Endemic areas appear to be Central and East Africa. In particular, visitors to the Kitum cave on top of Mt. Elgon have contracted Marburg. Marburg may also have a natural reservoir in Zimbabwe. The natural reservoir for the virus is unknown. Epidemiologists have tested bats, monkeys, spiders and ticks for the virus, but were not able to acquire definitive data.
Common factors indicate that the natural reservoir is part of rural Africa.
Secondary spread of the disease is via contact with infected persons or contact with blood, secretions, or excretions of infected persons. The virus may continue to be shed in the patient's semen for up to 3-4 months after illness. Sexual transmission of the disease did occur in one instance in Germany. As with Ebola, the exact mechanism of Marburg is unknown. However, virion surface spikes are made soley of large glycoprotein.