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Biomedical subjects

D Y Graham

Publications and source records attributed to D Y Graham.

At least 271 records · Page 15Linked to original sources
PubMed1996

Culture of Helicobacter pylori: effect of preimmersion of biopsy forceps in formalin.

BACKGROUND: Treatment of antibiotic-resistant Helicobacter pylori should be based on bacterial sensitivity testing that requires the ability to isolate the bacterium from gastric mucosal biopsies. The aim of this study was to determine whether the yield for detecting H. pylori infection by culture is reduced by immersion of biopsy forceps in formalin prior to obtaining the specimen. MATERIALS AND METHODS: Gastric antral mucosal biopsies (100 specimens) from 50 patients were obtained for culture of H. pylori. An antral biopsy was taken for culture, and with the same forceps a biopsy was taken for histological examination. The biopsy specimen was removed by shaking, whereas the forceps was immersed in 10% buffered formalin for the histological investigation. The forceps was then used without rinsing to obtain a second specimen for culture from an area adjacent to the first site. H. pylori status was determined by histological assessment with the Genta stain and a rapid urease test. RESULTS: Fifty patients with H. pylori infection documented by histological inquiry and positive rapid urease testing entered the study; 29 had duodenal ulcers, 5 had gastric ulcers, 1 had mucosal associated lymphoid tissue (MALT) lymphoma, and 15 were without ulcer disease. The results of culture both before and after immersion in formalin were identical. One patient had both cultures negative; the sensitivity of culture for detection of H. pylori infection was 98% (95% confidence interval = 93%-100%). CONCLUSION: Preimmersion of biopsy forceps in formalin does not adversely affect the ability to culture H. pylori.

Bacteriological Techniques↗
PubMed1996

Helicobacter pylori and socioeconomic factors in Russia.

BACKGROUND: The factors influencing the acquisition and prevalence of Helicobacter pylori infection remain incompletely understood. In Russia, the demographic and socioeconomic factors are relatively similar, allowing investigation of risk factors that might not be identifiable in a more diverse population. MATERIALS AND METHODS: Sero-prevalence of H. pylori infection was studied in 520 asymptomatic individuals between the ages of 1 and 75 years, residing in St. Petersburg, Russia. Forty-four children lived in orphanages or communal apartments. Demographic information and socioeconomic factors were evaluated, including educational level, income, and living conditions. Helicobacter pylori status was evaluated by using an enzyme-linked immunosorbent assay for anti-H. pylori IgG. RESULTS: The prevalence of H. pylori infection was 44% in children and 88% in adults (P < .001). In adults, H. pylori prevalence was independent of socioeconomic factors. The crude and the age-adjusted odds ratios (ORs) in children showed an inverse correlation between the mother's educational level and H. pylori seropositivity [e.g., OR, 1.8; (95% confidence interval (CI) = 1-3.2] for children whose mothers completed only 8 to 10 years of school compared to children whose mothers completed university. Overcrowding in childhood also was associated with increased H. pylori prevalence. Children from orphanages and communal apartments had the highest crowding index and also were at the greatest risk for H. pylori acquisition (age-adjusted OR, 2.1; 95% CI = 1.2-2.5). CONCLUSIONS: The prevalence of H. pylori infection in Russia correlated with socioeconomic factors, suggesting there are differences sufficient to affect H. pylori transmission. The prevalence of H. pylori infection during childhood forms the basis for the variances in prevalence among populations.

Adolescent↗
PubMed1996

Is antrum or corpus the best site for culture of Helicobacter pylori?

BACKGROUND: Isolating Helicobacter pylori on culture media and performing antibiotic susceptibility testing is potentially the most useful tool for guiding antibiotic therapy, especially when antimicrobial resistance is suspected. The aim of this study was to determine whether the yield of H. pylori culture was related to the site from which the gastric specimen was obtained either before or after therapy. METHODS: Gastric mucosal biopsies from the antrum and the corpus of the stomach were cultured. H. pylori status was determined by histological assessment using the Genta stain. RESULTS: Fifty-two patients with documented H. pylori infection were studied: Twenty-three were tested before antibiotic therapy and 29 after therapy had failed. In 47 patients (90%), both antral and corpus culture specimens were positive. In 5 patients (10%), only one site was positive, with three false-negative antral and two false negative corpus cultures. The overall sensitivity of culture in detecting H. pylori infection was 95% (95% confidence interval = 89-98%) and was not significantly different for the antrum or corpus, either before or after therapy. CONCLUSION: Culture of gastric biopsies from either the antrum or the corpus has an excellent diagnostic yield even in patients who failed antimicrobial therapy.

