Investigation of a cluster of acute epiglottitis in Vendée, western France, October - December 2022.

OBJECTIVES: In our investigation of an episode of clustered acute epiglottitis occurring in Vendée, western France, between October and December 2022, we described the reported cases and confirmed its unusual character at several geographic levels. METHODS: The investigation relied on three data sources: hospitalization and emergency department reports; national reference centre data; and data from the French syndromic surveillance system. RESULTS: The six patients were male, with an average age of 42 years [32-66]; all were hospitalized in an ICU, and one of them died. Documented risk factors for epiglottitis (active smoking, regular alcohol consumption, overweight) were present in the majority of cases. No causal pathogen was identified. Syndromic surveillance data confirmed increased acute epiglottitis at the local, regional and national levels. CONCLUSION: We not only characterized the episode of serious clustered acute epiglottitis in Vendée, but also observed a nationwide increase in this pathology occurring concomitantly with increased circulation in France of streptococcus A.

Isolation and expansion of pure and functional γδ T cells.

γδ T cells are important components of the immune system due to their ability to elicit a fast and strong response against infected and transformed cells. Because they can specifically and effectively kill target cells in an MHC independent fashion, there is great interest to utilize these cells in anti-tumor therapies where antigen presentation may be hampered. Since only a small fraction of T cells in the blood or tumor tissue are γδ T cells, they require extensive expansion to allow for fundamental, preclinical and ex vivo research. Although expansion protocols can be successful, most are based on depletion of other cell types rather than γδ T cell specific isolation, resulting in unpredictable purity of the isolated fraction. Moreover, the primary focus only lies with expansion of Vδ2+ T cells, while Vδ1+ T cells likewise have anti-tumor potential. Here, we investigated whether γδ T cells directly isolated from blood could be efficiently expanded while maintaining function. γδ T cell subsets were isolated using MACS separation, followed by FACS sorting, yielding >99% pure γδ T cells. Isolated Vδ1+ and Vδ2+ T cells could effectively expand immediately after isolation or upon freeze/thawing and reached expansion ratios between 200 to 2000-fold starting from varying numbers using cytokine supported feeder stimulations. MACS/FACS isolated and PHA stimulated γδ T cells expanded as good as immobilized antibody mediated stimulated cells in PBMCs, but delivered purer cells. After expansion, potential effector functions of γδ T cells were demonstrated by IFN-γ, TNF-α and granzyme B production upon PMA/ionomycin stimulation and effective killing capacity of multiple tumor cell lines was confirmed in killing assays. In conclusion, pure γδ T cells can productively be expanded while maintaining their anti-tumor effector functions against tumor cells. Moreover, γδ T cells could be expanded from low starting numbers suggesting that this protocol may even allow for expansion of cells extracted from tumor biopsies.

A Bispecific γδ T-cell Engager Targeting EGFR Activates a Potent Vγ9Vδ2 T cell-Mediated Immune Response against EGFR-Expressing Tumors.

Vγ9Vδ2 T cells are effector cells with proven antitumor efficacy against a broad range of cancers. This study aimed to assess the antitumor activity and safety of a bispecific antibody directing Vγ9Vδ2 T cells to EGFR-expressing tumors. An EGFR-Vδ2 bispecific T-cell engager (bsTCE) was generated, and its capacity to activate Vγ9Vδ2 T cells and trigger antitumor activity was tested in multiple in vitro, in vivo, and ex vivo models. Studies to explore safety were conducted using cross-reactive surrogate engagers in nonhuman primates (NHP). We found that Vγ9Vδ2 T cells from peripheral blood and tumor specimens of patients with EGFR+ cancers had a distinct immune checkpoint expression profile characterized by low levels of PD-1, LAG-3, and TIM-3. Vγ9Vδ2 T cells could be activated by EGFR-Vδ2 bsTCEs to mediate lysis of various EGFR+ patient-derived tumor samples, and substantial tumor growth inhibition and improved survival were observed in in vivo xenograft mouse models using peripheral blood mononuclear cells (PBMC) as effector cells. EGFR-Vδ2 bsTCEs exerted preferential activity toward EGFR+ tumor cells and induced downstream activation of CD4+ and CD8+ T cells and natural killer (NK) cells without concomitant activation of suppressive regulatory T cells observed with EGFR-CD3 bsTCEs. Administration of fully cross-reactive and half-life extended surrogate engagers to NHPs did not trigger signals in the safety parameters that were assessed. Considering the effector and immune-activating properties of Vγ9Vδ2 T cells, the preclinical efficacy data and acceptable safety profile reported here provide a solid basis for testing EGFR-Vδ2 bsTCEs in patients with EGFR+ malignancies.

