Clinical and Sociodemographic Characterization of Long COVID-19 in Costa Rica

Aim: to describe the clinical and sociodemographic profile of adults in Costa Rica who contracted Severe Acute Respiratory Syndrome Coronavirus type 2 and experienced symptoms for three months or longer after the acute phase of infection—classified as long COVID—and to compare them with adults without persistent symptoms, in order to identify factors linked to symptom persistence.

Methods: We carried out a retrospective descriptive study of Costa Rican adults recruited between January and October 2022. Eligibility required a laboratory-confirmed infection by Severe Acute Respiratory Syndrome Coronavirus type 2 at least three months before enrolment, documented by polymerase chain reaction, rapid antigen assay, or antibody-based test. Participants with compatible symptoms and an epidemiological link but no prior confirmation underwent serological testing for antibodies. An online questionnaire gathered demographic data, medical history, vaccination status, and symptoms. Based on these data, participants were classified as (1) individuals with symptoms lasting three months or longer (long COVID, strict phenotype) or (2) controls without prolonged symptoms; those reporting only nonspecific symptoms were excluded.

Results: among 448 participants, 193 met criteria for the strict long COVID phenotype, 198 served as controls, and 57 were excluded as indeterminate. The cohort was predominantly female (61.1 %) and younger than forty years (73.9 %). Most had a single documented infection (67.3 %), and 56.5 % reported acute-phase symptoms that limited daily activities. Complete vaccination was recorded in 91 %. The likelihood of long COVID was higher in females (probability ratio = 2.33; p value less than 0.001), in adults forty years or older (probability ratio = 1.82; p value = 0.039), in those whose acute symptoms restricted daily activities (probability ratio = 2.09; p value = 0.002), and in participants with mental-health disorders (probability ratio = 1.87; p value = 0.018). No associations emerged with vaccination status, smoking, alcohol use, physical activity, or number of comorbidities. Fifty-seven percent of long COVID cases reported poorer health than before the infection.

Conclusion: these findings align with international reports and underscore the need for prospective studies—particularly those stratified by sex—to clarify the long-term consequences of long COVID. They also highlight the urgency of comprehensive health policies to mitigate its impact on quality of life. This study provides the first snapshot of long COVID in Costa Rica and lays groundwork for future research on post-viral syndromes in this population.