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Posted on: April 12, 2023

Health Advisory: Marburg Virus Disease Outbreaks in Equatorial Guinea and Tanzania

Health Advisory: Marburg Virus Disease Outbreaks in Equatorial Guinea and Tanzania

April 12, 2023

Action Requested

  • Be aware of the potential risk of imported cases to the U.S. from two confirmed outbreaks of Marburg virus disease (MVD), one each in Equatorial Guinea and in Tanzania. 
    • There have been no confirmed U.S. cases from these outbreaks as of this advisory.
    • Do NOT defer routine laboratory testing or other measures necessary for standard patient care based on recent travel to Equatorial Guinea or Tanzania.
  • Systematically assess patients for the possibility of viral hemorrhagic fevers (including MVD or Ebola disease) through a triage and evaluation process, including a detailed travel history. 
  • Include MVD as a differential diagnosis for an ill person with history of a concerning exposure while in a MVD affected area (e.g., contact with a symptomatic person with suspected or confirmed MVD or an unknown illness; attending/participating in a funeral; visiting or working in a healthcare facility; having contact with bats or non-human primates; working or spending time in a mine/cave) within 21 days before symptom onset and who have clinical symptoms such as fever, headache, muscle and joint pain, fatigue, loss of appetite, gastrointestinal symptoms, or unexplained bleeding.
  • Consider, evaluate and appropriately manage alternative diagnoses such as malaria, COVID-19, influenza, or common causes of gastrointestinal and febrile illnesses in a patient with recent international travel.
    • Patients with a Marburg virus infection may present with concurrent infections (e.g., co-infection with malaria). Concurrent infection should be considered if a patient has a clinical and epidemiologic history compatible with MVD.
  • If a patient is determined to meet criteria for Marburg virus testing, consider patient a suspect case and manage under isolation precautions, which are the same as for Ebola Virus Disease, until a negative Marburg virus test result is received on a sample collected > 72 hours after symptom onset. 
    • Routine laboratory testing to monitor the patient’s clinical status and diagnostic testing for other potential causes of illness should be pursued while Marburg virus testing is underway. Do not delay Marburg virus diagnostic testing while awaiting other results.
  • If you have concerns about a patient with suspected MVD, immediately contact the Snohomish County Health Department Communicable Disease Program at 425-339-3503.
    • If a diagnosis of MVD is considered, public health staff will work with CDC and the clinical team to coordinate care and testing for the patient and ensure appropriate precautions are taken to help prevent potential spread.
  • If you have patients with planned travel to an MVD outbreak affected area, counsel them on ways to prevent exposure. They should avoid contact with blood and body fluids (or materials possibly contaminated with blood and body fluids) of people who are sick; funeral or burial practices that involve touching the body of someone who died from suspected or confirmed MVD; or contact with fruit bats and nonhuman primates and areas known to be inhabited by fruit bats (such as mines or caves).
  • Review and follow infection prevention and control measures.
    • In hospitals, CDC recommends a combination of infection prevention and control measures to prevent transmission of MVD. These infection prevention and control measures include personal protective equipment (PPE), patient placement, and patient care considerations. If MVD is suspected, patients should be isolated in a private room with a private bathroom or covered bedside toilet. 
    • Healthcare personnel should follow the same infection prevention and control measures as recommended for Ebola disease, including using recommended personal protective equipment (PPE) and limiting the number of personnel who enter the room for clinical evaluation and management.
    • Healthcare personnel can be exposed through contact with a patient’s body fluids, contaminated medical supplies and equipment, or contaminated environmental surfaces. Splashes to unprotected mucous membranes (e.g., the eyes, nose, or mouth) are particularly hazardous. Procedures that can increase environmental contamination with infectious material, involve handling of potentially contaminated needles or other sharps, or create aerosols should be minimized. Separate PPE guidance is available for managing clinically stable and clinically unstable patients.


CDC issued a Health Alert Network (HAN) Health Advisory on April 6 regarding Marburg virus disease, a rare but highly fatal viral hemorrhagic fever caused by two zoonotic viruses, Marburg virus and Ravn virus, that are closely related to ebolaviruses within family Filoviridae. In February and March 2023, two distinct outbreaks of Marburg virus were reported in Equatorial Guinea and Tanzania. These outbreaks mark the first time that Marburg virus has been identified in either Equatorial Guinea or Tanzania, though the virus has been identified previously in neighboring countries and the reservoir, the Egyptian fruit bat, is known to be present in both countries. Available information suggests that these outbreaks may have originated separately in each country. To date, there is no evidence that these two outbreaks are epidemiologically linked. Viral genetic sequencing from Tanzania is in process; these results, along with sequence data available from Equatorial Guinea, will further inform whether the outbreaks emerged separately through distinct animal-to-human spillover events.

A person with MVD is not contagious until symptoms appear. Symptoms may include fever, headache, muscle and joint pain, fatigue, loss of appetite, gastrointestinal symptoms, or unexplained bleeding. Marburg virus is spread through contact (through broken skin or mucous membranes) with the blood or other body fluids (including urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, or semen) of a person who is sick with or has died from MVD, with the body fluids of infected animals, or with needles or other fomites that are contaminated with the virus. Marburg virus is not spread through airborne transmission.

There is currently no Food and Drug Administration (FDA)-approved vaccine or treatment for MVD. In the absence of early diagnosis and appropriate supportive care, MVD has a high mortality rate of 23%–90%. With early intensive supportive care and fluid replacement, mortality rates may be lower.

For more detailed information, please see the full HAN Health Advisory.


Note: Recommendations for clinicians, infection prevention and control, and biosafety precautions that apply to Ebola Disease also apply to Marburg Virus Disease (MVD) in U.S. healthcare settings.

Infection Prevention 

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