Role of children in the Bulgarian COVID-19 epidemic: A mathematical model study

Latchezar Tomov; Hristiana Batselova; Snezhina Lazova; Borislav Ganev; Iren Tzocheva; Tsvetelina Velikova

doi:10.5493/wjem.v13.i3.28

Role of children in the Bulgarian COVID-19 epidemic: A mathematical model study

World J Exp Med. 2023 Jun 20;13(3):28-46. doi: 10.5493/wjem.v13.i3.28.

Authors

Latchezar Tomov¹, Hristiana Batselova², Snezhina Lazova^{3

4}, Borislav Ganev³, Iren Tzocheva⁵, Tsvetelina Velikova⁶

Affiliations

¹ Department of Informatics, New Bulgarian University, Sofia 1618, Bulgaria. luchesart@gmail.com.
² Department of Epidemiology and Disaster Medicine, Medical University, University Hospital "St George", Plovdiv 6000, Bulgaria.
³ Department of Pediatric, University Hospital "N. I. Pirogov", Sofia 1606, Bulgaria.
⁴ Department of Healthcare, Faculty of Public Health, Medical University of Sofia, Sofia 1527, Bulgaria.
⁵ Department of Pediatric, Medical Faculty, University Hospital "N. I. Pirogov", Sofia 1606, Bulgaria.
⁶ Medical Faculty, Sofia University, St. Kliment Ohridski, Sofia 1407, Bulgaria.

Abstract

Background: The coronavirus disease 2019 (COVID-19) pandemic affects all aspects of our lives, including children. With the advancement of the pandemic, children under five years old are at increased risk of hospitalization relative to other age groups. This makes it paramount that we develop tools to address the two critical aspects of preserving children's health - new treatment protocols and new predictive models. For those purposes, we need to understand better the effects of COVID-19 on children, and we need to be able to predict the number of affected children as a proportion of the number of infected children. This is why our research focuses on clinical and epidemiological pictures of children with heart damage post-COVID, as a part of the general picture of post-COVID among this age group.

Aim: To demonstrate the role of children in the COVID-19 spread in Bulgaria and to test the hypothesis that there are no secondary transmissions in schools and from children to adults.

Methods: Our modeling and data show with high probability that in Bulgaria, with our current measures, vaccination strategy and contact structure, the pandemic is driven by the children and their contacts in school.

Results: This makes it paramount that we develop tools to address the two critical aspects of preserving children's health - new treatment protocols and new predictive models. For those purposes, we need to understand better the effects of COVID-19 on children, and we need to be able to predict the number of affected children as a proportion of the number of infected children. This is why our research focuses on clinical and epidemiological pictures of children with heart damage post-COVID, as a part of the general picture of post-Covid among this age group.

Conclusion: Our modeling rejects that hypothesis, and the epidemiological data supports that. We used epidemiological data to support the validity of our modeling. The first summer wave in 2020 from the listed here school proms endorse the idea of transmissions from students to teachers.

Keywords: ARIMA; COVID-19; Cardiac involvement; Children; Multisystem inflammation in children; Pandemic; Regression model; Time-series modeling.