By Gary Evans, Medical Writer

As of June 20, 2018, the Ebola outbreak in Congo has been largely contained, but at the cost of the lives of two healthcare workers.

As this issue went to press, the last confirmed case-patient in Congo developed symptoms on June 2, 2018, and died on June 9, the World Health Organization (WHO) reported.1

From April 1 through June 18, there have been a total of 60 Ebola cases, including 28 deaths. The total includes 38 confirmed, 14 probable, and eight suspected cases.

“Five cases were healthcare workers, of which four were confirmed cases, and two died,” WHO reported.

Of 1,706 contacts of cases registered to date, 244 contacts remain under active follow-up as of June 18.

It was not known at press time whether the healthcare workers who acquired Ebola had received the experimental vaccine that has been implemented on an emergency-use basis.

Since the launch of the vaccination intervention on May 21 through June 17, a total of 3,137 people had been vaccinated in Congo. The vaccine, called rVSV-ZEBOV, was found to be highly protective against the virus in a trial conducted by WHO in Guinea in 2015. The vaccine has not yet been licensed by the FDA, and there is no recommendation for pre-exposure vaccination of U.S. healthcare workers.

In a triumph of genetic engineering, the vaccine consists of an animal vesicular stomatitis virus seeded with the protein of Zaire Ebola. It provokes a human immune response to the Ebola virus.

In a “ring” vaccination approach, contacts with an Ebola case include those living in the same household or those who were visited by the patient in the three weeks prior to diagnosis. Further, “contacts of contacts,” including neighbors or extended family members, also may be vaccinated.

“The ring is not necessarily a contiguous geographic area but captures a social network of individuals and locations that may include dwellings or workplaces further afield, where the index patient spent time while symptomatic, or the households of individuals who had contact with the patient during the illness or after his or her death,” WHO stated. “Experience suggests that each ring may be composed of an average of 150 persons.”

Vigilance in the U.S.

In the U.S., healthcare facilities are advised to be vigilant for travel cases linked to the outbreak.

“U.S. healthcare facilities should continue to seek travel histories as a routine part of initial patient triage and assessment,” says CDC spokeswoman Kate Fowlie. “In the context of the current outbreak, travel to the Ebola-affected health zones in [Congo] or contact with an individual with confirmed Ebola within the previous 21 days should trigger further symptom evaluation.”

Now is a good time for facilities to review their status as frontline, assessment, or treatment centers, and confirm that current health department contact information is readily available, she adds. The CDC recommends a strategy of “Identify, Isolate, and Inform,” which calls for immediately isolating suspected Ebola cases and alerting the facility’s infection preventionist and the health department.

For personal protective equipment (PPE), CDC recommends following its guidance2 for U.S. healthcare settings developed during the 2014-2015 outbreak. Some 11,000 people — including one in the U.S. — died during that outbreak, which also involved the Zaire strain of the Ebola virus.

Active surveillance activities are ongoing in Congo, including daily follow-up of contacts of cases in the community and at healthcare facilities. Infection prevention and control supplies, including PPE and disinfectants, have been provided to health facilities throughout the region.

In addition to the experimental vaccine, WHO is providing technical advice on the use of investigational therapeutics, which are being used for the first time to treat some cases as approved by an ethics review board.

As of June 19, 26 countries have implemented entry screening for international travelers coming from Congo, but there are currently no restrictions of international traffic in place. WHO continues to monitor travel and trade measures in relation to this event.

The index case for the current outbreak in Congo was reported on April 4. No Ebola cases were being treated in the U.S. as this report was filed, but the CDC deployed eight experts to the region to assist in the outbreak. The agency also posted a Level 1 Watch travel notice for Ebola in Congo.

“We are monitoring the outbreak and are not currently recommending people avoid travel,” Fowlie says.

Although the risk to most travelers is low, visitors to Congo should avoid contact with blood or body fluids, funeral or burial rituals that require handling a dead body, raw bush meat, and wild animals. The 2014 outbreak was thought to have begun with a child who was playing in a hollow tree full of bats, which can asymptomatically carry the virus.


1. WHO. Ebola virus disease – Democratic Republic of the Congo. June 20, 2018. Available at:

2. CDC. Ebola Virus Personal Protective Equipment. Available at: