Marburg and Ebola infections are spread through handling live or dead infected animals or by contact with skin or body fluids of an infected person who has symptoms or who has died.
Symptoms begin with a fever, muscle and body aches, headache, cough, and a sore throat, followed by vomiting and diarrhea as well as bleeding from the mouth, nose, or internal organs.
To confirm the diagnosis, doctors do blood and urine tests.
Strict isolation and sanitary precautions (and, for health care practitioners, use of protective clothing) are needed to prevent spread of the infection.
Treatment includes giving fluids by vein and other treatments to maintain body functions.
Marburg and Ebola virus infections are hemorrhagic fevers Hemorrhagic Fevers Overview Hemorrhagic fevers are serious viral infections characterized by bleeding (hemorrhage). Hemorrhagic fevers can be caused by many different types of virus. Depending on the type of virus, these... read more , characterized by bleeding. They are caused by viruses called filoviruses Filoviruses Arbovirus, arenavirus, and filovirus are viruses that are spread from animals to people and, with some viruses, from people to people. The animal involved depends on the type of virus. Many... read more . (Other viruses can cause other hemorrhagic fevers.)
Outbreaks of Ebola and Marburg virus infections started in Central and West Africa, probably because the infections are common in wild animals there. Such outbreaks are rare and, in the past, have not spread very far because they typically occurred in isolated, rural areas. However, travelers from those areas sometimes carry the infection to nearby areas or, rarely, outside of Africa.
In December 2013, a large Ebola virus outbreak began in rural Guinea (West Africa), then spread to densely populated urban regions in Guinea and to neighboring Liberia and Sierra Leone. It was first recognized in March 2014. Ebola outbreaks involved thousands of people, and about 59% of infected people died. A very small number of infected travelers (including health care workers returning home) have spread Ebola virus to Europe and North America. A few health care workers who helped treat the infected people in Europe and North America also acquired the infection. Sierra Leone, Guinea, and Liberia were declared free of Ebola in 2016.
An outbreak of Ebola also occurred in the Democratic Republic of the Congo in 2017 but was quickly contained. Another outbreak there was confirmed in May 2018 and ended in June 2020 with the help of vaccines. There have been small outbreaks since then in North Kivu and Guinea.
Transmission of Ebola and Marburg viruses
The Ebola and Marburg viruses are highly contagious.
These viruses usually infect animals and only occasionally spread to people. Because the original animal source of these viruses has not yet been identified precisely, doctors are not sure how the virus infects the first person in an outbreak. However, experts think that the first person is infected by handling or eating an infected animal, such as a fruit bat or primate (apes and monkeys). Marburg virus infections have occurred in people exposed to bats (for example, in mines or caves).
Once a person has been infected, the infection can then spread from person to person when people come in direct contact with the skin or body fluids (saliva, blood, vomit, urine, stool, sweat, breast milk, or semen) of an infected person. Evidence shows that people cannot transmit the infection before they develop symptoms. However, body fluids from dead people often transmit the infection, particularly to people who transport and prepare corpses for burial, but even touching a body can spread the infection.
Ebola is not thought to spread through the air (for example, in droplets dispersed when people cough or sneeze). If such spread does occur, it is probably very rare.
In some people who recover, the Ebola virus is eventually completely eliminated from their system, and they are no longer contagious. In other people, the virus remains for a time in areas of the body that are protected from attack by the immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more (such as the eyes or semen). The genetic material of the Ebola virus can remain in semen for a year or longer after men no longer have symptoms.
The Marburg virus can remain in semen for up to 7 weeks after men no longer have symptoms.
Symptoms of Ebola and Marburg Virus Infections
People develop the first symptoms about 2 to 20 days after exposure to the virus. At first, the symptoms usually resemble those of other, less dangerous viral infections. People have muscle aches, headache, sore throat, and cough. People also become sensitive to light, and the whites of the eyes may turn red.
Within a few days, more serious symptoms, such as the following, develop:
Severe vomiting and diarrhea
A tendency to bleed
Confusion, delirium, and coma
The vomiting and diarrhea cause dehydration Dehydration Dehydration is a deficiency of water in the body. Vomiting, diarrhea, excessive sweating, burns, kidney failure, and use of diuretics may cause dehydration. People feel thirsty, and as dehydration... read more , which, if untreated leads to low blood pressure (shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more ), abnormal heart rhythms Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more , and death.
