Detection of antibody to HIV in saliva: a brief review.

BACKGROUND

The possibility that saliva could be used for HIV screening and diagnosis has been known since 1986. Despite the obvious advantages over venepuncture of ease of collection, safety, compliance and cost, interest in salivary testing has grown relatively slowly. Several studies have demonstrated that salivary anti-HIV testing can be highly accurate, particularly if specimen collection procedure are optimal.

OBJECTIVE

To review current knowledge about the detection of anti-HIV in oral fluids, with an emphasis on the identification of optimal procedures.

STUDY DESIGN

In the light of existing published data, the factors leading to accurate salivary diagnosis of HIV infection were identified and reviewed.

RESULTS

To achieve the best results it is essential to collect oral fluid specimens that are rich in IgG. Most IgG in the oral cavity derives from the crevicular space between the gums and the teeth, and not from salivary glands. Available methods for collecting salivary specimens are discussed. Until these collection methods are fully validated, individual specimens or at least clinical ones found anti-HIV negative should be tested for total IgG before being reported on. There is a lack of proven confirmatory methods for salivary anti-HIV and this problem is reviewed. Salivary anti-HIV testing has been employed mostly for surveillance, but life insurance applicants are increasingly screened in this way and clinical applications are under active consideration. With appropriate safeguards, diagnostic and pre-blood donation salivary testing could be introduced shortly. The necessary technology is also available to develop rapid single-use salivary tests. This would bring anti-HIV testing closer to the patient.

CONCLUSIONS

Salivary tests for anti-HIV offer advantages of convenience, economy and safety, and are more acceptable to subjects than blood tests. Further evaluation of the collection devices and assays, the introduction of safeguards against inadequate sampling and the development of suitable confirmatory assays are required. When these deficiencies have been met, salivary tests may supersede tests on serum for HIV and also other infections.