News quality of the information available. national governments refocus their Ghys says the data improved after local programmes.” XVI International AIDS Confer- health officials were trained how to use According to Dr Ties Boerma, ence in Toronto, Canada more comprehensive computer pro- Director of WHO’s Department of grams to produce and analyse their own Measurement and Health Information An estimated 20 000 people descended information. “In the past, estimates were Systems, “this may have been valid on the Canadian city of Toronto in largely a Geneva-based before the 2006 Report August for the International AIDS exercise, with little on the global AIDS epi- Conference. Participants at the meet- involvement from the demic — but not any ing included scientists, health-care countries,” he says. “If The best more”. Nevertheless, workers, activists and civil, political analysts produce their Kenji Shibuya believes and business leaders. The conference own estimates, they we can do is to that harmonization theme was “Time to Deliver” and take it more seriously be completely still has a long way delegates called on the world to take than if it ‘dropped out’ transparent. to go. Boerma agrees: whatever steps were necessary to ensure of Geneva.” And if there is a “We won’t get the HIV/AIDS treatment and care were Many countries disagreement to truth easily”. available for all who needed them by have also expanded Much more invest- 2010. their surveillance explain very clearly ment is needed in systems. Until re- why. developing countries to cently, HIV and AIDS Dr Ties Boerma, Director of WHO’s improve data collec- estimates were based Department of Measurement and tion, such as national Health Information Systems. on tests of pregnant health surveys, says women visiting ante- Boerma. But even for natal clinics, mostly countries that do carry located in cities. The tests were useful in out national health surveys, there is no tracking trends, but had limitations for guarantee of accuracy. In South , measuring the actual size of the epidem- for example, response rates to national ic. Since 2000, a group of 20 countries health surveys are under 60% and in sub-Saharan Africa has conducted even lower than this among the white Thousands of people fill the streets of Toronto to rally for AIDS treatment. nationwide household surveys with population, making it hard to assess HIV testing, and some have expanded how representative the surveys are. their surveillance to antenatal clinics in Countries also rely on health workers to rural areas. When they looked at their report diseases, but in many developing respective countries as a whole, research- countries record-keeping and reporting ers in several countries discovered that are poor. the prevalence of HIV infection was far Another challenge is the availabil- lower than previously thought. ity of multiple sources of data — sur- Some commentators say the veys, civil registration and health facil- programmes still have a long way to ity and administrative records. These go. John Donnelly, who writes about data need to be harmonized to come global health issues for the Boston up with the best possible estimates, Globe, argues that UNAIDS and Boerma says. Another challenge, he WHO have been far too conservative says, is “an inclination to overestimate” The group, which uses dance to raise in downgrading their estimates. Don- for the sake of advocacy. AIDS awareness among young people, entertains nelly believes that as more information Boerma admits that it may never the crowd during a special concert held on the is gathered, HIV/AIDS prevalence be possible to come up with just one opening day of the meeting. figures will continue to drop. He says number when estimating the burden that instead of downgrading the figures of a disease or the size of an epidemic, slowly, it would be “more honest” to because there will always be a range admit that information from countries of uncertainty. Moreover, although that haven’t done nationwide health there may always be disagreements surveys is inaccurate, and to adjust the over the final estimates these often worldwide estimate based on results lead to constructive discussion and from those countries that have done better information. “The best we can the surveys. “The global estimate is an do is to be completely transparent,” he advocacy tool, and it [downgrading the says. “And if there is a disagreement to numbers] would be a huge embar- explain very clearly why.” O AIDS 2006 rassment,” he says. “But it would help Anita Elash, Paris Prevention outreach workers in the conference hall.

694 Bulletin of the World Health Organization | September 2006, 84 (9)