Asociación de los resultados de dos pruebas diagnósticas de infección por Helicobacter pylori / Association of the results of two diagnostic tests for Helicobacter pylori infection

Helicobacter pylori es un microrganismo que se considera que afecta al 50% de la población. Se realizó un estudio con diseño no experimental, correlacional y transversal, con el objetivo de determinar la asociación de los resultados de pruebas diagnósticas de infección por H. pylori a través de biopsia obtenida por endoscopía superior y prueba de antígeno de la superficie en mues-tras de heces en 100 pacientes atendidos en el Servicio de Gastroenterología del Centro Clínico Quirúrgico Ambulatorio (Hospital del Día) Efrén Jurado López del Instituto Ecuatoriano de Seguridad Social (IESS), en la ciudad de Guayaquil, Ecuador, durante 2019. La media de la edad en la muestra de estudio fue 37,5 años, con un predominio del género femenino (78%). El 65% de las pruebas de antígeno para la detección de H. pylori en heces resultaron negativas. Los repor-tes de las pruebas de antígeno en heces e histopatología permitieron apreciar diferencias entre estos, pero con predominio de las coincidencias en los diagnósticos positivos. Existió una asocia-ción estadísticamente significativa entre las lesiones inflamatorias de la mucosa gástrica producto de la gastritis crónica atrófica y la infección por H. pylori. Los resultados de las dos pruebas diag-nósticas tuvieron una correlación lineal positiva y débil con significación estadística.

Helicobacter pylori is a microorganism that affects 50% of the population worldwide. A study with a non-experimental, correlational, and cross-sectional design was carried out in order to determine the association of the results of diagnostic tests for H. pylori infection through biopsy obtained by upper endoscopy and surface antigen test in samples of feces in 100 patients. These ones were treated at the Gastroenterology Service of the Ambulatory Surgical Clinic Center (Hospital del Día) Efrén Jurado López of the Ecuadorian Institute of Social Security (IESS), in the city of Guayaquil, Ecuador, during 2019. The mean age in the study sample was 37.5 years old, with a predominance of the female gender (78%). 65% of stool antigen tests for H. pyloriwere negative. The reports of the stool antigen test and histopathology allowed to appreciate differences between them, but with a predominance of the coincidences in the positive diagno-ses. There was a statistically significant association between the inflammatory lesions of the gastric mucosa because of chronic atrophic gastritis and the infection by H. pylori. The results of the two diagnostic tests had a positive and weak linear correlation with statistical significance

Comparison of three methods based on endoscopic gastric biopsies for diagnosis of Helicobacter pylori active infection in a clinical setting.

CONTEXT: The correct diagnosis and effective treatment of Helicobacter pylori gastric infection are essential in controlling this infection. OBJECTIVE: To compare the diagnostic value of three tests based in endoscopic gastric biopsies histopathological evaluation with hematoxylin-eosin (H-E) staining, urease rapid test and microbiological culture for detecting Helicobacter pylori active infection, in order to make recommendations for daily clinical practice. METHODS: Gastric biopsies from 115 adult patients (85 female/30 male) were obtained by upper gastrointestinal endoscopy and studied by histopathological evaluation with H-E (antrum-corpus), urease test in 2 hours (antrum) and microbiological culture (antrum). RESULTS: Helicobacter pylori active infection was diagnosed in 67% of patients. Helicobacter pylori active infection was detected by histopathological evaluation with H-E, urease test and microbiological culture in 87%, 79% and 70% of the positive cases, respectively. There were significant differences when histopathological evaluation with H-E and urease test rapid test when compared with microbiological test (P<0.01). There was no significant difference between histopathological evaluation with H-E and urease test (P = 0.7). The kappa index of agreement for histopathological evaluation with H-E/urease test was 0.56, histopathological evaluation with H-E/microbiological culture 0.6, and urease test/microbiological culture 0.64. CONCLUSIONS: In a hospital setting like the one studied, histopathological evaluation with H-E and urease test are the most recommended tests for diagnosis of Helicobacter pylori active infection based in endoscopic biopsies. If pathological information of gastric lesions will be required, histopathological evaluation with H-E is essential. Urease test is mandatory if a prompt diagnosis is necessary. Microbiological culture can be used in cases of persistent or complicated infection, which may require studies on Helicobacter virulence or antimicrobial susceptibility. Selected cases might demand a combination of several tests. The three tests exhibit a good concordance level for Helicobacter pylori active infection diagnosis.

