Breaches of protocol happen here too. Read Hot Zone.
And this:
http://uk.reuters.com/article/2014/08/02/us-usa-healthcare-cdc-idUKKBN0G201A20140802
Read it already. Yes, breaches occur due to human error. From the sound of things in Africa, though, much of the transmission to healthcare workers had to do with very poor practices. These were likely due to poorly educated workers and the reality of a dearth of supplies/basic sanitation.
We are very blessed to have all of our modern conveniences, but the things that have made the biggest advances in medical care in the last 150 years or so in the West are the ability to keep feces and drinking water apart and the ability to sterilize medical equipment. Those things along with the knowledge about disease transmission and the importance of washing our hands are huge.
Africa is lacking in most of those things.