Molecular epidemiology of Shigella flexneri in a diarrhoea-endemic area of Lima, Peru.

A year-long community-based study of diarrhoeal diseases was conducted in Canto Grande, a periurban community in Lima, Peru. In 109 (34%) houses out of 323 that were visited, at least one individual was detected with shigellosis. The frequency of the 161 shigella isolates obtained was as follows: 117 S. flexneri (73%), 21 S. boydii (13%), 15 S. dysenteriae (9%), and 8 S. sonnei (5%). Using a non-radioactive ipaH gene probe as a molecular epidemiological tool, a total of 41 S. flexneri strains were shown to be distributed in 25 intra-family comparisons by pairs (icp). Further subdivision, based on a comparison of the serotype, plasmid profile, antibiotic resistances and ipaH hybridization patterns indicated that Group I, with 11 icp (44%), had strains that were identical. Group II with 8 icp (32%), had strains that were different and Group III with 6 icp (24%), had strains with the same serotype and identical ipaH profiles but with differences in other markers. This data indicates that a diversity of shigella clones circulated in this community resulting from both clonal spread and horizontal transfer of genetic elements. Furthermore, ipaH profiling of isolates can be used not only to differentiate between closely related shigella strains but also with other parameters, help to understand the dynamics of the generation of new clones of pathogenic bacteria.

Water cost and availability: key determinants of family hygiene in a Peruvian shantytown.

OBJECTIVES: This study was conducted to determine whether poor hygiene practices are owing to difficulty in getting enough water and/or to ignorance of sanitary principles. METHODS: In a water-scarce shantytown in Lima, Peru, we observed in 12-hour periods over 3 consecutive days the amount of water and soap used for personal and domestic activities in 53 families and the frequency with which direct fecal contamination of hands was interrupted by washing. We also surveyed women in a similar shantytown concerning their knowledge of hygiene to ascertain whether noncompliance was owing to ignorance. RESULTS: Three hundred fecal contamination events were registered, of which only 38 (13%) were interrupted by hand washing within 15 minutes. The mean 12-hour per capita amount of water and soap used by the families was low. More than 80% of the water stored by these families had fecal coliforms. Yet the level of knowledge concerning the importance of hand washing and other hygienic practices was high. CONCLUSIONS: In water-scarce areas, sanitary education programs probably will not change hygiene practices. In these areas, an adequate supply of water is essential for good hygiene.

Algunas características de la infección por Helicobacter pylori en el Perú / Various characteristics of Helicobacter pylori infection in Peru

En la presente serie, compuesta por 2011 pacientes estudiados, nuestras observaciones coinciden con lo reportado en otros países, en relación al porcentaje de hallazgo del H.pylory en los casos de gastritis crónica activa, úlcera p éptica gástrica, úlcera péptica duodenal y en la mucosa gástrica histológicamente normal. En el Perú, en pacientes con síntomas del tracto gastrointestinal superior, la infección por H. pylori se encuentra en porcentajes más elevados (84%) que lo reportado en naciones industrializadas. No observamos incremento de la infección con la edad, debido a que ésta, en nuestro medio, se adquiere en edades muy tempranas como hemos demostrado por la prueba de ELISA. La distribución ecológica de la bacteria, es igual en las tres regiones del Perú y sólo en as mujeres de nivel socioeconómico alto, la prevalencia de la infección es menor. El porcentaje de recurrencia después de tratamiento es superior al descrito en países industrializados

Algunas características de la infección por Helicobacter pylori en el Perú / Various characteristics of Helicobacter pylori infection in Peru

En la presente serie, compuesta por 2011 pacientes estudiados, nuestras observaciones coinciden con lo reportado en otros países, en relación al porcentaje de hallazgo del H.pylory en los casos de gastritis crónica activa, úlcera p éptica gástrica, úlcera péptica duodenal y en la mucosa gástrica histológicamente normal. En el Perú, en pacientes con síntomas del tracto gastrointestinal superior, la infección por H. pylori se encuentra en porcentajes más elevados (84%) que lo reportado en naciones industrializadas. No observamos incremento de la infección con la edad, debido a que ésta, en nuestro medio, se adquiere en edades muy tempranas como hemos demostrado por la prueba de ELISA. La distribución ecológica de la bacteria, es igual en las tres regiones del Perú y sólo en as mujeres de nivel socioeconómico alto, la prevalencia de la infección es menor. El porcentaje de recurrencia después de tratamiento es superior al descrito en países industrializados (AU)

Helicobacter pylori and progressive gastric pathology that predisposes to gastric cancer.

