On the face of it, it seems good news but a report today gives some reasons why this might not give the whole story. Factors which could distort the figures are:
- Initially, rates were obtained from testing in ante-natal clinics but, because they were naturally a young age group compared with the whole population and, since they were pregnant, clearly were having unprotected sex, these figures could have produced an inflated rate.
- More recently household surveys have been conducted, but high numbers refused to be tested and many others were absent from home, both of which could lead to apparently lowered rates of infection.
- The variety and unreliability of many survey methods, many being highly selective.
- Anti-retroviral drugs keep people infected with HIV alive and so boost the rates of HIV in the population. It could then follow that countries which do little by way of treating their infected population appear to have a declining rate.
The contributors to the report are suggesting that the story is a very complex one and that some comprehensive and long-term studies are carried out.