Gamma Delta T-Cell Based Cancer Immunotherapy: Past-Present-Future.

γδ T-cells directly recognize and kill transformed cells independently of HLA-antigen presentation, which makes them a highly promising effector cell compartment for cancer immunotherapy. Novel γδ T-cell-based immunotherapies, primarily focusing on the two major γδ T-cell subtypes that infiltrate tumors (i.e. Vδ1 and Vδ2), are being developed. The Vδ1 T-cell subset is enriched in tissues and contains both effector T-cells as well as regulatory T-cells with tumor-promoting potential. Vδ2 T-cells, in contrast, are enriched in circulation and consist of a large, relatively homogeneous, pro-inflammatory effector T-cell subset. Healthy individuals typically harbor in the order of 50-500 million Vγ9Vδ2 T-cells in the peripheral blood alone (1-10% of the total CD3+ T-cell population), which can rapidly expand upon stimulation. The Vγ9Vδ2 T-cell receptor senses intracellular phosphorylated metabolites, which accumulate in cancer cells as a result of mevalonate pathway dysregulation or upon pharmaceutical intervention. Early clinical studies investigating the therapeutic potential of Vγ9Vδ2 T-cells were based on either ex vivo expansion and adoptive transfer or their systemic activation with aminobisphosphonates or synthetic phosphoantigens, either alone or combined with low dose IL-2. Immune-related adverse events (irAE) were generally \mild, but the clinical efficacy of these approaches provided overall limited benefit. In recent years, critical advances have renewed the excitement for the potential of Vγ9Vδ2 T-cells in cancer immunotherapy. Here, we review γδ T-cell-based therapeutic strategies and discuss the prospects of those currently evaluated in clinical studies in cancer patients as well as future therapies that might arise from current promising pre-clinical results.

Replicative history marks transcriptional and functional disparity in the CD8+ T cell memory pool.

Clonal expansion is a core aspect of T cell immunity. However, little is known with respect to the relationship between replicative history and the formation of distinct CD8+ memory T cell subgroups. To address this issue, we developed a genetic-tracing approach, termed the DivisionRecorder, that reports the extent of past proliferation of cell pools in vivo. Using this system to genetically 'record' the replicative history of different CD8+ T cell populations throughout a pathogen-specific immune response, we demonstrate that the central memory T (TCM) cell pool is marked by a higher number of prior divisions than the effector memory T cell pool, owing to the combination of strong proliferative activity during the acute immune response and selective proliferative activity after pathogen clearance. Furthermore, by combining DivisionRecorder analysis with single-cell transcriptomics and functional experiments, we show that replicative history identifies distinct cell pools within the TCM compartment. Specifically, we demonstrate that lowly divided TCM cells display enriched expression of stem-cell-associated genes, exist in a relatively quiescent state, and are superior in eliciting a proliferative recall response upon activation. These data provide the first evidence that a stem-cell-like memory T cell pool that reconstitutes the CD8+ T cell effector pool upon reinfection is marked by prior quiescence.

Enhancement of NK Cell Antitumor Effector Functions Using a Bispecific Single Domain Antibody Targeting CD16 and the Epidermal Growth Factor Receptor.

The ability to kill tumor cells while maintaining an acceptable safety profile makes Natural Killer (NK) cells promising assets for cancer therapy. Strategies to enhance the preferential accumulation and activation of NK cells in the tumor microenvironment can be expected to increase the efficacy of NK cell-based therapies. In this study, we show binding of a novel bispecific single domain antibody (VHH) to both CD16 (FcRγIII) on NK cells and the epidermal growth factor receptor (EGFR) on tumor cells of epithelial origin. The bispecific VHH triggered CD16- and EGFR-dependent activation of NK cells and subsequent lysis of tumor cells, regardless of the KRAS mutational status of the tumor. Enhancement of NK cell activation by the bispecific VHH was also observed when NK cells of colorectal cancer (CRC) patients were co-cultured with EGFR expressing tumor cells. Finally, higher levels of cytotoxicity were found against patient-derived metastatic CRC cells in the presence of the bispecific VHH and autologous peripheral blood mononuclear cells or allogeneic CD16 expressing NK cells. The anticancer activity of CD16-EGFR bispecific VHHs reported here merits further exploration to assess its potential therapeutic activity either alone or in combination with adoptive NK cell-based therapeutic approaches.