Evidence is presented suggesting that infection by Helicobacter pylori triggers and continuously contributes to the pathophysiology of progressive gastric changes that can ultimately lead to gastric cancer. In Peru, especially in population groups of low socioeconomic status, infection by H. pylori begins earlier in life and is more prevalent and persistent than in developed countries. The infection produces a destructive lesion of the mucinous surface epithelium which probably enables other aggressive luminal factors to cause further mucosal damage. As a consequence, active chronic gastritis appears. The gastritis is of the superficial type at the beginning but may progressively change to atrophic. Chronic atrophic gastritis is found more frequently and at a younger age in dyspeptic patients with low socioeconomic status--that is, in patients having higher prevalence of persistent infection by H. pylori since earlier in life. When chronic atrophic gastritis becomes severe and extensive, hypochlorhydria ensues. Hypochlorhydria favors the appearance of bacterial overgrowth, nitrites, and N-nitroso compounds in the gastric lumen. N-nitroso compounds, because of their mutagenic-carcinogenic properties, probably induce gastric premalignant lesions like intestinal metaplasia and dysplasia of the gastric mucosa. Oral bismuth therapy apparently reverses H. pylori-associated gastric dysplasia. It is proposed that future programs designed for the control of gastric cancer would be incomplete if they do not include further evaluation of the many effects of infection by H. pylori on the gastric mucosa and of cost-effective methods to eradicate the infection.

[Various characteristics of Helicobacter pylori infection in Perú]. / Algunas características de la infección por Helicobacter pylori en el Perú.

The rate of infection by Helicobacter pylori in peruvian dyspeptic patients (84%) is higher than that reported in symptomatic patients from developed countries. Helicobacter pylori infection did not increase with age. The ecological distribution is similar in the three different geographical regions of Peru. Only women of high economic status had significantly lower rates of Helicobacter pylori infection compared to all other groups. The recurrence rate after treatment is higher than that reported from developed countries.

Algunas características de la infección por Helicobacter pylori en el Perú. / [Various characteristics of Helicobacter pylori infection in Perú]

The rate of infection by Helicobacter pylori in peruvian dyspeptic patients (84

) is higher than that reported in symptomatic patients from developed countries. Helicobacter pylori infection did not increase with age. The ecological distribution is similar in the three different geographical regions of Peru. Only women of high economic status had significantly lower rates of Helicobacter pylori infection compared to all other groups. The recurrence rate after treatment is higher than that reported from developed countries.

In vitro and in vivo effects of three bismuth compounds on fermentation by colonic bacteria.

Three bismuth compounds (tripotassium dicitrate bismuthate, bismuth subsalicylate, and bismuth subnitrate) were tested in vitro and in vivo for their effect on fermentation by colonic bacteria. The studies in vitro were done with use of a technique designed to determine the effect of each one of the bismuth compounds on the fermentation of several stool samples that had been mixed with lactose as additional fermentable substrate (fermentation of lactose-enriched stools, FLES). The three bismuth compounds reduced FLES significantly in 47 (81%) of 58 of the stool samples used to test their effect. Bismuth subsalicylate, which reduced FLES in 10 of 10 stool samples, showed the greatest reduction (mean reduction, 74%; P less than .0001). The in vivo studies, done in six flatulent patients, showed significant reduction (P less than .01) of colonic fermentation of ingested raffinose by oral bismuth subnitrate given for 8 days.

Decreased gastric acid secretion and bacterial colonization of the stomach in severely malnourished Bangladeshi children.

To assess the effect of malnutrition on gastric acidity and gastric bacterial colonization, we studied 35 severely malnourished Bangladeshi children before (0 wk) and after (3 wk) they received nutritional rehabilitation for 3 wk. These results were compared with those obtained from a similarly examined group of 20 better-nourished Bangladeshi children. Gastric acid output, both basal and after betazole stimulation, was significantly lower in the malnourished group at 0 wk compared with the better-nourished children (p less than 0.01): basal 0.22 vs. 0.52 mEq HCl/h and stimulated 0.90 vs. 2.5 mEq HCl/h. Both the concentration of acid and the rate at which gastric juice was secreted were decreased in the malnourished group but serum gastrin levels were not significantly different. After 3 wk, the malnourished children had improved from 61% (+/- 9.0%; SD) to 81% (+/- 8.1%) of expected weight-for-height and were not significantly different than the better-nourished group (86% +/- 11%). Nevertheless, gastric acid concentration remained depressed in the 3-wk group, although the rate of gastric juice secretion equaled levels observed in the better-nourished group. None of the better-nourished children had detectable gram-negative bacterial colonization of their gastric juice. In contrast, 26 of 32 (81%) malnourished children at 0 wk were colonized--even after betazole stimulation, 11 of 33 (33%) gastric juice samples yielded viable organisms--suggesting that the decrease in gastric acid output greatly reduced the gastric acid barrier. Interestingly, only 9 of 20 (45%) better-nourished children had gastric juice with basal pH values below 4.0, suggesting that the gastric acid barrier may be an intermittent defense factor in Bangladeshi children.

