France has recently witnessed a nationwide outbreak of measles. Data on severe forms of measles in adults are lacking. We sought to describe the epidemiologic, clinical, treatment, and prognostic aspects of the disease in adult patients who required admission to an intensive care unit (ICU). We performed a retrospective analysis of a cohort of 36 adults admitted to a total of 64 ICUs throughout France for complications of measles from January 1, 2009, to December 31, 2011. All cases of measles were confirmed by serologic testing and/or reverse transcription polymerase chain reaction. The cohort consisted of 21 male and 15 female patients, with a median age of 29.2 years (25thY75th interquartile range EIQR^, 27.2Y34.2 yr) and a median Simplified Acute Physiology Score (SAPS II) of 13 (IQR, 9Y18). Among the 26 patients whose measles vaccination status was documented, none had received 2 injections. One patient had developed measles during childhood. Underlying comorbid conditions included chronic respiratory disease in 9 patients, immunosuppression in 7 patients, and obesity in 3 patients, while measles affected 5 pregnant women. Respiratory complications induced by measles infection led to ICU admission in 32 cases, and measles-related neurologic complications led to ICU admission in 2 cases. Two patients were admitted due to concurrent respiratory and neurologic complications. Bacterial superinfection of measles-related airway infection was suspected in 28 patients and was documented in 8. Four cases of community-acquired pneumonia, 6 cases of ventilator-associated pneumonia, 1 case of tracheobronchitis, and 2 cases of sinusitis were microbiologically substantiated. Of 11 patients who required mechanical ventilation, 9 developed acute respiratory distress syndrome (ARDS). Among the patients with ARDS, extraalveolar air leak complications occurred in 4 cases. Five patients died, all of whom were severely immunocompromised. On follow-up, 1 patient had severe chronic respiratory failure related to lung fibrosis, and 2 patients had mild lower limb paraparesis along with bladder dysfunction, both of which were ascribable to measlesinduced encephalitis and myelitis. Among the 5 pregnant patients, the course of measles infection was uneventful, albeit 1 patient underwent emergent cesarean delivery because of fetal growth restriction. Measles is a disease with protean and potentially deceptive clinical manifestations, especially in the immunocompromised patient. Measlesassociated pneumonitis and its complications, and less commonly postinfectious encephalomyelitis, are the main source of morbidity and mortality. In contrast with the usually benign course of the disease in immunocompetent patients, measles occurring in immunocompromised patients gives rise to lethal complications including ARDS, with or without bacterial superinfection. Other patients potentially at high risk for severe measles are young adults and pregnant women. Measles pneumonitis may predispose to air leak disease in patients using mechanical ventilation. To date, vaccination remains the most potent tool to control measles infection. (Medicine 2013;92: 257Y272) Abbreviations: ADEM = acute disseminated encephalomyelitis; ARDS = acute respiratory distress syndrome, CAP = communityacquired pneumonia, CDC = Centers for Disease Control and Prevention, CFU = colony-forming units, chest CT = thoracic computed tomography, CK = creatinine kinase, CNS = central nervous system, CSF = cerebral spinal fluid, ECMO = extracorporeal membrane oxygenation, EEG = electroencephalogram, FLAIR = fluidattenuated inversion recovery, HIV = human immunodeficiency virus, ICU = intensive care unit, IgG = immunoglobulin G, IgM = immunoglobulin M, IQR = interquartile range, IVIG = intravenous immunoglobulin, MIBE = measles inclusion body encephalitis, MRI = magnetic resonance imaging, MSSA = methicillinsensitive Staphylococcus aureus, MV = measles