Background: Some patients suffer from persisting symptoms following COVID-19 infection, referred to as long COVID. The aims of the study were to estimate the prevalence and study the determinants of long COVID in Tunisia.

Methods: We surveyed a representative sample of COVID-19 survivors residing in Tunisia. We selected a random sample, stratified by age and region, among residents registered in the national surveillance database with a SARS-Cov-2 positive test taken from September 2020 to September 2021. We defined a patient with long COVID as having at least one self-reported symptom lasting for more than 4 weeks after the first confirmation of SARS-CoV-2 infection and not explained by an alternative diagnosis. Trained health care workers interviewed consenting respondents by phone using structured questionnaire. We estimated the prevalence of long COVID and the association between explanatory variables (socio-demographic, life style and comorbidities, SARS-Cov-2 history infection, COVID-19 vaccination status) and long COVID using a log-binomial model, reporting adjusted prevalence ratios (a-PR).

Results: Of 1094 persons contacted, 416 (38%) were recruited. Long COVID prevalence was 64% (267/416); 95%CI: 59%-69%. The sex-ratio (M:F) was 0.72. Age ranged from 1 to 101 years (median 41). The most common symptoms were: fatigue (63%), myalgia/arthralgia (33%) and cognitive symptoms (52%). Median duration of long COVID symptoms was 11 months (IQR: 3-14). In multivariate analysis, having more than three symptoms during acute infection (a-PR=1.5; 95%CI: 1.0-2.1), being a woman of childbearing age (a-PR=1.2; 95%CI: 1.0-1.4) and residence in the central region (a-PR=1.5; 95%CI: 1.1-2.0) were significantly associated with higher long COVID prevalence.

Conclusions: Long COVID is highly prevalent in Tunisia affecting patients with multiple symptoms initially, residing in central region and young women. We recommend enhancing health care access and medical follow-up during and after the infection, focusing on identified risk groups. We also recommend further research to optimize management of long COVID patients.