Oral immunization of rabbits with enterotoxigenic Escherichia coli protects against intraintestinal challenge.

The development of a successful oral vaccine against enterotoxigenic Escherichia coli depends upon the identification of appropriate protective antigens which can be delivered effectively to intestinal mucosa. We have determined in a modified RITARD model the relative protection against intraintestinal challenge afforded by oral immunization with live enterotoxigenic E. coli carrying different candidate antigens. Studies were done with both wild-type strains and genetically manipulated strains of enterotoxigenic E. coli (parent strain E1392/75 2A) which carried plasmids containing intact heat-labile toxin (LT) gene sequences or various mutations of the LT genes. Immunizations were done by orogastric tube inoculation on days 0, 7, and 14; challenges were done on day 33. Protection against diarrhea with a homologous challenge was found to be 84 to 100% (P less than 0.01). Protection against diarrhea with challenges in which specific antigens could be tested included the following: (i) O and H antigens (O6:H16), 87 to 100% protection with different E. coli strains with identical O and H antigens (P less than 0.01) but no protection against a heterologous challenge; (ii) LT or the B subunit of LT only, approximately 50% protection (P less than 0.02). These findings suggest that O antigens are highly protective in this model but afford only serotype-specific protection and that the B subunit (with or without the A subunit) affords less protection but confers cross-protection against heterologous strains producing LT. This model should be useful in further defining appropriate protective antigens for candidate enterotoxigenic E. coli vaccine strains.

Campylobacter pilórico y nivel socio-económico / Campylobacter pyloricus and socio-economic level

El presente trabajo tiene por objeto determinar si existe alguna relación entre el nivel socio-económico (NSE) de pacientes y la colonización del estómago por el Campylobacter pilórico (CP). Estudiamos diversos aspectos de esta bacteria en dos grupos de pacientes de NSE diferente, nos pareció de inicio apreciar una aparente diferencia en relación a la colonización del estómago por esta bacteria. Hemos evaluado 256 pacientes examinados mediante esofagogastroduodenoscopía (Panendocopio Olympus GIF-K2) por presentar síntomas del tracto gastrointestinal superior. De ellos, 143 pertenecen al Hospital Arzobispo Loayza (38 varones y 105 mujeres) y 122 a la práctica privada de 3 de los autores (77 varones y 45 mujeres), con edades comprendidos entre 16 y 75 años (media de 45.5 años). En cada caso se tomó biopsias del antro gástrico (curvatura mayor y menor) las que fueron coloreadas con hematoxilina-eosina y con plata. Tomando en cuenta recomendaciones para clasificar el NSE de acuerdo a la procedencia los pacientes fueron considerados habitantes de: distritos nucleares, distitos intermedios y distritos periféricos. Los cálculos estadísticas han revelado que aunque de acuerdo a la procedencia, los grupos de pacientes del Hospital Arzobispo Loayza y de la práctica privada tuvieron un NSE significativamente diferente, la frecuencia de infección por CP en ellos no mostró diferencia estadísticamente significativa. Lo cual parecería indicar pues, que el distrito del cual procede un paciente con trastornos del tracto gastrointestinal no es factor determinante de infección por CP

Campylobacter pilórico, gastritis crónica, úlcera gástrica y úlcera duodenal / Pyloric campylobacter, chronic gastritis, gastric ulcer and duodenal ulcer

