The public health applications of unlinked anonymous sevoprevalence monitoring for HIV in the United Kingdom

Background In order to monitor the epidemiology of human immunodeficiency v irus (HIV), integrated national programmes of unlinked anonymous (blinded) HIV serosurveys have taken place in the UK since 1990. Methods The programmes comprise multi-centre surveys primarily using specim ens gathered routinely for screening groups of patients. All specimens are irreversibly unlinked from patient identifiers before being tested. Results The surveys have met their prime aim of providing at low cost minim ally biased estimates of current HIV prevalence and trends in sentinel popu lations. The surveys have remained acceptable to professionals and the publ ic, being successfully implemented without breech of their founding princip les. The findings have had major public health applications, have influence d HIV policy and funding, been used for monitoring the spread of HIV, for t argeting and evaluating health promotion and improving projections of sever e HIV disease. The surveys have detected substantial prevalence rises and u nder-diagnosis of HIV which would otherwise have been unrecognised. The pro grammes' value is being increased by sub-typing HIV-1 isolates, capturing a dditional demographic information to detect spread among minority groups. T he same specimens are used for monitoring other infections (initially hepat itis A, B and C). Conclusions Monitoring HIV and other infections through unlinked anonymous HIV surveillance has become an integral essential part of national HIV and AIDS surveillance. Although it has unique applications the value of unlinke d anonymous surveillance is maximized when used in conjunction with behavio ural data, information from HIV and AIDS reporting, and behavioural data an d surveillance for other sexually transmitted infections.