Seasonal Trends and Epidemiological Characteristics of COVID-19 in Mexico City Primary Care Facilities: A Descriptive Study

Abstract

Aims: To determine Seasonal Trends and Epidemiological Characteristics on COVID-19 at a Primary Care Setting, in Mexico City. Study Design:  A descriptive and cross-sectional study was conducted. Place and Duration of Study: Ambulatory Care Medical Unit. The study was conducted from July 1st to November 30th, 2024, with Mexican patients attending the Family Medicine Speciality outpatient consultation at the Family Medicine Clinic “División del Norte”, in Mexico City, from January 1st, 2022 to December 31st, 2022. Methodology: Data on health and sociodemographic variables were collected through a retrospective design, using the SIMEF system. Results: We included 2,847 patients with COVID-19 (ICD-10 code U07.1), of a total of 17,918 persons, mainly females (n=1,868; 65.6%, CI95% 64.0-67.4). COVID-19 activity displayed seasonal patterns, with primary peaks occurring in winter and summer. The overall prevalence of COVID-19 was 15.9% (CI95% 13.3-16.4). However, the prevalence of COVID-19 varies significantly (p<0.001) across the major age groups: among children, it was higher (6.8%; CI95% 5.1-8.6) compared to adolescents (3.8%; CI95% 2.6-5.1) and elderly population (5.6%; CI95% 5.1-6.1). The mature adult population had the highest prevalence of COVID-19 (26.6%; CI95% 25.7-27.4). Similarly, the comorbidities in patients with COVID-19 vary significantly across major age groups. Among children, the most prevalent comorbidities are exclusively respiratory diseases (acute nasopharyngitis=17.54%, allergic rhinitis=14.03%). In adolescents there is a more diverse range of comorbidities (myopia=8.82%, gastroenteritis and colitis of unspecified origin=2.94%). In mature adults (acute pharyngitis; AP=9.65%, hypertension=8.11%, and type 2 diabetes; T2D=6.96%) and elderly (hypertension=25.84%, T2D=19.08%, and AP=8.45%), the top three diseases are the same but differ in order. Conclusion: The analysis of COVID-19 patients in the primary care level provides an overview of seasonal trends and epidemiological characteristics, identifying key areas for development interventions. The high incidence of respiratory infections in children underscores the need for targeted public health policies. Strengthening epidemiological surveillance and implementing age—and gender-specific prevention strategies are essential to effectively addressing seasonal patterns.