If you have been to these bakward places, like Africa, you will know the standards are not very high.
But what if you live in most of the rest of the world, USA, Canada, Mexico, Japan, most of Europe, the Nordic countries, etc, where medical practices are much higher, what then? Should you still reject blood because Africa has problems?
Here are some threads of interest:
http://www.jehovahs-witness.net/watchtower/medical/116373/1/NO-BENEFITS-TO-BLOOD-TRANSFUSION
A few years back (2006/7/8), the WAtchtower/Awake ran an article on the safety of blood. They were quoting information from an article whose main point was that the blood supply is getting safer across the world. I can't find the thread. But, even in super 3rd world countries were coming to be safer. I can't find the thread that discussed the misquotes. Wish I could, but am pressed for time.
Blood fractions can ALSO kill: http://www.jehovahs-witness.net/watchtower/medical/156346/1/Blood-Fractions-that-Kill