Laboratory Evaluation of a Smartphone-Based Electronic Reader of Rapid Dual Point-of-Care Tests for Antibodies to Human Immunodeficiency Virus and Treponema pallidum Infections

Abstract

Background Dual point of care tests for antibodies to human immunodeficiency virus (HIV) and Treponema (T.) pallidum allow for same-day testing and treatment and have been demonstrated to be cost-effective in preventing the adverse outcomes of HIV infection and syphilis. By recording and transmitting data as they are collected, electronic readers address challenges related to the decentralization of point of care testing. Methods We evaluated a smartphone-based electronic reader using 201 sera tested with two dual rapid tests for detection of antibodies to HIV and T. pallidum in Los Angeles, USA and Lima, Peru. Tests were read both visually and with the electronic reader. Enzyme immunoassay followed by Western blot and T. pallidum particle agglutination were the reference tests for HIV and T. pallidum, respectively. Results The sensitivities of the two rapid tests for detection of HIV were 94.1% and 97.0% for electronic readings. Both tests had specificity of 100% for detection of HIV by electronic reading. The sensitivities of the two rapid tests for detection of T. pallidum were 86.5% and 92.4% for electronic readings. The specificities for detection of T. pallidum were 99.1% and 99.0% by electronic reading. There were no significant differences between the accuracies of visual and electronic readings, and the performance did not differ between the two study sites. Conclusions Our results show the electronic reader to be a promising option for increasing the utility of point of care testing programs.

Field evaluation of a smartphone-based electronic reader of rapid dual HIV and syphilis point-of-care immunoassays

“…Our results showed that the performance of the E-reader correlated well with visual inspection. Our findings are similar to what has previously been reported during a laboratory evaluation of the HRDR-200 E-reader 21. While the E-reader did not improve antibody detection in our study, the non-inferiority to visual inspection by trained technicians may mean that E-readers can improve case detection in areas without personnel trained in interpretation of rapid immunoassays.…”

“…One previous study evaluated the performance of the First Response HIV 1+2/Syphilis Combo Card Test in a laboratory setting and found sensitivity and specificity of 95.2% and 100%, respectively, for HIV antibodies, and 91.2% and 100%, respectively, for T. pallidum antibodies 21. Our results demonstrated similarly high sensitivities and specificities, but differ from those findings in that our study was performed in a clinical setting using venous whole blood instead of using stored sera in the laboratory.…”

“…The First Response HIV 1+2/Syphilis Combo Card Test (Premier Medical Corporation, Nani Daman, India) was recently validated in a laboratory setting using the same E-reader as was used in the present study 21. Both immunoassays use a qualitative detection method via solid phase immunochromatographic assays.…”

“…In laboratory testing the reader has been shown to have greater analytic sensitivity than the naked eye (providing parts per billion level quantification) 20. Recently, the HRDR-200 E-reader was used in a laboratory setting to interpret rapid dual HIV and syphilis immunoassays, and was shown to be comparable with visual inspection 21. However, the HRDR-200 E-reader has not been assessed outside the laboratory setting.…”

Taking connected mobile-health diagnostics of infectious diseases to the field

“…via automated RDT measurements (Box 3). This approach capitalises on mobile phone imaging38 or video capture39 to enable the quantitative40 assessment of results with the potential for geotagging41 and rapid transmission of results to healthcare systems42. Similarly, mobile phone-based microscopy43 is now gaining traction in detecting microscopic parasitic infections44, and is rapidly approaching that of laboratory based microscopes with a significantly reduced upfront cost.…”