SYMPTOMATIC HIV-INFECTION IN INFANCY - CLINICAL AND LABORATORY MARKERS OF INFECTION

Objective. To investigate the usefulness oi immunological tests in the diagnosis of HIV infection in young symptomatic children (< 15 months of age), Design. Tests were evaluated in HIV-infected (HIV antibody- and PCR-positive) patients and non-infected individuals, Setting, Hosp italised patients in a referral centre (Red Cross War Memorial Childre n's Hospital, Cape Town), Patients, All admissions under 15 months of age who had HIV antibody requested were eligible, provided there was s ufficient serum (150 mu l) for further study, Overall, there were 201 symptomatic cases and 49 healthy controls, Twenty of the symptomatic c ases were HIV antibody-positive and 19 of these were HIV-infected on t he basis of a positive PCR for HIV viral product. Results. Of the test s we evaluated (total IgG, IgM, IgA and rheumatoid factors of the same classes), raised total IgG level (cut-off 18 g/l or above) was the mo st useful, We used a commercial radial immunodiffusion plate which was found to have excellent reproducibility (inter-assay coefficient of v ariation 3.2%), The test detected 16 of 19 infected infants (sensitivi ty 84%, negative predictive value 98%), With the exception of the find ing of oral thrush (odds ratio 7; P < 0.001), the clinical signs at pr esentation did not distinguish those who were HIV antibody-positive fr om those who were negative, Conclusions, In our study of hospital admi ssions, the finding of elevated IgG and HIV antibody was diagnostic of HIV infection, (The positive predictive value of the combination was 100%.) Likewise, the presence of raised IgG levels and oral candidosis had a high specificity for HIV infection (98%) but the sensitivity wa s low (37%).