Introduction:
Marburg virus disease (MVD) is a rare yet fatal condition that has resulted in large outbreaks in the recent past. It is caused by the Marburg virus belonging to the Filoviridae family (filovirus). The only other known member of the Filoviridae family is the Ebola virus. Both viruses cause rare diseases and outbreaks with high fatality rates. MVD is characterized by viral hemorrhagic fever with a fatality rate as high as 88 %.
In 1967 the Marburg virus was first discovered when two large outbreaks were reported concurrently in Marburg and Frankfurt in Germany and Belgrade, Serbia. The initial outbreak was due to laboratory exposure to African green monkeys imported from Uganda. Thirty-one individuals were seriously ill, including the laboratory workers, healthcare professionals, and family members who came in contact with them. The mortality rate was 23 %. Sporadic outbreaks of MVD have been reported throughout Africa as in Uganda, Zimbabwe, the Democratic Republic of the Congo, Kenya, Angola, and South Africa. In addition, cases have also been reported outside Africa, though infrequently.
How Is Marburg Virus Disease Transmitted?
The African fruit bat Rousettus aegyptiacus is the host of the Marburg virus. These fruit bats are residents of various caves and mines throughout Africa. Though the transmission from these bats to humans is unclear, unprotected contact with theinfected bat feces or aerosols is most likely the suspected transmission mode. Further, human-to-human transmission occurs via direct contact. It could be through:
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Cuts or bruises in the skin or mucous membrane.
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Infected blood or body fluids include sweat, saliva, semen, breast milk, urine, feces, or amniotic fluid.
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Contaminated objects of an infected person.
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Infection to the health care workers while treating an infected patient can happen with poor infection control, contaminated equipment, or improper sterilization protocol.
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Direct contact with the deceased body is also capable of transmitting the infection.
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Individuals can transmit the infection as long as the virus is present in their blood.
What Are the Signs and Symptoms of This Disease?
The period from the onset of infection to the appearance of the first symptoms is known as the incubation period, which is 2 to 21 days in MVD. After that, the disease begins abruptly with high-grade fever, chills, headache, and fatigue. The course of this disease is given below:
How Is This Disease Diagnosed?
Clinical diagnosis of MVD can be difficult as the signs and symptoms overlap various infectious diseases and other endemic conditions. Confirmatory diagnostic tests include:
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ELISA – Antigen and Antibody capture (enzyme-linked immunosorbent assay).
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PCR – Polymerase chain reaction.
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Virus isolation and culture.
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Electron microscopy.
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Serum neutralization assays.
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RT-PCR - reverse transcriptase polymerase chain reaction.
The samples collected from infected patients are considered extreme biohazards. Hence all samples should be handled with extreme caution. They should be transported with a triple packaging system and handled only in a high-containment laboratory. Antibody-ELISA is exceptionally beneficial for testing patients for follow-up, recovery, or during the later phases of the disease. In addition, Immunohistochemistry, PCR, virus isolation, and culture may be used in deceased patients to test retrospectively.
How Can MVD Be Treated?
Presently no vaccines or specific treatments have proved efficient in treating or preventing MVD. Therefore, supportive measures such as hydration, maintaining the fluid-electrolyte balance, sustaining the oxygen saturation and blood pressure, and specific treatments pertaining to complications or other adverse events are being followed to prevent fatalities.
Monoclonal antibodies and antivirals like Remdesivir and Favipiravir that have proved efficient in the Ebola virus clinical trials can also be studied and tested for MVD. Additionally, the European Medicine Agency (EMA) granted an Ebola vaccine regimen comprising Zabdeno (Ad26.ZEBOV) and Mvabea (MVA-BN-Filo) to deliver acquired immunity against the Ebola virus. These vaccines may prove efficacious against MVD; however, further clinical trials are required to assess the safety and efficacy against the Marburg virus.
What Are the Ways to Prevent MVD?
Increasing awareness and efficient community involvement are vital in preventing the spread of the disease. In addition, isolating the affected individuals, using appropriate protective measures, and prompt diagnosis is imminent to prevent a large outbreak or development of a pandemic. Certain measures to prevent and control the disease are:
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Reduce the risk of spread from the infected bats to humans. Individuals visiting the caves or mines infested with fruit bats should wear protective equipment such as a mask, gloves, eye shield, or protective face shield. In addition, they should take care not to touch rodent feces or droppings. In case of an outbreak, people who consume meat should cook it thoroughly before consuming it.
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Human-to-human transmission can be curtailed by restricting direct physical contact with the infected person. Appropriate isolation protocol should be followed. Health workers and caregivers should preferably wear personal protective equipment, which should be disposed of carefully after every visit. Good hand hygiene techniques should be strictly followed.
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Community spread can be restricted by increasing public awareness of the disease. In addition, maintaining good environmental hygiene, monitoring diseases, isolating the healthy from the sick, and safely burying the deceased can prevent contamination and control its spread.
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WHO recommends that affected male survivors practice safe sex for 12 months from the onset of symptoms or twice till their semen sample tests negative.
How to Control Infection in a Healthcare Setting?
Healthcare and laboratory workers must take extra caution and care to prevent nosocomial infections. Certain measures that could control the spread of the disease in a hospital environment are:
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Best hand hygiene practice.
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Respiratory hygiene.
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Use personal protective equipment such as a gown, mask, gloves, face shield, and eye shield.
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Safe injection procedures.
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Dignified and safe burial for the deceased.
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Appropriate infection control of the contaminated belongings such as clothing or bedding.
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The personal protective equipment should be removed and disposed of without causing any further contamination.
Which Specialists Treat Marburg Virus?
Hematologists, Infection-specialists, Critical care specialists, and pulmonologists are those who treat Marburg viral infection.
Conclusion:
MVD is a rare condition in humans. However, considering the fruit bats' widespread geographic distribution and the virus's prolonged incubation period, the potential risk for global spread is higher, thus posing a significant public health hazard. Prevention and control should be most emphasized, given the high fatality rates of MVD and no specific treatments or vaccines. Early awareness, sufficient isolation, and protection protocol improving diagnostics, particularly in rural areas, and effective community surveillance can help prevent a larger outbreak or possible future pandemic of Marburg virus disease.
