Just happend to read a paper in Scientific american about AIDS in Zimbabwe.
There was presented a theory suggesting that some of the sexual practices in
parts of Africa (here: Zimbabve), actually heavily increases the infection
rate of HIV. Dry sex, activily making inflammmations in the womans vagina to
increase the pleasuere of the man during intercourse, and active use of
several kinds of remedia which decreases the general health of the women,
were mentioned as examples of practices which increases the rate of
infection both to women and to men. Adding to the infectionrate is the lack
of will to use condoms by men in the presented study. The presented study
was only ablut to start but might give some explanations to why the
computerprogram gives such big difference in ability to calculate the
American and the African development of spread of AIDS.
I believe using a computer software to calculate a sexually transmitted
disease is very difficult then the infection rate seems to be affected by
sexual practices, which are very difficult to control for since people do
not easily talk about them, and the variation might be very high.
Health care would also be expected to interfere with the spread of a
diseasese. Was that taken into account when designing the software?