Evolution of long COVID over two years in hospitalised and non-hospitalised survivors in Bangladesh: a longitudinal cohort study

In developing settings, comparative data on COVID hospitalised survivors (HS) and non-hospitalised survivors (NHS) is scarce. We determined burdens, incidence, evolution, and associated factors of long COVID-19 over two years among these groups. We conducted a longitudinal cohort study in Dhaka, Bangladesh, and recruited confirmed COVID-19 survivors from December 2020 to May 2021 (previously reported). 346 survivors underwent in-person follow-ups at five, nine, 18 months and two years post-infection. The assessment included long COVID symptoms, cardiorespiratory function, neuropsychiatric conditions, quality of life, and laboratory tests. The outcomes included one or more symptoms and/or signs indicative of long COVID, aligning closely with the World Health Organization definition of post-COVID-19 condition. Of the 346 participants, we included 326 in the analysis. 78% of HS (n/N = 171/219) and 62% of NHS (n/N = 55/89) reported at least one sequela symptom. HS had higher odds of palpitations, headaches, dizziness, sleeping difficulties, brain fog, muscle weakness, joint pain, hypertension, insulin requirement, poor quality of life, and prolonged corrected QT intervals on electrocardiogram compared to NHS at two years (95% confidence interval (CI)>1). Regarding evolution, sequelae-symptoms, neurological outcomes, restrictive spirometry findings, and electrocardiogram abnormalities remained unchanged, although psychiatric sequelae, quality of life, and exercise capacity improved in both groups. Hospital readmission rates significantly increased (P < 0.05). The incidence rates of palpitations, cough, and hypertension were higher in HS compared to NHS (95% CI>1). Two or more vaccine doses decreased the risk of respiratory (adjusted risk ratio (aRR) = 0.76; 95% CI = 0.63-0.91) and psychiatric sequelae (aRR = 0.78; 95% CI = 0.66-0.92) than one or no doses. COVID-19 survivors, particularly HS, experienced a higher burden of persistent symptoms and health issues two years after infection. However, vaccination significantly reduced the risk of respiratory and psychiatric outcomes. These findings highlight the importance of ongoing vaccination programs and the need for targeted rehabilitation services in low-resource settings.