important facts
Marburg virus disease (MVD), formerly known as Marburg hemorrhagic fever, is a serious and often fatal disease in humans. The average case fatality rate for MVD cases is approximately 50%. Case fatality rates in past outbreaks have varied from 24% to 88%. Early supportive care with hydration and symptomatic treatment improves survival. There is currently no approved vaccine or antiviral treatment for MVD, but a variety of vaccines and drug treatments are under development. Rousettus aegyptiacus is a fruit bat in the family Pteropodidae and is considered the natural host of Marburg virus. Marburg virus is transmitted from fruit bats to humans and is spread to humans through human-to-human transmission. Community involvement is key to successfully controlling the outbreak.
overview
Orthomarburgvirus marburgense The species Marburg virus (MARV) and Ravn virus (RAVV) are the causative agents of Marburg virus disease (MVD). The disease has a mortality rate of up to 88%, but early and appropriate patient care can significantly reduce the mortality rate.
Both viruses are part of the Filoviridae family (Filoviruses), which includes the genus Orthoebolavirus. Although Ebola and Marburg disease are caused by different viruses, they are clinically similar. Although both diseases are rare, they can cause deadly outbreaks.
MVD was first detected in 1967 after two simultaneous outbreaks in Marburg and Frankfurt, Germany, and Belgrade, Serbia. These outbreaks were associated with laboratory studies using African green monkeys (Cercopithecus aethiops) imported from Uganda. Outbreaks and sporadic cases have since been reported in Angola, Democratic Republic of the Congo, Equatorial Guinea, Ghana, Guinea, Kenya, South Africa (in people with recent travel history to Zimbabwe), Tanzania, and Uganda. In 2008, two independent cases were reported from tourists who visited caves in Uganda that were home to colonies of Aedes aegypti bats. Rwanda reported its first domestic outbreak in September 2024, and Tanzania declared a new outbreak in January 2025.
contagion; infection
Initially, MVD infections in humans are caused by long-term exposure to mines and caves inhabited by colonies of Lucet fruit bats.
Once introduced into the human population, Marburg virus can be transmitted through direct contact with the blood, secretions, organs, and other body fluids of infected individuals (through broken skin or mucous membranes), and through direct contact with surfaces and materials. (bedding, clothing, etc.) are contaminated with these liquids.
Healthcare workers are frequently infected while treating patients with MVD. This occurred due to close contact with patients when infection prevention measures were not strictly practiced. Infection through contaminated syringes or needlesticks is associated with more severe disease, rapid deterioration, and possibly higher mortality rates.
Burial rituals that involve direct contact with the body of the deceased can also lead to Marburg virus infection.
People cannot transmit the disease before they develop symptoms and remain infectious as long as they have the virus in their blood.
Symptoms of Marburg virus disease
The incubation period (the period from infection until symptoms appear) is 2 to 21 days.
MVD begins suddenly with a high fever, severe headache, and severe fatigue. Muscle aches and pains are common features. Severe watery diarrhea, abdominal pain, cramps, nausea, and vomiting may begin on the third day. A non-itching rash has been reported in patients 2 to 7 days after the onset of symptoms.
Starting on the fifth day of illness, patients may develop bleeding symptoms such as vomit, fresh blood in the stool, and bleeding from the nose, gums, or vagina. Bleeding at the venipuncture site (where intravenous access is gained to administer fluids or take blood samples) may also be seen. Involvement of the central nervous system may result in confusion, irritability, and aggression. Orchitis (inflammation of one or both testicles) is occasionally reported in the later stages of the disease.
In fatal cases, death most often occurs within 8 to 9 days after the onset of symptoms, usually preceded by severe blood loss and shock.
diagnosis
Clinically, MVD can be difficult to differentiate from other infectious diseases such as malaria, typhoid fever, bacteriosis, meningitis, and other viral hemorrhagic fevers. The following diagnostic methods are used to determine whether your symptoms are caused by a Marburg virus infection:
Antibody Capture Enzyme-Linked Immunosorbent Assay (ELISA) Antigen Capture Detection Test Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) Assay Virus isolation by cell culture in a maximum containment laboratory.
Samples taken from patients pose a very serious biohazard risk. Laboratory testing on non-inactivated samples should be performed under maximum biological containment conditions. All non-inactivated biological specimens must be packaged using a triple packaging system for domestic and international transport.
Treatments and vaccines
Early intensive supportive care, including hydration and treatment of specific symptoms, can improve survival rates.
There are currently no vaccines or antiviral treatments approved for MVD.
In addition to candidate vaccines that can be evaluated in clinical trials, there are monoclonal antibody (mAb) and antiviral drug candidates.
Marburg virus in animals
Rousettus aegyptiacus Bats are considered the natural host of Marburg virus. These flying foxes have no obvious diseases. As a result, the geographic distribution of Marburg virus may overlap with the range of the Lucetus bat.
African green monkeys (Cercopithecus aethiops) imported from Uganda were the source of human infection during the first MVD outbreak.
