Cytokine profile of patients with chronic immune thrombocytopenia affects platelet count recovery after Helicobacter pylori eradication.

Helicobacter pylori eradication induces platelet recovery in a subgroup of patients with chronic immune thrombocytopenia (cITP), but the mechanisms involved are still not understood. We aimed to evaluate the effect of H. pylori eradication on platelet response and to identify the associated serum cytokine profile in 95 patients with cITP. Serum cytokine concentrations were determined by enzyme-linked immunosorbent assay prior to and 6 months after H. pylori eradication. Remission of cITP was observed in 17 (28·8%) of 59 patients in whom the bacterium was eradicated. Six months after treatment, a significant reduction in the concentrations of T-helper (Th) 1 and Th17 cells and an increase in T regulatory (Treg) and Th2-cell commitment cytokines were observed in patients who recovered, but not in those whose platelet count did not recover. Patients who had a platelet response to eradication of the bacteria had higher pre-treatment serum levels of γ-interferon (IFNG, IFN-γ), transforming growth factor-ß (TGFB1, TGF-ß) and interleukin 17 (IL17A, IL-17) than patients who did not respond, but only higher pre-treatment TGFB1 levels was independently associated with platelet response. In conclusion, amelioration of cITP after eradication of H. pylori was linked to a more efficient suppression of Th1 and Th17 response and a more pronounced Treg cell response.

STAT3 polymorphism and Helicobacter pylori CagA strains with higher number of EPIYA-C segments independently increase the risk of gastric cancer.

BACKGROUND: Because to date there is no available study on STAT3 polymorphism and gastric cancer in Western populations and taking into account that Helicobacter pylori CagA EPIYA-C segment deregulates SHP-2/ERK-JAK/STAT3 pathways, we evaluated whether the two variables are independently associated with gastric cancer. METHODS: We included 1048 subjects: H. pylori-positive patients with gastric carcinoma (n = 232) and with gastritis (n = 275) and 541 blood donors. Data were analyzed using logistic regression model. RESULTS: The rs744166 polymorphic G allele (p = 0.01; OR = 1.76; 95 % CI = 1.44-2.70), and CagA-positive (OR = 12.80; 95 % CI = 5.58-19.86) status were independently associated with gastric cancer in comparison with blood donors. The rs744166 polymorphism (p = 0.001; OR = 1.64; 95 % CI = 1.16-2.31) and infection with H. pylori CagA-positive strains possessing higher number of EPIYA-C segments (p = 0.001; OR = 2.28; 95 % CI = 1.41-3.68) were independently associated with gastric cancer in comparison with gastritis. The association was stronger when host and bacterium genotypes were combined (p < 0.001; OR = 3.01; 95 % CI = 2.29-3.98). When stimulated with LPS (lipopolysaccharide) or Pam3Cys, peripheral mononuclear cells of healthy carriers of the rs744166 GG and AG genotypes expressed higher levels of STAT3 mRNA than those carrying AA genotype (p = 0.04 for both). The nuclear expression of phosphorylated p-STAT3 protein was significantly higher in the antral gastric tissue of carriers of rs744166 GG genotype than in carriers of AG and AA genotypes. CONCLUSIONS: Our study provides evidence that STAT3 rs744166 G allele and infection with CagA-positive H. pylori with higher number of EPIYA-C segments are independent risk factors for gastric cancer. The odds ratio of having gastric cancer was greater when bacterium and host high risk genotypes were combined.

Single nucleotide polymorphisms of Helicobacter pylori dupA that lead to premature stop codons.

BACKGROUND: The detection of the putative disease-specific Helicobacter pylori marker duodenal ulcer promoting gene A (dupA) is currently based on PCR detection of jhp0917 and jhp0918 that form the gene. However, mutations that lead to premature stop codons that split off the dupA leading to truncated products cannot be evaluated by PCR. METHODS: We directly sequence the complete dupA of 75 dupA-positive strains of H. pylori isolated from patients with gastritis (n = 26), duodenal ulcer (n = 29), and gastric carcinoma (n = 20), to search for frame-shifting mutations that lead to stop codon. RESULTS: Thirty-four strains had single nucleotide mutations in dupA that lead to premature stop codon creating smaller products than the predicted 1839 bp product and, for this reason, were considered as dupA-negative. Intact dupA was more frequently observed in strains isolated from duodenal ulcer patients (65.5%) than in patients with gastritis only (46.2%) or with gastric carcinoma (50%). In logistic analysis, the presence of the intact dupA independently associated with duodenal ulcer (OR = 5.06; 95% CI = 1.22-20.96, p = .02). CONCLUSION: We propose the primer walking methodology as a simple technique to sequence the gene. When we considered as dupA-positive only those strains that carry dupA gene without premature stop codons, the gene was associated with duodenal ulcer and, therefore, can be used as a marker for this disease in our population.

