The West African country of Equatorial Guinea declared an outbreak of the Marburg virus disease in mid-February. There have been at least nine laboratory-confirmed cases, seven of which resulted in death, and 20 probable cases of dead individuals in this outbreak, according to the World Health Organization.
Now, authorities in Tanzania, in East Africa, have confirmed that country’s first-ever case of the fatal disease. Health officials are investigating a total of eight cases, five of whom have died, and they have identified a total of 161 contacts who are being monitored.
As most people know now from the height of the Covid-19 pandemic, a virus can spread from one country to another and hop from continent to continent through human transmission. In terms of infection, we are one community, which is why I turned to CNN Medical Analyst Dr. Leana Wen to ask about the Marburg virus. Wen is an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health
I asked about the disease’s symptoms, what makes it so dangerous, how it is spread, whether there is a vaccine, and how the disease is treated. Finally, who should worry about the Marburg virus?
CNN: What is the Marburg virus disease?
Dr. Leana Wen: The Marburg virus disease is caused by the Marburg virus, which is in the same family of viruses as the Ebola virus. Like Ebola, Marburg causes a severe hemorrhagic fever that impacts multiple organ systems and can include profuse bleeding, and affects both humans and nonhuman primates. The viral infection is a zoonotic disease, meaning that the origin of the disease is transmission from animals to humans. With previous outbreaks, fruit bats have been identified as the hosts of the Marburg virus, from which the virus is then transmitted to people.
CNN: What are symptoms and what makes this disease so dangerous?
Wen: Marburg virus disease is extremely deadly and is highly contagious when engaging in direct contact with an infected person. With previous outbreaks, case fatality rates have ranged from 24% to 88%, with an average fatality rate of around 50%. That means about half the people who contract the disease will die from it.
Symptoms often start suddenly, with infected patients experiencing high fever, headache, muscle aches and malaise. It’s also common to have abdominal pain and cramping and heavy watery diarrhea.
This disease, like Ebola, is a hemorrhagic fever, in which infected individuals bleed from multiple orifices. Externally, patients might bleed from the nose, gums and eyes, and internal bleeding manifests as blood in vomit, urine and stool. Severe blood loss can cause shock and death.
The incubation period — the period from infection to the start of symptoms — is as short as two days to as long as three weeks. Most symptoms start within a week, with death occurring between eight and nine days after initial symptoms.
CNN: How is the Marburg virus spread?
Wen: Similar to Ebola, Marburg is spread via direct person-to-person contact. That includes contact with blood or other bodily fluids or objects contaminated with the bodily fluids of an infected person — such as bedding, clothing, needles and other medical equipment. Some cases have also been documented in which semen from a man who has recovered from Marburg has resulted in transmission to his partners.
Those most at risk of Marburg are people in direct contact with infected individuals. That includes family members, caregivers and health care workers. Individuals with suspected or confirmed Marburg virus should be placed in isolation. Those caring for them should wear protective gowns, gloves and masks to prevent direct physical contact with the patient.
CNN: Is there a vaccine? How is Marburg virus disease treated?
Wen: No vaccine has been developed against the Marburg virus, though there is an experimental vaccine and other vaccine candidates. There is no specific antiviral treatment. Infected patients are treated with symptomatic and supportive therapies, meaning that they would get fluids, oxygen and blood transfusions as necessary.
CNN: Who should worry about the Marburg virus?
Wen: At this time, cases of the Marburg virus disease have been found in just the two countries, Equatorial Guinea and Tanzania. Efforts are underway to contain these outbreaks. Successful containment has occurred in the past. Marburg is not a new disease — it was detected in 1967 after simultaneous outbreaks in Germany and Serbia. Numerous outbreaks have occurred since, including in Uganda, Democratic Republic of the Congo and most recently, in 2022, in Ghana.
Though the Marburg virus causes severe disease, there are ways to contain it. Individuals transmitting it to others are generally symptomatic. In addition, the Marburg virus is not an airborne virus. That makes it easier to control compared with Covid-19, which is often transmitted by people who are not exhibiting symptoms and is so contagious that it does not require direct contact and can be carried on microscopic aerosols.
The two Marburg outbreaks in West and East Africa must be monitored closely. Health care workers in these regions should be on high alert, and efforts to test a vaccine and treatments should be expedited. At this time, there is no need for most of the world to worry about the danger of Marburg infection. However, the Marburg virus is yet another reminder of the many zoonotic pathogens that are capable of causing severe harm to human health.