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Jennifer Radlinsky, Sophia Ritscher, Gabriel Helupka, Kahlil Alavi, Emergency Management, Health, and Hazards Team

Salomon Montaguth, Álvaro Picón, Editor; Jennifer Loy, Chief Editor

Week of Monday, March 20, 2023

Marburg Virus Pathogen[1]

On Tuesday, March 21, Tanzania’s Ministry of Health announced efforts to contain a suspected Marburg virus disease (MVD) outbreak. Five people died from confirmed MVD infections in the Kagera region near the Ugandan border. This is the first outbreak of MVD in Tanzania and comes after a now-controlled Ebola outbreak in neighboring Uganda in January. After ruling out Ebola, and conclusively proving MVD causes viral infections, Tanzania declared a state of high alert,[2] given MVD’s high mortality rate and limited treatment options.[3]

Description of Pathogen

MVD is a rare but highly fatal hemorrhagic fever. This virus is a genetically unique zoonotic (animal-borne) RNA virus in the filovirus family. The only other known members of this virus family are the six Ebola virus species. MVD targets people and non-human primates. The reservoir host of this virus is the Egyptian Rousette fruit bat native to Africa. Infected bats do not show obvious signs of illness.[4] Climate does not affect the likelihood of MVD outbreaks. The Marburg virus can survive for many days in liquid or dried material. It can be inactivated by gamma irradiation, heating for 60-75 minutes at 60°C, boiling for five minutes, or through disinfectants.[5] People remain infectious as long as their blood contains the virus.[6]

After initial transmission from animal to human through prolonged exposure to mines or caves inhabited by fruit bats, the virus spreads through close person-to-person contact.[7] It spreads among humans when broken skin or mucous membranes in the eyes, nose, or mouth come into contact with:

  • Blood or bodily fluids (urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, and semen) of an infected or deceased person with MVD.[8]

  • Objects contaminated with body fluids of an infected or deceased person with MVD. This includes clothes, bedding, needles, syringes, or other medical equipment.[9]

  • The semen of a recovered person may still contain the virus and be able to transmit it for up to 12 months.[10] Data on this is limited; however, the Marburg virus persists in the testicles and inside of the eye, similar to the Ebola virus.[11] There is no evidence of transmission via vaginal fluids of a recovered person.[12]

The incubation period ranges from two to 21 days, and MVD’s onset is sudden and severe. Medical personnel and family members who care for MVD patients are at the highest risk of contracting the virus. Veterinarians, laboratory, or quarantine facility personnel working with African non-human primates have an increased risk of exposure.[13] Symptoms include high fever, strong headaches, muscle pains, nausea, vomiting, and diarrhea. Severe hemorrhagic manifestations develop between five and seven days. Death occurs most often between eight and nine days after symptom onset, typically preceded by severe blood loss and shock. The average MVD case fatality rate is around 50% but varies between 24% to 88%, depending on case management.[14] Patients surviving MVD typically did not show the most severe manifestations of the disease.[15] The recovery process is slow, and patients often suffer complications such as joint and muscle pains, fatigue, hepatitis, ocular disease, and psychosis.[16] Other long-term signs and symptoms include hair loss and liver and testicular inflammation.[17] No vaccine or antiviral medication against MVD exists.[18] Supportive care is the only known treatment, such as rehydration with oral or intravenous (IV) fluids. Maintaining a patient’s bodily systems, including blood pressure and oxygen levels, are the first treatment methods used. Replacement of blood loss and treatment for additional concomitant infections may be necessary.[19]


Tanzania Outbreak Region[20]

On March 21, laboratory tests confirmed MVD cases following an outbreak of a mysterious disease in the Kagera region. The outbreak occurred in the Bulinda and Butayaieba villages of Maruku and Kanyangereko wards, respectively, in Bukoba Rural District, Tanzania.[21] The disease killed five people and admitted two others to a health facility. These are the first-ever confirmed cases of MVD in Tanzania.[22] The climate of Tanzania ranges from tropical along the coast to temperate in the highland regions.[23] It has a diverse terrain with various valleys, plateaus, plains, and mountains. Tanzania is known for its wilderness and safaris. Mount Kilimanjaro is the highest point in Africa and is a dormant volcano in the Kilimanjaro region.[24] Coastal temperatures average between 27°C and 29° C. Temperatures in the northern and western regions range from 20°C to 30°C. Tanzania is located below the equator and has higher temperatures between December and March, while the coolest temperatures are between June and July. Tanzania usually has long rain periods between March and May. Short rain periods go from October to early December. Annual rainfall varies from 21.6 inches in the central region and up to 145 inches in the southern and western highlands.[25]