A Bispecific Single-Domain Antibody Boosts Autologous Vγ9Vδ2-T Cell Responses Toward CD1d in Chronic Lymphocytic Leukemia.

PURPOSE: Although considerable progress has been made with autologous T cell-based therapy in B-cell malignancies, application in chronic lymphocytic leukemia (CLL) lags behind due to disappointing response rates as well as substantial toxicity that is of particular concern in the elderly CLL population. Vγ9Vδ2-T cells form a conserved T-cell subset with strong intrinsic immunotherapeutic potential, largely because of their capacity to be triggered by phosphoantigens that can be overproduced by CLL and other malignant cells. Specific activation of Vγ9Vδ2-T cells by a bispecific antibody may improve the efficacy and toxicity of autologous T-cell-based therapy in CLL. EXPERIMENTAL DESIGN: We evaluated CD1d expression in a cohort of 78 untreated patients with CLL and generated and functionally characterized a CD1d-specific Vγ9Vδ2-T cell engager based on single-domain antibodies (VHH). RESULTS: CD1d was expressed by CLL in the majority of patients, particularly in patients with advanced disease. The CD1d-specific Vγ9Vδ2-T cell engager induced robust activation and degranulation of Vγ9Vδ2-T cells, enabling Vγ9Vδ2-T cells from patients with CLL to lyse autologous leukemic cells at low effector-to-target ratios. Expression of CD1d on CLL cells is upregulated by all-trans retinoic acid, and sensitizes the malignant cells to bispecific VHH-induced lysis. Furthermore, we provide evidence that the Vγ9Vδ2-T cell receptor retains responsiveness to phosphoantigens when the bispecific VHH is bound, and aminobisphosphonates can therefore enhance bispecific Vγ9Vδ2-T cell engager-mediated tumor-specific killing. CONCLUSIONS: Collectively, our data demonstrate the immunotherapeutic potential of this novel CD1d-specific Vγ9Vδ2-T cell engager in CLL.

Paediatric haemolytic uraemic syndrome related to Shiga toxin-producing Escherichia coli, an overview of 10 years of surveillance in France, 2007 to 2016.

IntroductionHaemolytic uraemic syndrome (HUS) related to Shiga toxin-producing Escherichia coli (STEC) is the leading cause of acute renal failure in young children. In France, HUS surveillance in children aged < 15 years was implemented starting from 1996.AimWe present the results of this surveillance between 2007 and 2016.MethodsA voluntary nationwide network of 32 paediatric departments notifies cases. Two national reference centres perform microbiological STEC confirmation.ResultsOver the study period, the paediatric HUS incidence rate (IR) was 1.0 per 100,000 children-years, with a median of 116 cases/year. In 2011, IR peaked at 1.3 per 100,000 children-years, and decreased to 1.0 per 100,000 children-years in 2016. STEC O157 associated HUS peaked at 37 cases in 2011 and decreased to seven cases in 2016. Cases of STEC O26-associated HUS have increased since 2010 and STEC O80 associated HUS has emerged since 2012, with 28 and 18 cases respectively reported in 2016. Four STEC-HUS food-borne outbreaks were detected (three STEC O157 linked to ground beef and raw-milk cheese and one STEC O104 linked to fenugreek sprouts). In addition, two outbreaks related to person-to-person transmission occurred in distinct kindergartens (STEC O111 and O26).ConclusionsNo major changes in HUS IRs were observed over the study period of 10 years. However, changes in the STEC serogroups over time and the outbreaks detected argue for continuing epidemiological and microbiological surveillance.

Sacroiliac Pain: Structural Causes of Pain Referring to the SI Joint Region.

