Diagnostic assays that can simultaneously determine the presence of infection with multiple pathogens are key for diagnosis and surveillance. Current multiplex diagnostic assays are complex and often have limited availability. We developed a simple, multianalyte, pathogen detection assay for screening and serosurveillance using the Luminex Magpix platform that is high throughput and can be helpful in monitoring multiple diseases. The Luminex bead-based 10-plex immunoassay for the detection of HIV-1, HIV-2, Treponema pallidum, hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus 1 (HSV-1), and HSV-2 infections was accomplished by coupling beads with specific antigens to detect IgG antibodies in plasma or serum samples. Each coupled antigen was systematically optimized, and the performance was evaluated using a panel of well-characterized specimens (n=417) that contained antibodies to HIV-1, HIV-2, T. pallidum, HBV, HCV, HSV-1, and HSV-2. The multiplex assay had a sensitivity of 92.2% (95% Clopper-Pearson confidence interval [CI], 90.2 to 94.0%) and a specificity of 98.1% (95% CI, 97.6 to 98.7%). The sensitivities and specificities for disease-specific biomarker detection ranged from 68.7 to 100% and 95.6 to 100%, respectively. The results showed that the 10-plex immunoassay had an overall agreement of 96.7% (95% CI, 96.7 to 97.3%) with reference tests and a corresponding kappa value of 0.91 (95% CI, 0.90 to 0.93). Kappa values for the individual pathogens ranged from 0.69 to 1.00. The assay is robust and allows the simultaneous detection of antibodies to multiple antigens using a small sample volume in a high-throughput format. This assay has the potential to simplify disease surveillance by providing an alternative to expensive and highly specialized individual tests.

The idea of specimen self-collection or self-STI testing is not new. In 2019, the World Health Organization (WHO) published the "WHO Consolidated Guideline on Self-Care Interventions for Health" as a first installment in a planned series for various diseases (8). The first document focused on "Sexual and Reproductive Health and Rights". Self-care including self-testing has the readily apparent benefits of privacy, confidentiality, speed, convenience, and access if the price is affordable. It is "people-centered" (9) and enables active participation in one's own health. It is also a health system approach as it can reduce burden on stretched systems with world-wide shortages in medical personnel or other barriers to health care access. Potential risks include: low specimen return rates, uncertain follow-up (linkage to care including treatment, repeat testing including test of cure, partner notification, counseling on risk reduction), unintended/unnecessary use (resulting in false positives with their own set of associated problems), incorrect use, lack of understanding of window periods (resulting in false negatives), lack of surveillance data generation, among other issues (9). The WHO systematically reviewed evidence for self-testing or specimen self-collection for GC, CT and syphilis, including US studies, and published a meta-analysis of available evidence (9). Programs offering self-collection of samples increased overall uptake of STI testing services (RR: 2.941, 95% CI 1.188 to 7.281) and case finding (RR: 2.166, 95% CI1.043 to 4.498), prior to the pandemic (9). U. S. laboratory research on the equivalence and/or superiority of self-collected versus provider-collected specimens for test sensitivity was reported by Gaydos et al (summarized or referenced in (10)). Based on this evidence, WHO issued a new recommendation in 2019 "Self-collection of samples for Neisseria gonorrhoeae and Chlamydia trachomatis should be made available as an additional approach to deliver STI testing services for individuals using STI testing services" (8). In addition, WHO issued a new and conditional recommendation: "Self-collection of samples for Treponema pallidum (syphilis) and Trichomonas vaginalis may be considered as an additional approach to deliver STI testing services for Individuals using STI testing services" (8). Thus, even before the COVID-19 pandemic, substantial expert agreement existed concerning benefits of this approach.