Marburg virus is an RNA virus of the Filoviridae family that causes the most virulent viral hemorrhagic fever indigenous to Africa. Since 1975, outbreaks have been reported in Kenya, South Africa, Zimbabwe, Ghana, Uganda, Angola, and Democratic Republic of Congo. In 2023, outbreaks were declared in Equatorial Guinea and Tanzania. In September 2024, Rwanda reported its first-ever Marburg virus disease outbreak. Tanzania declared another outbreak in January 2025. The mortality rate of Marburg is approximately 25%-90%, depending on the infecting viral strain.

Initial symptoms of Marburg include the sudden onset of 4-5 days of fever, chills, headache, weakness, myalgias, rash, chest pain, cough, sore throat, prostration, and conjunctivitis. The disease may progress to nausea, vomiting, diarrhea, abdominal pain, jaundice, pancreatitis, anorexia, photophobia, delirium, shock, liver failure, hemorrhaging, and multisystem dysfunction. Of note, in a 2023 case series of patients with Marburg virus disease in Equatorial Guinea, patients did not experience vomiting or diarrhea, and hemorrhagic signs appeared only at the terminal stage of the disease.

The incubation period is 2-14 days. The reservoir host of Marburg virus is a type of fruit bat native to Africa, the Egyptian rousette bat (Rousettus aegyptiacus). Human and nonhuman primates can become infected. Person-to-person transmission has been documented and may occur through contact with bodily fluids, including the bodily fluids of the deceased. There is no vaccine available, but convalescent human plasma may be helpful.

Zookeepers, tourists, owners of exotic pets, and veterinarians are susceptible to contracting Marburg.

In January 2009 the Centers for Disease Control and Prevention (CDC) confirmed the first known case of Marburg hemorrhagic fever in the United States. The patient had contracted the virus while visiting Uganda.