During infectious disease outbreaks, healthcare workers serve on the front lines to stop the spread of disease. Their critical role in response sometimes comes with a price: during the 2014-16 Ebola outbreak in West Africa, healthcare workers were between 21 to 32 times more likely to become infected than other members of the public in the affected communities. This week, as another Ebola outbreak occurs in the Democratic Republic of the Congo (DRC), Outbreak Observatory looks at the impact of healthcare worker infections, and the important role that the Ebola vaccine can play in reducing them.

New Outbreak, Old Foe

Since the virus discovery in 1976, Ebola Virus Disease (EVD) has struck dozens of times. Ten of these outbreaks have occurred in DRC, or Zaire, as it was formerly known, including an outbreak in Equateur province in May. In the last five years alone, EVD has struck the DRC a shocking four times. This time, just a week after DRC was declared free of Ebola in Equateur province, it announced that it had found a separate, unrelated outbreak of the disease in North Kivu.

According to the DRC Ministry of Health, as of August 8, there are 44 cases, 17 of which are confirmed, and 36 deaths in the affected region. Though genetic analysis of the North Kivu outbreak strain has provided some good news--the same Ebola vaccine that was used in the Equateur outbreak is likely to be as effective against the current outbreak--the fact that a separate outbreak of Ebola occurred in DRC so shortly after the previous one was contained is worrisome and suggests the need for continued vigilance.

Healthcare Worker Infections

In both of the recent Ebola outbreaks in DRC, healthcare workers have been among the reported cases. As of last week, at least three of the Ebola cases in North Kivu were healthcare workers, two of whom died. In the outbreak that was recently contained in Equateur province, 7 of 54 confirmed and probable Ebola cases occurred among healthcare workers, two of whom died.

As stated above, healthcare worker infections have been reported in previous Ebola outbreaks. Out of the more than 11,000 lives lost during the 2014-16 West African Ebola epidemic, 513 of those belonged to healthcare workers infected on the job. Additionally, 813 healthcare workers fell ill. The impact of these losses were huge, given the low number of healthcare workers in the region to begin with. The factors leading to healthcare worker infection are numerous. A study found that during the 2014-16 West African Ebola epidemic, one main factor leading to healthcare worker infection included overburdened facilities, characterized by insufficient staff to properly care for patients following infection control practices, such as safe donning and doffing of personal protective equipment (PPE). Another factor identified in the study included the compassionate care of colleagues, family, and friends outside of normal work hours and settings, which led to infrequent or insufficient use of PPE.

Infections among healthcare workers warrant special attention. First, in each of the areas where Ebola outbreaks have occurred, the ability to provide routine healthcare has historically been challenged by insufficient numbers of healthcare workers, medical supplies, and PPE. Further reducing the number of available healthcare workers due to illness not only increases the number of Ebola patients needing treatment in these strained systems, but decreases resources available to provide this treatment. The 2014- 2016 West African Ebola epidemic led to an 8% decrease in healthcare workers in Liberia, and a 23% decrease in health services in Sierra Leone.

Decreases in available healthcare workers may negatively affect the outcomes of patients. The availability of medical resources, such as adequate personnel and the availability of critical care, has been shown to increase Ebola patients’ chances of survival. As a result, much has been written on the disparity of survival rates among Ebola patients treated in low and high resource settings. But, an erosion of healthcare resources during Ebola outbreaks may also compromise the care of patients without Ebola. For example, a study estimated that the loss of healthcare workers (including midwives) to Ebola in West Africa would lead an additional 4,022 women to die in childbirth each year in Liberia, Guinea, and Sierra Leone.

An additional concern posed by healthcare worker infections is the potential for increased transmission within healthcare settings and from within health facilities to the surrounding community, whereby health facilities serve as amplifiers of disease into the surrounding community.

The Role of Vaccines

Although healthcare worker infection poses a huge threat to the lives of healthcare workers and the functioning of the entire health system, there is hope that new vaccines can improve their safety. In the years since the 2014-16 Ebola epidemic, pharmaceutical company Merck has rolled out an experimental vaccine, rVSV-ZEBOV, approved by the WHO for use in outbreak response. During the May outbreak of Ebola in DRC, the vaccine was used to protect healthcare workers and contacts. This vaccine was successfully used as part of a ring vaccination, helping to bring the outbreak to a halt just a few months after it began.

Roll-out of vaccines to healthcare workers in North Kivu has already begun. The WHO announced that on August 8, two provincial health officials and some first line health workers from a clinic in Mangina were the first to receive their vaccines. Vaccination of community members and their contacts are expected to take place soon. A group of experts from Guinea have also been deployed to supervise the effort.


With the outbreak still in its early stages, it is difficult to predict what impact the vaccine will have. Though the Ebola outbreak in Equateur province was successfully contained, it is worth noting that the North Kivu outbreak is occuring in a conflict zone, which will make contact tracing, treatment, and even ring vaccination much more challenging. However, it is hoped that vaccination will become a vital tool to protect healthcare workers, whose safety must be ensured to maintain the functioning of the healthcare system and contain outbreaks of Ebola and other diseases.

Photo: This picture illustrates many factors that had improved over time, during the course of the outbreak, including the burial team’s appropriate use of personal protective equipment, and use of a burial shroud for a deceased person of the Muslim faith, and improved marking of graves where people were buried in the cemetery. 

Photo courtesy of CDC/Carrie Nielsen, Ph.D.

Outbreak Observatory aims to collect information on challenges and solutions associated with outbreak response and share it broadly to allow others to learn from these experiences in order to improve global outbreak response capabilities.