Prevalence and outcomes associated with SARS-COV-2 antibody seropositivity among persons at risk for tuberculosis in a high HIV-burden setting: a cohort study in Lusaka, Zambia
Despite catastrophic predictions of the impact of the COVID-19 pandemic in Sub-Saharan Africa, SARS-CoV-2 transmission levels unexpectedly appeared to remain low across several variant waves. However, recent evidence from several African countries has demonstrated that as much as 50-80% of individuals have been infected with SARS-COV-2. Such persons are at risk for post-acute sequelae of COVID-19 (PASC, e.g., “Long COVID”), which may contribute to a decreased quality of life and productivity. Many individuals with PASC, but without a prior formal COVID-19 diagnosis may present to tuberculosis (TB) services in high burden settings with persistent respiratory symptoms and abnormal chest radiography. This may contribute to misdiagnosis and continued individual-level suffering, or in those with active TB disease, could contribute to poor TB treatment outcomes. However, the seroprevalence of SARS-COV-2, the prevalence of PASC and clinical outcomes among Africans with prior SARS-COV-2 infection and at high risk for TB, including how they may differ by HIV status, is poorly defined. To address these gaps, we will undertake a cohort study among SARS-CoV-2 IgG/IgM antibody positive patients nested within a large active TB case finding study in Lusaka, Zambia. In Aim 1 we will first determine the prevalence of SARS-CoV-2 IgG/IgM antibody positivity and pulmonary TB disease. In SARS-CoV-2 antibody positive participants we will assess clinical, functional, and radiographic characteristics by TB disease and HIV status. In Aim 2, participants with SARS-CoV-2 antibodies at baseline will be evaluated 2- and 6-months post-enrolment to determine the prevalence of persistent symptoms, functional impairment and radiographic abnormalities, and to characterize TB outcomes for those initiated on anti-TB treatment. The results of this study will provide key insight into the epidemiology and impact of COVID-19 among persons in Africa, including how it may differ by HIV status.