Seth Berkley ponders why the disease spreads faster in certain areas.

Seth Berkley:  One of the questions is why did the virus spread initially here in the United States and in Europe in men who were having sex with men and IV drug users, and have heterosexual spread occur here, but to a lesser degree, but in the developing world, these massive epidemics heterosexually. There’s been a lot of questions about that. Some people have postulated maybe the viruses, which are different -- the viruses that circulate different parts of the world so maybe the viruses perhaps were better adapted to heterosexual transmission in the developing world. Other people have postulated it’s because they were more other sexually transmitted infections or people’s immune systems were activated. But the answer is we really don’t understand why that is, but that being said, the explosions of disease in some places in Southern Africa, you have 30 to 40% of the adults infected and that’s all heterosexual transmission and it exploded from a time in Southern Africa 20 years ago when there was almost no epidemic. So there clearly is a different dynamic in those places.

Question: Are African strains more deadly?

Seth Berkley:  Southern Africa is infected with a CLAID-C virus. CLAID-C virus is also the virus that infects India and that area of the world. Some people have postulated that that particular strain might be a strain that transmits better to heterosexuals but somehow, we’ve been unable to prove that in a study. There had been other things that have come out of South Africa that have been of concern. There’s been extreme drug-resistant tuberculosis that’s been kind of a super strain. There’s also been pneumococcal disease which is a type of common pneumonia that’s been resistant to antibiotics. One point that’s important to think about, once upon a time, we thought about health being something that’s local. Today, health is not local. Health is global. We have to worry about epidemics and disease and antibiotic usage anywhere in the world because people are moving, viruses are moving all the time so it points out the importance of really understanding and working in these parts of the world both for the good of doing the right thing for those places but also for the importance of protecting us.