Dengue and COVID-19: Managing Undifferentiated Febrile Illness during a "Twindemic"

Long-term Sequelae Following Dengue Infection vs SARS-CoV-2 Infection in a Pediatric Population: A Retrospective Cohort Study

Background

Long-term postacute sequelae following SARS-CoV-2 infection in children have been extensively documented. However, while persistence of chronic symptoms following pediatric dengue infection has been documented in small prospective cohorts, population-based studies are limited. We evaluated the risk of multisystemic complications following dengue infection in contrast to that after SARS-CoV-2 infection in a multiethnic pediatric Asian population.

Methods

This retrospective population-based cohort study utilized national COVID-19/dengue registries to construct cohorts of Singaporean children aged 1 to 17 years with either laboratory-confirmed dengue infection from 1 January 2017 to 31 October 2022 or confirmed SARS-CoV-2 infection from 1 July 2021 to 31 October 2022. Cox regression was utilized to estimate risks of new-incident cardiovascular, neurologic, gastrointestinal, autoimmune, and respiratory complications, as identified by national health care claims data, at 31 to 300 days after dengue infection vs COVID-19. Risks were reported by 2 measures: adjusted hazard ratio (aHR) and excess burden.

Results

This study included 6452 children infected with dengue and 260 749 cases of COVID-19. Among children infected with dengue, there was increased risk of any postacute gastrointestinal sequelae (aHR, 2.98; 95% CI, 1.18-7.18), specifically appendicitis (aHR, 3.50; 95% CI, 1.36-8.99), when compared with children infected with SARS-CoV-2. In contrast to cases of unvaccinated COVID-19, children infected with dengue demonstrated lower risk (aHR, 0.42; 95% CI, .29-.61) and excess burden (-6.50; 95% CI, -9.80 to -3.20) of any sequelae, as well as lower risk of respiratory sequelae (aHR, 0.17; 95% CI, .09-.31).

Conclusions

Lower overall risk of postacute complications was observed in children following dengue infection vs COVID-19; however, higher risk of appendicitis was reported 31 to 300 days after dengue infection vs SARS-CoV-2. Public health strategies to mitigate the impact of dengue and COVID-19 in children should consider the possibility of chronic postinfectious sequelae.

Effects of Recent Prior Dengue Infection on Risk and Severity of Subsequent SARS-CoV-2 Infection: A Retrospective Cohort Study

Background and Aims

Elucidating whether prior dengue potentially confers cross-protection against COVID-19 is of public health importance in tropical countries at risk of overlapping dengue and COVID-19 epidemics. However, studies to date have yielded conflicting results. We aimed to assess effects of recent prior dengue infection on risk and severity of subsequent SARS-CoV-2 infection among adult Singaporeans.

Methods

A retrospective cohort study including all adult Singaporeans aged ≥18 years was conducted from 1 July 2021 through 31 October 2022, when a dengue outbreak driven by the DENV3 serotype preceded subsequent waves of SARS-CoV-2 Delta/Omicron transmission in Singapore. SARS-CoV-2 and dengue infection status were classified using national registries. Cox regression models adjusted for demographics, COVID-19 vaccination status, comorbidity, and socioeconomic-status were used to assess risks and severity (hospitalization, severe illness) of SARS-CoV-2 infection occurring after previous recorded dengue infection.

Results

A total of 3 366 399 individuals were included, contributing 1 399 696 530 person-days of observation. A total of 13 434 dengue infections and 1 253 520 subsequent SARS-CoV-2 infections were recorded; with an average of 94.7 days (standard deviation = 83.8) between dengue infection and SARS-CoV-2 infection. Preceding dengue infection was associated with a modest increase in risk of subsequent SARS-CoV-2 infection (adjusted hazards ratio [aHR] = 1.13; 95% confidence interval [CI], 1.08-1.17), and significantly elevated risk of subsequent COVID-19 hospitalization (aHR = 3.25; 95% CI, 2.78-3.82) and severe COVID-19 (aHR = 3.39; 95% CI, 2.29-5.03).

Conclusions

Increased risk of SARS-CoV-2 infection and adverse COVID-19 outcomes were observed following preceding dengue infection in a national population-based cohort of adult Singaporeans. This observation is of significance in tropical countries with overlapping dengue and COVID-19 outbreaks.

Dengue versus COVID-19: comparing the incidence of cardiovascular, neuropsychiatric and autoimmune complications

BACKGROUND

While persistence of chronic symptoms following dengue infection has been documented in small prospective cohorts, population-based studies are limited. The post-acute risk of new-incident multi-systemic complications following dengue infection was contrasted against that following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a multi-ethnic adult Asian population.

METHODS

National testing and healthcare claims that databases in Singapore were utilized to build a retrospective population-based adult cohort with laboratory-confirmed infection during overlapping waves of SARS-CoV-2 and dengue transmission (1 July 2021 to 31 October 2022). Risks of new-incident cardiovascular/neuropsychiatric/autoimmune complications 31-300 days of post-dengue infection, contrasted with SARS-CoV-2 infection, were estimated using Cox regression with overlap weights. Risks were reported in terms of adjusted hazard ratio (aHR) and excess burden per 1000 persons.

RESULTS

11 707 dengue-infected individuals and 1 248 326 contemporaneous coronavirus disease 2019 (COVID-19) cases were included; the majority had mild initial infection not requiring hospitalization. Amongst dengue-infected individuals, there was 21% [aHR = 1.21 (1.06-1.38)] increased risk of any sequelae, with 55% [aHR = 1.55 (1.27-1.89)] increased risk of cardiovascular sequelae. Specifically, increased risk of dysrhythmias [aHR = 1.79(1.35-2.37)], ischemic heart disease [aHR = 1.45(1.12-1.89)], other cardiac disorders [aHR = 2.21(1.54-3.16)] and thrombotic disorders [aHR = 2.55(1.50-4.35)] was noted. Elevated risk of individual neuropsychiatric sequelae, including cerebrovascular disorders [aHR = 1.49(1.09-2.13)], cognition/memory disorders [aHR = 2.13(1.55-2.93)], extrapyramidal/movement disorders [aHR = 1.98(1.33-2.94)] and anxiety disorders [aHR = 1.61(1.01-2.56)], was observed in dengue-infected individuals compared to COVID-19 cases. Elevated risks of post-acute sequelae in dengue survivors were observed when contrasted against COVID-19 survivors infected during Delta/Omicron predominance, as well as across vaccination strata.

CONCLUSION

Increased risk of post-acute cardiovascular/neuropsychiatric complications was observed in dengue survivors, when contrasted against COVID-19 survivors infected during Delta/Omicron predominance.

RESEARCH IN CONTEXT

COVID-19: Current Status and Future Prospects

This second Special Issue in a series of Special Issues in Tropical Medicine and Infectious Disease looks at recent global research on the current Coronavirus (COVID-19) Pandemic [...].