BACKGROUND: The currently reported incidence of primary sacroiliac joint (SIj) pathology ranges from 15% to 30%. The differential diagnosis of SIj region pain includes pain generated from the lumbar spine, the SIj, and the hip joint. The origins of SIj dysfunctions are controversial and pain generation from this joint has been questioned. PURPOSE: Retrospectively analyze the relative incidence of lumbar spine, SIj, and hip joint etiologies in patients complaining of ≥50% SIj region pain. STUDY DESIGN: This is a retrospective cohort case series. METHODS: Inclusion criteria: chief complaint SIj pain (≥50% of overall complaint). In total, 124 patients charts were reviewed from a single spine surgeon's clinic. All patients were evaluated by the same 2 practitioners and all cases were reviewed for clinical examination findings, diagnostic tests performed, final diagnosis, treatment, and clinical follow-up. RESULTS: After complete diagnostic workup, 112 (90%) had lumbar spine pain, 5 (4%) had hip pain, 4 (3%) had primary SIj pain, and 3 (3%) had an undetermined source of pain upon initial diagnosis. SIj pain generation was confirmed via fluoroscopy-guided diagnostic injections. Following designated treatment, 11 (9%) patients returned to clinic at an average of 2.4 years complaining of continued/recurrent SIj region pain. Further investigation revealed 6 patients had confirmed pain generation from the lumbar spine, 3 patients had confirmed pain generation from the SIj, and 2 patients had undetermined sources of pain. CONCLUSIONS: The SIj is a rare pain generator (3%-6%) in patients complaining of ≥50% SIj region pain and is a common site of referral pain from the lumbar spine (88%-90%). Clinicians ought to quantify areas of pain (via percent of overall complaint) when interviewing their patients complaining of low back pain to distinguish potential pain generators. Recommended breakdown of areas of interest include axial low back, SIj region, buttock/leg, groin/anterior thigh.

Corrigendum: CD1d-Invariant Natural Killer T Cell-Based Cancer Immunotherapy: α-Galactosylceramide and Beyond.

[This corrects the article DOI: 10.3389/fimmu.2018.01519.].

CD1d-Invariant Natural Killer T Cell-Based Cancer Immunotherapy: α-Galactosylceramide and Beyond.

CD1d-restricted invariant natural killer T (iNKT) cells are considered an attractive target for cancer immunotherapy. Upon their activation by glycolipid antigen and/or cytokines, iNKT cells can induce direct lysis of tumor cells but can also induce an antitumor immune response via their rapid production of proinflammatory cytokines that trigger the cytotoxic machinery of other components of the innate and adaptive immune system. Here, we provide an overview of various therapeutic approaches that have been evaluated or that are currently being developed and/or explored. These include administration of α-GalCer or alternative (glyco) lipid antigens, glycolipid-loaded antigen-presenting cells and liposomes, strategies that enhance CD1d expression levels or are based on ligation of CD1d, adoptive transfer of iNKT cells or chimeric antigen receptor iNKT cells, and tumor targeting of iNKT cells.

High Proportion of Asymptomatic Infections in an Outbreak of Hepatitis E Associated With a Spit-Roasted Piglet, France, 2013.

BACKGROUND: On 11 December 2013, 3 clustered cases of hepatitis E were reported on a French coastal island. Individuals had taken part in a wedding meal that included a spit-roasted piglet. The piglet had been stuffed with a raw stuffing partly made from the liver. Investigations were carried out to identify the vehicle of contamination and evaluate the dispersion of the hepatitis E virus (HEV) in the environment. METHODS: A questionnaire was administered to 98 wedding participants who were asked to give a blood sample. Cases were identified by reverse transcription-polymerase chain reaction and serological tests. A retrospective cohort study was conducted among 38 blood-sampled participants after the exclusion of 14 participants with evidence of past HEV infection. Relative risks (RR) and 95% confidence intervals were calculated based on food consumed at the wedding meal using univariate and multivariable Poisson regressions. Phylogenetic analyses were performed to compare the clinical HEV strains. Strains were detected in the liquid manure sampled at the farm where the piglet was born and in the untreated island wastewater. RESULTS: Seventeen cases were identified, 70.6% were asymptomatic. Acute HEV infection was independently associated with piglet stuffing consumption (RR = 1.69 [1.04-2.73], P = .03). Of clinical strains from the index cases, veterinary and environmental HEV strains were identical. CONCLUSIONS: Our investigation attributed this large HEV outbreak to the consumption of an undercooked pig liver-based stuffing. After infection, the cases became a temporary reservoir for HEV, which was detected in the island's untreated wastewater.

Conceptualizing Forest Degradation.