Anti-Bacterial Agents↗
PubMed1996

Presence of the cagA gene in the majority of Helicobacter pylori strains is independent of whether the individual has duodenal ulcer or asymptomatic gastritis.

BACKGROUND: Helicobacter pylori infection presents as many different diseases, including asymptomatic gastritis, peptic ulcer disease, and gastric cancer. Although the virulence factor(s) responsible for different H. pylori-related diseases have not been identified, several candidate genes are being investigated for such an association. The polymerase chain reaction (PCR) frequently is used to assess the presence of genetic factors associated with pathogenesis of disease; the cagA gene and its product have been postulated to have a disease-specific relationship to peptic ulcer and gastric cancer because of differential expression in these diseases compared to histological gastritis alone. MATERIALS AND METHODS: Genomic DNA was amplified by PCR, using synthetic oligonucleotide primers to the cagA gene to determine the prevalence of the cagA gene in 60 H. pylori isolates obtained from well-documented duodenal ulcer or asymptomatic gastritis patients (30 each). Results were confirmed by hybridization with a 1.4-Kb cagA probe. RESULTS: The expected PCR product was obtained in 90% of isolates from duodenal ulcer patients, compared to 70% of isolates from individuals with asymptomatic gastritis. The PCR products were polymorphic in size, suggesting cagA gene sequence differences among isolates. Evaluation for the presence of the cagA gene by hybridization with a 1.4-Kb cagA probe showed a homologous product in 29 of 30 strains [96.7%; 95% confidence interval (CI) = 83-100%] from duodenal ulcer patients versus 25 of 30 strains (83.3%; 95% CI = 65-94%) obtained from individuals with asymptomatic gastritis (p = 0.19). CONCLUSIONS: The high prevalence of the cagA gene in asymptomatic gastritis suggests that it will not prove to be a useful marker to distinguish more virulent or disease-specific H. pylori strains. The genetic heterogeneity among H. pylori strains makes PCR an unwise choice as the single method to determine prevalence of a putative virulence factor. In evaluation of the prevalence of a gene or genetic factor in a population of H. pylori, hybridization with extended probes might be important to ensure that the results are representative of the organism's genotype.

Adult↗
PubMed1996

Twenty-minute fasting version of the US 13C-urea breath test for the diagnosis of H. pylori infection.

BACKGROUND: In large-scale multi-center clinical trials, the US 13C-urea breath test (UBT) has proven to have a sensitivity and specificity of approximately 95%. Ingestion of a meal to delay gastric emptying has advantages of increasing the level of signal as well as prolonging the duration of significantly increased 13C excretion, at the expense of requiring 40 to 60 minutes to complete the test. Our aim was to explore the utility of the 13C-UBT with a total duration of 30 minutes or less. METHODS: After a baseline breath sample was obtained, 125 mg of 13C-urea was given in 100 ml of water, and additional breath samples were taken after 20 and 30 minutes. The results of the UBT were compared to histological assessment, culture, and the rapid urease test. 13C-UBTs were carried out on normal volunteers who underwent gastroscopy during which six mucosal biopsies were taken. Three biopsies were for histological evaluation (Genta stain), two for culture, and one was for agar gel rapid urease testing. The UBT was conducted 2 to 3 days either before or after the endoscopic procedure. RESULTS: The cutoff value for a positive UBT was enrichment of 2.4 delta/1000 (delta over baseline). Of the 66 tests, 51/1000 were Helicobacter pylori-positive. There were no false positive UBTs and only two false negative UBTs at 20 minutes (sensitivity, 96%; specificity, 100%). At 30 minutes, one other UBT was false negative (gray zone of 2.36/1000) (sensitivity, 94%; specificity, 100%). CONCLUSION: These results suggest that omission of the meal and shortening the duration of the US 13C-UBT to 20 minutes still may maintain excellent specificity and sensitivity of the test.

Adult↗
PubMed1996

Helicobacter pylori infection, gastritis, and the temperature of choice for hot drinks.

