Eficacia y seguridad de la sutura ajustable en estrabismos horizontales: estudio comparativo de niños frente a adultos / Efficacy and safety of adjustable suture in horizontal strabismus: Comparative study of children versus adults

Objetivo Los procedimientos con sutura ajustable permiten abordar la imprevisibilidad de algunos resultados postoperatorios en la cirugía de estrabismo. El propósito del estudio fue comparar la efectividad de la sutura ajustable y no ajustable en el tratamiento del estrabismo horizontal en niños y en adultos. Método Estudio prospectivo en el que se incluyeron pacientes sometidos a cirugía de estrabismo para la corrección de un estrabismo horizontal con sutura colgante fija (grupo de sutura no ajustable) y sutura ajustable. Se registraron la agudeza visual, la ambliopía, la desviación, la afectación de los músculos oblicuos, las cirugías previas, el nistagmo, la necesidad de ajuste y las complicaciones. Las variables se registraron en el postoperatorio inmediato, a la semana y a los 3 y 6meses. Resultados Se incluyeron 186 pacientes: 157 (84,4%) con sutura ajustable y 29 (15,6%) con sutura no ajustable, de los cuales 119 eran niños y 67 eran adultos. En el postoperatorio, 19 niños (16,0%) y 19 adultos (28,4%) requirieron un ajuste (p=0,044). De 157 pacientes con sutura ajustable, se ajustó al 20% (32/157). El éxito tras el ajuste fue superior para la sutura ajustable (91,72% vs 79,31%; p=0,043) y se mantuvo los 6meses (p<0,05). La cirugía previa (p=0,004) y la exotropía (p=0,018) se relacionaron con la necesidad de ajuste. Conclusiones Un 20% de pacientes con estrabismo horizontal se pueden beneficiar de un ajuste postoperatorio para mejorar el resultado quirúrgico. La sutura ajustable mostró ser superior frente a la sutura colgante fija y supone una excelente opción quirúrgica tanto en niños como en adultos (AU)

Objective Adjustable suture procedures allow addressing the unpredictability of some postoperative results in strabismus surgery. The purpose of the study was to compare the effectiveness of adjustable and non-adjustable suture in the treatment of horizontal strabismus in children and adults. Methods Prospective study including patients undergoing strabismus surgery to correct horizontal strabismus with fixed hanging suture (non-adjustable suture group) and adjustable suture. Visual acuity, amblyopia, deviation, oblique muscle involvement, previous surgeries, nystagmus, need for adjustment, and complications were recorded. The variables were recorded in the immediate postoperative period, at one week and at 3 and 6months. Results 186 patients were included: 157 (84.4%) with adjustable suture and 29 (15.6%) with non-adjustable suture, of which 119 were children and 67 were adults. Postoperatively, 19 children (16.0%) and 19 adults (28.4%) required adjustment (P=.044). Of 157 patients with adjustable suture, it was adjusted in 20% (32/157). Success after adjustment was higher for adjustable suture (91.72% vs 79.31%; P=.043) and remained for 6months (P<.05). Previous surgery (P=.004) and exotropia (P=.018) correlated with the need for adjustment. Conclusions 20% of patients with horizontal strabismus can benefit from a postoperative adjustment to improve the surgical result. The adjustable suture was shown to be superior to the fixed hanging suture and is an excellent surgical option, both in children and adults (AU)

Efficacy and safety of adjustable suture in horizontal strabismus: Comparative study of children versus adults.

OBJECTIVE: Adjustable suture procedures allow addressing the unpredictability of some postoperative results in strabismus surgery. The purpose of the study was to compare the effectiveness of adjustable and non-adjustable suture in the treatment of horizontal strabismus in children and adults. METHODS: Prospective study including patients undergoing strabismus surgery to correct horizontal strabismus with fixed hanging suture (non-adjustable suture group) and adjustable suture. Visual acuity, amblyopia, deviation, oblique muscle involvement, previous surgeries, nystagmus, need for adjustment, and complications were recorded. The variables were recorded in the immediate postoperative period, at one week and at 3 and 6 months. RESULTS: 186 patients were included: 157 (84.4%) with adjustable suture and 29 (15.6%) with non-adjustable suture, of which 119 were children and 67 were adults. Postoperatively, 19 children (16.0%) and 19 adults (28.4%) required adjustment (p = 0.044). Of 157 patients with adjustable suture, it was adjusted in 20% (32/157). Success after adjustment was higher for adjustable suture (91.72% vs 79.31%; p = 0.043) and remained for 6 months (p < 0.05). Previous surgery (p = 0.004) and exotropia (p = 0.018) correlated with the need for adjustment. CONCLUSIONS: 20% of patients with horizontal strabismus can benefit from a postoperative adjustment to improve the surgical result. The adjustable suture was shown to be superior to the fixed hanging suture and is an excellent surgical option, both in children and adults.

