He then started to think carefully and observing Roger's body and reactions. He tried to get to a conclusion by closely analysing Roger's life and past. He knew that Roger did not get AIDS by homosexual contact and concluded by his studies that many AIDS patients were not even sexual related. It strikes more males than females. Life expectancy after diagnosis seems to be the same for male and female 35 to 40 months.
Sexual activity seems to be a predominant factor.
Meaning that there are a higher percentage of AIDS victims that are sexually active than those who are not. Bob's daughter asked Roger about his disease and then came up with a definition of AIDS, which she had learned at school that enlightened Bob. AIDS means that the immune system of the person who has AIDS isn't working properly. Bad things made the immune system quit working. He concluded that drugs were the cause of AIDS in Roger for he had misused them for many years.