BACKGROUND: The role of the temperature of the diet as a potential etiological factor for gastritis or peptic ulcer disease has been postulated since the beginning of the century. Animal studies have demonstrated damage to gastric mucosa caused by hot water at 60 to 80 degrees C. In the pre-Helicobacter pylori era it was reported that the majority of ulcer patients preferred hot drinks. It also was reported that the temperature of choice for drinks increased with severity of histological grade of gastritis. We evaluated the association between the preferred temperature of hot drinks and the presence of H. pylori infection. METHODS: We tested the temperature of choice for hot drinking liquids among 12 H. pylori-negative and 43 H. pylori-positive volunteers. We also compared the effect of H. pylori therapy on hot drink temperature preference and, in 32 individuals, whether there was a relation between temperature and the degree of gastric atrophy. RESULTS: There was no difference in the preferred temperature for hot drinks between those volunteers with and without H. pylori infection (63.4 degrees +/- 6 degrees C compared to 61.3 degrees +/- 7 degrees C, respectively) (mean +/- 1 SD, p = .3). There was no change in preferred temperature after successful therapy of the H. pylori infection compared to unsuccessful H. pylori therapy, nor was there a correlation between the preferred temperature and the presence, absence, or degree of gastric atrophy (r2 < 0.001). CONCLUSION: The temperature of preference for hot drinks was not influenced by H. pylori infection or by the presence of atrophic gastritis.

Adult↗
PubMed1996

The best gastric site for obtaining a positive rapid ureas test.

BACKGROUND: Rapid ureas tests (RUTs) provide a simple, sensitive method of detecting Helicobacter pylori infection. OBJECTIVES: Our aim, therefore, was to determine whether the yield of detecting H. pylori infection by RUT varied depending on the site of gastric biopsy. MATERIALS AND METHODS: Gastric biopsies were obtained from 50 patients for RUT by use of hpfast (GI Supply, Camp Hill, PA). Biopsies were taken from the prepyloric greater curve antrum, from the gastric angle, and from the greater curve in mid-corpus. One biopsy specimen was placed in the RUT gel, and the biopsy from the adjacent mucosa was placed in formalin for subsequent histological evaluation by using the Genta stain. RUTs were examined and scored at intervals of 5, 10, 15, 30, and 45 minutes and after 1, 2, 4, and 24 hours. RESULTS: Fifty patients were entered in the rest (150 RUTs), 32 having H. pylori infection. There were no false-positive RUTs (specificity, 100%). The gastric angle site was positive in 100%. The prepyloric site was positive in 87%, and the corpus site was positive in 84.4% (p < .052 for angle or prepyloric antrum versus corpus). The most common pattern was for all to be positive (74%). The median time to positivity was similar with angle and prepyloric sites (37.5 and 60 minutes, respectively, p = not significant) and shorter than the corpus biopsy (180 minutes); (p < .05 for angle or prepyloric antrum versus corpus). CONCLUSION: The maximum probability for detecting H. pylori infection using a RUT is to obtain a biopsy from the gastric angle. To prevent missing a positive result when intestinal metaplasia is present, we recommend that (at a minimum) biopsies be taken from both the angle and the corpus.

Bacterial Proteins↗
PubMed1996

Mutations in 23S rRNA are associated with clarithromycin resistance in Helicobacter pylori.

Twelve clarithromycin-resistant Helicobacter pylori isolates (100% of resistant isolates examined) from seven different patients each contained an A-->G transition mutation within a conserved loop of 23S rRNA. A-->G transition mutations at positions cognate with Escherichia coli 23S rRNA positions 2058 and 2059 were identified. Clarithromycin-susceptible H. pylori isolates from 14 different patients displayed no polymorphisms in a conserved loop within domain V of 23S rRNA. The study is the first to report mutations in H. pylori associated with resistance to an antimicrobial agent used in established peptic ulcer treatment regimens.

Anti-Bacterial Agents↗
PubMed1996

Population genetic analysis of Helicobacter pylori by multilocus enzyme electrophoresis: extensive allelic diversity and recombinational population structure.

Genetic diversity and relationships in 74 Helicobacter pylori isolates recovered from patients assigned to distinct clinical categories were estimated by examination of allelic variation in six genes encoding metabolic housekeeping enzymes by multilocus enzyme electrophoresis. Seventy-three distinct allele profiles, representing multilocus chromosomal genotypes, were identified. All six loci were highly polymorphic, with an average of 11.2 alleles per locus. The mean genetic diversity in the sample was 0.735, a value that exceeds the level of diversity recorded in virtually all bacterial species studied by multilocus enzyme electrophoresis. A high frequency of occurrence of null alleles (lack of enzyme activity) was identified and warrants further investigation at the molecular level. Lack of linkage disequilibrium (nonrandom association (of alleles over loci) indicates that horizontal transfer and recombination of metabolic enzyme genes have contributed to the generation of chromosomal diversity in H. pylori. In this sample of isolates, there was no statistically significant association of multilocus enzyme electrophoretic types or cluster of related chromosomal types and disease category.