Response Challenges

The main challenge in responding to an MVD outbreak is the lack of vaccine and antiviral treatment options.[26] The Tanzanian health sector is underfunded and understaffed, and a large share of the population does not have health insurance.[27] This could prevent infected people from seeking treatment and aid the spread of MVD. Rural areas, like the affected Bulinda and Butayaieba villages,[28] have minimal access to sanitation facilities and drinking water, increasing the likelihood of the Marburg virus spreading further.[29] However, non-existence or poor infrastructure in remote areas challenge this. Challenges include only laboratory tests being able to diagnose it and symptoms similar to malaria, likely leading to false health scares. There is currently no widespread readily available testing for MVD. Long-term response challenges include the continued testing capacities for male MVD survivors and the distribution of condoms, as semen may be contagious for up to 12 months after recovery.[30]

Travel Warnings

There is currently no vaccine or specific treatment available for MVD.[31] Individuals traveling domestically or internationally to Tanzania should avoid visiting infected regions like Kagera. Travelers without necessary reasons for visiting Kagera should consider delaying their plans or finding alternative Tanzanian locations. The potential for further outbreaks is very likely; the Tanzanian government will very likely enforce travel or movement restrictions if MVD spreads to other parts of the country. Travelers should plan ahead, follow public health guidance, and monitor reliable local news sources while traveling through infected regions. It is recommended that travelers avoid public transport or high-density areas near infected regions to reduce exposure to MVD. Travelers should avoid excursions to caves or mines. Foreign travelers requiring assistance should contact their local embassy in Tanzania and monitor their travel and health alerts.

The Tanzanian government implemented contact tracing procedures and quarantine measures for infected persons. Travelers to and from Kagera will likely be subject to enhanced health screenings. Travelers should wash their hands with soap and water regularly and wear masks.[32] Travelers should avoid contact with all body fluids. Individuals should avoid contact with chimpanzees, gorillas, monkeys, bats, and forest antelopes. The manipulation or consumption of bushmeat from these primates is a likely virus vector and should be avoided. All animal products, particularly blood and meat products, should be thoroughly cooked before consumption in the affected areas.[33] If a traveler experiences symptoms consistent with MVD during or after travel, they should isolate themselves and call a healthcare facility immediately to inform staff that they have been to an MVD outbreak area.[34]

Countries in sub-Saharan Africa will very likely be on high alert, likely increasing testing and surveillance of the outbreak in Tanzania. This will likely lead to the discovery of more cases in several other locations. MVD is very likely to spread nationally in Tanzania. MVD will likely spread to nearby countries due to minimal movement restrictions, its transmission through body fluids, the incubation period, and the current challenges in diagnosing MVD. Travelers should monitor the outbreak throughout the African continent and avoid any new infected regions, such as Kie-Ntem, Litoral, and Centre-Sur provinces in Equatorial Guinea.[35] Travelers should check WHO advice, listen to public health authorities, and follow reliable news sources for current outbreak updates. The Counterterrorism Group (CTG) will monitor the outbreak and assess the security risks in Tanzania and throughout the region by creating travel security reports. CTG provides actionable information to travelers and practical advice on safety concerns.

Political Effects/Effects on Terrorism

The MVD outbreak in the Kagera region is unlikely to result in political instability due to the low number of cases. Should the Tanzanian government fail to take appropriate containment measures, the risk of political instability and exploitation by terror groups increases. Although Tanzania regained political stability in 2021[36] and showed resilience toward terrorism, the risk of terrorist attacks remains high.[37] Since 2009 Tanzania has experienced low-level and sporadic terrorist attacks. The reluctance of Tanzanian intelligence and law enforcement to investigate these attacks and determine the full extent of Al-Shabaab’s presence in Tanzania[38] results in a roughly even chance that terrorist groups could exploit the MVD outbreak. They will likely target critical interests like places of worship or transport hubs while Tanzanian officials focus their attention on containing the Marburg virus spread.

