro Mayorkas, deputy secretary of homeland security, said in the press release.
Enhanced monitoring
Without any exit or entry screening, three people with Ebola are estimated to depart from Guinea, Liberia and Sierra Leone per month, according to a recent study published in The Lancet.
Researchers from the University of Toronto examined international flight schedules collected by the International Air Transport Association to predict the number of exported Ebola infections based on WHO virus surveillance data from the three countries. When accounting for significant reductions in air travel since the outbreak began — 51% in Liberia, 66% in Guinea and 85% in Sierra Leone — 2.8 people with Ebola would leave the three countries each month, the researchers estimated.
In an accompanying commentary, Benjamin J. Cowling, PhD, BSc, FFPH, of the University of Hong Kong, and Hongjie Yu, MD, MPH, of the Chinese Center for Disease Control and Prevention, reiterated the need for international support in the effective implementation of exit screening. They cautioned, however, that it may not be enough, because of Ebola’s long incubation period and rapid disease progression.
“In addition to any entry or exit screening, vigilance within countries is essential for early detection of imported cases of Ebola virus disease,” they wrote.
In another measure after implementing entry screening, the CDC will conduct active monitoring of travelers returning to the United States from Guinea, Liberia and Sierra Leone to quickly identify people with fever or symptoms of Ebola. The 21-day post-arrival monitoring will take place in six states where approximately 70% of the incoming travelers are bound: Georgia, Maryland, New Jersey, New York, Pennsylvania and Virginia.
State and local health officials in the six states will work with the CDC to actively monitor the arrivals, who will be required to report their temperature daily and the presence or absence of Ebola symptoms. Arrivals will be required to provide extensive contact information for the active monitoring period.
References:
Bogach II. Lancet. 2014;doi:10.1016/S0140-6736(14)61828-6.
CDC. Guidance on Personal Protective Equipment To Be Used by Healthcare Workers During Management of Patients with Ebola Virus Disease in U.S. Hospitals, Including Procedures for Putting On (Donning) and Removing (Doffing). Available at: www.cdc.gov/vhf/ebola/hcp/procedures-for-ppe.html. Accessed Oct. 25, 2014.
Cowling BJ. Lancet. 2014;doi:10.1016/S0140-6736(14)61895-X.
Disclosure: Bogach and two other researchers report ties to BioDiaspora, a social benefit corporation which models global infectious disease threats. Cowling reports research funding from MedImmune and Sanofi Pasteur, and he consults for Crucell.
Perspective
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It is somewhat surprising that the two Dallas nurses became infected, when they were using personal protective equipment, but it appears that what they used was inadequate. When health care workers (HCWs) become infected, it is important to revisit each step of the process to understand what went wrong and to learn from the error. For the very few individuals who will continue to come to the United States with Ebola, we’ll know the additional steps that need to be done to protect HCWs. There will be more cases, mainly HCWs coming back from Africa after being infected.
I am certain that most hospitals know what to do when they see a patient with suspected Ebola infection. Once you know or suspect someone has this diagnosis, the vast majority of hospitals activate disaster plan procedures, which they all have practiced. They know how to triage patients, how to provide intensive care and how to implement proper infection control. It’s a question of being retrained in what most every hospital in the United States knows. It comprises the same processes we learned to do in the middle of an anthrax scare or an influenza epidemic. It’s not new, but it has different twists to it: Asking the right questions at intake to consider the diagnosis, and if confirmed, taking the utmost precaution with proper protective equipment, along with training on how to put on and remove equipment, when a patient has a high viral load and therefore has very infectious body fluids.
It’s unfortunate that the Dallas hospital was the first to see a patient with Ebola. The diagnosis was delayed and they weren’t completely prepared after Mr. Duncan was admitted. But at that time, there were only four designated hospitals in the United States that are specifically set up for this type of situation, with everything in place ahead of time. Other hospitals all over the country are now ready, but the reality is they’re probably never going to see a patient with Ebola.Perspective
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The entry screening makes sense. I don’t consider it very invasive. I don’t know the specifics, but there are many simple ways to take peoples’ temperature. However, it will be minimally effective, particularly if they’ve been screened when exiting West Africa. They would have to develop their fever within the small window of the flight. I don’t think it would be worth it if it was very expensive or invasive, but it’s such a simple thing to do to prevent an occasional case, and it is likely to add some reassurance for the general public. The reason we’re not going to have a serious epidemic is because our public health infrastructure is much more robust than what is available in West Africa. We have the ability to do good infection control, identify potentially infected people, isolate them and track down their contacts. There may be some secondary cases, but there will never be thousands and thousands of cases here.
Monitoring those returning from the affected area for the 21-day incubation period is reasonable, but is not a guarantee for two reasons. First, it is generally impossible for a patient to absolutely identify when they acquired the virus, so this estimation of 21 days is an educated guess. The only way to really establish an incubation period is to expose a large number of people and then track when they become ill. In addition, 21 days is not designed to identify all cases: It is designed to identify 95% of cases. In most diseases, there are outliers. Although 95% is a very reasonable goal in West Africa, some people may not be comfortable with 95% in this country. Though obviously, prolonging the quarantine for everyone to identify an occasional outlier has its own problems.