virus, NO = inhaled nitric oxide, NSAID = nonsteroidal antiinflammatory drug, PIE = postinfectious encephalitis and/or myelitis, RT-PCR = reverse transcription polymerase chain reaction, SAPS II = Simplified Acute Physiology Score, VAP = ventilator-associated pneumonia, WHO = World Health Organization. Medicine & Volume 92, Number 5, September 2013 www.md-journal.com 257 From AP-HP, Service de Réanimation Médico-Chirurgicale, Université Paris Diderot, Sorbonne Paris Cité Hôpital Louis Mourier, Colombes (CR, JDR, JM, DD, SG); Department of Intensive Care Medicine, Lapeyronie University Hospital, Montpellier (KK, SM); Institut National de la Santé et de la Recherche Médicale, INSERM U722, Paris (JDR, JM, DD, SG); Universite Paris Diderot, Sorbonne Paris Cité, UMR 722, Paris (JDR, JM, DD, SG); AP-HP, Service de Pneumologie et Réanimation, Hôpital Tenon, Universite Pierre-et-Marie-Curie, Paris (JM); Aix-Marseille Université, Faculté de Médecine, URMITE UMR CNRS 7278, Marseille, and APHM, Hôpital Nord, Réanimation des Détresses Respiratoires et des Infections Sévères, Marseille (AR); AP-HP, Service de Réanimation Médicale et des Maladies Infectieuses, Université Paris Diderot, Sorbonne Paris Cité, Hôpital BichatClaude-Bernard, Paris (RS); Service de Réanimation Médicale, Hôpital Saint-André, CHU Bordeaux, Bordeaux (OG); Service d’Anesthésie et Réanimation, Polyclinique Bordeaux Nord Aquitaine, Bordeaux (WP); Hospices Civils de Lyon, Service de Réanimation Médicale, Hôpital de la Croix Rousse, Lyon (CG); AP-HP, Hôpital de Bicêtre, Service de Réanimation Médicale, Le Kremlin-Bicêtre (JLT); CHU Clermont-Ferrand, Unité de Réanimation Médicale, Pôle REUNNIRH, Hôpital G Montpied, Clermont-Ferrand (NM); Medical-Surgical Intensive Care Unit, SaintEtienne University Hospital, and Jean Monnet University, Saint-Etienne (MD); Medico-Surgical Intensive Care Unit, Avicenne Teaching Hospital, Bobigny (FC); AP-HP, Service de Pneumologie et Réanimation Médicale, Groupe Hospitalier Pitié-Salpêtrière, Paris (MS); and Medical Intensive Care Unit, Tours University Hospital, Tours (EM); France. Financial support and conflicts of interest: The authors have no funding or conflicts of interest to disclose. Reprints: Stéphane Gaudry, MD, Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, 178 rue des Renouillers, 92110 Colombes, France (e-mail: stephane.gaudry)lmr.aphp.fr). Copyright * 2013 by Lippincott Williams & Wilkins ISSN: 0025-7974 DOI: 10.1097/MD.0b013e3182a713c2 Copyright © 2013 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. INTRODUCTION M easles virus (MV) is a small spherical, enveloped, singlestranded RNA virus belonging to the genus Morbillivirus in the family Paramyxoviridae. Despite the availability of an effective vaccine for more than 30 years, measles still represents a major harbinger of death in low income countries, affecting chiefly malnourished infants and claiming about 150,000 lives per year. Although it was supposedly on the verge of extinction in France, MV has reemerged spectacularly since 2008 with over 20,000 registered cases of measles. In the last 3 years, outbreaks have repeatedly been reported elsewhere in Europe, calling into question the assumption that measles is a disease confined to developing countries. Recent works have pointed to insufficient vaccine coverage as the main reason for the resurgence of measles, strengthening claims that this disease is likely to pose unique challenges over the coming years. Another major source of concern is the growing proportion of young adults affected by the epidemics, an age group more prone to severe complications such as encephalitis and pneumonia. In comparison to the profuse data available on recent measles epidemics, to our knowledge a study addressing the specificities of severe measles affecting an adult population had yet to be conducted. Herein, we report 36 cases of patients with measles requiring ICU admission.