Comparison of three methods based on endoscopic gastric biopsies for diagnosis of Helicobacter pylori active infection in a clinical setting / Comparação de três métodos baseados em biopsias gástricas endoscópicas para o diagnóstico da infecção ativa pelo Helicobacter pylori em um ambiente clínico

CONTEXT: The correct diagnosis and effective treatment of Helicobacter pylori gastric infection are essential in controlling this infection. OBJECTIVE: To compare the diagnostic value of three tests based in endoscopic gastric biopsies histopathological evaluation with hematoxylin-eosin (H-E) staining, urease rapid test and microbiological culture for detecting Helicobacter pylori active infection, in order to make recommendations for daily clinical practice. METHODS: Gastric biopsies from 115 adult patients (85 female/30 male) were obtained by upper gastrointestinal endoscopy and studied by histopathological evaluation with H-E (antrum-corpus), urease test in 2 hours (antrum) and microbiological culture (antrum). RESULTS: Helicobacter pylori active infection was diagnosed in 67 percent of patients. Helicobacter pylori active infection was detected by histopathological evaluation with H-E, urease test and microbiological culture in 87 percent, 79 percent and 70 percent of the positive cases, respectively. There were significant differences when histopathological evaluation with H-E and urease test rapid test when compared with microbiological test (P<0.01). There was no significant difference between histopathological evaluation with H-E and urease test (P = 0.7). The kappa index of agreement for histopathological evaluation with H-E/urease test was 0.56, histopathological evaluation with H-E/microbiological culture 0.6, and urease test/microbiological culture 0.64. CONCLUSIONS: In a hospital setting like the one studied, histopathological evaluation with H-E and urease test are the most recommended tests for diagnosis of Helicobacter pylori active infection based in endoscopic biopsies. If pathological information of gastric lesions will be required, histopathological evaluation with H-E is essential. Urease test is mandatory if a prompt diagnosis is necessary. Microbiological culture can be used in cases of persistent or complicated infection, which may require studies on Helicobacter virulence or antimicrobial susceptibility. Selected cases might demand a combination of several tests. The three tests exhibit a good concordance level for Helicobacter pylori active infection diagnosis.

CONTEXTO: O diagnóstico correto e o tratamento eficaz da infecção pelo Helicobacter pylori são essenciais no controle desta infecção. OBJETIVO: Comparar o valor de três testes de diagnóstico baseado em biopsias gástricas endoscópicas: avaliação histopatológica com hematoxilina-eosina (H-E), teste da urease e cultura microbiológica para a detecção da infecção ativa pelo H. pylori, com a finalidade de recomendações para a clínica diária prática. MÉTODOS: Biopsias gástricas de 115 pacientes (85 mulheres e 30 homens) foram obtidas por endoscopia digestiva alta e estudadas por avaliação histopatológica com H-E (antro-corpo), teste de urease em 2 horas (antro) e cultura microbiológica (antro). RESULTADOS: Infecção ativa pelo H. pylori foi diagnosticada em 67 por cento dos pacientes e detectada pela avaliação histopatológica com H-E, pelo teste de urease e pela cultura microbiológica em 87 por cento, 79 por cento e 70 por cento dos casos positivos, respectivamente. Houve diferenças significativas quando a avaliação histopatológica com H-E e o teste rápido de urease quando comparadas com a cultura microbiológica (P<0,01). Não houve diferença significativa entre a avaliação histopatológica com H-E e o teste de urease (P = 0,7). O índice kappa para avaliação histopatológica com H-E/teste de urease foi de 0,56, avaliação histopatológica com H-E/cultura microbiológica 0,6, e teste de urease/cultura microbiológica 0,64. CONCLUSÕES: Em condições similares ao estudado, avaliação histopatológica com H-E e teste de urease são os testes mais recomendados para o diagnóstico de infecção ativa pelo H. pylori com base em biopsias endoscópicas. A avaliação histopatológica com H-E é essencial quando exigido o estudo de lesões gástricas. O teste de urease é obrigatório no caso de diagnóstico precoce rápido. A cultura microbiológica pode ser usada em casos de infecção persistente ou complicada, que podem exigir estudos sobre a virulência ou susceptibilidade do Helicobacter aos antimicrobianos. Os casos selecionados podem exigir a combinação de vários testes. Os três testes apresentam bom nível de concordância para o diagnóstico da infecção ativa pelo H. pylori.

