Marburg virus is the causal agent of Marburg virus disease (MVD), an illness with a case fatality ratio of up to 88 per cent, but can be significantly lower with proper patient care. Marburg virus disease was initially found in 1967 after simultaneous epidemics in Marburg and Frankfurt in Germany; and in Belgrade, Serbia.
Marburg and Ebola viruses are both members of the Filoviridae family (filovirus) (filovirus). Though caused by separate viruses, the two diseases are clinically identical. Both diseases are rare and have the capacity to generate outbreaks with significant death rates.
Two big outbreaks that occurred simultaneously in Marburg and Frankfurt in Germany, and in Belgrade, Serbia, in 1967, led to the earliest detection of the disease. The outbreak was related with laboratory activity employing African green monkeys (Cercopithecus aethiops) brought from Uganda.
Subsequently, outbreaks and sporadic cases have been recorded in Angola, the Democratic Republic of the Congo, Kenya, South Africa (in a person with recent travel history to Zimbabwe) and Uganda. In 2008, two distinct cases were recorded in travellers who had visited a cave inhabited by Rousettus bat colonies in Uganda.
When humans are exposed to Rousettus bat colonies for an extended period of time, they are at risk of contracting MVD.
Infected people’s blood, saliva, organs, or other bodily fluids spread Marburg through direct human-to-human contact (through broken skin or mucous membranes), as do surfaces and objects (e.g. bedding, clothing) contaminated with these fluids.
Patients with MVD, whether suspected or confirmed, have repeatedly exposed healthcare personnel to the virus. When infection control procedures are not rigorously followed, this has happened because of the close contact with patients. Transmission via contaminated injection equipment or by needle-stick injuries is linked to a more severe disease, rapid deterioration, and possibly a greater mortality rate.
Direct touch with the deceased’s body during a funeral or memorial service can also spread the Marburg virus.
As long as a person’s blood retains the virus, they are infectious.
Symptoms of Marburg virus disease
When a person is infected, the incubation period can range from 2 to 21 days.
Symptoms of Marburg virus infection include high fever, excruciating headache, and a general feeling of malaise. One of the most prevalent symptoms is soreness and stiffness in the muscles. Severe watery diarrhoea can start on day three, as might abdominal pain and cramping, nausea, and vomiting.
Having diarrhoea for a week or more is not uncommon. A “ghost-like” drawn appearance, deep set eyes, expressionless face and profound tiredness have been noted for individuals at this stage. Non-itchy rash appeared in the majority of patients 2–7 days after the onset of symptoms in the 1967 European outbreak.
Most patients experience severe hemorrhagic symptoms within five to seven days, and fatal cases almost always involve bleeding in some fashion, sometimes from several locations. Nose, gum, and vaginal bleeding are frequently seen in patients with fresh blood in their vomitus and faeces.
Venepuncture sites (where intravenous access is established to administer fluids or collect blood samples) are particularly vulnerable to spontaneous bleeding, which can be a major source of concern. High fevers have been a common occurrence in the most severe stages of sickness.
Confusion, impatience, and violence might result from central nervous system involvement. Rare cases of orchitis (inflammation of one or both testicles) in the advanced stages of the disease have been recorded in the literature (15 days).
Most deaths occur within eight to nine days of the onset of symptoms, usually following a period of significant blood loss and shock.
Clinicians may have a hard time telling the difference between MVD and other infectious disorders such as malaria, typhoid fever, shigellosis, and meningitis. Confirmation of Marburg virus infection is made using the following diagnostic techniques.
- antibody-capture enzyme-linked immunosorbent assay (ELISA)
- antigen-capture detection tests
- serum neutralization test
- reverse transcriptase polymerase chain reaction (RT-PCR) assay
- electron microscopy
- virus isolation by cell culture.
Clinicians may have a hard time telling the difference between MVD and other infectious disorders such as malaria, typhoid fever, shigellosis, and meningitis. These diagnostic procedures are used to confirm that the symptoms of Marburg virus infection are real.
Treatment and vaccines
MVD vaccines and antiviral therapies are currently not available due to a lack of FDA approval. Supportive care, such as oral or intravenous rehydration, as well as treatment of specific symptoms, improves survival.
Antivirals such as Remdesivir and Favipiravir, which have been used in clinical studies for Ebola Virus Disease (EVD), could be studied for MVD or used under compassionate use/expanded access as monoclonal antibodies (mAbs) are currently being developed.
The European Medicines Agency (EMA) approved Zabdeno (Ad26.ZEBOV) and Mvabea (MVA-BN-Filo) in May 2020 for use in the treatment of EVD. Four proteins from Zaire’s Zaire Ebolavirus and three other viruses of the same type are produced by a virus known as MVA in the Mvabea (filoviridae). The vaccine may be able to protect against MVD, but clinical trials have not yet established its efficacy.
Marburg virus in animals
Marburg virus is known to live naturally in Rousettus aegyptiacus bats. The fruit bats appear to be healthy. As a result, it’s possible that the Marburg virus’s geographic spread will overlap with that of Rousettus bats.
During the first Marburg outbreak, humans were infected by African green monkeys (Cercopithecus aethiops) imported from Uganda.
Many different Ebola viruses have been used to inoculate pigs in the lab, and the results suggest that pigs are sensitive to filovirus infection and shed virus. In the event of an outbreak of MVD, pork should be regarded a potential amplifier host. Even though no other domestic animals have been linked to filovirus outbreaks, it is prudent to treat them as amplifier hosts until the contrary is demonstrated.