Adult↗
PubMed1996

Direct activity of recombinant human lactoferrin against Helicobacter pylori.

We report the activity of recombinant human lactoferrin against Helicobacter pylori. Lactoferrin exerted a time- and dose-dependent action against 8 of the 13 clinical isolates of H. pylori tested in vitro. These results highlight a potential therapeutic use for lactoferrin against H.pylori infection.

Anti-Bacterial Agents↗
PubMed1996

Evaluation of three commercial enzyme immunoassays compared with the 13C urea breath test for detection of Helicobacter pylori infection.

The diagnostic significance of the serological detection of antibodies to Helicobacter pylori has been established by numerous investigators. Reports of the clinical reliabilities of commercial enzyme immunoassay (EIA) kits available for this purpose vary as a result of the different H. pylori antigen sources and reference methods used. The 13C urea breath test (UBT) has been shown to be an extremely accurate and reliable method of detecting H. pylori infection. We used the 13C urea breath test as the confirmatory method for H. pylori status to evaluate three commercially available EIA kits designed to detect immunoglobulin G antibodies to H. pylori. These kits were the HM-CAP EIA kit (Enteric Products, Inc.), the PYLORI STAT EIA kit (BioWhittaker, Inc.), and the G.A.P. kit (Bio-Rad Laboratories/Biomerica, Inc.). The evaluations were performed in a double-blind manner with samples from 473 clinically characterized patients. This group included patients with symptomatic gastrointestinal disorders as well as nonsymptomatic volunteers. The sensitivities of the kits were as follows: HM-CAP, 98.4%; PYLORI STAT, 99.2%; and G.A.P., 100%. The specificities were as follows: HM-CAP, 96.4%; PYLORI STAT, 90.1%; and G.A.P., 26.0%. Although the HM-CAP and PYLORI STAT kits performed comparably, the G.A.P. test yielded significantly more false-positive results and an unacceptably high number of indeterminate results.

Antibodies, Bacterial↗
PubMed1996

Identification of Mycobacterium avium complex in sarcoidosis.

Cell wall-defective bacteria which later reverted to acid-fast bacilli have been isolated from sarcoid tissue. These have not been conclusively shown to be mycobacteria. Specific PCR assays were applied to identify mycobacterial nucleic acids in these cultured isolates and in fresh specimens obtained from patients with sarcoidosis. Positive amplification and hybridization were observed with Mycobacterium avium complex- and/or Mycobacterium paratuberculosis-specific probes in five of the six cultured isolates and two fresh skin biopsy samples and one cerebrospinal fluid specimen. There was no amplification or hybridization with Mycobacterium tuberculosis or M. avium subsp. silvaticum probes, respectively. Patients' sera were also tested for antibody reactivities by immunoblotting with M. paratuberculosis recombinant clones expressing the 36,000-molecular-weight antigen (36K antigen) (p36) and the 65K heat shock protein (PTB65K). All seven sarcoidosis, four of six tuberculosis, and all six leprosy patient serum specimens showed strong reactivity with p36 antigen. In contrast, 13 of 38 controls showed only weak reactivity with p36 (P = 0.002 for controls versus sarcoidosis samples). Similarly, PTB65K reacted with high intensity with sera from 5 of 5 sarcoidosis, 5 of 6 tuberculosis, and 5 of 6 leprosy patients, compared with its low-intensity reaction with 5 of 22 controls (P = 0.001 for controls versus sarcoidosis samples). This study demonstrates the isolation and/or identification of M. paratuberculosis or a closely related M. avium complex strain from sarcoid skin lesions and cerebrospinal fluid. Furthermore, the reactivity of antibodies in sarcoid patient sera against p36 and PTB65K antigens was comparable to the reactivity of sera obtained from patients with known mycobacterial disease. Collectively, these data provide further support for the theory of the mycobacterial etiology of sarcoidosis.

DNA, Bacterial↗
PubMed1996

Effects of aspirin and Helicobacter pylori on the gastroduodenal mucosal permeability to sucrose.