Natural history of Helicobacter pylori infection in childhood: eight-year follow-up cohort study in an urban community in northeast of Brazil.

BACKGROUND: Helicobacter pylori infection is acquired predominantly in childhood. There is also evidence that children loss the infection. Therefore, factors that account for children remain infected need to be investigated because once established the infection persists throughout the life unless treated. METHODS: This study aimed to evaluate the H. pylori infection in children of a low-income community at baseline and 8years later to determine the predictor factors linked to the maintenance, acquisition, and loss of the infection using regression models of generalized estimating equations. H. pylori status was determined by (13) C-urea breath test. RESULTS: Data from 37.7% (133/353) of the children were available. No difference between the characteristics of the included and nonincluded children was observed. The prevalence of infection increased from 53.4 to 64.7%. Thirty-nine children (29.3%) remained noninfected, 47.4% remained infected, 17.3% became infected, and 6.0% lost the infection. Factors associated with to remain infected compared with to remain noninfected included the age, increased number of children in the household, and the use of well water instead of municipal water. The acquisition of the infection was associated with the male gender. CONCLUSION: Factors linked to remain and to gain H. pylori infection in a poor region were increased number of children in the household and the male gender. Also, the acquisition rates were higher than the loss rates, which lead to an increase in the infection prevalence with age.

Higher frequency of cagA EPIYA-C phosphorylation sites in H. pylori strains from first-degree relatives of gastric cancer patients.

BACKGROUND: To evaluate the prevalence of more virulent H. pylori genotypes in relatives of gastric cancer patients and in patients without family histories of gastric cancer. METHODS: We evaluated prospectively the prevalence of the infection by more virulent H. pylori strains in 60 relatives of gastric cancer patients comparing the results with those obtained from 49 patients without family histories of gastric cancer. H. pylori status was determined by the urease test, histology and presence of H. pylori ureA. The cytotoxin associated gene (cagA), the cagA-EPIYA and vacuolating cytotoxin gene (vacA) were typed by PCR and the cagA EPIYA typing was confirmed by sequencing. RESULTS: The gastric cancer relatives were significant and independently more frequently colonized by H. pylori strains with higher numbers of CagA-EPIYA-C segments (OR = 4.23, 95%CI = 1.53-11.69) and with the most virulent s1m1 vacA genotype (OR = 2.80, 95%CI = 1.04-7.51). Higher numbers of EPIYA-C segments were associated with increased gastric corpus inflammation, foveolar hyperplasia and atrophy. Infection by s1m1 vacA genotype was associated with increased antral and corpus gastritis. CONCLUSIONS: We demonstrated that relatives of gastric cancer patients are more frequently colonized by the most virulent H. pylori cagA and vacA genotypes, which may contribute to increase the risk of gastric cancer.

dupA polymorphisms and risk of Helicobacter pylori-associated diseases.

The dupA of Helicobacter pylori has been suggested as a virulence marker associated with the development of duodenal ulcer disease. However, the studies performed in different geographical areas have shown that there are variations in the prevalence of dupA and its association with H. pylori clinical outcomes. Our group did not observe associations between the presence of dupA and H. pylori clinical outcomes in Brazil. On the other hand, we observed 2 mutations in the sequence of dupA that lead to stop codons: a deletion of an adenine at position 1311 and an insertion of an adenine at position 1426 of the gene. Our aim was to evaluate associations of the presence of dupA with duodenal ulcer and gastric cancer, considering dupA-positive only those H. pylori strains that do not have the mutations in the gene sequence. We also evaluated the effect of infection with a strain carrying an intact dupA on the gastric mucosa histology and IL-8 gastric levels. Colonization with strains that had the intact dupA was negatively associated with gastric carcinoma (p=0.001, OR=0.32, 95% CI=0.16-0.66). The presence of dupA was also associated with an increased degree of antral mucosa inflammation (p=0.01) and with decreased corpus atrophy (p<0.01) as well as with increased gastric mucosa IL-8 levels (p=0.04). In conclusion, the infection with a H. pylori strain containing the dupA without the stop codon polymorphisms is associated with a lower risk of development of gastric carcinoma in Brazilian subjects.

