Marburg Virus Outbreak In Rwanda Infects Healthcare Workers

The deadly Marburg virus recently surfaced in an explosive outbreak for the first time in Rwanda, where the Ministry of Health reported the first cases on September 27^th. Since then, 46 cases have been reported, with 12 deaths. The majority of cases have occurred in healthcare workers. The source of the outbreak is under investigation.

What Is Marburg Virus?

Marburg virus, like its cousin, Ebola, can lead to large outbreaks with death occurring in up to 90% of those infected. Disease begins with an influenza-like illness including a high fever, weakness, sore throat, headache, body aches and sometimes a spotty red rash. After a few days, patients can move into a “wet” phase with significant vomiting and diarrhea. Near the end of the first week and into the second week of illness, the blood pressure can drop and victims go into shock, develop blood oozing from intravenous sites or sites of blood draws and ultimately may proceed to death. There are no licensed treatments or vaccines, although there are many candidate products being tested. The Sabin Vaccine Institute is providing an investigational vaccine to Rwanda for testing among healthcare workers at risk.

How Do Marburg Outbreaks Start?

Marburg and Ebola viruses have a way of targeting unprepared healthcare facilities. The healthcare facility may be quiet, until a sudden explosive outbreak occurs, seemingly coming from nowhere. The typical sequence starts when an infected patient is admitted and not properly diagnosed, because many other diseases causing fever may appear similar early in illness. Caregivers, laboratory workers, as well as family members who have close contact with the patient or their diagnostic samples are particularly susceptible to infection, because the diseases spread through blood or body fluids. As the illness progresses, patients may expel large amounts of infected vomit or diarrhea, which hold high concentrations of contagious virus. Anyone handling blood is also at risk, due to extremely high viral concentrations.

Where Did Marburg Come From?

Although cave-dwelling African fruit bats appear to harbor Marburg virus, the virus is stealthy. Initial human exposure may occur directly from contact with bats, other infected animals, such as a monkey or an infected human. Marburg first surfaced in 1967 in Marburg and Frankfurt, Germany and Belgrade, Yugoslavia, after African green monkeys were imported for scientific research. Thirty-one individuals who had contact with the infected animals, animal tissues, or direct contact with human victims became ill and seven died. Marburg virus has demonstrated the ability to resurface in the past few years in new and unexpected places. In 2023 alone, Equatorial Guinea and Tanzania experienced their first-ever outbreaks of Marburg. It also surfaced for the first time in Ghana in 2022.

How Do We Prevent Spread Of Marburg In Healthcare Facilities?

In the 2013-2016 outbreak of Ebola virus disease in West Africa, cases in healthcare workers occurred in higher proportions compared to the rest of the population. Even more concerning was that the proportions of deaths in healthcare workers also exceeded those of the civilian populations. Due to the high risk to healthcare workers, organizations such as the CDC and WHO have developed guidelines on how to manage patients with Ebola and Marburg safely.

The key to preventing the spread of infection in a healthcare facility is to have a plan for baseline infection prevention, with the ability to ramp up to specific viral hemorrhagic fever precautions once infected patients are identified. This may sound simple, but it requires resources for the appropriate personal protective equipment, dedicated care teams and regular training. This is challenging to achieve in developed nations and even more so in resource-limited settings, especially those that have not previously managed infected patients.

The challenge of caring for patients infected with viral hemorrhagic fevers, such as Ebola, Lassa and Marburg has long been recognized. The United States Army Medical Research Institute of Infectious Diseases, USAMRIID, even created its own intensive care unit in the late 1960s, nicknamed the “Slammer” (because admission to the unit felt like being incarcerated) to care safely for patients infected with such viruses, or even an unknown, deadly pathogen. The facility had all the trappings of a biosafety level 4 “maximum containment” laboratory: caregivers donned blue space suits while providing patient care, the air exhausted from the unit was HEPA filtered, liquid waste was steam-sterilized before leaving the facility and caregivers exited through a decontamination shower.

The Slammer was the first of its kind and had the most sophisticated capabilities in the United States. Prior to the 2013-2016 Ebola outbreak, three other facilities became operational and cared for patients during the outbreak: Emory University Hospital in Atlanta; the University of Nebraska Medical Center in Omaha and the NIH’s Clinical Center in Bethesda, Maryland. Subsequently, these and other partner organizations in the United States, teamed up to form the National Emerging Special Pathogens Education Center, NETEC, to help train and assess hospitals for their preparedness to manage viral hemorrhagic fevers and other special pathogens. Since 2016, several similar biocontainment facilities have stood up at major medical centers across the country as concern for importation of exotic and potentially deadly emerging diseases has increased. The framework for response has divided hospitals into three tiers of response: frontline healthcare facilities to rapidly assess and triage potential patients; Ebola assessment hospitals to isolate and evaluate potential patients and Ebola treatment centers to be ready to provide definitive care safely of any diagnosed viral hemorrhagic fever patients.

The Marburg outbreak in Rwanda continues to evolve, with more patients continuing to be identified. Two individuals, who had potential exposure while in Rwanda were recently evaluated in Germany and found to be negative. Healthcare providers should be on alert for potential cases arriving in their hospitals, so that they are not caught by surprise and can activate appropriate safety measures, as needed. Hopefully, the vaccine clinical trial will provide useful data to move us on a pathway closer to having an effective vaccine. In the meantime, our best option is to prevent further spread of illness in health facilities and to provide supportive care for ill patients.