Staphylococcus cohnii endocarditis in native valve.

We present a first case of Staphylococcus cohnii endocarditis in an 80-year-old patient with a history of valve regurgitation. Endocarditis by this organism has not been reported previously. The patient declined treatment and died a few days later. When present, S. cohnii endocarditis has a poor prognosis as a result of associated comorbidities and the infection itself.

Long-term response control in a patient with metastatic squamous cell lung cancer after treatment with nivolumab: a case report.

INTRODUCTION: Nivolumab is a fully human programmed death control immune point 1 immune checkpoint inhibitor antibody which promotes antitumor immunity. Cutaneous toxicity associated with nivolumab, immune system related, could be linked to a more durable response in patients with squamous cell lung cancer. CASE REPORT: We present the case of a 62-year-old male diagnosed with metastatic squamous cell lung cancer, who was treated with nivolumab after cytotoxic chemotherapy. After treatment discontinuation, due to grade 2 cutaneous toxicity, the patient is maintaining with durable partial response for more than one year with close follow-up. MANAGEMENT AND OUTCOME: Cumulative doses of nivolumab could cause immunological toxicities that may prolong survival of these patients even after discontinuation of treatment. DISCUSSION: Nivolumab was approved by European Medicines Agency (EMA), as second-line therapeutic, for the treatment of squamous cell lung cancer, showing a median of 9.23 months of overall survival. The development of immune-related skin toxicities has been associated with greater clinical benefit in patients with lung cancer. When cutaneous toxicity forces to nivolumab suspension, in certain cases, the option of not starting again and closely following up the patient may appear reasonable, even though there are no survival data in this context. Suspension of treatment with close monitoring of these patients until progression may be an alternative, since immune-related skin toxicities could be related to a greater clinical benefit and a durable response to nivolumab.

[Dosage of presurgical cefazolin in obese and non-obese patients. Does weight matter?] / Dosificación de cefazolina prequirúrgica en pacientes obesos y no obesos. ¿Importa el peso?

OBJECTIVE: Evaluation of the effectiveness of a standard dose of cefalozin 2 grams for surgical site infection (SSI) prevention in obese patients compared to non-obese patients. There is no still controversy surrounding which is the best dosage of this antibiotic in obese patients for surgical prophylaxis. METHODS: Retrospective review of men who received prophylactic cefazolin between January 1st, 2019 and June 30th, 2019 in a traumatology department of a university hospital. Patients were stratified into 2 groups: obese (≥ 100 kg and body mass index (BMI)> 30 kg / m2) and non-obese. Patients without a 90 days follow-up after surgery and/or with an active infection at the time of surgery and/or treated with immunosuppressants were excluded. Demographic data, height, real weight, smoking, diabetes, concomitant use of immunosuppressants, surgery data and presence of infection until day 90 were collected. RESULTS: A total of 57 patients underwent traumatic surgery with prophylactic cefazolin, 26 non-obese and 23 obese, were studied. Both groups presented statistically significant differences in weight, BMI and post-surgery use of cefazolin. No significant differences were observed in the other variables. Two obese (8.7%) and two non-obese (7.7%) patients developed SSIs after 63 days post-surgery on average, following the difference between the groups being statistically non-significant. CONCLUSIONS: This study shows that there is no significant difference in SSI with a standard prophylactic dose of two grams of cefazolin between obese and non-obese patients.

The Mexican consensus on the diagnosis and treatment of diverticular disease of the colon. / Consenso mexicano sobre el diagnóstico y tratamiento de la enfermedad diverticular del colon.