Higher number of Helicobacter pylori CagA EPIYA C phosphorylation sites increases the risk of gastric cancer, but not duodenal ulcer.

BACKGROUND: Helicobacter pylori infection is one of the most common infections worldwide and is associated with gastric cancer and peptic ulcer. Bacterial virulence factors such as CagA have been shown to increase the risk of both diseases. Studies have suggested a causal role for CagA EPIYA polymorphisms in gastric carcinogenesis, and it has been shown to be geographically diverse. We studied associations between H. pylori CagA EPIYA patterns and gastric cancer and duodenal ulcer, in an ethnically admixed Western population from Brazil. CagA EPIYA was determined by PCR and confirmed by sequencing. A total of 436 patients were included, being 188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis. RESULTS: The number of EPIYA C segments was significantly associated with the increased risk of gastric carcinoma (OR=3.08, 95% CI=1.74 to 5.45, p<10-3) even after adjustment for age and gender. Higher number of EPIYA C segments was also associated with gastric atrophy (p=0.04) and intestinal metaplasia (p=0.007). Furthermore, patients infected by cagA strains possessing more than one EPIYA C segment showed decreased serum levels of pepsinogen I in comparison with those infected by strains containing one or less EPIYA C repeat. Otherwise, the number of EPIYA C segments did not associate with duodenal ulcer. CONCLUSIONS: Our results demonstrate that infection with H. pylori strains harbouring more than one CagA EPIYA C motif was clearly associated with gastric cancer, but not with duodenal ulcer.Higher number of EPIYA C segments was also associated with gastric precancerous lesions as demonstrated by histological gastric atrophic and metaplastic changes and decreased serum levels of pepsinogen I.

Younger siblings play a major role in Helicobacter pylori transmission among children from a low-income community in the Northeast of Brazil.

BACKGROUND AND AIMS: To further evaluate intrafamilial transmission of H. pylori infection during childhood, we investigated the prevalence of H. pylori in family members from a poor H. pylori high-prevalence urban community in the Northeast of Brazil. METHODS: H. pylori infection was investigated in 570 members of 128 households, by (13) C-urea breath test in children and by ELISA in mothers and other adult relatives. RESULTS: The overall prevalence of H. pylori infection (376/570) increased with age (p < .001) and ranged from 28.9%, in children aged 6 months to 5 years, to 82% in adults over 40 years. An H. pylori positive mother and the number of infected siblings are independent risk factors for childhood H. pylori infection (OR = 2.2, 95% CI = 1.0-4.6 and OR = 4.3, 95% CI = 2.3-8.1, respectively) The number of siblings, number of younger siblings, and number of infected younger siblings were also associated with the infection in the univariate analysis. The number of infected younger siblings remained independently associated with the infection (p = .000), even after controlling for all the above cited variables, in addition to the H. pylori status of siblings and mothers, age, number of people per room, and number of children in the household. CONCLUSION: The transmission of H. pylori occurs from infected mothers to their offspring and among siblings, notably from younger siblings to the older ones.

Lack of association between Helicobacter pylori infection with dupA-positive strains and gastroduodenal diseases in Brazilian patients.

Duodenal ulcer-promoting gene (dupA) was recently described as a new putative Helicobacter pylori virulence marker associated with an increased risk for duodenal ulcer and reduced risk for gastric carcinoma in Japan and Korea. Since differences regarding the association among H. pylori markers and H. pylori-associated diseases have been demonstrated around the world, we evaluated the presence of the gene in 482 strains from Brazilian children (34 with duodenal ulcer and 97 with gastritis) and adults (126 with duodenal ulcer, 144 with gastritis and 81 with gastric carcinoma) by PCR using the described primers and an additional set of primers based on Brazilian strain sequences. The results were confirmed by sequencing. The presence of cagA was investigated by PCR and also included in the analysis. dupA was present in 445 (92.32%) and absent in 29 (6.02%) strains. All samples from children with and without duodenal ulcer were dupA-positive (p=1.0). No association was observed among the strains from adults with gastritis (92.36%), duodenal ulcer (87.30%, p=0.30) and gastric carcinoma (87.65%, p=0.31). Conversely, cagA-positve status remained independently associated with duodenal ulcer (children: odds ratios (OR)=5.58, 95% confidence intervals (CI)=1.67-18.50; adults: OR=3.33, 95% CI=2.14-5.19) and gastric carcinoma (OR=6.58, 95% CI=3.51-12.30) in multivariate analyses. The presence of dupA was significantly higher in strains from children than in those from adults (p=0.01). In conclusion, dupA is highly frequent and not associated with H. pylori-associated diseases in both Brazilian adults and children, which points to regional differences in the distribution of the gene.

