Clinical Overview of Marburg Virus Disease

Overview

Marburg virus disease is a rare, severe viral hemorrhagic fever that affects both people and other primates. The disease can lead to serious illness or death. Symptoms can appear suddenly and may include fever, rash, and severe bleeding.

Cause

MVD is caused by infection with one of two orthomarburgviruses, Marburg virus or Ravn virus.

Exposure risks

Family members and healthcare workers caring for patients infected with an orthomarburgvirus who have not used proper infection prevention and control measures are at a higher risk of becoming infected.

Certain occupations, such as veterinarians and laboratory or quarantine facility workers who handle non-human primates recently imported from Africa, may also be at increased risk of exposure to orthomarburgviruses.

Exposure risk can be higher for people in contact with infected non-human primates, travelers visiting enzootic regions in Africa who have contact with Egyptian rousette fruit bats (Rousettus aegyptiacus), which spread the virus, or enter caves or mines inhabited by these bats.

Incubation period

The incubation period for orthomarburgviruses ranges from 2-21 days from exposure.

Mortality rates

MVD has a high mortality rate of 20%–90%, depending on the virus strain and the level of case management. With early intensive supportive care and fluid replacement, mortality rates might be lower.

Clinical features

Early stage of disease

Patients with MVD generally have an abrupt onset of fever and symptoms typically 8 to 10 days after exposure. However, fever is not universally exhibited by all patients with MVD. Initial signs and symptoms are nonspecific and may include elevated body temperature or subjective fever, chills, myalgia, and fatigue. These are known as "dry" symptoms.

Malaria is the most common cause of acute undifferentiated fever after travel to sub-Saharan Africa and some other tropical areas. If applicable, follow Clinical Guidance: Malaria Diagnosis & Treatment in the U.S., as diagnostics should be done promptly and treatment instituted immediately. Typhoid fever, meningococcemia, and other bacterial infections, like pneumonia, also have similar nonspecific symptoms and can be confused with MVD.

Mid-late stage of disease

Four to five days after symptom onset, patients can progress to gastrointestinal symptoms, or "wet" symptoms. "Wet" symptoms can include severe watery diarrhea, nausea, vomiting, and abdominal pain. Other symptoms, such as chest pain, shortness of breath, headache, or confusion, may develop. Patients often have eye irritation and redness. Hiccups have been reported. Seizures may occur, and cerebral edema has been reported.

Bleeding is not universally present. However, it can manifest later in the course of disease as petechiae, ecchymosis or oozing from venipuncture sites, mucosal hemorrhage, or blood in stool or vomitus.

Patients may develop a mixture of flat and raised lesions on the skin, which are red in color, by days 5 to 7, usually involving the neck, trunk, and arms, that can peel or flake off.

Pregnant people may experience spontaneous miscarriages.

Patients with fatal disease usually develop more severe clinical signs early during infection and die typically between days 6 and 16 of complications, including multiorgan failure and septic shock. In nonfatal cases, patients may have fever for several days and improve, typically around day 6. Patients who survive can have a prolonged convalescence.

Prevention

There is no Food and Drug Administration (FDA)-approved vaccine for MVD. However, trials with an investigational vaccine are underway in Rwanda via the Ministry of Health, with a focus on healthcare workers.

Screening

Evaluate the patient

Early consideration of MVD in the differential diagnosis of a patient with consistent clinical and epidemiological factors is essential for providing appropriate and prompt patient care and preventing further transmission of the infection. It is important to systematically assess patients through a screening process and treat infections as soon as they are discovered.

Notify your health department

Healthcare providers with concerns about MVD infection in a patient should contact their jurisdictional health department immediately via the 24-hour Epi-On-Call contact list and follow jurisdictional protocols for patient assessment.

Clinical teams should coordinate with public health officials and CDC to assess the risk of MVD based on the clinical presentation and epidemiologic risk factors. This will help determine if testing is needed and what other causes of illness should be considered (e.g., malaria). This coordination can ensure proper patient care and appropriate precautions are taken to help prevent potential spread within the healthcare setting. Timely identification of other more likely pathogens and access to routine laboratory testing, such as blood counts and chemistries, are essential for providing appropriate patient care.

Treatment

There is no specific treatment for MVD. Supportive hospital therapy should be utilized, which includes:

• Balancing the patient's fluids and electrolytes
• Maintaining oxygen status and blood pressure
• Replacing lost blood and clotting factors
• Treatment for any complicating infections

Long-term effects

MVD is fatal in up to 90% of patients infected with the virus. There are little data on the persistence of orthomarburgviruses in survivors of MVD; however, since orthoebolaviruses and orthomarburgviruses are in the same virus family (Filoviridae), it can be assumed that orthomarburgviruses can persist in the same "immunologically privileged sites" as orthoebolaviruses: the testes, aqueous humor, placenta, and central nervous system.

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