What is Marburg Fever?
The Marburg virus (MARV) is an extremely harmful RNA virus that is part of the Filoviridae family. It causes Marburg virus disease (MVD), a rare and severe fever that can result in excessive bleeding. This disease has a high death rate, making the Marburg virus one of the deadly pathogens known to us. The Marburg virus disease was first identified after an outbreak in 1967, which was traced back to imported African green monkeys from Uganda. Because of this, it was initially known as the green monkey disease.
Later, it was discovered that the Rousettus fruit bat is the carrier or ‘animal reservoir’ for the virus. It is believed that humans can get infected by inhaling waste matter from these bats or by coming in contact with bodily fluids of sick patients. Once the virus enters the human body, it starts to multiply rapidly and spread. This leads to a range of symptoms including fever, a general feeling of discomfort or malaise, muscle pain, and disorders related to blood clotting. If not managed in time, these symptoms can further lead to shock, failure of multiple organs, and sadly, death in many cases.
What Causes Marburg Fever?
Marburg virus disease is caused by a very dangerous type of virus belonging to the Marburgvirus and Ebolavirus family. These types of viruses have a casing, consist of a single strand of RNA, and are known for causing severe illness in humans.
There are many kinds of viruses in this virus family, but only those in the Marburgvirus or Ebolavirus category can cause disease in humans. They have a reputation because they can cause severe illnesses and have high fatality rates.
Within the Marburgvirus group, there is one type called ‘Marburg Marburgvirus’ which includes the Marburg virus and the Ravn virus. The Marburg virus can be further divided into different variants; Marburg Muskoke, Marburg Angola, Ci67, Ozolin, and isolates within a variant (Pop, Ci67).
The World Health Organization classifies the Marburg virus as a Group 4 pathogen. This means it poses a high risk to individuals and communities.
Risk Factors and Frequency for Marburg Fever
The Marburg virus disease, also known as MVD, first appeared in August 1967. This outbreak happened in Marburg and Frankfurt, Germany, as well as Belgrade, Yugoslavia. African Green monkeys brought from Uganda were traced as the source of the disease. During this outbreak, 31 people became severely sick from the virus, with seven deaths recorded. The virus was named after Marburg, the city where most cases occurred. Some evidence also pointed to the virus potentially being spread through sexual contact. This conclusion came after traces of the virus were found in a patient’s semen.
The next instance of the virus occurred eight years later, infecting an Australian traveller. He had recently travelled through Zimbabwe and passed on the infection to two other individuals in St. Johannesburg, South Africa. Regrettably, he did not survive. Both secondary cases recovered fully. There have been several more outbreaks since then; the most notable happened in the Democratic Republic of Congo from 1998 to 2000, and Angola between 2004 and 2005. The outbreak in the Democratic Republic of Congo saw 154 cases with 128 deaths, while the Angola outbreak had 252 cases and 227 deaths. It was thought that the virus spread in Angola due to contaminated blood transfusion equipment in a paediatric ward.
Scientists have used genomic analysis to understand more about the virus. It seems that the disease initially entered the public from a single introduction. From there, it continued to spread from person to person, without any clear source of infection. Other countries that have reported Marburg disease outbreaks include Guinea, Kenya, and Serbia.
The Egyptian fruit bat is believed to be the carrier of Marburg. The bats can carry and spread the virus without showing any signs of infection. Almost all primary infections in humans have been linked to entering cave environments that contain infected bats. For example, one large outbreak in the Democratic Republic of Congo took place near a goldmine located in a bat-infested cave.
There is some uncertainty as to whether only the Egyptian fruit bat carries the virus, or if other bat species can also be hosts. The virus can spread to humans from animal carriers. This could happen via another mammal like a bat, or an intermediate host, such as non-human primates. However, it’s not yet clear how exactly this transmission occurs and what specific bodily fluids are involved. Marburg virus can also occur through person-to-person contact, usually through body fluids such as sweat, saliva, blood, urine, faeces, or breast milk.
Signs and Symptoms of Marburg Fever
The Marburg virus is more likely to affect individuals who have been in close contact with bat excrement, particularly in areas where the virus is common (such as Africa), or those who enter habitats of the African fruit bat (Rousettus aegyptiacus). Individuals also at risk are those who directly interact with sick people carrying the Marburg virus, such as family and hospital staff, or those who come into contact with infected non-human primates.
After being exposed to the Marburg virus, there is typically an incubation period lasting between 3 and 21 days. Following this, the progress of the disease generally consists of three stages:
- The initial generalization phase: Patients usually experience symptoms similar to the flu, such as high fever, chills, body aches, joint pain, headache, and fatigue. Some individuals may also have gastrointestinal symptoms. Around days 5 to 7, the severity of symptoms can increase, and it is common to develop a red, non-itchy skin rash.
- The early organ phase: There may be symptoms such as eye inflammation, variations in body temperature, and signs of hemorrhagic fever – these can include bleeding from the gums, vomiting of blood, rectal bleeding, small red spots on the skin, and bleeding from injection sites.
- The late organ/convalescence phase: In this phase, patients may develop neurological symptoms, like agitation, seizures, confusion, and even coma. After day 13, they either pass away due to the disease or enter a protracted period of recovery.
