Surveys provide essential information

EDITOR—Kessel et al voice concerns about the ethics of unlinked anonymous surveys and the proportion of the public who seem to be aware of such surveys.1

The need to use the unlinked anonymous technique for surveillance of HIV was evident once it was appreciated that data from diagnostic testing, or obtained after explicit consent for unlinked testing, inevitably produced biased estimates of the prevalence of HIV.2 The technique was adopted nationally in 1990 only after extensive consultation and general agreement that, with safeguards, it was legal and ethical.3 The surveys, which are overseen by the Department of Health, provide information that would otherwise not be available and is essential for planning and monitoring the control of the spread of HIV.4 They use blood that would eventually be discarded, which is left over after the completion of screening tests in genitourinary medicine and antenatal clinics. Before testing, every specimen is irreversibly unlinked from information that would identify the source individual. Hence infection status can never be traced back to a person. Essentially, the results represent groups in the community and not individuals.2 4

Unlinked anonymous surveys in the United Kingdom started only after approval by local ethics committees, and refusals have been rare. Recently, these committees approved extension of the technique for surveillance of hepatitis A, B, and …