Marburg Virus - An Overview on Infection Prevention and Control

What Is Marburg Virus?

Marburg virus (MARV) is an RNA virus that belongs to the Filovirus (Filoviridae) family. It is a cousin to the Ebola virus and is equally deadly. It is known to have limited strain variations and a slow mutation rate.

The virus is named after the place where it was first discovered, Marburg (Germany), in a laboratory in 1967. The virus has had several outbreaks since its first discovery, the most recent being in Equatorial Guinea (a country in Central Africa) on February 14th, 2023.

Where Is Marburg Virus Found?

The first case recorded was a scientist working in a laboratory on an African green monkey (Cercopithecus aethiops). This was widespread among close workers and family members.

The common factor among most reported cases later was that the individuals would have recently visited caves or worked in mines colonized by fruit bats (Rousettus aegyptiacus) and probably came in contact with infected fruit bats.

Since then, the reservoir for this virus has been claimed to be the fruit bats and seems to be spread across the African continent.

How Does Marburg Virus Spread?

• Prolonged exposure to the virus through feces, blood, or saliva of infected bats.

• A healthy individual comes in contact with an infected individual through:

  • Blood, such as contact with cuts and bruises.

  • Secretions such as sweat, urine, or other bodily fluids.

  • Surfaces or materials contaminated with infected bodily fluids (for example, clothing, vessels)

  • Hospital care (for example, health worker taking care of infected patients without protection)

• Recovered individuals are considered infected as long as one's blood contains the virus.

• The burial of individuals deceased due to the virus must be done with preventive measures.

What Does Marburg Virus Do to Humans?

Marburg virus causes hemorrhagic fever in humans. A fever is termed hemorrhagic when the virus can attack the blood vessels, causing them to bleed, interfering with the individual's clotting mechanism, and subsequently disrupting the regulation of the body.

What Are the Symptoms of Being Infected With the Marburg Virus?

The interval from getting the infection to the onset of symptoms (incubation period) varies from two to 21 days. The symptoms are as follows:

• High-grade fever and chills.

• Severe headache.

• Extreme discomfort (malaise).

• Extreme lack of energy (lethargy).

• Muscle aches.

• Chest pain.

• Abdominal pain.

• Flat and raised skin lesions (maculopapular rash) - often on the chest, back, and stomach.

• Severe diarrhea, watery diarrhea causing dehydration.

• Nausea and vomiting.

• Severe cases may show:

  • Hemorrhaging (bleeding) from nose, gums, and catheter site for hospitalized patients.

  • Jaundice.

  • Disorientation, aggression, and confusion.

  • Liver failure.

  • Pancreatitis (inflammation of the pancreas).

  • Shock.

  • Multiple organ dysfunction.

  • Orchitis (inflammation of one or both testicles)- rarely.

The fatality rate of the virus is 23 to 90 %. An individual may succumb to the disease on the eighth or ninth day from the onset of symptoms due to hemorrhaging, multi-organ failure, and shock.

How Is Marburg Virus Diagnosed?

Clinical signs and symptoms resemble any other viral disease. Therefore, only a diagnostic method can determine whether the Marburg virus causes the infection. Any of the following tests may confirm the virus:

• Antigen-capture enzyme-linked immunosorbent assay (ELISA).

• IgM antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) (IgM-ELISA).

• Antigen-capture detection tests.

• Serum neutralization test.

• Reverse transcriptase polymerase chain reaction (RT-PCR) assay.

• Electron microscopy.

• Virus isolation by cell culture (only in high-containment laboratories).

• In Deceased Patients:The following may be done to detect the virus:

• Immunohistochemistry.

• Virus isolation (only in high containment laboratories).

• PCR of blood or tissue specimens.

What Is the Treatment for the Marburg Virus?

The treatment modality focuses on increasing the survival rate of the infected with supportive care. It includes:

• Rehydration to balance lost fluid and electrolytes.

• Maintain oxygen status and blood pressure.

• Control bleeding and replacing the lost blood.

• Medications for fever and aches.

• Medication to control diarrhea and vomiting.

• Severe cases - hospitalization following strict protocol to control the spread.

How to Prevent the Spread of Marburg Virus?

A series of preventive measures can control the spread of the virus.

• Contact tracing in bat or human origin, recent travel history, primary and secondary contacts.

• Wear protective gear (gloves, masks, face shield, and appropriate clothing) when;

  • Taking care of infected individuals.

  • Visiting caves and mines (colonized with fruit bats).

  • Attending the burial of infected individuals.

• Cook all animal products well during a virus outbreak.

• Wash hands regularly and effectively.

• Isolate the sick from the healthy for 21 days.

• Isolate oneself for 21 days if known to be a primary or secondary contact with an infected individual.

• Infected individuals must be in a clean environment and must practice basic hygiene measures.

• Educate the individuals and community about the virus, the ways it can transmit, and the required containment measures.

• If infected, WHO (World Health Organization) recommends practicing safe sex for 12 months or until semen tests negative twice for the virus.

  • Transmission of the virus through semen seven weeks after recovery has been recorded.

• Prevention and control in the health sector will include :

  • Healthcare workers must take extra precautions when handling needles, bedding, and surfaces that may have come in contact with patients.

  • Health workers must wear proper protective gear (face shield, gloves, masks, gowns) when handling patients.

  • Follow strict disinfection procedures for contaminated equipment and areas.

  • Lab services with the highest level of biosafety precautions (biosafety level 4), especially in remote areas, can increase the rate of sample testing, thereby, faster disease control.

  • Transportation of viral samples must follow the protocol and triple packaging to prevent accidental exposure to the virus.

• Vaccines for preventing and controlling the Marburg virus have not been approved, but studies and clinical trials are underway to approve an effective vaccine at the earliest.

• Studies have shown pig farms to be a potential risk for viral transmission. Hence, as a preventive measure, limited and careful consumption of pigs is advised during an outbreak.

Does Marburg Virus Persist in Recovered Individuals?

Yes, the Marburg virus persists in recovered individuals in areas where foreign tissue (the virus) can survive for an indefinite time (immune-privileged sites).

The sites may include:

• Placenta, amniotic fluid, and fetus of an infected pregnant woman.

• Breastmilk, if a breastfeeding woman was infected.

• Inside of the eye.

• Testicles.

Only a negative blood report confirms the individual is recovered completely.

Conclusion:

The Marburg virus outbreaks in the past have shown the severity of the infection, and the fatality ratio strengthens the same. However, healthcare workers can help break the spread chain of the virus, using appropriate containment measures (with cooperation and help from the community) until an appropriate vaccine is available.