Several close contacts of a Scottish nurse who was recently hospitalized with severe complications following an earlier Ebola infection have been vaccinated with an experimental vaccine, similar to ring vaccination taking place in Guinea and Sierra Leone.

In research developments, a study of personal protective equipment (PPE) shed new light on Ebola contamination during removal, and new mathematical modeling estimates based on response data say that earlier delivery of Ebola treatment beds to Sierra Leone could have halved the number of deaths.

Contacts offered VSV-EBOV

Nurse Pauline Cafferkey got sick in late December after returning from working in Sierra Leone and was hospitalized in London, then released on Jan 24. However, she was hospitalized again at Royal Free Hospital on Oct 9 after getting sick with what doctors call a complication of her previous illness, which they said doesn't reflect a new case of Ebola.

She is being treated in the facility's high-containment unit, however, but health officials say the risk to the public remains extremely low. The Ebola virus has been known to linger in protected immune sites such as the eyes. Also, long-term effects from the disease can be debilitating.

Fifty-eight people have been identified as close contacts, National Health Service (NHS) Greater Glasgow and Clyde said yesterday in a statement. Among them are healthcare workers, family, friends, and community members.

An expert group has recommended that, as a precaution, people who may have had contact with the woman's body fluid be offered vaccination, which has been administered. The vaccine is VSV-EBOV, which is in phase 3 trials in Guinea and Sierra Leone. The vaccine was developed by Canadian scientists and is licensed by NewLink Genetics and Merck. Early results of a ring vaccination trial in Guinea suggested that it is highly effective.

Of 40 close contacts who were confirmed to have had direct contact with the woman's body fluids and were offered the vaccine, 25 accepted it, and 15 declined or were unable to be immunized because of pre-existing medical conditions.

The NHS said all 58 contacts will be closely monitored, with the 25 who were vaccinated undergoing even closer monitoring, due to the experimental nature of the vaccine, which has been known to cause a rise in body temperature—which can also be an Ebola infection symptom—among about a quarter of those who receive VSV-EBOV.

PPE experiments, training needs

Meanwhile, PPE experiments that used fluorescent lotion in place of Ebola virus or other pathogens shed new light on contamination risk during doffing and can be a useful part of training for healthcare workers, according to a research team from Ohio. The group published its findings yesterday in JAMA Internal Medicine.

The study consisted of a convenience sample of healthcare workers from four northeastern Ohio hospitals and was conducted from late October 2014 through the end of March. Glove and gown simulations using the fluorescent lotion to assess the frequency of contamination were done at the facilities.

Researchers also tested the frequency of contamination in Ebola training sessions that include removal of full-body-coverage PPE. At one of the hospitals, the team tested an educational intervention designed to reduce contamination.

Of 435 gown and glove removal simulations, contamination of skin or clothing occurred in 200 (46%), with a similar pattern seen at each of the four hospitals. Contamination occurred more frequently with glove removal than with gowns and when observers saw lapses in technique. Contamination occurred a third of the time, even when observers noted no technique lapses.

The intervention consisted of an educational session based on US Centers for Disease Control and Prevention (CDC) protocols, with the study following staffers practicing removal of gloves that were contaminated with the fluorescent lotion.

Researchers found that the intervention reduced skin and clothing contamination during glove and gown removal, with improvements that were sustained at the 1- and 3-month marks.

They concluded that contamination of skin and clothing occurs frequently during glove and down doffing and that an intervention that combines practice with visual feedback can reduce the risk.

In an editorial that accompanied the study, two experts from Virginia Commonwealth University wrote that the experiment's visual feedback training appears to be effective and that standardized training methods for donning and doffing PPE are long overdue. The experts are Michelle Doll, MD, and Gonzalo Bearman, MD, MPH, with the division of infectious disease in the university's medical school.

A standard, accepted, and validated training protocol hasn't been developed, and debates remain on what constitutes proper donning and doffing, they wrote. Though the CDC's protocols are widely used, even those recommendations have been found by some to be insufficient.

Targeted training on PPE removal and an ongoing emphasis on rigorous hand hygiene are critical steps for empowering healthcare works, the two wrote, not just for pathogens such as Ebola but also for routine care procedures.

Ebola bed impact estimate

Meanwhile, modeling projections from researchers at the London School of Hygiene and Tropical Medicine (LSHTM) examining the impact of increasing Ebola treatment beds in Sierra Leone suggested that adding thousands of beds over the fall and winter averted 57,000 infections and 40,000 deaths. The group published its findings yesterday in Proceedings of the National Academy of Sciences (PNAS).

From September 2014 to February 2015, Sierra Leone received more than 1,500 treatment beds for Ebola holding centers and another 1,200 for its Ebola treatment units, according to the study.

The group's analysis suggests that introducing the beds 1 month earlier may have halved the outbreak.

Study coauthor John Edmunds, MSc, PhD, said in an LSHTM press release that there has been much criticism regarding the world's slow response to the outbreak, and that the study suggests that deploying the beds earlier could have reduced the size of the outbreak and saved thousands of lives. "The way we prepare for, and respond to, future outbreaks of Ebola and other infectious diseases needs to be strengthened," he said.

See also:

Oct 12 NHS statement

Oct 9 CIDRAP News story "UK nurse has Ebola relapse as J&J vaccine trial starts"

Oct 12 JAMA Intern Med study

Oct 12 JAMA Intern Med commentary

Oct 12 PNAS abstract

Oct 12 LSHTM press release