Since the publication of the 2008 guidelines on the diagnosis and treatment of diverticular disease of the colon by the Asociación Mexicana de Gastroenterología, significant advances have been made in the knowledge of that disease. A systematic review of articles published in the medical literature from January 2008 to July 2018 was carried out to revise and update the 2008 guidelines and provide new evidence-based recommendations. All high-quality articles in Spanish and English published within that time frame were included. The final versions of the 43 statements accepted in the three rounds of voting, utilizing the Delphi method, were written, and the quality of evidence and strength of the recommendations were established for each statement, utilizing the GRADE system. The present consensus contains new data on the definition, classification, epidemiology, pathophysiology, and risk factors of diverticular disease of the colon. Special emphasis is given to the usefulness of computed tomography and colonoscopy, as well as to the endoscopic methods for controlling bleeding. Outpatient treatment of uncomplicated diverticulitis is discussed, as well as the role of rifaximin and mesalazine in the management of complicated acute diverticulitis. Both its minimally invasive alternatives and surgical options are described, stressing their indications, limitations, and contraindications. The new statements provide guidelines based on updated scientific evidence. Each statement is discussed, and its quality of evidence and the strength of the recommendation are presented.

Consenso mexicano sobre el diagnóstico y tratamiento de la enfermedad diverticular del colon / The Mexican consensus on the diagnosis and treatment of diverticular disease of the colon

Desde la publicación en 2008 de las guías de diagnóstico y tratamiento de la enfermedad diverticular del colon de la Asociación Mexicana de Gastroenterología ha habido avances significativos en el conocimiento de esta enfermedad. Se realizó una revisión sistemática de la literatura en PubMed de enero de 2008 a julio de 2018 con el fin de revisar y actualizar las guías 2008 y proporcionar nuevas recomendaciones basadas en la evidencia. Se incluyeron todas las publicaciones en español e inglés, de alta calidad. Se redactaron los enunciados, que fueron votados utilizando el método Delphi. Se estableció la calidad de la evidencia y la fuerza de las recomendaciones según el sistema GRADE para cada enunciado. Cuarenta y tres enunciados fueron finalmente votados y calificados. Se informan nuevos datos sobre definición, clasificación, epidemiología, fisiopatología y factores de riesgo. Se revisó con especial énfasis la utilidad de la tomografía computarizada y de la colonoscopia, así como los métodos endoscópicos para el control de la hemorragia. Se discutió sobre el tratamiento ambulatorio de la diverticulitis no complicada, el papel de la rifaximina y la mesalazina, en el manejo de la diverticulitis aguda complicada tanto en sus alternativas mínimamente invasivas hasta las opciones quirúrgicas con énfasis en sus indicaciones, limitaciones y contraindicaciones. Los nuevos enunciados proporcionan directrices basadas en la evidencia actualizada. Se presentan la discusión, el grado y la fuerza de la recomendación de cada uno de ellos.

First epidemiologic study in Argentina of the prevalence of BK viruria in kidney transplant patients.

BACKGROUND: The worldwide seroprevalence of human BK polyomavirus (BKV) in adults is 80%. About 10%-60% of renal transplant recipients experience BKV infection, nephropathy of the graft may occur in 5% of the cases, and up to 45% lose the graft. The aim of this work was to describe the prevalence of BK viruria during the 1st year after transplantation. METHODS: An epidemiologic multicenter cross-sectional study was carried out in consecutive patients at each site with kidney transplantation from August 2011 to July 2012. Clinically significant viruria was defined as >10(7) copies/mL. Viral DNA was extracted with the use of silica columns. Quantification was performed with the use of real-time polymerase chain reaction with primers that amplify a fragment of the large T-antigen gene and with a specific Taqman-MGB probe for BKV. For each assay, a standard curve with a quantified plasmid was included. RESULTS: Of 402 renal transplant recipients at 18 renal transplant sites, we analyzed 382; median age was 46.33 years, and 46.40% were female. The median of the temporal distribution for urine samples was 153 days. BK virus was detected in 50/382 samples (13%), 18 with values >10(7) copies/mL (4.7%). The median of the distribution of positive values was 123 days and the highest frequency of positive values was in months 3-7. The conditions of recipient older than 34 years and donor older than 41 years were the only ones that showed statistically significant association with BK viruria. No association with any specific immunosuppressive drug was observed. CONCLUSIONS: This is the first multicenter study conducted in Argentina to determine the prevalence of BK viruria in renal transplant recipients. Because of the growing number of the population susceptible to this infection, it is important to register and describe data about its epidemiology and associated risk factors.

The effect of single-file reciprocating systems on Substance P and Calcitonin gene-related peptide expression in human periodontal ligament.

