Prevalence and socioeconomic determinants of post-acute sequelae of SARS-CoV-2 among individuals from a peri-urban township and an informal settlement in Johannesburg, South Africa

Background. Individuals infected with SARS-CoV-2 who develop COVID-19 are susceptible to persistent symptoms and sequelae, referred to as post-acute sequelae of SARS-CoV-2 (PASC). The prevalence of PASC is estimated to range between 10% and 30%. However, there is a paucity of data from African countries. Objectives. To investigate the prevalence and sociodemographic determinants of PASC in a peri-urban township and an informal settlement in South Africa (SA) during the COVID-19 pandemic. Methods. A prospective cohort study was conducted among individuals residing in sampled households within the Soweto and Thembelihle Health and Demographic Surveillance System in Gauteng Province, SA. Between August 2021 and January 2022, all individuals from 214 sampled households were tested for SARS-CoV-2 and followed up for 6 months for symptoms. The prevalence of PASC, defined as persistence of symptoms through to at least 30 (PASC-30) and 90 (PASC-90) days, was evaluated, and determinants of PASC were identified using logistic regression models. Results. There were 268 individuals with documented COVID-19 illness identified, of whom 65.3% (n=175) were female. The median age was 24 years. The overall prevalence of PASC-30 was 23.9% (95% confidence interval (CI) 19.2 - 29.3), including 24.6% (95% CI 19.7 - 30.3) and 12.5% (95% CI 3.5 - 36.0) in individuals who were unvaccinated or had received a COVID-19 vaccine, respectively (p=0.283). The overall prevalence of PASC-90 was 2.2% (95% CI 1.0 - 4.8). Factors associated with PASC-30 included living in an informal (39.2%, 105/268) v. formal settlement (60.6%, 163/268) (adjusted odds ratio (aOR) 4.1, 95% CI 2.1 - 8.3), although participants living in larger households (aOR 0.8, 95% CI 0.7 - 0.9, p=0.011) were less likely to report PASC-30 than those from smaller households. Age, gender, marital status, level of education, employment status, vaccination status and the presence of comorbidities were not significantly associated with PASC. Conclusion. PASC-30 (23.9%) was prevalent at the population level in individuals with documented COVID-19, particularly among residents of informal settlements, while PASC-90 (2.2%) was low. Further exploration into PASC within informal settlements is imperative to comprehensively understand these findings.