Infectious Disease Emergencies in Older Adults in India: A Prospective Observational Study Comparing Youngest Old, Middle Old, and Oldest Old Patients.

Background and aims: Infections remain a common cause of emergency department (ED) admissions in older adults, particularly in low and middle-income countries. This study investigates the clinical and microbiological spectrum and outcomes of infection-related emergencies in older adults in North India, comparing the youngest old (65-74 years), middle old (75-84 years), and oldest old (≥85 years) patients.

Patients and methods: This prospective observational study included older patients (≥65 years) with community-acquired infections admitted to the medical ED of a tertiary care academic hospital in North India from June 2023 to May 2024. Patients with hospital-acquired infections, including those that developed during prior admissions at referring hospitals, were excluded.

Results: We enrolled 300 patients (mean age 74.2 years, 51% males), including 164 youngest old, 92 middle old, and 44 oldest old. The most prevalent infections were pneumonia (39.3%), urinary tract infection (UTI) (13.3%), cholangitis (9.3%), and tuberculosis (7.7%). Microbiological confirmation was achieved in 37.3%, with frequent isolation of drug-resistant organisms such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecium. The oldest old group presented more acutely with severe illness and had a higher incidence of pneumonia (56.8%), lower UTI rates (2.3%), and fewer microbiological diagnoses (13.6%). In-hospital mortality was 32.0%, highest in pneumonia (47.1%) and tuberculosis (47.8%), and lowest in UTI (14.7%). Baseline Acute Physiology and Chronic Health Evaluation (APACHE)-II score independently predicted mortality (OR 1.081, 95% CI: 1.013-1.153, p = 0.019).

Conclusion: Infection-related emergencies in older adults, especially the oldest old, pose diagnostic challenges and carry high mortality. Pneumonia is a major cause of ED admission and death among older adults in India.

How to cite this article: Kadar H, Erla SR, Angrup A, Bhatia M, Sharma N, Pannu AK. Infectious Disease Emergencies in Older Adults in India: A Prospective Observational Study Comparing Youngest Old, Middle Old, and Oldest Old Patients. Indian J Crit Care Med 2025;29(7):569-577.