(J-392) Repurposing a SARS-CoV-2 Diagnostic Infrastructure for Widely Accessible Respiratory and Sexual Infection Testing

Introduction:: In July 2020, the Clemson University REDDI Lab was established and subsequently developed a saliva-based multiplex RT-qPCR diagnostic assay in response to the COVID-19 pandemic (1). Almost three years later, testing and positivity rates for COVID-19 have decreased significantly. However, university- and community-wide testing for other diseases, such as respiratory (RIs) or sexually transmitted infections (STIs), is still in high demand (2-4). Using a diagnostic infrastructure created for pandemic preparedness, the REDDI Lab validated diagnostic panels for RIs, and will validate diagnostic panels for STIs in order to provide cheaper and more easily accessible infectious disease testing.

Materials and Methods:: For RI diagnostics, saliva samples (n = 68) were collected from patients and tested using either the Cepheid Xpert® Xpress SARS-CoV-2/Flu/RSV kit as well as the BD Veritor Influenza A/B clinical kit (n = 46) or the TigerSaliva laboratory developed test (LDT) (1). Samples were incubated with 10 μL of DNase I, and RNA was manually extracted using the MagMAXTM Viral/Pathogen Nucleic Acid Isolation Kit per manufacturer’s protocol. Samples were treated with 50 μg of Proteinase K, and eluted RNA was quantified with a UV-Vis spectrophotometer. For STI diagnostics, we will use a similar method utilizing blood and urine samples.

Results, Conclusions, and Discussions:: Results and Discussion: We evaluated the sensitivity of our multiplex RT-qPCR assay via ten-fold serial dilutions of synthetic RNA for SARS-CoV-2, influenza A, and influenza B. Efficiencies and R2 values for each are listed in Table 1. When tested in saliva with paired nasopharyngeal (NP) swabs, the total accuracy of the assay for influenza A was 93.48%, and clinical sensitivity and specificity were 85% and 100%, respectively. We were unable to investigate clinical accuracy for influenza B as it was not circulating in our area at the time. We also conducted a survey (n = 969) to gauge university students’ opinions on testing and vaccination policies for COVID-19 and flu. Respondents reported a higher likelihood to seek testing for an infection at our on-campus testing center than any other means, including an on- or off-campus healthcare provider or an at-home self -test. This is true for multiple levels of symptom severity, including a hypothetical exposure to COVID-19, expression of mild symptoms of an unknown infection, or expression of severe symptoms of an unknown infection. These results furthered motivation to incorporate testing for other diseases in a university setting.

Conclusions: We expanded upon our pre-existing SARS-CoV-2 surveillance protocol to also detect influenza A and B. We are also currently validating an LDT for detection of chlamydia, gonorrhea, ureaplasma, mycoplasma, HIV I and II, and syphilis. Using our pandemic-preparedness infrastructure, we can provide low-cost, high-throughput diagnostic testing to a university population.

Acknowledgements (Optional): : The authors thank Clemson’s administration, medical staff, and clinical lab employees at the REDDI Lab who helped implement and manage SARS-CoV-2 testing. Thank you to Dr. Mark Blenner for initial project consulting. We thank Dr. Ted Swann and the staff at Redfern Health Center for assistance with sample collection. Thank you to the REDDI Lab social media team for recruitment flier design and distribution. Thank you to Creative Inquiry students for preliminary data collection. This project was funded by SC Governor and Joint Bond Review Committee, NIH NIGMS 3P20GM121342-03S1, NIH U01AA029328, and Clemson University Office of Creative Inquiry and Undergraduate Research.

References (Optional): : 1. Ham, R. and Smothers, A. et al. J. Vis. Exp. 180 (2022).
2. Bonnet, S. et al. Sex. Transm. Dis. 48, e91-e93 (2021).
3. Stanford, K. et al. Front. Reprod. Health. 5, (2023).
4. Chow, E. et al. Nat. Rev. Microbiol. 21, 195-210 (2022).