AIM: To quantify the effect of two single-file reciprocating root canal preparation systems on Substance P (SP) and Calcitonin gene-related peptide (CGRP) expression in healthy human periodontal ligament (PDL). METHODOLOGY: Forty PDL samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. Prior to extraction, 20 of these premolars were divided equally in two groups, and then, root canals were prepared using one of two different single-file systems: WaveOne and Reciproc. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All PDL samples were processed, and SP and CGRP were measured by radioimmunoassay. RESULTS: Greater SP and CGRP expression were found in the hand instrumentation group (1.220 pmol SP and 0.084 pmol CGRP per mg of PDL), followed by the WaveOne group (0.908 pmol SP and 0.046 pmol CGRP per mg of PDL) and the Reciproc group (0.511 pmol SP and 0.022 pmol CGRP per mg of PDL). The lower SP and CGRP values were associated with the intact control group (0.453 pmol SP and 0.018 pmol CGRP per mg of PDL). The Kruskal-Wallis test revealed significant differences between groups (P < 0.001). Post hoc Tukey HSD tests revealed significant differences in SP and CGRP expression between intact teeth in the control group and all the other groups (P < 0.001) except with the Reciproc group (P = 0.165 and P = 0.42 for SP and CGRP, respectively). Hand instrumentation was associated with significant differences with all the other groups (P < 0.001). Differences between the WaveOne and Reciproc groups were also significant (P < 0.001). CONCLUSION: Substance P and CGRP expression in PDL cells increased when teeth were prepared with WaveOne as well as with hand instrumentation. Reciproc maintained SP and CGRP levels in line with the negative control group.

Results of the conversion to everolimus in renal transplant recipients with posttransplantation malignancies.

Management of posttransplantation malignancies should include control of the neoplasia and preservation of renal function. Conversion to everolimus (EVL) would potentially have both effects. Twenty-one patients were converted to EVL due to posttransplantation neoplasms. We have presented herein descriptive data and postconversion (PC) outcomes among subjects of mean age 53.6 +/- 10.1 years (range, 36-69), 57.1% were males, undergoing conversion at 108.2 +/- 74.7 (range, 5-316) months after transplantation. All patients received standard immunosuppressive therapy and 9.5% had been induced with thymoglobulin. Malignant neoplasms were as follows: skin (n = 7), gynecological (n = 3), gastrointestinal (n = 3), PTLD (n = 2), renal (n = 2), CNS (n = 1), seminoma (n = 1), Kaposi's sarcoma (n = 1), and prostate cancer (n = 1). PC to EVL, calcineurin inhibitors (CNIs) were discontinued in 18 of 19 patients, mycophenolate in 9/12, and azathioprine in 5/7; all patients continued to receive steroids. In 16 patients (79%) tumors were removed. Chemotherapy was performed in 2 patients with PTLD and radiotherapy was performed in 1 patient with prostate cancer. Mean follow-up was 505 days (range, 59-1151); baseline glomerular filtration rate (GFR) was 53.5 +/- 21.6 mL/min versus 48.5 +/- 25.7 mL/min (P = not significant [NS]) at the last control. One patient experienced graft loss at day 744 after conversion due to chronic rejection. Adverse events were observed in 57% of patients and 28% displayed infections; no patient discontinued EVL. There were 2 deaths: 1 due to an infection and the other due to postsurgical complication. No deaths due to cancer progression were observed. The results observed in this series suggested that conversion to EVL for a posttransplantation neoplasm is a valid therapeutic alternative to preserve graft function and control disease progression.

Case report of a kidney transplant recipient converted to everolimus due to malignancy: resolution of bronchiolitis obliterans organizing pneumonia without everolimus discontinuation.

The use of proliferative signal inhibitors (PSIs) in immunosuppression-related malignancies opens new roads for increasing the survival and quality of life in patients with solid organ transplantation. A 56-year-old female recipient of a living donor renal allograft (1990), who was immunosuppressed with cyclosporine (CsA; Neoral), azathioprine, and steroids, did initially well with acceptable renal function. During the last 5 years she required local therapy due to posterior vaginal lip human papillomavirus (HPV) lesions. In 2000, she discontinued azathioprine and the CsA doses were reduced to 100 mg daily. The local lesion showed a good response to reduced immunosuppression. In February 2005, the lesion reappeared and a biopsy showed malignancy. Local surgery was performed and CsA was replaced by everolimus (EVL; Certican). Two months after treatment initiation, the patient developed cough, dyspnea, and low-grade fever. Chest X-ray showed a lesion at the base of the left lung compatible with pneumonitis. After fiberbronchoscopy a diagnosis of bronchiolitis obliterans organizing pneumonia (BOOP) was obtained. She was treated with increased doses of oral steroids. EVL was never discontinued. The radiological lesion disappeared and the malignancy is currently in remission. In summary, a case of gynecological cancer in a renal transplant recipient was treated by surgical removal. After 1 year of immunosuppression with EVL, no recurrence has been observed. The adverse event (BOOP) was probably related to the PSI treatment and was controlled with an increased dose of steroids without discontinuing EVL.

