The CD4 Surveillance Scheme monitors national trends in immunosuppression among HIV-infected adults by analysis of CD4 cell counts.
Analysis of CD4 cell counts combined with other HIV surveillance data provides information on late diagnoses, trends in immunosuppression and the population effect of antiretroviral therapy. Results are interpreted and compared across population groups.
Laboratories across England, Wales and Northern Ireland that perform CD4 T-lymphocyte counts and are involved in the NEQAS quality assurance scheme are invited to participate in the CD4 Surveillance Scheme. Over 60 laboratories currently participate in the scheme.