Currently, only Two Nations – Tanzania and Equatorial Guinea have declared a Marburg Virus Disease outbreak in 2023.
Most Recently, Tanzania has declared its first-ever outbreak of Marburg Virus Disease (MVD) On 21st March 2023.
- In Tanzania, a total of Eight cases were confirmed including Five Deaths (22nd March 2023)
Earlier, Equatorial Guinea had declared an outbreak of MVD on 13th Feb 2023.
What is Marburg Virus Disease (MVD)
Earlier, known as Hemorrhagic Fever Disease. MVD is caused by a Virus belonging to the Filovirus family. MVD resembles Ebola as both the Ebola virus and the Marburg virus share the same family -the Filovirus family. The Filovirus family consists of only two viruses- Marburg Virus and Ebola Virus. That is why both Ebola and Marburg virus share some many characteristics and are clinically similar.
Read about another viral disease “H3N2 Influenza” currently posing a threat, especially in India.
The First Case of Marburg Virus Disease and Outbreak
It was first discovered in the Europe – Marburg (Germany) in 1967. Green African Monkey imported from Uganda was the source of first case of MVD.
Where Does The Marburg Virus Reside
The reservoir host of the Marburg virus is a type of Fruit Bat – Egyptian Fruit (rosette) Bat.
Taken at Rothschild Boulevard, Tel Aviv, Israel.
Transmission of Marburg Virus
Initially from infected animals (mainly Egyptian fruit bats) to humans and then human-to-human transmission.
From Bats to Human Transmission of Warburg Virus
Occurs through feces or aerosol of infected bats. Prolonged exposure to mines or caves inhabited by Rousettus bat colonies may transmit the disease.
Human-to-Human Transmission of Warburg Virus
Direct contact with the blood, secretions, organs or other bodily fluids of infected people with broken skin or mucous membranes of healthy individuals. Also, contacts of surfaces and materials (e.g. bedding, clothing) contaminated with these fluids can transmit the virus.
Symptoms of Marburg Virus Disease
Incubation period of Marburg Virus Disease -time taken for symptoms to appear after exposure to the virus, ranges from 2-21 days. it depends upon the infectious dose and route.
Symptoms of Marburg Virus Disease include
- At the Onset (Sudden) – Fever, chills, Headache, and generalized muscle pains (Myalgia).
- Around the Third Day – the patient may develop Nausea/ Vomiting, Abdominal Cramps and Watery Diarrhea which may persist for a week.
- Around Fifth Day –
- Maculopapular non-itchy Rash may develop and other symptoms may become increasingly severe. symptoms may include – Jaundice, severe Weight loss, liver Failure, Pancreatitis, Delirium, Hemorrhagic manifestations, shock and multiorgan failure.
- Fatal cases usually have bleeding, often from multiple areas – from the nose, gums, and vagina. it may be accompanied by Fresh blood in vomitus, Feces and Spontaneous bleeding at venipuncture sites. That is why it was known as Marburg Hemorrhagic Fever earlier.
- In Fatal cases, Death usually occurs between the 8th – and 9th Day of onset of symptoms.
The clinical picture of MVD is not specific. Similar clinical features may be seen in Malaria, Typhoid or Viral Hemorrhagic fever such as Lassa Fever or Ebola.
Case Fatality Rate of Marburg Virus Disease
It ranges from 23%-90% according to CDC and 24%-88% as per WHO. The average case fatality rate of Marburg Virus Disease is around 50%.
Diagnosis of Marburg Virus Disease
Clinically, it is very difficult to diagnose because of the overlapping clinical picture with other diseases. Diagnosis of Marburg Virus Disease can be made by the following molecular/ serological Diagnostic Methods:
- Antigen – capture ELISA
- IgM capture ELISA
- RT-PCR assay
- Virus isolation – only to be done in a high-containment laboratory
Treatment of Marburg Virus Disease
Since there is no specific treatment for Marburg Virus Disease, Supportive therapy remains the mainstay of treatment. supportive therapy includes-
- Maintaining fluid and electrolyte balance.
- Maintaining Blood Pressure, oxygen status and other vitals.
- Replacing the lost blood.
- Treatment of other specific complications.
Although there are some Monoclonal Antibodies and some Anti-viral under Development.
Vaccine of Marburg Virus Disease
Though there is no vaccine available currently, but The European Medicines Agency (EMA) granted the marketing authorization to some vaccines in 2020. The efficacy of these vaccines has not yet been proven in clinical trials.
Prevention of Marburg Virus Disease and Outbreak
- Avoid contact with blood and body fluids (such as urine, faeces, saliva, sweat, vomit, breast milk, amniotic fluid, semen, and vaginal fluids) of people who are sick.
- Avoid contact with items that may have come in contact with an infected person’s blood or body fluids (such as clothes, bedding, needles, and medical equipment).
- Gloves and appropriate personal protective equipment should be worn when taking care of ill patients.
- Proper prompt, safe and dignified funeral or burial practices should be followed as per protocol.
- Avoid contact with fruit bats and non-human primates (such as monkeys and chimpanzees).
- Also avoid the blood, fluids, or raw meat prepared from fruit bats or non-human primates or unknown animals.
- Avoid areas known to be inhabited by fruit bats (such as mines or caves).
Is Marburg Virus Dangerous
Q: Do I need to worry about Marburg Virus Disease?
A: Marburg Virus Disease is a rare disease and active cases are present in only two nations in the African continent (Tanzania and Equatorial Guinea). But its case fatality rate is very high (may reach 90%) and can be transmitted from human to human which is the worrisome thing about this disease. Proper information and awareness at individual, community and country levels can best strategy to deal with it.
Marburg Virus in India
No case of Marburg Virus disease is present in India currently. Even though we must be aware of the disease surveillance and strategy should be there beforehand.
Marburg Virus Disease in Animals
- Rousettus aegyptiacus bats (Egyptian fruit bats):- are the natural hosts (Reservoir) for the Marburg virus. The virus does not cause any apparent disease in bats but can infect other animals.
- African green monkeys:- imported from Uganda were the source of infection for humans during the First Marburg outbreak.
- pigs: -Experimental inoculations in pigs show that pigs are susceptible to filovirus infection and can shed the virus. Therefore, pigs should be considered as potential amplifier hosts during MVD outbreaks.
- Domestic animals:- As a precautionary measure they should be considered as potential amplifier hosts until proven otherwise.
Precautionary measures in pig farms in Africa can prevent pigs from becoming infected through contact with fruit bats. Such infection could potentially amplify the virus and cause or contribute to MVD outbreaks.
How long Marburg Virus remain in Recovering patients
- Marburg virus can persist in immune-privileged sites like testicles and the inside of the eye, in some people who have recovered from Marburg virus disease.
- In women who have been infected while pregnant, the virus persists in the placenta, amniotic fluid and fetus.
- In women who have been infected while breastfeeding, the virus may persist in breast milk.
- Marburg virus transmission via infected semen has been documented up to seven weeks after clinical recovery. More surveillance data and research are needed on the risks of sexual transmission.
Is Relapse or Reinfection possible with Marburg virus
Yes, though very rare but documented.
References list:-
- World Health Organization
- cdc.gov.in
- https://www.ncbi.nlm.nih.gov
Very useful information by Dr Kaundal