Cytokine expression profile over time in severely burned pediatric patients.

A severe burn leads to hypermetabolism and catabolism resulting in compromised function and structure of essential organs. The massive release of cytokines is implicated in this hypermetabolic response. The aim of the present study was to compare cytokine expression profiles from severely burned children without signs of infections or inhalation injury (n = 19) to the cytokine profiles from normal, noninfected, nonburned children (n = 14). The Bio-Plex suspension array system was used to measure the concentration of 17 cytokines. The expression of proinflammatory and anti-inflammatory cytokines was maximal during the first week after thermal injury. Significant increases were measured for 15 mediators during the first week after thermal injury: interleukin (IL) 1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 p70, IL-13, IL-17, interferon gamma, monocyte chemoattractant protein 1, macrophage inflammatory protein 1beta, and granulocyte colony-stimulating factor (P < 0.05). Granulocyte-macrophage colony-stimulating factor was significantly increased during the second week after burn (P < 0.05). Within 5 weeks, the serum concentrations of most cytokines decreased, approaching normal levels. When compared with the cytokine levels measured in normal children, a total of 16 cytokines were significantly altered (P < 0.05). After severe burn, a specific cytokine expression profile is observed in patients without complications such as inhalation injury or sepsis. The cytokine concentrations decrease during 5 weeks after burn but remain elevated over nonburned values. Furthermore, the elevation in most serum cytokine levels during the first week after burn may indicate a potential window of opportunity for therapeutic intervention.

History of breastfeeding and Helicobacter pylori infection in children: results of a community-based study from northeastern Brazil.

The aim of this study was to evaluate the role of breastfeeding and the infection status of the mother in the acquisition of Helicobacter pylori infection in a poor urban community in northeastern Brazil. Helicobacter pylori status was evaluated by 13C-urea breath test in individuals under the age of 14 years and by ELISA in the mothers. The prevalence of H. pylori infection was 55.8% (197/353) in the children and it increased with age (P<0.0001). Of the children in whom breastfeeding status was known, 93.2% (316/339) were breastfed. The H. pylori prevalence did not differ between breastfed and never breastfed children (55% vs. 52%) even when children were breastfed for >6 months. The prevalence of infection was much higher in children whose mothers were H. pylori infected than in children whose mothers were not infected, resulting in a crude odds ratio (OR) of 3.11 (95% CI 1.57-6.19) and 2.40 after adjustment for potential confounders (95% CI 1.12-5.15). This study suggests that breastfeeding does not protect against acquisition of H. pylori in northeastern Brazil; conversely, an infected mother may have an important role in transmission of the disease to the child.

Helicobacter pylori infection in adults from a poor urban community in northeastern Brazil: demographic, lifestyle and environmental factors.

We investigated the prevalence and the risk factors for infection with Helicobacter pylori in a randomly-selected population of adults from a low-income community in Northeastern Brazil. Helicobacter pylori infection was determined by ELISA. Risk factors were assessed using a structured interview. Two hundred and four individuals were included in the study, including 49 males and 155 females, ranging from 18 to 80 years old. Overall, 165 of 204 participants (80%) were H. pylori positive, without significant gender differences (p= 0.49). The infection rate was of 84.7% in subjects 18 to 30 years of age, increasing to 92% in subjects 46-60 years old. Above 60 years old, the prevalence decreased slightly. As a whole, the prevalence of infection did not increase significantly (p=0.147) with age. There were no significant differences in the prevalence of H. pylori infection, when patients were classified by age, smoking habit, educational level, alcohol consumption, the number of persons per room, the number of children per household, the number of adults per household, cup-sharing, household pets, toilet location, number of persons per bed and medical history of antibiotic and raw vegetable ingestion. In conclusion, no risk factors associated with infection was found in these adults, suggesting that the infection, even in a poor population, may be acquired predominantly during childhood; the relatively high prevalence that we observed may be more due to a cohort effect than to acquisition of infection during adulthood.

Prevalence of Helicobacter pylori infection in Fortaleza, Northeastern Brazil.

