Feasibility of a Pilot Crowdsourced Syndromic and Virological Surveillance Platform for Respiratory Illness in South Africa, CoughWatchSA, 2022

BACKGROUND: Digital participatory surveillance (DPS) may provide information on reported influenza-like illnesses (ILI). Combining DPS with laboratory testing allows pathogen identification. We assessed the feasibility of DPS and home-based self-swabbing (HBSS) in South Africa. METHODS: We enrolled a cohort of individuals aged ≥ 18 years who completed weekly respiratory symptoms questionnaires from March to October 2022. We calculated the weekly percentage of reported ILI and COVID-19 and compared it with weekly private sector respiratory consultations (WPSRC). Symptomatic participants were offered HBSS for influenza and SARS-CoV-2 detection by polymerase chain reaction (PCR). We assessed six feasibility indicators. RESULTS: Recruitment capability: Twenty-six percent (249/954) of participants accessed the platform and enrolled, and 92% (81/88) of participants eligible for HBSS were enrolled. Acceptability: Fifteen percent (32/249) completed the acceptability questionnaire with 100% (32/32) willing to participate in future studies, and 16% (39/249) withdrew from the study. Representativeness: Fifty percent (125/249) were aged 18-39 years, predominantly female 71%, and 79% had a tertiary qualification. Reliability: Thirty-eight percent (80/210) were active participants, median weekly active participation of 23% (interquartile range [IQR]: 19%-29%). Accuracy: Two percent (31/1440) and 25% (359/1440) of reports met ILI and COVID-19, respectively. Influenza and SARS-CoV-2 were detected in 7% (6/81) and 32% (26/81) of tested samples, respectively. There was low correlation with WPSRC (0.08, 95% CI, 0.27-0.43) for ILI and (0.36, 95% CI, 0.11-0.62) for COVID19. Usefulness: Symptoms were reported in 32% (459/1440) of reports, and 11% (49/459) sought medical care. CONCLUSION: The study was feasible; however, low enrolment numbers limit power. Linkage to HBSS was successful and demonstrates the potential for pathogen confirmation.