DATA: South Africa life expectancy

Average life expectancy across many parts of sub-Saharan Africa plummets as a result of the HIV epidemic, as low-income countries find themselves ill-equipped to manage an epidemic of this proportion. High drug prices mean that they cannot get vital lifesaving medicines to the people who need them most. But after generics become available, countries start huge antiretroviral treatment programmes which bring about marked improvements in life expectancy over the following few years.