The prevalence of Helicobacter pylori infection was assessed in a randomly selected sample of individuals from low-income community in Fortaleza, Northeastern Brazil. Overall, 384 out of 610 participants (62.9%) were H. pylori positive. A 47.5% infection rate was found in subjects aged six months to 10 years old, increased to 73.3% in subjects aged 11-20 years and then continued to increase with age reaching up to 87% in those over 60 years old. After this age group, the prevalence decreased slightly. The prevalence of infection increased significantly with age (p<0.0001).

Unintended consequences of Helicobacter pylori infection in children in developing countries: iron deficiency, diarrhea, and growth retardation.

Helicobacter pylori infection is predominantly acquired early in life. The prevalence of the infection in childhood is low in developed countries, whereas in developing countries most children are infected by 10 y of age. In poor resource settings, where malnutrition, parasitic/enteropathogen and H. pylori infection co-exist in young children, H. pylori might have potentially more diverse clinical outcomes. This paper reviews the impact of childhood H. pylori infection in developing countries that should now be the urgent focus of future research. The extra-gastric manifestations in early H. pylori infection in infants in poor resource settings might be a consequence of the infection associated initial hypochlorhydria. The potential role of H. pylori infection on iron deficiency, growth impairment, diarrheal disease, malabsorption and cognitive function is discussed in this review.

IL2-330G polymorphic allele is associated with decreased risk of Helicobacter pylori infection in adulthood.

We evaluated whether polymorphisms in genes coding molecules linked to the innate and adaptive immune response are associated with susceptibility to Helicobacter pylori infection. IL1B-511C-->T, IL1B-31T-->C, IL1RN allele 2, IL2-330T-->G, TNFA-307G-->A, TLR2Arg677Trp, TLR2Arg753Gln, TLR4Asp299Gly, and TLR5(392STOP) polymorphisms were determined in 541 blood donors. IL2-330T-->G allele carriers had a decreased H. pylori infection risk (OR=0.63, 95% CI=0.43-0.93) after adjustment for demographic and environmental factors. Hence, we investigated whether the polymorphism is functional by evaluating IL-2 serum concentration in 150 blood donors and 100 children. IL-2 pro-inflammatory and anti-inflammatory properties were indirectly investigated by determining serum IFN-gamma and IL-10/TGF-beta levels. The polymorphism was associated with increased mean IL-2 levels in H. pylori-positive adults (2.65 pg/mL vs. 7.78 pg/mL) and children (4.19 pg/mL vs. 8.03 pg/mL). Increased IL-2 was associated with pro-inflammatory activity in adults (IFN-gamma=18.61 pg/mL vs. 25.71 pg/mL), and with anti-inflammatory activity in children (IL-10=6.99 vs. 14.17 pg/mL, TGF-beta=45.88 vs. 93.44 pg/mL) (p<10(-3) for all). In conclusion, in the context of H. pylori infection, IL2-330 T-->G polymorphism is functional and is associated with decreased risk of infection in adults.

Helicobacter pylori colonization among children up to 6 years: results of a community-based study from Northeastern Brazil.

AIM: To determine the prevalence and risk factors associated with Helicobacter pylori infection among children up to 6 years. METHODS: Cross-sectional study carried out in a poor urban community in Fortaleza Northeast Brazil. A standardized questionnaire was applied. Helicobacter pylori status was evaluated by (13)C-urea breath test ((13)C-UBT) in children up to 48 months and by ELISA in the mothers. Sera were assayed by the Cobas Core anti-H. pylori IgG EIA. RESULTS: The overall prevalence of H. pylori infection was 40% (88/217), 41% (46/112) boys and 40% (42/105) girls were infected. The prevalence rate of infection by H. pylori increased significantly with age, from 29% (27/93) in the youngest group (3 months to 2 years) to 59% (35/59) in the oldest group (6 years), (p < 0.001). There was no significant difference in the prevalence of infection between gender, height and weight adjusted for age, history of breastfeeding, mother's education, number of people per room, number of people per bed, smoking habit of the mother and children's history of antibiotic intake. A significant difference was found in the prevalence of H. pylori infection and H. pylori status of mother (p = 0.02; odds ratio (OR) 2.98; 95% confidence interval (CI): 1.19-7.46) that remained significant after adjustment for covariates in multivariate analysis (p = 0.012; OR 4.65; 95%CI: 1.39-15.58). CONCLUSIONS: This study shows that children living in low socioeconomic status and poor hygienic conditions are infected very early in childhood. It identifies age and H. pylori positive mother as independent risk factors for infection.

