BACKGROUND: Measuring CD4 counts remains an important component of HIV care. The VISITECT® CD4 is the first-ever instrument-free low-cost point-of-care CD4 test with results interpreted visually after 40 minutes, providing a result of above or below 350 CD4 cells/mm(3). METHODS: Field performance and diagnostic accuracy of the test was assessed among HIV-infected pregnant women in South Africa. A nurse performed testing at the point-of-care using both venous and finger-prick blood, and a counsellor and laboratory staff tested venous blood in the clinic laboratory (four VISITECT® CD4 tests/participant). Performance was compared to the mean CD4 count from duplicate flow cytometry tests on venous blood (FACSCalibur Trucount). FINDINGS: In 2017, 156 patients were enrolled, providing a total of 624 VISITECT® CD4 tests (468 venous and 156 finger-prick samples). Of 624 tests, 28 (4.5%) were inconclusive. Generalised Linear Mixed Modelling showed better performance of the test on venous blood (sensitivity=81.7%, 95%CI=72.3-91.1; and specificity=82.6%, 95%CI=77.1-88.1) than on finger-prick specimens (sensitivity=60.7%, 95%CI=45.0-76.3; and specificity=89.5%, 95%CI=83.2-95.8; p=0.001). No difference in performance was detected by cadre of health worker (p=0.113) or between point-of-care versus laboratory-based testing (p=0.108). CONCLUSIONS: Adequate performance of VISITECT® CD4 with different operators and at the point-of-care, and no need of electricity or instrument, shows the potential utility of this device, especially for facilitating decentralization of CD4 testing services in rural areas.
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FUNDING: Funding was provided by the Saving Lives at Birth partners and the Australian NHMRC Project Grant GNT1063725.