Due to the risk of infection from fruit bat contact, precautionary measures are needed in African pig farms. MVD outbreaks may be sparked or exacerbated by such an infection.
Prevention and control
Case management, monitoring and contact tracking, a strong laboratory service, safe and respectful burials, and societal mobilisation are all necessary components of a successful epidemic control strategy. When it comes to preventing and responding to outbreaks, community involvement is essential. Human transmission of Marburg can be minimised by educating the public about risk factors and precautions they can take.
Several aspects of risk reduction should be emphasised in messaging:
Reducing the risk of bat-to-human transmissionresulting from exposure to fruit bat colonies in mines or caves for an extended period of time. People should wear gloves and other protective clothes when working in mines or caverns where fruit bat colonies live or visiting as a tourist (including masks). It is imperative that all animal products (blood and flesh) be fully prepared before ingestion if an outbreak is to take place.
Limiting community exposure to sick individuals’ bodily fluids, which are a major source of human-to-human transmission. Physical contact with Marburg patients should be avoided. Handling sick patients at home calls for the use of gloves and other personal protective equipment (PPE). After visiting sick family members in the hospital and after caring for unwell patients at home, it is important to wash one’s hands frequently.
Those living in Marburg-affected areas should do everything they can to keep the general public well-informed about the disease’s characteristics and the precautions that must be taken to prevent an outbreak.
Protective measures include burying those who have passed away quickly, safely, and with dignity; tracking those who may have been exposed to the Marburg virus and keeping track of their health for 21 days; isolating those who are healthy from those who are infected; caring for confirmed patients; and maintaining a clean environment.
minimising the potential for sexual transmission. Until their semen tests negative for Marburg virus a second time, WHO recommends that male survivors of Marburg virus disease practise safer sex and hygiene for a period of 12 months following the onset of symptoms. Soap and water should be used to cleanse hands after contact with bodily fluids. Male and female convalescent patients who have tested negative for Marburg virus should not be isolated, according to WHO guidelines.
Controlling infection in healthcare settings
Regardless of the patient’s suspected diagnosis, healthcare staff should always take normal measures when caring for them. Some of the most important of these are proper hand and respiratory hygiene, the use of personal protection equipment (PPE), safe injection techniques, and appropriate burial procedures.
For patients with a suspected or confirmed Marburg virus infection, healthcare staff who care for them should take extreme precautions to avoid contact with their blood, bodily fluids, and contaminated surfaces or materials, such as clothing and bedding. A clean, non-sterile long-sleeved gown and gloves should be worn by health-care workers when they are in close proximity (within one metre) to patients with MVD (sterile gloves for some procedures).
There is also a danger to laboratory employees. The handling and processing of samples from humans and animals for the examination of the Marburg infection should be done by professionals who have been properly trained.
Marburg viral persistence in in people recovering from Marburg virus disease
The virus that causes Marburg virus sickness can recur in persons who have recovered from the disease and have a healthy immune system. The inside of the eye and the testicles are two examples of these locations.
The virus can be found in the placenta, amniotic fluid, and developing foetus of women who were infected while pregnant.
If a woman is infected while breastfeeding, the virus may remain in her milk for some time after the infection.
People who have recovered from MVD have had uncommon but recorded cases of relapse-symptomatic disease in the absence of re-infection. This phenomenon has yet to be fully explained.
Infected semen have been reported to transmit Marburg virus for up to seven weeks following clinical recovery. To better understand the dangers of sexual transmission, as well as the presence of a viable and transmissible virus in the semen, more data and research are needed. In the meantime, and in light of the available evidence, WHO advises:
Within three months following the commencement of the disease, male Marburg survivors should be registered in semen testing programmes and offered semen testing when they are psychologically and physically ready. In the event of two consecutive negative test results, a sperm sample should be tested.
In order to ensure safer sexual practises until their semen has tested negative for Marburg virus twice, all Marburg survivors and their partners should receive counselling.
Condoms should be given to survivors.
Survivors of the Marburg massacre and their sexual partners had two options:
take a complete break from any sexual activity
use condoms correctly and consistently until their semen has been tested twice and has come back negative for the Marburg virus.
Survivors who have tested negative for the Marburg virus can resume normal sexual behaviours with little fear of spreading the illness to others.
In the 12 months following the onset of symptoms or until their semen tests undetectable (negative) for Marburg virus twice, male survivors of Marburg virus disease should practise safer sexual behaviours and cleanliness.
It is imperative that survivors wash their hands thoroughly with soap and water after any physical contact with semen, including masturbation, until their semen has been tested for Marburg two times and has come back negative both times. During this time, used condoms should be handled with care and disposed of properly to avoid coming into contact with any seminal fluids or other reproductive fluids.
Survivors and their loved ones deserve to be treated with decency and care.
Keeping an eye on Marburg virus sickness and helping at-risk nations establish preparation plans are two ways WHO strives to prevent outbreaks of the disease. Ebola and Marburg virus epidemics can be controlled with the help of the following document:
As soon as an outbreak is recognised, the WHO provides help for monitoring, community involvement, case management, laboratory services, contact tracing, infection control, logistical support and training and aid with proper burial practises…
Follow digitalnewsexpert.com for more developments in the near future.