Experimental inoculation of pigs with different ortho-Ebola virus species showed that pigs are susceptible to filovirus infection and shed virus. Therefore, pigs should be considered as a potential amplification host during MVD outbreaks. Pig farms in Africa require precautions to avoid infection of pigs through contact with flying foxes.
prevention and control
Community involvement is key to successfully controlling outbreaks. Outbreak control depends on the use of a variety of interventions, including case management, surveillance and contact tracing, good testing services, infection prevention and control in health facilities, safe and dignified burials, and social mobilization. .
Increasing awareness about the risk factors for MVD and preventive measures that individuals can take is an effective way to reduce human infection.
Risk mitigation messages should focus on several elements.
Reduces the risk of bat-to-human infection caused by long-term exposure to mines and caves inhabited by fruit bat colonies. Anyone visiting or working in mines or caves inhabited by fruit bat colonies should wear gloves and other suitable protective clothing (including a mask). During an outbreak, all animal products (blood and meat) should be thoroughly cooked before consumption. Reduces the risk of person-to-person transmission within the community due to direct or close contact with infected patients, especially contact with body fluids. Close physical contact with people with MVD should be avoided. Patients with suspected or confirmed MVD should be isolated to designated treatment centers for early care and avoid household transmission. Communities affected by MVD should strive to ensure that residents are adequately informed both about the nature of the disease itself and about the disease. Epidemic containment measures include safe and dignified burial of the dead, identification of people who may have been in contact with MVD cases, monitoring health status for 21 days, and isolating healthy and sick people to prevent further infection. This includes: Providing treatment to patients with confirmed infections and maintaining good hygiene and a clean environment should be observed.
Infection control in medical settings
Healthcare professionals should always take standard precautions when caring for patients, regardless of the presumed diagnosis. These include basic hand hygiene, respiratory hygiene, use of personal protective equipment (to prevent droplets and contact with infectious material), safe injection methods, and safe and dignified burial methods.
Healthcare workers caring for patients with suspected or confirmed MVD should take special infection precautions to prevent contact with the patient’s blood and body fluids and contaminated surfaces and materials, such as clothing and bedding. Measures need to be taken.
Laboratory personnel are also at risk. Samples taken from humans and animals for investigation of Marburg virus infection must be handled by trained staff and processed in appropriately equipped laboratories.
MVD Survivor Care
All survivors, their partners and families deserve respect, dignity and compassion. WHO does not recommend isolation of convalescent male or female patients who test negative for Marburg virus. MVD survivors can suffer from both clinical and psychological sequelae. WHO encourages affected countries to consider establishing survivor care programs to reduce sequelae, support reintegration into the community, and provide counseling and biological testing.
Marburg virus is known to persist in immune privileged areas in some people who recover. These areas include the testicles and the inside of the eye. Extrapolating from data on other filoviruses, this virus can persist in the placenta, amniotic fluid, and fetus of women infected during pregnancy, and in the breast milk of women infected during lactation. Recurrence of symptoms in people who have recovered from MVD in the absence of reinfection is a rare but documented event. The reasons for this phenomenon are still not fully understood.
Transmission of Marburg virus through infected semen has been documented up to 7 weeks after clinical recovery. To reduce the risk of potential infection from exposure to infected semen, a semen testing program should be implemented to:
Where appropriate, provide counseling to male MVD survivors and their sexual partners to inform them of potential risks and adhere to safer sexual practices (including provision of condoms and proper hand and personal hygiene) to support you. and
Perform monthly semen tests until you receive two consecutive negative test results.
After two consecutive negative test results, MVD survivors can safely resume normal sexual activity while minimizing the risk of Marburg virus infection. In the absence of a semen testing program, male survivors are required to follow safer sex practices for 12 months.
WHO response
WHO aims to prevent MVD outbreaks by maintaining surveillance of MVD disease and helping countries at risk develop preparedness plans. The following documents provide overall guidance for controlling Ebola and Marburg disease outbreaks.
Ebola hemorrhagic fever and Marburg virus disease outbreaks: preparedness, vigilance, control and assessment
When an outbreak is detected, WHO responds by supporting surveillance, community engagement, case management, testing services, infection prevention and control, logistics, and training and assistance on safe burial practices.
Table: Chronology of major Marburg virus disease outbreaks
Country Number of Cases Number of Deaths Number of Fatality Rates 2024 Rwanda 661,523% 2023 Tanzania 9,667% 2023 Equatorial Guinea 403,588% 2022 Ghana 3,267% 20 21 Guinea 11100%2017 Uganda 33100%2014 Uganda 11100%2012 Uganda 15427%2008 Netherlands (formerly Uganda) 11100 %2008 United States of America (formerly Uganda) 100% 2007 Uganda 4250% 2005 Angola 37432988% 1998-2000 Democratic Republic of the Congo 154 12883%1987 Kenya 11100%1980 Kenya 2150%1975 Southern Africa 3133%1967 Yugoslavia 200%1967 Germany 29724%
