Epidemiology of COVID-19 in Individuals under 18 Years Old in Cartagena, Colombia: An Ecological Study of the First 14 Months of the Pandemic

Abstract

The epidemiology of the coronavirus disease (COVID-19) has been scarcely described in individuals under 18 years old, particularly during the first months of the pandemic. The study aimed to describe the COVID-19 epidemiology in the Colombian department of Bolívar from March 2020 to April 2021 among individuals under 18 years. Furthermore, we explored whether the use of data generated by a Bolívar reference laboratory captures the departmental epidemiology. Two information sources were used; the national COVID-19 surveillance system and the Bolívar COVID-19 reference laboratory. In using a population-based ecological approach and information from confirmed symptomatic cases, epidemic curves and heat maps were constructed to assess the COVID-19 dynamics and patterns by sex, age, and residence (Cartagena vs. 45 other municipalities). The COVID-19 incidence was comparable between males and females but varied by age group, being higher in children aged 10 years and older. Cartagena had a significantly higher number of cases and experienced early epidemic peaks. Our analyses suggest that information generated by the reference laboratory does not capture the COVID-19 departmental epidemiology, despite conducting population-based surveillance across Bolívar. The study provides a retrospective characterization of the COVID-19 epidemiology in an understudied population and information that may be useful for future evidence-based responses.

Keywords: COVID-19; Colombia; SARS-CoV-2; adolescent; child.

Figure 1

Comparison of epidemic curves based on data from two data sources, as of 31 April 2021. Daily new confirmed COVID-19 cases in Bolívar were used to build epidemic curves using 7-day moving averages. The curves were constructed using public information from the Colombian National Institute of Health (CNIH) and Unidad de Investigación molecular (UNIMOL) of the Universidad de Cartagena. Red boxes indicate the time frames for which the epidemic curves had a similar pattern; ~3 and ~4 months for Cartagena (A) and other Bolívar municipalities (B), respectively.

Figure 2

Epidemic curves and their patterns of daily new confirmed COVID-19 cases in Cartagena and other municipalities of Bolívar, as of 31 April 2021. Daily cases per 100,000 population were plotted using 7-day moving averages by date of symptom onset (panels (A,B)), date of reporting (panels (C,D)), and date of diagnosis (panels (E,F)). Epidemic curves (panels (A,C,E)) and heat maps (panels (B,D,F)) were constructed using linear and “log (x + 1)” scales to improve readability, respectively.

Figure 3

Age-stratified epidemic curves for Bolívar and Cartagena, as of 31 April 2021. Daily confirmed new cases were presented using epidemic curves (panels (A,D)) and stacked area plots (panels (B,E)) on linear scales, while cases per 100,000 population were presented using heat maps (panels (C,F)) with log (x + 1) scales to improve readability. Data for Cartagena (panels (A–C)) and other municipalities of Bolívar (panels (D–F)) were presented using symptom onset dates and 7-day moving averages.

Figure 4

Sex-stratified epidemic curves for Bolívar and Cartagena, as of 31 April 2021. Daily confirmed new cases were presented using epidemic curves (panels (A,D)) and stacked area plots (panels (B,E)) on linear scales, while cases per 100,000 population were presented using heat maps (panels (C,F)) with log(x + 1) scales to improve readability. Data for Cartagena (panels (A–C)) and other municipalities of Bolívar (panels (D–F)) were presented using symptom onset dates and 7-day moving averages.

Figure 5

Distribution of cases by gender and age, as of 31 April 2021. The distribution of confirmed new cases in Cartagena and other municipalities of Bolívar per 100,000 population was plotted in Panel (A,B), respectively. The 95% confidence intervals of the cumulative incidences were in parenthesis.