Diarrhoea. You might not like thinking about it but it beats dying from it. A we saw with cholera, diarrhoea can be seriously dehydrating and that can kill you very quickly. In Africa diarrhoea, due to a variety of causes, kills more children than either malaria or AIDS. That's an amazing fact. Also shocking is that most of these deaths are preventable for a cost of less than $0.30.
Time magazine had an interesting article on the topic last August:
Can One Pill Tame the Illness No One Wants to Talk About?
The World Health organization also had a report last year called:
Diarrhoea: why children are still dying and what can be done
“It is a tragedy that diarrhoea, which is little more than an inconvenience in the developed world, kills an estimated 1. 5 million children each year,” said UNICEF Executive Director, Ann M. Veneman. "Inexpensive and effective treatments for diarrhoea exist, but in developing countries only 39 per cent of children with diarrhoea receive the recommended treatment.”