Equatorial Guinea, a country in Central Africa, confirmed its first Marburg Virus Disease outbreak on Tuesday, according to the World Health Organization (WHO). One patient has tested positive for the disease, while 16 are suspected to have the infection. There have been nine deaths so far. The source of the outbreak is yet to be identified.

Marburg virus disease is one among the various diseases in the WHO’s list of priority pathogens. Others include Covid-19, Crimean-Cong hemorrhagic fever, Ebola virus disease, Lassa fever, Middle East respiratory syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), Nipah and henipaviral diseases, Rift Valley fever, Zika and Disease X. The list is expected to be updated this year.¹ 

Marburg virus disease, earlier known as Marburg hemorrhagic fever, is a rare but highly infectious and potentially fatal disease in humans. It first came to light in 1967 when two outbreaks of severe febrile illness associated with hemorrhage and shock occurred at the same time in Marburg and Frankfurt in Germany and in Belgrade, Yugoslavia. The disease is endemic in Africa and outbreaks have been reported in African countries like Angola, the Democratic Republic of the Congo, Kenya, South Africa, Uganda and Ghana.² 

At present, Marburg virus disease is categorized as a Risk Group 4 pathogen by the WHO indicative of high individual and community risk and which requires Biosafety Level 4 containment.³

Here are some key facts about the disease.²

• Causative agent: Marburg virus, is a Filovirus and belongs to the same Filoviridae family as the Ebola virus

• Transmission: The African fruit bats (Pteropodidae family), which reside in caves, are considered to be the natural hosts of the virus and transmit it to humans. The virus also spreads via direct contact with body fluids (blood, saliva and urine) of an infected person or animal or through unsafe injection practices or contaminated objects and surfaces. Human to human transmission occurs. Burial of the deceased patients can also contribute to the spread of the virus.

• Incubation period: 2 to 21 days

• Symptoms: Sudden onset of high fever, severe headache, severe malaise, myalgia. On the third day of the illness, severe watery diarrhea, abdominal pain/cramping, nausea and vomiting may occur. The appearance of the patients has been described as “ghost-like” with “deep-set eyes, expressionless faces” and extreme lethargy. Severe bleeding from several sites may occur between 5th and the 7th days of the illness causing severe blood loss and shock leading to death, which may occur between the 8^th and 9th day.

• Case fatality rate: The average case fatality rate is around 50% (varies from 24% to 88%)

• Differential diagnosis: Ebola virus disease, malaria, typhoid fever, leptospirosis, rickettsial infections, meningitis, plague (in the early phase of the illness) 

• Diagnosis: ELISA, RT PCR, serum neutralization test, electron microscopy and cell culture to isolate the virus

• Treatment: Mainly supportive as there is no specific antiviral treatment.

• Vaccine: There are no vaccines for Marburg virus disease.

In this age of globalization, geographical boundaries have disappeared. This allows highly infectious pathogens to travel around the world, outside the endemic regions, to areas where they were previously not known to occur. Though the Covid pandemic put the breaks on global travel for some time, countries have reopened their borders.

Hence, robust surveillance systems should be in place and monitoring should be continuous to preempt any outbreaks. The general public must be educated about these diseases so that they can take adequate precautions.

References

1. https://www.who.int/news/item/21-11-2022-who-to-identify-pathogens-that-could-cause-future-outbreaks-and-pandemics, Nov. 21, 2022. Accessed on Feb. 15, 2023.
2. WHO Marburg virus disease Fact sheet.7 August 2021. https://www.who.int/news-room/fact-sheets/detail/marburg-virus-disease. Accessed on Feb. 15, 2023. 
3. Hunter N, Rathish B. Marburg Fever. [Updated 2022 Feb 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK578176/