Bacterias enteropatógenas en la comunidad étnica añu de la Laguna de Sinamaica, Estado Zulia, Venezuela / Enteropathogenic bacteria in the añu ethnic community from Laguna de Sinamaica, Zulia State, Venezuela

Los estudios poblacionales sobre prevalencia de enteropatógenos bacterianos son escasos, particularmente en comunidades indígenas. En el presente estudio se investigó la prevalencia de bacterias enteropatógenas en muestras de materia fecal correspondientes a 378 individuos de la etnia añu, de diferente edad y género, residentes en la Laguna de Sinamaica, estado Zulia. Se realizó el cultivo bacteriológico convencional, excluyendo las categorías diarreogénicas de Escherichia coli. Se obtuvieron 71 cultivos positivos (18,8%), con predominio de las infecciones por un solo agente (58 casos, 81,7%), aunque también se detectaron asociaciones entre dos o tres especies (15,5% y 2,8%, respectivamente). En total se aislaron 86 cepas bacterianas, cuya distribución fue la siguiente: Aeromonas spp.: 34 aislamientos (39,5%), Vibrio spp.: 27 (31,4%), Shigella spp.: 11 (12,8%), Campylobacter spp.: 9 (10,5%), Plesiomonas shigelloides: 3 (3,5%) y Salmonella enterica: 2 (2,3%). V. parahaemolyticus resultó la especie predominante (15/86; 17,4%). El riesgo de infección por bacterias enteropatógenas resultó 2,6 veces superior para niños lactantes y preescolares (p < 0,01). La mayoría de los individuos participantes negó presentar sintomatología gastrointestinal. Los resultados demuestran una alta prevalencia de enteropatógenos bacterianos entre la población añu estudiada, con una distribución mayoritaria de las especies que habitualmente forman parte de la microbiota normal de las aguas.

Population studies on prevalence of enteropathogenic bacteria are few, especially in indigenous communities. In the present study we investigated the prevalence of enteropathogenic bacteria in feces samples corresponding to 378 individuals from the añu ethnic community with various ages and gender, living at the Laguna de Sinamaica, Zulia State. A conventional bacteriological culture was done, excluding Escherichia coli diarrheogenic categories. Seventy one positive cultures were obtained (18.8%) with predominance of single agent infections (58 cases, 81.7%), even though associations between two or three species were also detected (15.5% and 2.8% respectively). A total of 86 bacterial strains were isolated, with the following distribution: Aeromonas spp, 34 (39.5%) isolates; Vibrio spp, 27 (31.4%); Shigella spp, 11 (12.8%); Campylobacter spp, 9 (10.5%); Plesiomonas shigelloides, 3 (3.5); and Salmonella enterica, 2.3%). V. parahaemolyticus turned out to be the predominant species (15/86, 17.4%). The enteropathogenic bacterial infection risk was 2.6 higher for lactating and preschool children (p< 0.01). Most of the participating individuals denied presence of gastrointestinal symptoms. The results showed a high prevalence of bacterial enteropathogens in the añu population studied, with a mayor distribution of the species which habitually are part of normal water microbiology.

Nuevas evidencias sobre la utilidad diagnóstica de una fórmula no comercial para la detección de la actividad de ureasa de helicobacter pylori en biopsias gástricas / New evidences about the diagnostic usefulnes of a non-commercial test for detection of helicobacter pylori urease activity in gastric biopsies

La asociación entre la infección por Helicobacter pylori y el desarrollo de enfermedades gastroduodenales y cáncer gástrico, exige disponer de pruebas confiables para diagnosticar esta infección. La prueba rápida de ureasa, ampliamente difundida, es una herramienta valiosa para este fin, pero su elevado costo limita su aplicabilidad en nuestro medio. En el presente trabajo se evaluó la validez diagnóstica de una prueba de ureasa no comercial y de bajo costo, preparada con agar urea de Christensen, aplicada a biopsias gástricas antrales de 75 adultos sintomáticos, sometidos a endoscopia gastrointestinal. Como criterio de infección, se empleó la positividad a cualquiera de las siguientes metodologías: cultivo bacteriológico, coloración histológica de Giemsa y reacción en cadena de la polimerasa. De 37 pacientes en quienes se detectó la infección, 35 fueron correctamente diagnosticados mediante esta prueba (94.6 por ciento). 29 de ellos (82.8 por ciento) fueron detectados a las dos horas de incubación. Al realizar la lectura a las 24 horas de incubación, se redujo significativamente la tasa de falsos negativos, y se incrementaron la sensibilidad y la exactitud diagnóstica. En conclusión, el comportamiento de la prueba de ureasa ensayada sugiere que ésta es una herramienta altamente confiable y de bajo costo para el diagnóstico de la infección por H. pylori en individuos sometidos a endoscopia gastrointestinal