Also, STDs cause infertility, and may cause woman to take multiple partners to achieve pregnancy and avoid social stigma. Includes odds of transmission for each sex act, duration of infectiousness per individual, and no. of new sex partners per year. Due to severity of epidemic, would need a very powerful vaccine, high vaccination rates to slow AIDS in some populations. Some problem in inadequate blood bank screening, ritual scarification. Little issue with IV drug use.
Authors recommend much more research, especially on behavior.
Need to recognize there are many heterogeneous African populations, and not overgeneralize. Should combine sociodemographic study with biological studies.