Forest degradation is a global environmental issue, but its definition is problematic. Difficulties include choosing appropriate reference states, timescales, thresholds, and forest values. We dispense with many such ambiguities by interpreting forest degradation through the frame of ecological resilience, and with reference to forest dynamics. Specifically, we define forest degradation as a state of anthropogenically induced arrested succession, where ecological processes that underlie forest dynamics are diminished or severely constrained. Metrics of degradation might include those that reflect ecological processes shaping community dynamics, notably the regeneration of plant species. Arrested succession implies that management intervention is necessary to recover successional trajectories. Such a definition can be applied to any forest ecosystem, and can also be extended to other ecosystems.

Community Incidence of Campylobacteriosis and Nontyphoidal Salmonellosis, France, 2008-2013.

Community incidence estimates are necessary to assess the burden and impact of infections on health and to set priorities for surveillance, research, prevention, and control strategies. The current study was performed to estimate the community incidence of campylobacteriosis and nontyphoidal salmonellosis in France from the number of laboratory-confirmed cases reported to the national reference center (NRC). The probabilities of a case in the community visiting a doctor, having a stool sample requested, having a positive laboratory test, and having the case reported to the NRC were estimated using data of national surveillance systems, national hospitalization and health insurance databases, and specific surveys informing about these parameters. Credible intervals (CrI) were calculated using Monte Carlo simulation. In addition, we estimated the number of hospitalizations for both infections in France. The annual community incidence rate in France is estimated at 842 cases per 100,000 (90%CrI 525-1690) for campylobacteriosis and 307 cases per 100,000 (90%CrI 173-611) for salmonellosis. The annual number of hospitalizations is estimated at 5182 for campylobacteriosis and 4305 for salmonellosis. The multiplication factors between cases ascertained by the surveillance system and cases in the community were 115 for campylobacteriosis and 20 for salmonellosis. They are consistent with estimates reported in other countries, indicating a high community incidence of campylobacteriosis and salmonellosis in France.

Associations of age and sex with the clinical outcome and incubation period of Shiga toxin-producing Escherichia coli O104:H4 infections, 2011.

We pooled data on adults who reported diarrhea or developed life-threatening hemolytic uremic syndrome (HUS) in any of 6 closed cohorts from 4 countries (1 cohort each in Denmark, France, and Sweden and 3 in Germany) that were investigated during a large outbreak of Shiga toxin-producing Escherichia coli (STEC) O104:H4 infection in 2011. Logistic regression and Weibull regression for interval censored data were used to assess the relation of age and sex with clinical outcome and with incubation period. Information on the latter was used in a nonparametric back-projection context to estimate when adult cases reported in Germany were exposed to STEC O104:H4. Overall, data from 119 persons (median age, 49 years; 80 women) were analyzed. Bloody diarrhea and HUS were recorded as the most severe outcome for 44 and 26 individuals, respectively. Older age was significantly associated with bloody diarrhea but not with HUS. Woman had nonsignificantly higher odds for bloody diarrhea (odds ratio = 1.81) and developing HUS (odds ratio = 1.83) than did men. Older participants had a statistically significantly reduced incubation period. The shortest interval that included 75% of exposures in adults spanned only 12 days and preceded outbreak detection. In conclusion, the frequency of bloody diarrhea but not of HUS and the length of the incubation period depended on the age of individuals infected with STEC O104:H4. A large number of people were exposed to STEC O104:H4 for a short period of time.

What is the incubation period for listeriosis?

BACKGROUND: Listeriosis is a foodborne infection with a low incidence but a high case fatality rate. Unlike common foodborne diseases, the incubation period can be long. The first incubation periods were documented during a large listeriosis outbreak published in 1987 by Linnan and al. in the New England Journal of Medicine (range: 3 days to 70 days). Data on the incubation period of listeriosis are scarce. Our study aim was to estimate precisely the incubation period of listeriosis using available data since 1987. METHODS: We estimated the incubation period of listeriosis using available published data and data from outbreak investigations carried out by the French National Institute for Public Health Surveillance. We selected cases with an incubation period calculated when a patient had a single exposure to a confirmed food source contaminated by Listeria monocytogenes. RESULTS: We identified 37 cases of invasive listeriosis (10 cases with central nervous system involvement (CNS cases), 15 bacteraemia cases and 12 pregnancy-associated cases) and 9 outbreaks with gastroenteritis. The overall median incubation period of invasive listeriosis was 8 days (range: 1-67 days) and differed significantly by clinical form of the disease (p<0.0001). A longer incubation period was observed for pregnancy-associated cases (median: 27.5 days; range: 17-67 days) than for CNS cases (median: 9 days; range: 1-14 days) and for bacteraemia cases (median: 2 days; range: 1-12 days). For gastroenteritis cases, the median incubation period was 24 hours with variation from 6 to 240 hours. CONCLUSIONS: This information has implications for the investigation of food borne listeriosis outbreaks as the incubation period is used to determine the time period for which a food history is collected. We believe that, for listeriosis outbreaks, adapting the exposure window for documenting patients' food histories in accordance with the clinical form of infection will facilitate the identification of food products as the source of contamination. We therefore propose to take an exposure window of 14 days before the diagnosis for CNS and bacteraemia cases, and of 6 weeks before the diagnosis, for pregnancy-associated cases.

