Marburg Virus Disease (MVD) is a rare but severe viral hemorrhagic fever with a high case fatality rate. This disease is caused by the Marburg virus, a pathogen belonging to the same Filoviridae family as the more widely known Ebola virus. The virus was first identified in 1967 following simultaneous outbreaks in laboratories in Marburg and Frankfurt, Germany, and in Belgrade, Serbia. These initial cases were traced to African green monkeys imported from Uganda for research purposes.
Symptoms and Progression of the Disease
The incubation period, the time from infection to the onset of symptoms, ranges from 2 to 21 days. During this period, an infected individual shows no signs of illness and cannot transmit the virus. The disease begins abruptly with symptoms that include a high fever, a severe headache, chills, and general weakness or malaise. Many individuals also experience significant muscle and joint pain.
Three to five days after the first symptoms appear, the illness progresses to severe gastrointestinal issues. Patients may develop severe watery diarrhea, abdominal pain, cramping, nausea, and vomiting. A non-itchy rash, most prominent on the trunk of the body, may also develop. The appearance of patients has been described as “ghost-like,” with drawn features, deep-set eyes, and expressionless faces.
In severe cases, hemorrhagic manifestations begin between five and seven days after symptom onset. This can involve bleeding from multiple sources, including in vomit and feces, as well as from the nose, gums, and vagina. The central nervous system can also be affected, leading to confusion, irritability, and aggression. The disease can progress to shock, liver failure, and multi-organ dysfunction, with fatal cases often occurring 8 to 9 days after symptoms begin.
Transmission from Animals and Between People
The initial transfer of the Marburg virus to humans is believed to occur from its natural reservoir, the African fruit bat, Rousettus aegyptiacus. Human infection can result from prolonged exposure to environments inhabited by these bat colonies, such as mines or caves. This spillover event introduces the virus into the human population.
Once a person is infected, human-to-human transmission becomes the primary driver of outbreaks. The virus spreads through direct contact with an infected individual’s blood, secretions, organs, or other bodily fluids. This contact must occur through broken skin or mucous membranes. Fluids with a high concentration of the virus, such as feces, vomit, saliva, and urine, are particularly infectious.
Surfaces and materials, like bedding and clothing, that have been contaminated with these infectious fluids can also serve as a source of transmission. Unsafe burial ceremonies, where mourners have direct contact with the body of someone who has died from MVD, represent another significant route of transmission. The virus can also persist in the semen of men who have recovered from the illness for up to seven weeks, allowing for transmission through sexual contact.
Diagnosis and Medical Management
Distinguishing Marburg Virus Disease from other infectious diseases like malaria or typhoid fever can be difficult in the early stages. The initial flu-like symptoms are not unique, so laboratory testing is required for a definitive diagnosis.
Several laboratory tests are used to confirm an MVD diagnosis.
- Antibody-capture enzyme-linked immunosorbent assay (ELISA), which detects antibodies the body produces to fight the virus.
- Antigen-capture detection tests.
- Reverse transcriptase polymerase chain reaction (RT-PCR) assays to identify the virus’s genetic material.
- Virus isolation in cell cultures, which must be done in high-containment laboratories.
Currently, there are no approved antiviral treatments or vaccines specifically for Marburg Virus Disease. Medical care is supportive, focusing on managing the patient’s specific symptoms and providing rehydration with oral or intravenous fluids. This supportive care, which includes managing electrolytes and any secondary infections, can improve survival rates.
Outbreak Containment and Prevention
Controlling a Marburg virus outbreak relies on a combination of public health strategies. Rapid surveillance and case investigation are foundational for identifying new cases quickly. Once a case is confirmed, contact tracing is initiated to find everyone who may have been exposed to the infected individual, so they can be monitored for symptoms.
Isolating infected patients is a primary measure to prevent further spread. This involves care in specialized facilities where barrier nursing techniques can be implemented. Healthcare workers use personal protective equipment, including gowns, gloves, masks, and eye protection, to avoid direct contact with infectious bodily fluids. Strict adherence to these protocols is necessary to protect medical staff and other patients.
Community engagement is another component of preventing the spread of MVD. Public health campaigns raise awareness about the risk factors for infection and the protective measures individuals can take. This includes promoting safe and dignified burial practices that avoid direct contact with the deceased and encouraging people to avoid caves and mines inhabited by fruit bats.