What is Marburg Virus?

What is marburg virus disease?

Marburg virus disease is a rare deadly infection with a death rate of up to 88%, according to the World Health Organisation (WHO). It is caused by Marburg virus, a haemorrhagic fever virus that puts severe stress on the body, from the same family of viruses as Ebola. First recognised in 1967, this zoonotic virus (a virus that spreads from animals to humans) originates from the Egyptian fruit bat, and is capable of spreading through contact with bodily fluids and surfaces. This article will give an insight into Marburg virus and its effect on humans.

Overview

Marburg virus is a member of the Filoviridae family, also known as filo viruses. You might know its well-known cousin, the Ebola virus, which comes from the same family.

Filoviruses cause severe haemorrhagic fever in people and non-human primates. They are RNA viruses, the most common type of emerging viruses due to their ability to mutate quickly. The COVID-19 and flu viruses also have RNA genomes, which is why they have so many variants. 

Marburg virus disease is an infection in humans and non-human primates that causes hemorrhagic fever. It has a death rate of up to 88%, and there is no current treatment. 

How deadly is marburg virus disease?

On average, the death rate is around 50%. Depending on the virus strain and disease management, it can range from 24% to 88%.¹

Causes of marburg virus disease

Where did it originate from?

In 1967, the first outbreaks of Marburg virus disease happened simultaneously in Marburg and Frankfurt, both in Germany, and Belgrade, Serbia. The outbreaks originated from African green monkeys, Cercopithecus aethiops, which were imported from Uganda for laboratory testing in these cities. There were 37 cases reported, 9 of whom died. 

The natural hosts of Marburg virus are Egyptian fruit bats (Rousettus aegyptiacus). This bat species is found in Africa, the Middle East, the Mediterranean, and the Indian subcontinent, dwelling in caves or mines. Egyptian fruit bats are a reservoir host, meaning that they can carry and spread this virus without showing symptoms. Outbreaks of Marburg virus disease have been strongly linked with people who work in mines or visit caves inhabited by these bats.

How does a virus transmit from bats to humans?

Zoonotic is a term used to indicate viruses or other germs that can be transmitted from animals to people. While Marburg virus spreads between species, the disease presents differently in people compared to animals. 

The latest outbreak of Marburg virus disease was reported on February 12 2023 in Equatorial Guinea. Nine deaths were reported along with 16 other suspected cases. For case updates on Marburg virus disease and other contagious diseases around the world, look out for reports on the WHO’s Disease Outbreak News page. 

How does Marburg virus spread?

Marburg virus is present in the bodily fluids (such as blood, saliva, and urine) of infected people and animals.¹

Someone can become infected through:

• direct contact with these bodily fluids
• indirect contact with contaminated surfaces or fabrics

How long does Marburg virus last on surfaces and in the air?

Research has found that Marburg virus can survive on surfaces for up to 5 days. In the air, the amount of infectious virus reportedly decreases by 5% per minute, indicating that if an infected person sneezed, the virus-containing droplets could potentially hang in the air for several minutes before settling onto surfaces.² 

Signs and symptoms of marburg virus disease

The incubation period (the time between exposure to Marburg virus and symptoms starting) of Marburg virus disease can vary between 2 and 21 days, according to the WHO. Supportive care in the earliest stage of the disease can improve chances of survival.

In the first few days of symptoms (days 1 - 4), flu-like symptoms may come on abruptly. 

Between days 2 - 5, 50-75% of patients experience gastrointestinal symptoms such as loss of appetite, stomach aches, nausea, diarrhoea, and vomiting.¹

In days 5 - 7, symptoms of haemorrhagic fever may present, with bleeding from orificesand broken skin. 

The disease can become more severe from day 8 onwards. Neurological issues such as seizures and disorientation may appear. As the body shuts down, levels of blood components become abnormal, which leads to issues like: 

• disseminated intravascular coagulation: a condition that causes blood to clot abnormally
• lymphopenia: the blood does not contain enough white blood cells, which affects the immune system
• thrombocytopenia: the blood does not contain enough platelets, which are important for blood clotting to control bleeding

Death usually occurs 8-16 days after the onset of symptoms, and is often caused by dehydration, internal bleeding and multiorgan failure.¹

Several possible complications that can arise during recovery, including:¹

• joint pain
• uveitis - inflammation of middle layer of the eye 
• orchitis - inflammation of the testicles
• hepatitis - inflammation of the liver
• pericarditis - inflammation of the lining of the heart

Due to the immense strain that fighting the infection puts on the body, patients may have an appearance of:

• ”ghost-like” features
• deep-set eyes
• lethargy
• a non-itchy rash

Who is at the highest risk?

You have a higher risk of infection with Marburg virus if you have:

• visited an area where Egyptian fruit bats reside
• been in contact with someone infected with Marburg virus
• worked with samples that contain Marburg virus

How is Marburg virus disease diagnosed?

Symptoms of Marburg virus disease are similar to other viral diseases. Marburg viral infection can therefore only be confirmed through various lab-based diagnostic tests:

• enzyme-linked immunosorbent assay (ELISA) to detect antibodies or viral proteins
• serum neutralisation tests to detect antibodies
• PCR tests to detect viral RNA
• electron microscopy to view the virus
• virus isolation in cell culture to ‘copy’ the virus for further tests 

All these methods focus on identifying unique parts of the virus to ensure proper diagnosis.

Management and treatment for marburg virus

There are currently no vaccines or antiviral therapies to provide immunity or kill the virus.

Treating the symptoms and staying hydrated early into infection can improve chances of survival. In a hospital setting, therapy includes balancing patient fluids and electrolytes, oxygen levels, and blood pressure, as well as replenishing blood.³

When in contact with someone with Marburg virus disease, it is essential to wear personal protective equipment (PPE), including a gown, gloves, and a face mask. To prevent transmission through surfaces, it is important to sanitise them with a disinfectant. Some effective surface disinfectants include 70% ethanol solutions. 

Important note: you should NOT ingest any disinfectant products, including ethanol, methanol, or bleach. It will cause bodily harm and potentially death.

If you suspect that you have Marburg virus disease, you must do the following:

Isolate yourself to prevent the spread of the virus. The virus is spread through contact with bodily fluids directly or on surfaces.

Contact your healthcare provider or local health department. Discussing your symptoms over the phone or video call is a safe way for your healthcare provider to assess your symptoms and plan treatment without the risk of infecting others. They may ask questions about your symptoms and travel history to determine if you have been to high-risk areas or had contact with someone infected.

Follow instructions from healthcare professionals. They may recommend testing to confirm Marburg virus infection and tell you how to get to hospital safely for monitoring and treatment of symptoms.

Summary

Marburg virus is an RNA virus, which originates from Egyptian fruit bats but was first identified in African green monkeys in labs. It causes Marburg virus disease, a deadly hemorrhagic fever with a death rate of up to 88%. It spreads through contact with bodily fluids, and can survive on surfaces for up to 5 days. 

Symptoms begin 2-21 days after infection and it is essential to provide supportive care early. Symptoms can last for up to 16 days, with more damage presenting over the course of the disease. 

The people at highest risk include those living in or visiting areas where Egyptian fruit bats live, and those in contact with infected people without the use of proper PPE. 

Diagnosis of Marburg virus disease involves identifying the virus in the lab. With no vaccine or antiviral therapy, symptoms are treated in hospital. Proper PPE and isolation are essential to prevent outbreaks of Marburg virus disease.