Outbreak of Shiga toxin-producing Escherichia coli O104:H4 associated with organic fenugreek sprouts, France, June 2011.

BACKGROUND: On 22 June 2011, 8 patients with hemolytic uremic syndrome (HUS) or bloody diarrhea were reported in France. All 8 were attendees of a community center event on 8 June near Bordeaux. Three Escherichia coli cases were confirmed by isolation of Shiga toxin-producing E. coli O104:H4 stx2 aggR producing a cefotaximase (CTX-M) ß-lactamase (STEC O104:H4); the same rare serotype caused the outbreak in Germany in May-July 2011. An investigation was initiated to describe the outbreak, identify the vehicle for infection, and guide control measures. METHODS: We conducted a retrospective cohort study among all adults attending the event, including food handlers. A standardized questionnaire was administered to participants. A case was an attendee who developed HUS or diarrhea between 8 and 24 June. Cases were confirmed by isolation of STEC O104:H4 or O104 serology. Relative risks (RRs) and 95% confidence intervals (CIs) by exposure were calculated using a Poisson regression model. RESULTS: Twenty-four cases were identified (14% attack rate). Of these, 18 (75%) were women, 22 (92%) were adults, 7 (29%) developed HUS, 5 (21%) developed bloody diarrhea, and 12 (50%) developed diarrhea. Ten (42%) cases were confirmed. Fenugreek was the only sprout type with an independent association to illness (RR, 5.1; 95% CI, 2.3-11.1) in multivariable analysis. CONCLUSIONS: This investigation identified a point-source STEC O104:H4 outbreak associated with consumption of fenugreek sprouts. Comparison of results from French and German STEC O104:H4 outbreak investigations enabled identification of a common food vehicle, fenugreek sprouts, and resulted in implementation of Europe-wide control measures in July 2011.

Epidemic profile of Shiga-toxin-producing Escherichia coli O104:H4 outbreak in Germany.

BACKGROUND: We describe an outbreak of gastroenteritis and the hemolytic-uremic syndrome caused by Shiga-toxin-producing Escherichia coli in Germany in May, June, and July, 2011. The consumption of sprouts was identified as the most likely vehicle of infection. METHODS: We analyzed data from reports in Germany of Shiga-toxin-producing E. coli gastroenteritis and the hemolytic-uremic syndrome and clinical information on patients presenting to Hamburg University Medical Center (HUMC). An outbreak case was defined as a reported case of the hemolytic-uremic syndrome or of gastroenteritis in a patient infected by Shiga-toxin-producing E. coli, serogroup O104 or serogroup unknown, with an onset of disease during the period from May 1 through July 4, 2011, in Germany. RESULTS: A total of 3816 cases (including 54 deaths) were reported in Germany, 845 of which (22%) involved the hemolytic-uremic syndrome. The outbreak was centered in northern Germany and peaked around May 21 to 22. Most of the patients in whom the hemolytic-uremic syndrome developed were adults (88%; median age, 42 years), and women were overrepresented (68%). The estimated median incubation period was 8 days, with a median of 5 days from the onset of diarrhea to the development of the hemolytic-uremic syndrome. Among 59 patients prospectively followed at HUMC, the hemolytic-uremic syndrome developed in 12 (20%), with no significant differences according to sex or reported initial symptoms and signs. The outbreak strain was typed as an enteroaggregative Shiga-toxin-producing E. coli O104:H4, producing extended-spectrum beta-lactamase. CONCLUSIONS: In this outbreak, caused by an unusual E. coli strain, cases of the hemolytic-uremic syndrome occurred predominantly in adults, with a preponderance of cases occurring in women. The hemolytic-uremic syndrome developed in more than 20% of the identified cases.