Testing for Marburg Fever
Patients who are infected with the Marburg virus, called MARV infection, might experience changes in their medical tests. For instance, their alanine and aspartate aminotransferase (ALT and AST, substances associated with liver and heart damage) numbers may increase, as well as their serum creatinine levels (linked to kidney function). Blood tests might also show a lower-than-normal number of lymphocytes (a kind of white blood cell) and platelets (cells that help blood to clot), both of which are symptoms of a serious condition known as disseminated intravascular coagulation. All these changes can take place within the first week after symptoms start.
The Centers for Disease Control and Prevention (CDC) explains that doctors utilize a variety of medical tests like ELISA testing, polymerase chain reaction (PCR), and IgM-capture ELISA, to diagnose the virus within the first few days of symptoms appearing. GP-based ELISA tests are used to detect specific types of antibodies, but PCR is the most commonly used method to differentiate between different virus variants and to detect the disease in its early stages. IgG-capture ELISA, on the other hand, is typically used later on in the disease or even after recovery. Isolation of the virus is done in high-level safety labs, such as a biosafety level 4 laboratory due to its high-risk nature.
Bodily fluids like blood and tissue specimens (especially those collected during an autopsy) are usually used for these diagnostic tests. If you’re in the US and suspect that you or someone else has this infection, your healthcare provider should reach out to the state health department immediately for advice on further testing and how best to care for the patient.
Treatment Options for Marburg Fever
Currently, there is no approved treatment for the Marburg virus. During outbreaks, the main form of care focuses on supportive measures. The CDC and the World Health Organization (WHO) have made a guidance for infection control. These measures include isolating patients in their own rooms with closed doors, wearing appropriate protective gear, using disposable medical equipment when possible, limiting the use of needles, avoiding procedures that create aerosols, washing hands frequently, monitoring and managing health workers who may have been exposed, and preventing visitors from entering patient rooms.
Although there’s no approved treatment, several drugs are being developed to address the issue. Galidesivir (BCX4430) is an antiviral drug that works by blocking a protein necessary for the virus to multiply. The drug was effective in both rodent models and a type of monkey called cynomolgus macaques when it was given within 48 hours of exposure to the virus. A preliminary trial in humans has been completed, but the results have not been detailed.
Further antiviral drugs that are being tested include favipiravir and remdesivir. However, these drugs have not yet been found to significantly improve survival rates. Interferon-beta, which is a protein that our bodies naturally produce in response to viral infections, has been found to extend survival times in monkeys.
Treatments using antibodies, which are proteins that your immune system produces to fight off harmful substances like viruses, are also being studied. A human-made antibody called MR 191-N was successful in saving the lives of monkeys infected with the Marburg virus. Since similar treatments have been effective for the closely-related Ebola virus, scientists are optimistic that this could be a promising treatment for the Marburg virus as well.
Efforts to create a vaccine for the Marburg virus are also underway. The need for an effective vaccine was postponed after the 2013 Ebola epidemic. Different formats for the vaccine are being investigated, including ones using nonreplicating virus, segments of viral genetic material, and live but weakened virus. The challenge now is to gather enough data to determine which format is most effective.
What else can Marburg Fever be?
In the early stages of the disease, diagnosing Marburg fever can be challenging because its symptoms are quite vague and resemble those of many other infectious diseases. These are some of the conditions that doctors may consider when diagnosing Marburg fever:
- Ebola virus disease
- Lassa fever
- Dengue fever
- Malaria
- Typhoid fever
- Rickettsial illness (infections caused by bacteria)
- Shigellosis (bacterial infection that affects the digestive system)
- Meningitis (inflammation of the protective membranes of the brain and spinal cord)
What to expect with Marburg Fever
Currently, there is no approved treatment for the Marburg virus, and doctors can only provide supportive care to manage symptoms. This makes the disease’s outlook quite grim with a high likelihood of death. The best care for this disease is provided in specialized units equipped to handle biological threats.
It’s crucial that all folks who interact directly with the patient, such as healthcare workers, use personal protective equipment (PPE) properly, maintain hand hygiene, and limit the use of needles and sharp objects to reduce the risk of getting infected at work. Controlling future outbreaks is essential to stop new infections and prevent the virus from spreading further.
The differences in how severe the disease is during outbreaks is believed to depend on the availability of medical care, the amount of virus a person is exposed to, how a person got infected, the aggressiveness of the particular virus strain, and the overall health condition of the population.
Possible Complications When Diagnosed with Marburg Fever
Marburg virus disease can lead to serious complications, including indications of hemorrhagic fever, failure of multiple body systems, shock, and eventually, death. One major concern is the virus spreading to others. To prevent this, it’s necessary to use suitable personal protective equipment and take preventative steps when taking care of infected patients or handling individuals who have died from the disease. Plus, the Marburg virus decreases the body’s ability to fight off infections, making it susceptible to secondary infections. These secondary infections need to be identified and treated correctly.
Concerns and Complications:
- Indications of hemorrhagic fever
- Failure of multiple body systems
- Shock
- Potential death
- Virus spreading to others
- Necessity of personal protective equipment and preventative steps
- Potential for secondary infections due to immunosuppression
Preventing Marburg Fever
If you live in or are traveling to areas where Marburg virus disease is common, it’s crucial to learn about the early warning signs and symptoms of this illness. This knowledge will help you detect the disease at an early stage, which is key for effective treatment. It’s equally important to understand how to prevent this infection and steer clear of bats as they can carry this virus.
If you or someone around you has contracted this virus, it’s crucial to follow instructions about quarantine and isolation. This means keeping the sick person separated from others until they recover, to prevent the virus from spreading further. This is a vital practice to safeguard your health and the health of others.