BACKGROUND: A non-invasive marker is needed to identify patients with significant gastrointestinal injury due to non-steroidal anti-inflammatory drugs. Gastrointestinal permeability to sucrose has been suggested as such a test. AIMS: To assess the utility of sucrose permeability as a marker of gastroduodenal mucosal injury after single and multiple doses of aspirin, to identify the site of increased sucrose permeability, to explore the relation between sucrose permeability and endoscopic findings, and to evaluate whether Helicobacter pylori infection influenced gastroduodenal sucrose permeability. METHODS: After a fasting urine was obtained, 500 ml of a solution containing 100 g of sucrose was ingested. Urine was collected for five hours and assayed for sucrose by high performance liquid chromatography. Sucrose permeability was also assessed 20 minutes after ingestion of 650 mg of aspirin and eight to 12 hours after a 72 hour course of 650 mg aspirin four times a day. The site of increased permeability was identified after pyloric occlusion with a double balloon tube. RESULTS: Thirty seven healthy volunteers participated. Sucrose permeability (mean (SEM)) increased after both single (195.2 (27) mg and multiple (196.4 (31) mg) doses of aspirin compared with baseline (53.7 (10) mg; p < 0.0005). Balloon pyloric occlusion confirmed that the site of increased sucrose permeability was the stomach. The effect of aspirin on sucrose permeability was similar in those with and without H pylori infection. CONCLUSION: These results confirm the use of sucrose permeability as a marker of aspirin induced gastroduodenal mucosal injury and identify the stomach as the major site of increased permeability. H pylori infection does not seem to change gastric mucosal sucrose permeability either at baseline or after ingestion of aspirin.

Adult↗
PubMed1996

Serum CagA antibodies in asymptomatic subjects and patients with peptic ulcer: lack of correlation of IgG antibody in patients with peptic ulcer or asymptomatic Helicobacter pylori gastritis.

AIM/BACKGROUND: Several studies have suggested that Helicobacter pylori which express CagA may be more virulent than those that do not, but limited populations have been studied to date. The aim of this study was to confirm and extend the association of CagA positive H pylori strains in a different geographical area and to a large, well defined patient population. METHOD: A validated ELISA for serum IgG to CagA was used to investigate the prevalence of CagA seropositivity in 100 patients with peptic ulcer compared with 77 with H pylori infection without ulcer disease in a North American population. The extent of antral and corpus inflammation and H pylori density in relation to CagA seropositivity in 40 subjects with H pylori infection were assessed semiquanitatively. All studies were carried out in a coded and blinded manner. RESULTS: The prevalence of serum IgG CagA antibodies was higher in H pylori infected patients with ulcer (59%) compared with healthy H pylori infected volunteers (44%), but the difference was not significant. In contrast, the titre of serum IgG anti-CagA antibodies was higher among the seropositive subjects without ulcer disease, but again the difference was not significant. Comparison of histological features between asymptomatic individuals with H pylori infection in relation to CagA IgG antibody status revealed no differences in infiltration with acute inflammatory cells, H pylori density, or gastritis index. There was no relation evident between the degree of polymorphonuclear cell infiltration and the serum IgG antibody titre to CagA. Mononuclear cell infiltration in the antrum, but not the corpus, was greater in those with CagA IgG compared with those without (median score 5 v 3). CONCLUSIONS: A right association between the presence or titre of serum IgG to CagA and peptic ulcer disease, greater H pylori density or infiltration of the mucosa with acute inflammatory cells could not confirmed in a North American population. Perhaps geographical differences in the prevalence of circulating H pylori strains are responsible for the discrepant results reported.

Antibodies, Bacterial↗
PubMed1996

Comparison of rapid serological tests (FlexSure HP and QuickVue) with conventional ELISA for detection of Helicobacter pylori infection.

