The epidemiology of Hajj-related critical illness

Abstract

The annual Hajj experience has direct relevance for other jurisdictions planning rapid deployment strategies for intensive care for large groups during expected or emergent events. Approximately 2-3 million Muslims from over 160 countries travel to Saudi Arabia each year for Hajj. These pilgrims are typically older adults with a spectrum of comorbid conditions and of various ethnicities. This, coupled with a 2-wk period of physical migration in close contact with others, can lead to acute and critical illness from a variety of infectious and noninfectious causes and a requirement for full-scale but temporary intensive care to a large population. We describe patient characteristics, patterns of disease, and critical illness, including episodes of Influenza A 2009 (H1N1), therapies delivered, and clinical outcomes. Prospective cohort study of 110 critically ill patients in four hospitals during the 2009 ("1431": November 18 to December 4) Hajj in Saudi Arabia. Median (interquartile range) age was 60.5 (51.3-70) yrs, 69 (62.7%) were male, and Acute Physiology and Chronic Health Evaluation IV score was 60.5 (47-78.3). Forty-one patients (37.3%) were critically ill due to cardiovascular diseases (23.6% with myocardial infarction); 51 (46.4%) had severe infections (21.8% with H1N1); electrolyte disturbance (21.8%); or pulmonary illness (15.5%). Sixty patients (54.6%) required ventilation. Median predicted mortality by Acute Physiology and Chronic Health Evaluation IV was 14% while actual short-term mortality was 6.4% (p = .009). Longer-term mortality may be higher. Both event-specific conditions and patient-specific comorbid conditions are common causes of critical illness during large gatherings. With the ability to provide temporary but full-service intensive care, morbidity and mortality due to critical illness can be low, even among an older patient population and difficult care conditions.