Complex sentence: For comparison, Lassa fever is estimated to kill about 5000 people a year in West Africa, and in Western countries, medical mistakes kill between 44,000 to 400,000 people a year.
Split into simpler sentences: For comparison, lassa fever is estimated to kill about 5000 people a year in West Africa. In comparison to western countries, medical mistakes kill between 44,000 to 400,000 people a year.