Abstract Body

Gaps persist in HIV testing globally for children who missed testing in prevention of mother to child transmission of HIV programs. Oral mucosal transudate rapid HIV tests (OMT) have been shown to be highly sensitive in adults but their performance has not been established in children. We validated the OraQuick ADVANCE Rapid HIV-1/2 Antibody test against blood based rapid diagnostic testing (BBT) in children aged 18 months to 18 years in Kenya and Zimbabwe.

ART naïve children were tested for HIV using a series of rapid OMT and BBT. BBT followed the Kenyan and Zimbabwean national algorithms (Determine, followed by First Response [3rd generation] if Determine was reactive). The Determine test used in Zimbabwe was 4th generation, detecting antibodies and antigen; the Determine test used in Kenya was 3rd generation, detecting antibodies only. OMT samples were collected and interpreted by research staff; BBT were performed and interpreted by clinic or research staff. Sensitivity and specificity were calculated using the national algorithms as gold standard; secondary analysis excluded 2 cases where OMT was positive but national algorithm was initially falsely negative. Binomial distribution was used for 95% confidence intervals [95%CI].

A total of 1,622 children were enrolled, median age was 7 years (IQR: 4,12); 2 (0.1%) were 18-24 months; 1310 (80.8%) were 2-12 years; 301 (18.6%) were 13-18 years. Among the 56 children positive by BBT, 56 (sensitivity: 100% [97.5%CI: 93.7-100%]) were positive by OMT. Among the 1566 children negative by BBT, 1564 (specificity: 99.9% [95%CI: 99.5-100.0%]) were negative by OMT. Due to clinical presentation and OMT results, the 2 children who initially tested BBT negative and OMT positive were subsequently confirmed positive within 1 week by further tests; one (9 years) by ELISA and the second (2 years) by First Response and a third test, INSTI. Excluding these 2 children, the sensitivity and specificity of OMT compared to BBT were each 100% (97.5%CI: 93.7-100% and 99.8-100%, respectively).

When compared to the national algorithms, OMT did not miss any positive children. This data suggests that OMT tests are valid in this age range and may be useful for facility or community-based use. Future research should explore the acceptability and uptake of OMT use by caregivers and health care workers in diverse settings to improve pediatric HIV testing coverage globally.