Recommendations for AOCs

Agencies, organizations, and companies (AOCs) associated with healthcare, education, the service industry, or mining should implement strict hygiene and safety measures, including routinely washing and sanitizing all material that came into contact with infected patients, to prevent the Marburg virus from spreading further. Medical workers are very likely to be infected while treating suspected MVD patients if proper precautions are not practiced. To prevent a large-scale outbreak of MVD, infected patients should be isolated and quarantined, and healthcare workers should wear PPE.[39] PPE should be widely distributed in the affected areas. During past Ebola outbreaks, people and the environment were sprayed with chlorine-based disinfectant, however, this is not a recognized outbreak control measure. Spraying humans with chlorine leads to adverse health effects and potentially discourages the community from complying with other prevention measures.[40] Similarly, foreign rapid response teams should respect local customs to ease possible tensions and ensure future cooperation of locals. Traditional burial rites should be conducted with precautions, including wearing PPE and placing the deceased in body bags to prevent soil containment.[41]

The coordination of local, national, and international partners is needed to quickly deliver medical personnel, medical equipment, personal protective equipment (PPE), isolation tents, and other needed goods. International support through the World Health Organization (WHO) or Médecins Sans Frontières (MSF) is almost certainly needed. AOCs should reinforce their readiness to respond to an outbreak. Increased testing for MVD and contact tracing of confirmed cases is essential in containing the virus. AOCs should inform residents in affected areas of the risks of contracting MVD and how to protect themselves. Protective measures include reducing exposure to mines and caves that are inhabited by fruit bats and minimizing interpersonal contact and group gatherings; this includes safe and prompt burials of the deceased, increasing hygiene and food safety measures, like avoiding consumption of raw meat, and reducing the risk of sexual transmission after recovery by practicing safer sex for up to 12 months.[42]

Isolation or recovery of patients can lead to reduced livelihoods and food insecurity due to decreased or diverted resources. Stigmatization of survivors results in further livelihood reduction and increases the need for better access to psychological support. AOCs should provide resources for these patients and secure their livelihoods.[43]


[1]Micrograph of the Marburg virus” by The University of Texas Medical Branch at Galveston licensed under CC BY-SA 4.0

[2]Marburg Virus Spreads in Tanzania, Health Officials on High Alert, VOA News, MArch 22, 2023,

[3]Marburg virus disease, World Health Organization, 2021,

[4]Marburg (Marburg Virus Disease), CDC, 2023,

[5]Factsheet about Marburg virus disease, European Centre for Disease Prevention and Control, 2022,

[6]Marburg virus disease, World Health Organization, 2021,

[7]Marburg Virus Disease, World Health Organization, 2023,

[8]Marburg (Marburg Virus Disease) Transmission, CDC, 2023,


[10]Marburg virus disease (MVD), International Federation of Red Cross and Red Crescent Societies, 2022

[11]Marburg (Marburg Virus Disease) Transmission, CDC, 2023,


[13]Marburg (Marburg Virus Disease), CDC,

[14]Marburg virus disease, World Health Organization,

[15]“Clinical aspects of Marburg hemorrhagic fever,” Future Virology,


[18]Marburg virus disease, World Health Organization,

[19]Marburg (Marburg Virus Disease), CDC,

[21]“Tanzania: Mysterious Disease Kills 5 in Northwest Tanzania”, AllAfrica, March 2023,

[22]Tanzania Confirms First-Ever Outbreak of Marburg Virus Disease, AllAfrica, March 2023,

[23]The World Factbook, Central Intelligence Agency,

[26]Marburg virus disease, World Health Organization,

[27]Social Situation, Federal Ministry for Economic Cooperation and Development,

[28]“Tanzania: Mysterious Disease Kills 5 in Northwest Tanzania,” AllAfrica, March 2023,

[29]Social Situation, Federal Ministry for Economic Cooperation and Development,

[30]Marburg virus disease (MVD), International Federation of Red Cross and Red Crescent Societies,


[32]HEALTH ALERT – U.S. EMBASSY DAR ES SALAAM, TANZANIA, US State Department, March 2023,

[33]Factsheet about Marburg virus disease, European Centre for Disease Prevention and Control,

[34]Marburg in Tanzania, Center for Disease Control and Prevention, March 2023,

[35]Equatorial Guinea confirms eight more Marburg cases - WHO, Reuters, March 2023,

[36]Political situation, Federal Ministry for Economic Cooperation and Development,

[37]Tanzania: Extremism and Terrorism, Counter Extremism Group,


[39]Marburg virus disease, World Health Organization, August 2021,

[40]Marburg virus disease (MVD), International Federation of Red Cross and Red Crescent Societies,

[41]Marburg virus disease, World Health Organization, August 2021,

[42]Marburg virus disease, World Health Organization, August 2021,

[43]Marburg virus disease (MVD), International Federation of Red Cross and Red Crescent Societies,



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