After obtention of two consecutive negative test results, MVD survivors can safely resume normal sexual practices with minimized risk of Marburg virus transmission. In the absence of semen testing programme, male survivors should follow safer sex practices for 12 months.

When an outbreak is detected WHO responds by supporting surveillance, community engagement, case management, laboratory services, infection prevention and control, logistical support and training and assistance with safe burial practices.

Once introduced in the human population, Marburg virus can spread through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.

Marburg virus (MARV) and Ravn virus (RAVV) of the species Orthomarburgvirus marburgense are the causative agents of Marburg virus disease (MVD), a disease with a case fatality ratio of up to 88%, but can be much lower with good and early patient care.

Laboratory workers are also at risk. Samples taken from humans and animals for investigation of Marburg virus infection should be handled by trained staff and processed in suitably equipped laboratories.

Samples collected from patients are an extreme biohazard risk; laboratory testing on non-inactivated samples should be conducted under maximum biological containment conditions. All non-inactivated biological specimens should be packaged using the triple packaging system when transported nationally and internationally.

Both viruses are part of the Filoviridae family (filovirus) of which Orthoebolavirus genus belongs to. Though caused by different viruses, Ebola and Marburg  diseases are clinically similar. Both diseases are rare but have the capacity to cause outbreaks with high fatality rates.

Experimental inoculations in pigs with different Orthoebolavirus species indicated  that pigs are susceptible to filovirus infection and shed the virus. Therefore, pigs should be considered as a potential amplifier host during MVD outbreaks. Precautionary measures are needed in pig farms in Africa to avoid pigs becoming infected through contact with fruit bats.

Initially, human MVD infection results from prolonged exposure to mines or caves inhabited by Rousettus fruit bat colonies.

Health-care workers have frequently been infected while treating patients with suspected or confirmed MVD. This has occurred through close contact with patients when infection control precautions are not strictly practiced. Transmission via contaminated injection equipment or through needle-stick injuries is associated with more severe disease, rapid deterioration, and, possibly, a higher fatality rate.

Raising awareness of risk factors for MVD  and protective measures that individuals can take is an effective way to reduce human transmission.

MVD begins abruptly, with high fever, severe headache and severe malaise. Muscle aches and pains are a common feature. Severe watery diarrhoea, abdominal pain and cramping, nausea and vomiting can begin on the third day. Non-itchy rash have been reported in patients  between 2 and 7 days after onset of symptoms.

Community engagement is key to successfully controlling any outbreaks. Outbreak control relies on using a range of interventions, such as case management, surveillance and contact tracing, good laboratory service, infection prevention and control in health facilities, safe and dignified burials, and social mobilization.

Marburg virus is known to persist in immune-privileged sites in some people who have recovered. These sites include the testicles and the inside of the eye. Extrapolating from data on other filoviruses, the virus may persist in the placenta, amniotic fluid and foetus of women infected while pregnant and in breast milk of women infected while breastfeeding.  Relapse-symptomatic illness in the absence of re-infection in someone who has recovered from MVD is a rare event, but has been documented. Reasons for this phenomenon are not yet fully understood.

MVD was initially detected in 1967 after simultaneous outbreaks in Marburg and Frankfurt in Germany; and in Belgrade, Serbia. These outbreaks were associated with laboratory work using African green monkeys (Cercopithecus aethiops) imported from Uganda. Subsequently, outbreaks and sporadic cases have been reported in Angola, Equatorial Guinea, the Democratic Republic of the Congo, Ghana, Guinea, Kenya, South Africa (in a person with recent travel history to Zimbabwe), Tanzania and Uganda. In 2008, two independent cases were reported in travellers who had visited a cave inhabited by Rousettus aegyptiacus bat colonies in Uganda.

Marburg virus transmission via infected semen has been documented up to seven weeks after clinical recovery. To mitigate the risk of potential transmission via exposure to infected semen, a semen testing programme should be implemented to:

Rousettus aegyptiacus bats are considered natural hosts for Marburg virus. There is no apparent disease in these fruit bats. As a result, the geographic distribution of Marburg virus may overlap with the range of Rousettus bats.

Healthcare workers should always take standard precautions when caring for patients, regardless of their presumed diagnosis. These include basic hand hygiene, respiratory hygiene, use of personal protective equipment (to block splashes or other contact with infected materials), safe injection practices and safe and dignified burial practices.

African green monkeys (Cercopithecus aethiops) imported from Uganda were the source of infection for humans during the first MVD outbreak.

Healthcare workers caring for patients with suspected or confirmed MVD should apply extra infection control measures to prevent contact with the patient’s blood and body fluids and contaminated surfaces or materials such as clothing and bedding.

It can be difficult to clinically distinguish MVD from other infectious diseases such as malaria, typhoid fever, shigellosis, meningitis and other viral haemorrhagic fevers. Confirmation that symptoms are caused by Marburg virus infection are made using the following diagnostic methods:

WHO aims to prevent MVD outbreaks by maintaining surveillance for MVD disease and supporting at-risk countries to develop preparedness plans. The following document provides overall guidance for control of Ebola and Marburg disease outbreaks:

All survivors, their partners and families should be shown respect, dignity and compassion. WHO does not recommend isolation of male or female convalescent patients whose blood has been tested negative for Marburg virus. MVD survivors might suffer from both clinical and psychological sequelae. WHO encourages affected countries to consider the establishment of a survivor care programme to alleviate sequelae, support to community reintegration and offer counselling and biological testing.

In fatal cases, death occurs most often between 8 and 9 days after symptom onset, usually preceded by severe blood loss and shock.

From day 5 of the disease, patients may develop  haemorrhagic manifestations, including fresh blood in vomitus and faeces, bleeding from the nose, gums, and vagina. Bleeding at venepuncture sites (where intravenous access is obtained to give fluids or obtain blood samples) can also be observed. Involvement of the central nervous system can result in confusion, irritability, and aggression. Orchitis (inflammation of one or both testicles) has been reported occasionally in the late phase of disease.

People cannot transmit the disease before they have symptoms and remain infectious as long as their blood contains the virus.

Burial ceremonies that involve direct contact with the body of the deceased can also contribute in the transmission of Marburg virus.

There are candidate monoclonal antibodies (mAbs) and antivirals, along with candidate vaccines that can be evaluated in clinical trials.