Diversos trabajos demuestram un elevado porcentaje de hallazgo del campylobacter pilórico en casos de gastritis crónica y úlcera péptica. Presentamos nuestra experiencia en 672 pacientes evaluados mediante esofagogastroduodenoscopía, por presentar síntomas del tracto gastrointestinal superior. Se utilizó el Panendoscopio Olympus GIF-k2 tomándose dos biopsias del antro gástrico. Los especimenes fueron sometidos a coloración con hematoxilinaeosina y con plata, métodos que nos han dado los mejores resultados diagnósticos. El diagnóstico de úlcera gástrica o duodenal se hizo sobre la base del hallazgo endoscópico y para el diagnóstico de gastritis crônica se consideró el criterio histológico. La gastritis se ha dividido en activa e inactica. Se ha cuantificado el daño mucinoso y el grado colonización bacteriana. Hemos encontrado a la bacteria en el 91.8% de pacientes con gastritis crónica activa, 72.7% con úlcera gástrica y 84.2% con úlcera duodenal. Nuestros resultados sosn concordantes con los de otros autores. Concluimos que el campylobacter pilórico no es un germen oportunista en el estómago, pues produce cuadro inflamatorio y daño celular mucinoso. Su presencia puede jugar algún rol en la etiopatogenia de la úlcera péptica y gastritis

Campylobacter pilórico y nivel socio-económico / Campylobacter pyloricus and socio-economic level

El presente trabajo tiene por objeto determinar si existe alguna relación entre el nivel socio-económico (NSE) de pacientes y la colonización del estómago por el Campylobacter pilórico (CP). Estudiamos diversos aspectos de esta bacteria en dos grupos de pacientes de NSE diferente, nos pareció de inicio apreciar una aparente diferencia en relación a la colonización del estómago por esta bacteria. Hemos evaluado 256 pacientes examinados mediante esofagogastroduodenoscopía (Panendocopio Olympus GIF-K2) por presentar síntomas del tracto gastrointestinal superior. De ellos, 143 pertenecen al Hospital Arzobispo Loayza (38 varones y 105 mujeres) y 122 a la práctica privada de 3 de los autores (77 varones y 45 mujeres), con edades comprendidos entre 16 y 75 años (media de 45.5 años). En cada caso se tomó biopsias del antro gástrico (curvatura mayor y menor) las que fueron coloreadas con hematoxilina-eosina y con plata. Tomando en cuenta recomendaciones para clasificar el NSE de acuerdo a la procedencia los pacientes fueron considerados habitantes de: distritos nucleares, distitos intermedios y distritos periféricos. Los cálculos estadísticas han revelado que aunque de acuerdo a la procedencia, los grupos de pacientes del Hospital Arzobispo Loayza y de la práctica privada tuvieron un NSE significativamente diferente, la frecuencia de infección por CP en ellos no mostró diferencia estadísticamente significativa. Lo cual parecería indicar pues, que el distrito del cual procede un paciente con trastornos del tracto gastrointestinal no es factor determinante de infección por CP (AU)

[Campylobacter pyloridis and socioeconomic levels]. / Campylobacter pilórico y nivel socio-económico.

The purpose of this study was to determine if there was any relationship between the socio-economic level of patients and the colonization of the stomach by Campylobacter pyloridis. We have studied 256 patients who underwent esophagogastroduodenoscopy because they had upper gastrointestinal symptoms of this group, 143 from Arzobispo Loayza Hospital (38 males and 105 females) and 122 from the private practice of three of the authors (77 males and 45 females). The ages ranged from 16 to 75 years (media 45.5 years). In each case biopsies of the antrum were taken and stained with hematoxylin-eosin and Warthin-Starry Silver Stein. We classified patients into 3 different groups based on where they lived: nuclear districts, intermediate districts, and peripheral districts. In Lima, the type of district from the patient strongly correlates with their socio-economic status. The hospital and private patients differed significantly in the distribution of which type of district their patients came from. In contrast there was a no marked similarity between these two patient groups in their rate of colonization by Campylobacter pyloridis. It appears that the socio-economic level of peruvian patients, presenting to clinic with symptomatic gastro-intestinal disease is not an important factor with pyloric campylobacter infection.

[Campylobacter pyloric, chronic gastritis, gastric ulcer and duodenal ulcer]. / Campylobacter pilórico, gastritis crónica, úlcera gástrica y úlcera duodenal.

After the initial report of Marshall and Warren, several publications have also demonstrated the presence of pyloric campylobacter in an elevated percentage of cases of chronic gastritis and peptic ulcer. We present our experience studying 672 patients examined by esophagogastroduodenoscopy after referral to clinical because of upper gastrointestinal symptoms. We used an Olympus GIF-K2 panendoscope taking two biopsies from the gastric antrum. Specimens were stained with hematoxilin-eosin and silver. In our experience these methods have given us the best results in detecting this bacteria. Diagnosis of gastric and duodenal ulcer was made by endoscopic criteria and chronic gastritis diagnosed by histology. Chronic gastritis was categorized into active and inactive based in the invasion of polymorphonuclear into mucosa. We have also quantitated damage of the mucin producing cells as well as the degree of bacterial colonization. We have found pyloric campylobacter in 91.8% of patients suffering from chronic active gastritis, 72.7% of patients with diagnosis of gastric ulcer and 84.2% of cases of duodenal ulcer. Our results agree with the ones reported by other authors. We conclude that pyloric campylobacter is not an opportunist microorganism within the stomach because it produces inflammatory changes as well as damage of the mucin producing cells. Its presence may play some role in the etiology of gastritis and peptic ulcer disease.

