Transmission

It is unknown how Marburg virus or Ravn virus, collectively called marburgviruses, first spread from the animal host to people; however, research has shown that virus is shed in oral secretions, urine and feces from infected Egyptian rousette bats. For the 2 cases in tourists visiting Uganda in 2008, unprotected contact with infectious bat feces or urine droplets are the most likely routes of infection.

After this initial spillover of virus from host animal to people, transmission occurs through person-to-person contact. The virus spreads through contact (such as through broken skin or mucous membranes in the eyes, nose, or mouth) with:

• Blood or body fluids (urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid, and semen) of a person who is sick with or died from Marburg virus disease (MVD), or
• Objects contaminated with body fluids from a person who is sick with or has died from MVD (such as clothes, bedding, needles, and medical equipment).
• Semen from a man who recovered from MVD (through oral, vaginal, or anal sex). Data on marburgviruses is limited; however, they are known to persist in the testicles and inside of the eye, similar to ebolaviruses. Since marburgviruses and ebolaviruses are both in the same virus family (Filoviridae) it can be assumed that persistence of marburgviruses in other immune privileged sites (placenta, central nervous system) may be similar. There is no evidence that marburgviruses can spread through sex or other contact with vaginal fluids from a woman who has had MVD.

Spread of marburgviruses between people has occurred in close environments and among contacts. A common example is through caregivers in the home or in a hospital (nosocomial transmission).

In previous outbreaks, people who have handled infected nonhuman primates or have come in contact with their body fluids have become infected with the virus. Laboratory exposures can also occur when lab staff handle live virus.