1876 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 27, No. 7, July 2021 RESEARCH S higa toxin–producing Escherichia coli (STEC) infec- tion is an environmental foodborne or waterborne disease that causes bloody diarrhea. Approximately 5%–20% of cases are complicated by hemolytic uremic syndrome (HUS) (1,2). Shiga toxins (Stx) can cause acute microvascular injury, leading to thrombotic microangiopathy (TMA), which is characterized by hemolytic anemia and thrombocytopenia, and in the scenario of HUS, associated with acute kidney injury (3). Researchers estimate that the global prevalence of STEC infection is ≈43.1 acute illnesses/100,000 per- son-years, causing ≈3,890 annual cases of STEC-asso- ciated HUS (4). STEC-associated HUS occurs mostly in children; sporadic cases are rare in adults. Among children, STEC-associated HUS is the most frequent form of TMA and the leading cause of acute renal failure (3). In France, surveillance for STEC-associated HUS in children <15 years of age Shiga Toxin–Associated Hemolytic Uremic Syndrome in Adults, France, 2009–2017 Benoît Travert, 1 Antoine Dossier, 1 Matthieu Jamme, Aurélie Cointe, Yahsou Delmas, Sandrine Malot, Alain Wynckel, Amélie Seguin, Claire Presne, Miguel Hie, Ygal Benhamou, David Ribes, Gabriel Choukroun, Steven Grangé, Alexandre Hertig, Emilie Cornec-Le Gall, Lionel Galicier, Eric Daugas, Lila Bouadma, François-Xavier Weill, Elie Azoulay, Fadi Fakhouri, Agnès Veyradier, Stéphane Bonacorsi, Julien Hogan, Véronique Frémeaux-Bacchi, Eric Rondeau, Patricia Mariani-Kurkdjian, Paul Coppo, Centre de Référence des Microangiopathies Thrombotiques 2 Author afliations: Centre de Référence des Microangiopathies Thrombotiques, Paris, France (B. Travert, A. Dossier, M. Jamme, Y. Delmas, S. Malot, A. Wynckel, A. Seguin, C. Presne, M. Hie, Y. Benhamou, G. Choukroun, S. Grangé,A. Hertig, L. Galicier, E. Azoulay, F. Fakhouri, A. Veyradier, V. Frémeaux-Bacchi, E. Rondeau, P. Coppo); Université de Paris, Paris (B. Travert, A. Dossier, A. Cointe, L. Galicier, E. Daugas, L. Bouadma, E. Azoulay, A. Veyradier, S. Bonacorsi, J. Hogan, V. Frémeaux-Bacchi, P. Mariani-Kurkdjian); Hôpital Bichat—Claude Bernard, Paris (B. Travert, A. Dossier, E. Daugas, L. Bouadma); Sorbonne-Université, Paris (M. Jamme, M. Hie, A. Hertig, E. Rondeau, P. Coppo); HôpitalTenon, Paris (M. Jamme, E. Rondeau); Hôpital Robert-Debré, Paris (A. Cointe, S. Bonacorsi, J. Hogan, P. Mariani-Kurkdjian); Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France (Y. Delmas); Hôpital Maison Blanche, Reims, France (A. Wynckel); Centre Hospitalier Universitaire de Caen, Caen, France (A. Seguin); Centre Hospitalier Universitaire d’Amiens, Amiens, France (C. Presne, G. Choukroun); Groupement Hospitalier Pitié-Salpêtrière, Paris (M. Hie, A. Hertig); Centre Hospitalier Universitaire de Rouen, Rouen, France (Y. Benhamou, S. Grangé); Centre Hospitalier Universitaire de Toulouse, Toulouse, France (D. Ribes); Centre Hospitalier Universitaire de Brest, Brest, France (E. Cornec-Le Gall); Hôpital Saint-Louis, Paris (L. Galicier, E. Azoulay); Institut Pasteur, Paris (F.-X. Weill); Centre Hospitalier Universitaire de Nantes, Nantes, France (F. Fakhouri); Hôpital Lariboisière, Paris (A. Veyradier); Hôpital Européen Georges Pompidou, Paris (V. Frémeaux-Bacchi); Hôpital Saint Antoine, Paris (P. Coppo) DOI: https://doi.org/10.3201/eid2707.204638 1 These frst authors contributed equally to this article. 2 Members of this group are listed at the end of this article. We conducted a retrospective study on hemolytic uremic syndrome caused by Shiga toxin–producing Escherichia coli (STEC) in 96 adults enrolled in the cohort of the Na- tional Reference Center for Thrombotic Microangiopathies network in France during 2009–2017. Most infections were caused by STEC strains not belonging to the O157 or O104 serogroups. Thirty (31.3%) patients had multiple risk factors for thrombotic microangiopathy. In total, 61 (63.5%) patients required dialysis, 50 (52.1%) had a serious neurologic com- plication, 34 (35.4%) required mechanical ventilation, and 19 (19.8%) died during hospitalization. We used multivariate analysis to determine that the greatest risk factors for death were underlying immunodefciency (hazard ratio 3.54) and severe neurologic events (hazard ratio 3.40). According to multivariate analysis and propensity score-matching, eculi- zumab treatment was not associated with survival. We found that underlying conditions, especially immunodefciency, are strongly associated with decreased survival in adults who have hemolytic uremic syndrome caused by STEC.