Gastric epithelial cell proliferation and cagA status in Helicobacter pylori gastritis at different gastric sites.

OBJECTIVE: Helicobacter pylori infection causes hyperproliferation which is believed to predispose to the development of gastric carcinoma. The aim of this study was to analyze epithelial cell proliferation topographically in H. pylori gastritis in relationship to cagA status. MATERIAL AND METHODS: The proliferative index (PI: Ki-67-labeled nuclei/total number of foveolar nuclei) was determined in gastric mucosa biopsies taken at the antrum (lesser and greater curvatures), incisura, and corpus (greater curvature) from 78 patients with H. pylori gastritis and 20 H. pylori-negative patients. H. pylori and cagA status were determined by polymerase chain reaction (PCR) and serology. RESULTS: PIs were significantly higher in H. pylori- and cagA-positive patients, in comparison with H. pylori- and cagA-negative patients, at all sites (p

Immunoblotting for the serodiagnosis of Helicobacter pylori infection in Brazilian patients with and without gastric carcinoma.

We evaluated the performance of a commercial immunoblotting in the serodiagnosis of Helicobacter pylori infection in Brazilian patients. The presence of anti-H. pylori antibodies was also investigated in a group of 20 duodenal ulcer patients after successful treatment. One hundred and ninety one patients were studied. Among the 164 infected patients, 46 had gastric carcinoma. The duodenal ulcer patients were treated with antimicrobial drugs and the eradication of the microorganism was confirmed in all of them one month after the end of the treatment by the 13C-urea breath test. Sera were assayed for H. pylori antibodies using the Helicoblot 2.0 (Genelabs Diagnostics, Singapore). The sensitivity, specificity, positive, and negative predictive values of the test were 93.9%, 92.6%, 98.7%, and 71.4%, respectively. The sensitivity of the test was similar in patients with (93.5%) and without (95.7%) gastric carcinoma. Twenty-four months after the end of the treatment, the band of 116 kDa was still detected in one of the patients. In conclusion, the Helicoblot 2.0 is an accurate test to diagnose H. pylori infection and although it can not be employed to monitor the bacterium eradication, it may be useful for diagnosing past infection, especially in gastric carcinoma patients.

Helicobacter pylori infection in adults from a poor urban community in northeastern Brazil: demographic, lifestyle and environmental factors

We investigated the prevalence and the risk factors for infection with Helicobacter pylori in a randomly-selected population of adults from a low-income community in Northeastern Brazil. Helicobacter pylori infection was determined by ELISA. Risk factors were assessed using a structured interview. Two hundred and four individuals were included in the study, including 49 males and 155 females, ranging from 18 to 80 years old. Overall, 165 of 204 participants (80 percent) were H. pylori positive, without significant gender differences (p= 0.49). The infection rate was of 84.7 percent in subjects 18 to 30 years of age, increasing to 92 percent in subjects 46-60 years old. Above 60 years old, the prevalence decreased slightly. As a whole, the prevalence of infection did not increase significantly (p=0.147) with age. There were no significant differences in the prevalence of H. pylori infection, when patients were classified by age, smoking habit, educational level, alcohol consumption, the number of persons per room, the number of children per household, the number of adults per household, cup-sharing, household pets, toilet location, number of persons per bed and medical history of antibiotic and raw vegetable ingestion. In conclusion, no risk factors associated with infection was found in these adults, suggesting that the infection, even in a poor population, may be acquired predominantly during childhood; the relatively high prevalence that we observed may be more due to a cohort effect than to acquisition of infection during adulthood.

Prevalence of Helicobacter pylori infection in Fortaleza, Northeastern Brazil

A prevalência da infecção pelo Helicobacter pylori foi avaliada em amostra randomizada de indivíduos de uma comunidade urbana de baixa renda em Fortaleza, Estado do Ceará. O H. pylori foi detectado em 384 (62.9 por cento) dos 610 participantes. A taxa de infecção foi de 47.5 por cento em indivíduos com seis meses a 10 anos de idade, aumentou para 73.3 por cento entre indivíduos com 11 a 20 anos, e continuou a aumentar com a idade, atingindo 87 por cento naqueles com aproximadamente 60 anos. Após essa idade, a prevalência diminuiu discretamente. A prevalência da infecção aumentou significantemente com a idade (p<0.0001).