HIV testing among injecting drug users in Glasgow

The use of saliva rather than blood for epidemiological studies of HIV prevalence, especially among injecting drug users, has several practical advantages. In a cross-sectional, behavioural and prevalence study among drug users in Glasgow during 1990, salivary samples were therefore obtained by the use of salivettes. Such samples were requested for anonymous anti-HIV testing from 498 persons in locations varying from residential rehabilitation centres to the open streets. Of this number, 35 refused to give a sample, resulting in a compliance rate of 93%. Of the 463 salivettes received by the laboratory, eight were found to be dry. Of the remaining 455 specimens, eight were found to be positive for HIV-1 antibody by means of an IgG antibody capture ELISA, so giving a prevalence rate of 1.8%. The results of testing saliva and blood spot samples collected at the same time on filter paper from 98 persons for HIV-1 antibody were 100% concordant. The study confirms the experience of others that specimens of saliva are easy to collect under variable conditions by non-medical staff and demonstrates that the salivette can provide an HIV antibody test result the same as that obtained from a blood spot. The prevalence of HIV antibody determined in this study is similar to that of other studies taking place in the city during the same period of time.