Bleeding begins within the first few days. Bleeding under the skin can be seen as purplish spots or patches (bruises), and the gums, nose, rectum, or internal organs may bleed, as may puncture wounds (as result from drawing blood or starting an intravenous line).
After about 5 days, a rash, mainly on the trunk, appears.
During the second week of symptoms, the fever breaks and either people begin to recover or their organs malfunction (called organ failure). From 25 to 90% of infected people die depending in large part on the level of medical care available. Compared with Marburg virus infection, Ebola is more likely to be fatal, averaging a 59% death rate. Recovery takes a long time.
Diagnosis of Ebola and Marburg Virus Infections
Blood and urine tests
Identifying Ebola in people who have been infected for only a few days is difficult because early symptoms, such as fever, can be caused by more common infections. However, if people with these symptoms are in or have traveled from areas where Ebola is occurring, doctors suspect Ebola. The Centers for Disease Control and Prevention (CDC) has provided guidelines for health care practitioners to enable them to evaluate travelers returning from such areas.
If doctors suspect Ebola, they take samples of blood and urine from the person and test them to confirm the infection.
A similar approach can be used if Marburg virus infection is suspected.
Public health officials are notified if an Ebola or a Marburg virus infection is diagnosed.
Prevention of Ebola and Marburg Virus Infections
Several vaccines and antiviral drugs have been developed. An Ebola vaccine in use in West Africa on a limited scale during outbreaks since 2016 was approved by the US Food and Drug Administration in December 2019 for use in people 18 years of age and older. Two Ebola vaccines Ebola Vaccine rVSV-ZEBOV is the only vaccine approved for use in the United States by the U.S. Food and Drug Administration (FDA) for prevention of Ebola virus disease caused by Zaire ebolavirus species.... read more are in routine use in the Democratic Republic of the Congo (DRC).
Strict isolation is needed to prevent spread. Isolating people with symptoms of possible Ebola or Marburg virus infection in facilities used only for that purpose can help. These facilities can safely handle the infected body fluids. Individuals who have been in contact with infected people should be vaccinated.
Staff members caring for people with Ebola must be completely covered in protective clothing, including head gear equipped with a respirator. Even though the infections are not thought to be spread through the air, precautions against such spread are taken. Other staff members must be available to help those wearing protective clothing remove the protective clothing.
Diligently cleaning and disinfecting surfaces and equipment that may be contaminated is crucial, as is making sure that body fluids (such as blood, sweat, vomit, feces, and urine) are handled safely.
For people who have traveled to or are in an area affected by an Ebola outbreak, the following is recommended:
Using good hygiene, such as washing their hands with soap and water or an alcohol-based hand sanitizer and avoiding contact with other people's blood and body fluids
Not handling items that may have come in contact with an infected person’s blood or body fluids (such as clothes, bedding, needles, and medical equipment)
Not participating in funeral or burial rituals that require handling the body of someone who has died of Ebola
Avoiding contact with bats and primates (such as apes and monkeys) and not eating raw or inadequately cooked meat prepared from these animals
Avoiding facilities in West Africa where Ebola patients are being treated
After returning, monitoring their health for 21 days and seeking medical care immediately if they develop symptoms suggesting Ebola
Although no infections are known to have been transmitted by sexual intercourse or breastfeeding, the number of people studied has been low. Thus, there are no firm guidelines on how long people should abstain from unprotected sexual intercourse, breastfeeding, or close personal contact. However, to be safe, doctors from the World Health Organization (WHO) recommend that men refrain from sexual intercourse for at least 7 weeks after recovery. If the men do have intercourse before 7 weeks, they should wear a condom.
Treatment of Ebola and Marburg Virus Infections
Antiviral drug treatment
Supportive treatment involves
Giving fluids intravenously (IV) to maintain blood pressure and the balance of electrolytes Overview of Electrolytes Well over half of the body's weight is made up of water. Doctors think about the body's water as being restricted to various spaces, called fluid compartments. The three main compartments are... read more (such as sodium, potassium, and calcium)
Treating symptoms, including giving pain relievers
Two monoclonal antibody treatments (called REGN-EB3 and mAb-114) are currently available to treat Ebola virus infection caused by the Zaire Ebola virus. Both of these treatments were tested during the 2018 to 2020 Ebola outbreak in the DRC and were very effective, curing about 90% of people when the drug was given within the first few days after infection.
These new drugs have not been tested in people with Marburg virus infection, so there is still no effective treatment for infection with that virus.
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