BACKGROUND: There is a need for accurate and rapid tests for Helicobacter pylori infection especially since the recent National Institutes of Health Consensus Development Conference on H. pylori in peptic ulcer disease charged the medical community with treating H. pylori infection in all patients with H. pylori and ulcer disease. METHODS: We prospectively compared a simple, rapid serological test (FlexSure HP, SmithKline Diagnostics) for the detection of serum IgG antibodies against H. pylori with another rapid test (QuickVue, Quidel) and two enzyme immunoassays (HM-CAP, Enteric Products, and PyloriStat, BioWhittaker). Serum samples from 551 individuals including both symptomatic patients (196) and asymptomatic volunteers (355) were tested for the presence of IgG antibodies against H. pylori. The presence or absence of active H. pylori infections was determined using the [13C]-urea breath test. RESULTS: All of the serological tests performed well. FlexSure HP had calculated sensitivity, specificity, and accuracy of 94.4, 87.6, and 91.1%, respectively, relative to the urea breath test. In 49 of the 551 samples, the urea breath test and FlexSure HP did not agree. Those samples were tested with HM-CAP immunoassay to confirm presence or absence of IgG antibodies against H. pylori. After the resolution of the discordant results, the sensitivity, specificity, and accuracy of FlexSure HP were 96.0, 95.1, and 95.6%, respectively, and were comparable to HM-CAP and PyloriStat. FlexSure HP was compared with histology or culture in 75 cases, and the accuracy was 100%. FlexSure HP and QuickVue were compared using 200 serum samples. FlexSure HP was more specific (88.7 vs 79.4%) and accurate (91 vs 84%) than QuickVue (p < 0.05 for both), relative to the urea breath test with discordant samples unresolved. FlexSure HP was also simpler to use, easier to interpret, and faster than QuickVue. FlexSure HP required no sample dilution, one reagent, four steps, and 5 min to complete. CONCLUSION: FlexSure HP is an excellent option for in-office tests for the physician who desires immediate results or for small laboratories that do not have the volume of H. pylori testing to justify ELISA test formats.

Adolescent↗
PubMed1996

Choosing the best anti-Helicobacter pylori therapy: effect of antimicrobial resistance.

BACKGROUND: The development of effective therapies for the treatment of Helicobacter pylori infection has been a long and arduous process. There is considerable confusion about which is the best. METHODS: We review approaches to understanding the results of trials evaluating potentially new therapies and those comparing two or more potentially good regimens with particular emphasis on the role of antimicrobial resistance on the outcome of therapy. RESULTS: Antimicrobial resistance in vitro does not always correlate with poor results with multi-drug treatment regimes. Although it is not known if clinical resistance defined as failure of a therapy might be a better predictive of subsequent failure, overall effectiveness is influenced most strongly by the drug with the poorest cure rates in the presence of resistant microorganisms. Development of resistance is reduced in multiple drug therapies. Bismuth may be an especially useful antimicrobial in this regard because it is an effective topical therapy that markedly reduces the bacterial load. Resistance to antimicrobials can be thought of as a statistical event estimated as a proportion of the H.pylori population in the stomach (e.g., 1 in 10(8) bacteria). Elimination of most organisms with the first dose of bismuth might decrease likelihood of survival of resistant strains that were already present. CONCLUSION: Results of large clinical trials are needed to provide accurate estimation concerning the effectiveness of the different treatment regimes using different dosages, dosing intervals, and duration of therapy. For interpretation and comparison, clinical trials must report the overall effectiveness as well as effectiveness of the regimen separately for those with resistant and sensitive H.pylori.

Anti-Bacterial Agents↗
PubMed1996

Low point prevalence of peptic ulcer in normal individuals with Helicobacter pylori infection.

OBJECTIVE: A recent study from Italy reported a high prevalence of ulcer disease in asymptomatic Helicobacter pylori infection. Such results are at variance with previous endoscopy screening studies. Our study was performed to obtain data on ulcer prevalence in normal H. pylori-infected subjects in the United States. METHODS: One hundred and ninety healthy individuals of either gender, over the age of 18, were studied. After completion of a detailed questionnaire and a urea breath test for H. pylori status, endoscopy was performed. Ulcer was defined as a mucosal ulceration > 5 mm in diameter and with apparent depth. RESULTS: There were 108 (57%) women and 82 (43%) men. The mean (+/-SD) age was 38.9 (+/-10.7) yr, range 21-79 yr. Careful history obtained after enrollment revealed presence of dyspeptic symptoms in 35 subjects (18%); the remaining 155 individuals were completely symptom-free. Infection with H. pylori was present in 102 subjects (54%). The infection rate was highest in Hispanics (70%), followed by African-Americans (58%), Caucasians (38%), and Asians (17%). The prevalence increased with age. Only two (1%) of 190 subjects, both with H.pylori infection, had peptic ulcer. In the H. pylori-infected group, the prevalence of peptic ulcer was 2%. CONCLUSION: In the United States, significant unrecognized and asymptomatic gastroduodenal disease is uncommon in H. pylori-infected individuals. These findings do not support the need for a mass screening program for H. pylori infection or for the use of antimicrobial treatment of asymptomatic subjects with this infection.

Adult↗