Marburg hemorrhagic fever is a rare, severe type of hemorrhagic
fever which affects both humans and non-human primates. Caused by a genetically
unique zoonotic (that is, animal-borne) RNA virus of the filovirus family, its
recognition led to the creation of this virus family. The four species of Ebola
virus are the only other known members of the filovirus family.
Marburg virus was first recognized in 1967, when outbreaks of
hemorrhagic fever occurred simultaneously in laboratories in Marburg and
Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia). A total of 37
people became ill; they included laboratory workers as well as several medical
personnel and family members who had cared for them. The first people infected
had been exposed to African green monkeys or their tissues. In Marburg, the
monkeys had been imported for research and to prepare polio vaccine.
Where do cases of Marburg hemorrhagic fever occur?
Recorded cases of the disease are rare, and have appeared in
only a few locations. While the 1967 outbreak occurred in Europe, the disease
agent had arrived with imported monkeys from Uganda. No other case was recorded
until 1975, when a traveler most likely exposed in Zimbabwe became ill in
Johannesburg, South Africa - and passed the virus to his travelling companion
and a nurse. 1980 saw two other cases, one in Western Kenya not far from the
Ugandan source of the monkeys implicated in the 1967 outbreak. This patient's
attending physician in Nairobi became the second case. Another human Marburg
infection was recognized in 1987 when a young man who had traveled extensively
in Kenya, including western Kenya, became ill and later died.
Where is Marburg virus found?
Marburg virus is indigenous to Africa. While the geographic
area to which it is native is unknown, this area appears to include at least
parts of Uganda and Western Kenya, and perhaps Zimbabwe. As with Ebola virus,
the actual animal host for Marburg virus also remains a mystery. Both of the
men infected in 1980 in western Kenya had traveled extensively, including
making a visit to a cave, in that region. The cave was investigated by placing
sentinels animals inside to see if they would become infected, and by taking
samples from numerous animals and arthropods trapped during the investigation.
The investigation yielded no virus: The sentinel animals remained healthy and
no virus isolations from the samples obtained have been reported.
How do humans get Marburg hemorrhagic fever?
Just how the animal host first transmits Marburg virus to
humans is unknown. However, as with some other viruses which cause viral
hemorrhagic fever, humans who become ill with Marburg hemorrhagic fever may
spread the virus to other people. This may happen in several ways. Persons
handling infected monkeys who come into direct contact with them or their
fluids or cell cultures, have become infected. Spread of the virus between
humans has occurred in a setting of close contact, often in a hospital.
Droplets of body fluids, or direct contact with persons, equipment, or other
objects contaminated with infectious blood or tissues are all highly suspect as
sources of disease.