yeah, I thought it was due to the black death. See, all those people in europe didnt die in vain but to give some of us immunity to HIV. wiki says 10% of the population have at least one of the genes, so would that be 1% have both and are immune?
As to the circumcisoin studies.
http://medicine.plosjournals.org/archive/1549-1676/2/11/pdf/10.1371_journal.pmed.0020298-S.pdf has a 2005 study by auvert taljaard et al.
Its finding was that the control group (told to wait for a circumcision) had more hiv infections in the follow up period than did the group who had circumcisions. Stated 20 cases in the circumcision group and 49 in the control. However, within the confidence intervals of the data,allowing for random variation, it would be possible for the true statistical result to be that the circumcision group did worse. Applicants to the study had 4.5% incidence of HIV. incidence of catching hiv seems to be about 1% per year overall during the study. During the first 3 months the incidence rate amongst those circumcised was about half what it was later. This might reflect the fact they were told not to have sex for 6 weeks after surgery, which would be exactly half the period. proof the best way to avoid hiv is not to have sex?
The circumcision group had 5% incidence of visits to clinics for genital problems within the last 12 months, and the control group 7%. Before the trial both groups had 10%. People who attended a clinic were 6x more likely to turn out to be hIV positive than others. That means either circumcision reduced all genital infections, or for some reason the circumcision group was being more careful than the control group, although supposedly both groups received the same councilling about safe sexual behaviour and use of condoms.
The result for circumcision was 40% the rate of HIV infections in the follow up period than the control group. However, if you were catholic or protestant, then you had only 50% the rate of infection. If you were over 21 then you were twice as likely as the control group to catch hiv. Alternatively, if you were under 21 you had the same chance as the control group. if you were zulu you had 85% the chance of the control group of catching HIV and Sotoh, just slightly worse than control. drinking alcohol put up your risk rate 30%. Being married reduced your risk to 60% of control group.
About 3% of circumcisions had some sort of complication. About 15 (1%) remained dissatisfied at the end of the study,21 months after operating, divided roughly equal between problems urinating, dissatisfaction with appearance and mild or moderate erectile dysfunction.
A rather odd result is that participants enrolled later in the study had only 60% the chance overall of catching HIV per year as those enrolled earlier. national health education working?
sixteen people out of 3,000 died during the study, which apparently is about normal for that location and agegroup.