Ebola, Marburg, and Hemorrhagic Fever

If AIDS is one of the slowest killers, taking a leisurely 10 years or so to kill its victims, Ebola is one of the fastest.    It first came to attention in 1976 when the "index case" (i.e. the first observed case) showed up at the Yambuki Mission Hospital and was mis-diagnosed as showing early signs of malaria.  He was given an injection of Chloroquine.  Apparently the same needle was used on this patient as on a number of other patients subsequently, and they developed symptoms as well.  The Index case, a mission worker, who had been on a road trip with six other mission workers, visiting several other towns in the region, and had bought smoked and fresh antelope and monkey meat on August 22, was admitted to the Yambuku Mission Hospital on Sept 1 after a "relapse" of his symptoms of what was thought to be malaria.  At that time he suffered hemorrhages and gastrointestinal bleeding, and finally died on September 8.

 To make a long story short by October 24, there had been 318 cases of the hitherto unknown disease and 280 deaths and 38 serologically confirmed cases which survived the infection.  The fact that the outpatient clinic was re-using needles and rinsing them out in a pan of warm water was implicated later as facilitating the spread of the epidemic.  By the beginning of October 11 of the 17 staff at the hospital had died from the disease and the hospital was closed.   This may have been the one thing that had the most to do with the ending of the epidemic, as the poorly trained nurses dispensed death continually, still sharing needles up until the closure of the hospital at Yambuku. 

Don't share needles and wear a protective suit

The agent of the disease was found to be related but antigenically distinct from Marburg Virus.  Marburg is a town in Germany where there is a research facility by the drug company Hoechst.  In 1967 workers were accidentally  exposed to the infected tissues of grivets, a type of monkey used for research purposes whose natural habitat is in Ethiopia and Sudan.  The virus that infected the workers also causes a severe hemorrhagic fever that in the 1967 outbreak killed 7 of 31 workers infected with it at the facility for a mortality of 23%. 

Both viruses are classed as part of the family Filoviridae, which are filamentous RNA viruses, the defining characteristics of which are outlined here.  They seem to have as their reservoir in nature, bats. 

In the case of Ebola one outbreak apparently was caused when the index case individual visited a cave near the Uganda / Zaire border.  Bats carry the virus and excrete it in their droppings while not themselves seriously affected by it.  The virus is apparently transmitted to animals such as apes or monkeys when bats feeding at night defecate on foliage which primates subsequently consume.