Use of enteric-coated mycophenolate sodium in de novo renal transplant recipients with high incidence of delayed graft function.

Patients with delayed graft function (DGF) are at risk of increased incidence for acute rejection episodes (ARE). Mycophenolate mofetil or induction therapy has produced a reduction in ARE incidence. An open, prospective, 3-month trial was performed in a group of Argentinian renal transplant recipients. We recruited 46 patients, 71.7% men, aged 41.7 +/- 13.8 years; including 36 (78.3%) recipients of cadaveric donors (CD) who were aged 43.4 +/- 15.5 years with a cold ischemia time of 19.4 hours +/- 5.4 minutes, and 10 (27.7%) recipients of living donors (LD) aged 37.8 +/- 12.9 years. HLA mismatches >or= 3 were observed in 58.4% of CD and in 7% of LD. All patients received two doses of basiliximab (20 mg each, days 0 and 4), cyclosporine microemulsion (CsA-ME) monitored by the second-hour concentrations (C2), enteric-coated mycophenolate sodium (EC-MPS; 720 mg twice a day, and steroids. A 58% incidence of DGF was observed. At the end of the third month the incidence of biopsy-proven ARE was 15%, with a median serum creatinine of was 1.54 +/- 0.42 mg/dL, including three grafts lost. Two patients died. No patient required EC-MPS dose discontinuation but 20% of patients required dose adjustments. The absence of discontinuations and the low incidence of dose adjustments of EC-MPS in this high-risk de novo population provided support of a suitable tolerability profile for this EC-MPS, and the possibility to impact efficacy results.

Two-hour post-dose cyclosporine levels in renal transplantation in Argentina: a cost-effective strategy for reducing acute rejection.

UNLABELLED: Monitoring of cyclosporine (microemulsion CsA) at 2 hours post-dose (C2), a measure of absorption and exposure, appears superior to trough (C0) monitoring for prediction of rejection risk. The purpose of this study was to determine whether C2 was cost-effective compared to C0 in Argentina. METHODS: A predictive decision model was adapted to Argentina to predict costs associated with C0 and C2 measurements in the first year after transplantation. Patients were treated with microemulsion CsA, steroids and azathioprine or MMF. Parameter estimates for the C0 strategy were based on event rates observed in published clinical trials. The model was adapted to Argentinean health system through local protocols and expert opinions; costs were valued in Argentinean pesos and converted to US dollars (1 USD = 2.85 ARS). RESULTS: Incidence of acute rejection was predicted to be 25.0% at 1-year among patients monitored by C0 and 18.0% by C2. Graft survival was predicted to be 1.4% lower in the C0 group. No important differences were identified in co-morbidity, C0 and C2 monitoring costs, and in ambulatory-based adverse events between C0 and C2 cohorts. The model predicted an average cost per patient of $16,269 for C0 and $16,343 for C2 testing (year 1). Sensitivity analyses indicated that the average daily dose of microemulsion CsA was the most important parameter leading to the incremental cost per patient. CONCLUSIONS: C2 is expected to provide a potentially important reduction in the risk of acute rejection without increasing the estimated cost of care in the first year post-transplant.

Rapamycin in lung transplantation: preliminary results.

