Moupali Das of the San Francisco Department of Public Health presented evidence to show that the city’s intensive testing and treatment policy was beginning to result in a declining HIV infection rate there. Similar evidence was presented from the province of British Columbia in Canada.
The evidence presented still leaves some questions unanswered, however.
- Is the reduction in viral load in the HIV-positive population (the ‘community viral load’ or CVL) really the cause of the decreased level of diagnoses seen in San Francisco in the last few years, or is it due to the success of prevention campaigns and reductions in risky behaviour?
- Do reduced diagnoses really indicate reduced incidence of infection?
- Is reducing the average viral load of diagnosed people a good indicator of the average infectiousness of people with HIV in the community – or do high viral loads in the minority who remain undiagnosed make this an unreliable indicator?
The answers to these questions are crucial as the future direction of HIV prevention policy may depend on them, in particular whether to concentrate on suppressing viral load or on behaviour change as the mainspring of prevention.