Tina Rosenberg writes:
Four years ago, I visited a hospital in a Johannesburg township of Alexandra where just over half of all pregnant women agreed to take an AIDS test. At the same time at the Chris Hani Baragwanath Hospital in Soweto, 98 percent of pregnant women took an AIDS test. There, women are informed that the test is part of the standard package of prenatal tests. A woman can opt out if she chooses.
This makes a lot of sense. AIDS testing was designed to be opt in back when there was no overwhelming reason for people to know their H.I.V. status, as there was very little that could be done for them if they tested positive. Today, even in the poorest countries, patients who learn they are H.I.V. positive can get lifesaving therapy and pregnant woman can take medicines to avoid passing the virus along to their babies.
The change to opt-out helped Botswana increase acceptance of AIDS tests from 64 percent to 83 percent in just one year. Test rates in clinics in Zimbabwe went from 65 percent to 99 percent with a similar change. In 2004, the United Nations AIDS agency and the World Health Organization began recommending opt-out testing in countries where AIDS is widespread.