Campylobacter pilórico y nivel socio-económico. / [Campylobacter pyloridis and socioeconomic levels]

The purpose of this study was to determine if there was any relationship between the socio-economic level of patients and the colonization of the stomach by Campylobacter pyloridis. We have studied 256 patients who underwent esophagogastroduodenoscopy because they had upper gastrointestinal symptoms of this group, 143 from Arzobispo Loayza Hospital (38 males and 105 females) and 122 from the private practice of three of the authors (77 males and 45 females). The ages ranged from 16 to 75 years (media 45.5 years). In each case biopsies of the antrum were taken and stained with hematoxylin-eosin and Warthin-Starry Silver Stein. We classified patients into 3 different groups based on where they lived: nuclear districts, intermediate districts, and peripheral districts. In Lima, the type of district from the patient strongly correlates with their socio-economic status. The hospital and private patients differed significantly in the distribution of which type of district their patients came from. In contrast there was a no marked similarity between these two patient groups in their rate of colonization by Campylobacter pyloridis. It appears that the socio-economic level of peruvian patients, presenting to clinic with symptomatic gastro-intestinal disease is not an important factor with pyloric campylobacter infection.

Detección del Campylobacter pilórico en pacientes con enfermedades gastroduodenales / Detection of pyloric Campylobacter in patients with gastroduodenal diseases

Presentamos un estudio de 127 pacientes a quienes con fines diagnósticos se efectuó esofagogastroduodenoscopía. Se tomaron muestras de cepillado y biopsias del esófago, estómago y duodeno, que han sido examinadas por coloración con Gram, cultivo de cepillado y biopsia y estudio histológico de las biopsias con coloración con hematoxilina-eosina y plata con el fin de detectar la presencia de Campylobacter pilórico. En la gastritis crónica activa hemos hallado la bacteria en 91% de casos, en 73% en la úlcera péptica gástrica y en 84% en la úlcera péptica duodenal. Cuando se encuentra campylobacter en el antro, la distribución es igual en el cuerpo y cardias. Comparando los diferentes métodos que hemos empleado, los mejores resultados obtendos en forma decreciente, han sido con la coloración con plata, Gram, hematoxilina-eosina, cultivo de biopsia y cultivo de cepillado. En nuestra serie de estudio en algunos casos se ha hallado campylobacter en esófago y duodeno con la coloración con Gram y por cultivo no habiéndose detectado con las coloraciones de plata y hematoxilina-eosina, lo que sugiere que la contaminación procedente del estómago puede ser un problema para tomar muestras del esófago y duodeno al investigar la presencia de campylobacter pilórico

Detección del Campylobacter pilórico en pacientes con enfermedades gastroduodenales / Detection of pyloric Campylobacter in patients with gastroduodenal diseases

Presentamos un estudio de 127 pacientes a quienes con fines diagnósticos se efectuó esofagogastroduodenoscopía. Se tomaron muestras de cepillado y biopsias del esófago, estómago y duodeno, que han sido examinadas por coloración con Gram, cultivo de cepillado y biopsia y estudio histológico de las biopsias con coloración con hematoxilina-eosina y plata con el fin de detectar la presencia de Campylobacter pilórico. En la gastritis crónica activa hemos hallado la bacteria en 91% de casos, en 73% en la úlcera péptica gástrica y en 84% en la úlcera péptica duodenal. Cuando se encuentra campylobacter en el antro, la distribución es igual en el cuerpo y cardias. Comparando los diferentes métodos que hemos empleado, los mejores resultados obtendos en forma decreciente, han sido con la coloración con plata, Gram, hematoxilina-eosina, cultivo de biopsia y cultivo de cepillado. En nuestra serie de estudio en algunos casos se ha hallado campylobacter en esófago y duodeno con la coloración con Gram y por cultivo no habiéndose detectado con las coloraciones de plata y hematoxilina-eosina, lo que sugiere que la contaminación procedente del estómago puede ser un problema para tomar muestras del esófago y duodeno al investigar la presencia de campylobacter pilórico (AU)