RESUMEN
Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.
Asunto(s)
Anticuerpos Antibacterianos/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Infecciones por Helicobacter/diagnóstico , Helicobacter pylori/inmunología , Gastropatías/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Medios de Cultivo , Femenino , Gastritis/microbiología , Gastritis/patología , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/clasificación , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Humanos , Inmunoglobulina G/sangre , Jamaica/epidemiología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Gastropatías/epidemiología , Gastropatías/patología , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/patología , Ureasa/metabolismoRESUMEN
Across populations of children, Helicobacter pylori prevalence ranges from under 10% to over 80%. Low prevalence occurs in the U.S., Canada, and northern and western Europe; high prevalence occurs in India, Africa, Latin America, and eastern Europe. Risk factors include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; however, it is consistently associated with antral gastritis, although its clinical significance is unclear. Duodenal ulcers associated with H. pylori are seldom seen in children under 10 years of age. H. pylori-infected children demonstrate a chronic, macrophagic, and monocytic inflammatory cell infiltrate and a lack of neutrophils, as compared with the response observed in adults. The effect of H. pylori infection on acid secretion in children remains poorly defined. The events that occur during H. pylori colonization in children should be studied more thoroughly and should include urease activity, motility, chemotaxis, adherence, and downregulation of the host response. The importance of virulence determinants described as relevant for disease during H. pylori infection has not been extensively studied in children. Highly sensitive and specific methods for the detection of H. pylori in children are needed, especially in younger pediatric populations in which colonization is in its early phases. Criteria for the use of eradication treatment in H. pylori-infected children need to be established. Multicenter pediatric studies should focus on the identification of risk factors, which can be used as prognostic indicators for the development of gastroduodenal disease later in life.
Asunto(s)
Protección a la Infancia , Infecciones por Helicobacter , Niño , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/patología , Infecciones por Helicobacter/terapia , Helicobacter pylori , HumanosRESUMEN
We describe the clinical characteristics of inflammatory bowel disease (IBD) African-American compared with non-African-American children. We identified 172 children with IBD; forty-nine (29%) were African-American. Median symptom duration before IBD diagnosis in African-American children (6 months) was shorter than that of non-African-American children (10 months). The most frequent presenting symptom was hematochezia (ulcerative colitis) and abdominal pain (Crohn's disease) in both racial groups. The estimated incidence of Crohn's disease in African-Americans ranged from 7 per 100,000 to 12 per 100,000, whereas the observed incidence in those with ulcerative colitis was between 5 and 7 per 100,000 during the 10 years of the study. Our pilot study suggests that IBD may be more common in African-American children than previously reported. Prospective population-based studies would be useful to determine whether inheritable factors linked with ethnicity are associated with IBD.