Frequency and Mortality of Adult Meningitis, Pneumonia, or Bacteremia in Colombia from 2015 to 2022: A Retrospective Database Study in a Health Maintenance Organization.

Background: Meningitis, pneumonia, and bacteremia, prevalent community-acquired diseases that can lead to multi-organ failure, are influenced by age, comorbidities, and living conditions. Despite meningitis surveillance in Colombia, information on pneumonia and bacteremia remains limited. This study aims to determine frequency of these diseases among Colombian patients and estimate related healthcare resources. Objective: To measure the frequency and mortality of meningitis, pneumonia, and bacteremia in all diagnosed adult patients in Colombia from 2015 to 2022. Methods: This retrospective study analyzed adult (≥18 years) patients, from structured data collection (International Classification of Diseases, Tenth Revision) in a health maintenance organization (HMO). Diagnosis of a first meningitis, pneumonia, or bacteremia episode-unknown cause (bacterial etiology undetermined)-between 2015 and 2022 was reviewed. Index date was defined as when the diagnosis was registered. Frequency was calculated by dividing the number of cases by the number of members in the HMO system over the study period. Results: Among 112 205 patients, 96.0% had pneumonia, 6.2% bacteremia, and 0.4% meningitis, not mutually exclusive. Inpatient pneumonia incidence, which peaked in 2019 and dropped post-COVID pandemic, was 167 cases per 100 000 person-years in 2022. Incidence of meningitis, pneumonia, and bacteremia was higher in patients over 60 years. Common comorbidities were chronic obstructive pulmonary disease and cardiovascular disease. Bacteremia incidence decreased from 143 cases per 100 000 in 2015 to 69.6 in 2022. Meningitis incidence dropped from 5.3 to 2.2 cases per 100 000 in the COVID period. All-cause mortality rates were 12.0%, 33.5% and 13.8% for pneumonia, bacteremia, and meningitis, respectively. Discussion: This study is the first to use health electronic databases from an HMO to estimate the burden of these diseases in Colombian patients. Incidence was consistent with COVID-period patterns observed in other studies. Mortality rates were higher with bacteremia. Comorbidities like chronic pulmonary disease, cardiovascular disease, kidney diseases, and dementia were linked with increased incidence and mortality, emphasizing the need for targeted healthcare interventions and vaccination programs. Conclusion: Incidence and mortality, whether pneumonia (inpatient or outpatient), bacteremia, or meningitis with bacteremia, vary with age and comorbidities, while all-cause mortality was greater for bacteremia than pneumonia or meningitis.