INTRODUCTION: Rapamycin is a potent immunosuppressive agent with a different mechanism of action and different adverse effects from those of calcineurin inhibitors (CNIs). OBJECTIVE: To analyze our experience with rapamycin in patients undergoing lung transplantation and heart-lung transplantation in our center. PATIENTS AND METHODS: Patients were treated with rapamycin when showing chronic rejection and/or toxicity associated with the CNI after lung transplantation or heartlung transplantation. Patients with chronic rejection were administered rapamycin in combination with CNIs, whereas the CNIs were eliminated in patients with toxicity. RESULTS: Since October 2001, 7 patients (4 women), of mean age 45+/-15 years, received treatment with rapamycin (heart-lung transplantation, 2 cases; lung transplantation, 5 cases). The indications were chronic rejection in 4 patients and CMIs toxicity in 3 patients (kidney failure in 2 cases and optic neuropathy in 1 case). Pulmonary function stabilization was observed in 3 of 4 patients receiving rapamycin for chronic rejection. In the 3 patients with CNIs toxicity elimination of these drugs did not result in pulmonary functional deterioration. Patients with kidney failure showed an improvement in creatinine levels; visual acuity improved in the patient with optic neuropathy. We observed 2 infectious complications (pneumococcal pneumonia and pulmonary aspergillosis), which resolved with treatment. CONCLUSION: Rapamycin is an alternative for lung-transplant recipients who develop chronic rejection and/or CNIs toxicity.

Total serum bile acids in renal transplanted patients receiving cyclosporine A.

BACKGROUND: A direct relationship between serum bile acids (SBA) and hepatic and hepatobiliary dysfunction has been demonstrated. However, there is little evidence that SBA are related to renal insufficiency. In a previous study, we showed that hemodialysis patients with advanced chronic renal failure (ACRF) have an increase of SBA in predialysis and a decrease in postdialysis. Consequently, it was assumed that the restoration of renal function in transplanted patients might decrease SBA levels. AIM OF THIS STUDY: Transplanted patients receiving cyclosporine A (CyA) were studied by monitoring CyA and SBA levels to determine if a probable relationship exists between renal function, CyA treatment and SBA levels. SUBJECTS. MATERIALS AND METHODS: SBA levels were determined in 15 recently transplanted patients receiving CyA for 18 months and longer. In addition, 22 renal patients transplanted not less than 6 years ago were also included in the study and were characterized as the stable group. Five patients from this group received mycophenolate or azathioprine instead of CyA as immunosuppressant. In addition to SBA and CyA, creatinine, cholesterol, y-GT, viral markers and triglycerides were also determined in all patients. RESULTS: A significant and constant increase in SBA levels was observed in the recently transplanted group. However, after 18 months, SBA levels gradually decreased to those of patients considered stable under CyA treatment. In both recently transplanted and stable patients who received CyA, SBA values remained higher than normal, but stable patients under mycophenolate or azathioprine treatment showed no such increase. CONCLUSIONS: In recently transplanted patients, in patients studied for 18 months post transplant and in stable patients receiving CyA, the increase of SBA levels might be related to CyA treatment. This effect might be attributed to its cholestatic effect and also to a modification in uptake, metabolism, synthesis and excretion of SBA in the hepatocyte. These conclusions are supported by the results obtained in stable transplanted patients without CyA treatment showing normal SBA levels.

Evaluación de técnicas moleculares e inmunoenzimáticas para la detección de escherichia coli enterohemorrágico en brotes de toxi infecciones alimentarias / Evaluation of molecular and immunoenzymatic assays for detecting enterohemorrhagic escherichia coli in food borne outbreaks

Background: Enterohemorrhagic Escherichia coli (EHEC), is an emergent pathogen that causes sporadic infections and outbreaks of gastroenteritis associated with consumption of contaminated food products. Because detection of EHEC in diarrhea patients is not routinely performed, infection is most probably underestimated. Aim: To compare three techniques to detect EHEC: Colony hybridization with DNA probes, polymerase chain reaction (PCR) for the detection of stx1 and stx2 genes and immunoenzymatic detection by ELISA (Premier EHEC) of Stx1 and Stx2 toxins. Material and methods: Four outbreaks of food-borne gastroenteritis were studied including 16 patients and 78 strains of E coli. Twenty one (26,9 percent) strains, hybridized with the stx1 probe, 1 (1,3 percent) hybridized only with the stx2 probe and 36 (46,1 percent) with both probes. PCR amplification for cytotoxin genes was observed in 6 strains (7,7 percent) from the second outbreak studied. The immunoenzimatic assay detected the cytotoxins in 18 (23,0 percent), of the 78 studied strains. Agreement between probes and ELISA was 44,8 percent, between PCR and probes 34,7 percent and 82,4 percent between ELISA and PCR. Conclusions: These results indicate a variable yield among different EHEC detection techniques. Considering PCR as the gold standard, ELISA technique showed a better sensitivity and specificity than probes