Predictors of severe measles outcomes in hospitalized patients in Jerusalem, 2025

Measles is a vaccine-preventable disease. Defining risk factors for poor outcomes in hospitalized patients can improve future measles outbreak preparedness.

Data were collected on all confirmed measles cases that were evaluated at one of the emergency departments (ED) in the three main hospitals in Jerusalem from the first reported case of the current outbreak on April 10^th to December 31^st, 2025. Demographic, clinical, and laboratory data were analyzed using robust Poisson multivariable models to calculate incidence rate ratios (IRR) for hospitalization, intensive care unit (ICU) admission, extracorporeal membrane oxygenation (ECMO) and death.

Among 786 individuals who visited the ED with confirmed measles, the rates of hospital admission (≥1 day), ICU, ECMO and death were 83.4%, 6.4%, 0.8%, and 1.4%, respectively. Complete data were available for 567 patients, of whom 303 (53.4%) were males. Median age was 2.1 years (IQR 1.2-3.8), and 474 (83.6%) were younger than 5 years. Most patients were unvaccinated (91.0%). Secondary infections were frequent, including lobar pneumonia (28.7%) and community-acquired bacteremia (3.5%). Respiratory support and severe dehydration were associated with hospital admission (IRR 1.4, 95% CI 1.3-1.5; p<0.001 and 9.5, 4.8-18.4; p<0.001, respectively) and ICU admission (IRR 1.3, 1.2-1.4; p<0.001 and 5.2, 2.1-12.4; p<0.001, respectively). Community-acquired bacteremia was associated with death or ECMO (IRR 44.5, 12.5-158.6; p<0.001).

Despite high access to medical care in this urban setting, measles caused substantial morbidity and mortality. Respiratory compromise, severe dehydration, and bacteremia identified patients at increased risk of severe outcomes.