Chronic sequelae complicate convalescence from both dengue and acute viral respiratory illness

PLoS Negl Trop Dis. 2022 Aug 18;16(8):e0010724. doi: 10.1371/journal.pntd.0010724. eCollection 2022 Aug.


Long Covid has raised awareness of the potentially disabling chronic sequelae that afflicts patients after acute viral infection. Similar syndromes of post-infectious sequelae have also been observed after other viral infections such as dengue, but their true prevalence and functional impact remain poorly defined. We prospectively enrolled 209 patients with acute dengue (n = 48; one with severe dengue) and other acute viral respiratory infections (ARI) (n = 161), and followed them up for chronic sequelae up to one year post-enrolment, prior to the onset of the Covid-19 pandemic. Baseline demographics and co-morbidities were balanced between both groups except for gender, with more males in the dengue cohort (63% vs 29%, p<0.001). Except for the first visit, data on symptoms were collected remotely using a purpose-built mobile phone application. Mental health outcomes were evaluated using the validated SF-12v2 Health Survey. Almost all patients (95.8% of dengue and 94.4% of ARI patients) experienced at least one symptom of fatigue, somnolence, headache, concentration impairment or memory impairment within the first week of enrolment. Amongst patients with at least 3-months of follow-up, 18.0% in the dengue cohort and 14.6% in the ARI cohort experienced persistent symptoms. The median month-3 SF-12v2 Mental Component Summary Score was lower in patients who remained symptomatic at 3 months and beyond, compared to those whose symptoms fully resolved (47.7 vs. 56.0, p<0.001), indicating that patients who self-reported persistence of symptoms also experienced functionally worse mental health. No statistically significant difference in age, gender distribution or hospitalisation status was observed between those with and without chronic sequelae. Our findings reveal an under-appreciated burden of post-infection chronic sequelae in dengue and ARI patients. They call for studies to define the pathophysiology of this condition, and determine the efficacy of both vaccines as well as antiviral drugs in preventing such sequelae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / complications
  • Convalescence
  • Dengue* / complications
  • Dengue* / epidemiology
  • Disease Progression
  • Humans
  • Male
  • Pandemics
  • Post-Acute COVID-19 Syndrome
  • Respiratory Tract Infections* / complications
  • Respiratory Tract Infections* / epidemiology

Grants and funding

This work was funded by a SingHealth Foundation Research Grant (SHF/FG622P/2016) awarded to YET, and the National Research Foundation through the Singapore MIT Alliance for Research and Technology Antimicrobial Resistance Integrative Research Group with funding awarded to RS and EEO. SK receives salary support through a Transition Award (MOH-TA19may-0003), and JGL and EEO through a Clinician Scientist Award (MOH-CSAINV19may-0002 and MOH-000332-00 respectively), all awarded by the National Medical Research Council of Singapore. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.