There are still some things that we know about HIV and AIDS.
For example, do not really know why it is that HIV and AIDS are both so common in some African countries but not in Europe or America, although we do have some theories.
Factors that may contribute include the much higher prevalence of sexually transmitted diseases not covered in Africa (which usually increases the likelihood of HIV transmission) and, quite possibly, differences in HIV subtypes.
Also, people who have a poorer general health (including those with malaria or tuberculosis) are more likely to have higher amounts of HIV in their body fluids, making them more likely to transmit the virus. (more…)
