The USA has a higher rate of HIV than Europe where only Muslims and Jews circumcise. It is more of a behavior thing and access or willingness to take precautions for "safer sex" as they call it. Perhaps American men don't like condoms as "It doesn't feel as good" whereas an uncut European man has more sensitivity and doesn't mind a little less or is more aware of the risks due to better sex ed and schools handing out condoms. Abstinence only is sticking one's head in the sand. People are people. So we have more teen pregnancy here than in European countries despite behavior being about the same or even that Europeans have more sex as they are less puritanical.
Comparing Americans to Africans rather than others with similar genetics, economics, access to medicine and hygiene is like comparing apples to oranges. In any non-biased study one has to have two groups that are as alike as possible except the one thing being studied. They used to do a lot of studies of Japanese-Americans vs. Japanese nationals as that worked great. Now there are more Eurasians here, Japanese-Americans marry other Asians and so on. And in such a study that is good only for those with pure Japanese genes. Disease studies are very specific to genetics, socio-economics, educational background and gender else it biases the study and makes it worthless. Prosperous Americans are healthier and live longer than poor people. A rich white on average lives a decade longer than an impoverished Black in the US. US Blacks in turn outlive most Africans by a decade or more. They have better food, better medicine, access to clean water and better hygiene. Not knowing that one is diabetic or has hypertension (high blood pressure) is dangerous and sometimes deadly.
The French and Japanese smoke like chimneys but get less lung cancer with the same amount of cigarettes a day than an American. Why? Perhaps green tea and red wine help prevent it but studies are still pending.
Women react very differently to HIV infection than men and have different symptoms of the same illnesses so now they have to study both sexes for things like heart attacks, drug reactions and so on.
The USA has plenty of money to invent better ways to kill people (the military) but just try to get money for health research or public health. There is damned little.
There are lies, damned lies and statistics. People can lie using bad statistics.
