[Relationship between Helicobacter pylori infection and histopathological features of nodular gastritis in children].

OBJECTIVE: To study the relationship between Helicobacter pylori (Hp) infection and histopathological features of nodular gastritis (NG) in children. METHODS: A total of 213 children who had undergone gastroscopy due to upper gastrointestinal symptoms were enrolled and were divided into NG and non-NG groups according to endoscopic appearance. The histopathological features of gastric mucosa were evaluated using the updated Sydney System. The rates of Hp infection, moderate to severe inflammation and lymphoid follicles formation of gastric mucosa were compared between the two groups. RESULTS: Thirty-eight (17.8%) of the subjects were diagnosed with NG. The NG group had significantly increased rates of Hp infection (86.8% vs 14.3%; P<0.01), moderate to severe inflammation (81.6% vs 15.4%; P<0.01) and lymphoid follicles formation of gastric mucosa (52.6% vs 10.3%; P<0.01) compared with the non-NG group. NG had a high specificity (96.8%) and a positive predictive value (86.8%) for the diagnosis of Hp infection. NG was observed in 33 (56.9%) of 58 Hp-positive children and in 5 (3.2%) of 155 Hp-negative children (P<0.01). Hp-positive children had higher rates of moderate to severe inflammation (86.2% vs 5.2%, P<0.01) and lymphoid follicles formation of gastric mucosa (84.2% vs 14.9% P<0.01) compared with Hp-negative children. There were significant differences in Hp colonization, degree of inflammation and inflammation activity in gastric tissues between the NG and non-NG groups (P<0.01). CONCLUSIONS: NG is a special sign of Hp infection in children, which mostly shows moderate to severe inflammation of gastric mucosa, and can be used as an endoscopic indicator of Hp infection. Hp eradication therapy should be considered in the treatment of NG.

Microvascular structural changes in esophageal squamous cell carcinoma pathology according to intrapapillary capillary loop types under magnifying endoscopy.

BACKGROUND: The intrapapillary capillary loop (IPCL) characteristics, visualized using magnifying endoscopy, are commonly assessed for preoperative evaluation of the infiltration depth of esophageal squamous cell carcinoma (ESCC). Japan Esophageal Society (JES) classification is the most widely used classification. Microvascular structural changes are evaluated by magnifying endoscopy for the presence or absence of each morphological factor: tortuosity, dilatation, irregular caliber, and different shapes. However, the pathological characteristics of IPCLs have not been thoroughly investigated, especially the microvascular structures corresponding to the deepest parts of the lesions' infiltration. AIM: To investigate differences in pathological microvascular structures of ESCC, which correspond to the deepest parts of the lesions' infiltration. METHODS: Patients with ESCC and precancerous lesions diagnosed at Peking University Third Hospital were enrolled between January 2019 and April 2023. Patients first underwent magnified endoscopic examination, followed by endoscopic submucosal dissection or surgical treatment. Pathological images were scanned using a three-dimensional slice scanner, and the pathological structural differences in different types, according to the JES classification, were analyzed using nonparametric tests and t-tests. RESULTS: The 35 lesions were divided into four groups according to the JES classification: A, B1, B2, and B3. Statistical analyses revealed significant differences (a P < 0.05) in the short and long calibers, area, location, and density between types A and B. Notably, there were no significant differences in these parameters between types B1 and B2 and between types B2 and B3 (P > 0.05). However, significant differences in the short calibers, long calibers, and area of IPCL were observed between types B1 and B3 (a P < 0.05); no significant differences were found in the density or location (P > 0.05). CONCLUSION: Pathological structures of IPCLs in the deepest infiltrating regions differ among various IPCL types classified by the JES classification under magnifying endoscopy, especially between the types A and B.

Epidemiological and clinical features of functional dyspepsia in a region with a high incidence of esophageal cancer in China.

BACKGROUND: Functional dyspepsia (FD) has rarely been investigated in areas with a high prevalence of esophageal squamous cell carcinoma (ESCC). This study aims to reveal the epidemiological and clinical features of FD and organic dyspepsia (OD) in such a population. METHODS: A middle-aged and elderly population-based study was conducted in a region with a high incidence of ESCC. All participants completed the Gastroesophageal Reflux Disease Questionnaire and Functional Gastrointestinal Disease Rome III Diagnostic Questionnaire, and they underwent gastroscopy. After exclusion of gastroesophageal reflux disease, uninvestigated dyspepsia (UID) was divided into OD and FD for further analyses. RESULTS: A total of 2916 participants were enrolled from July 2013 to March 2014 in China. We detected 166 UID cases with questionnaires, in which 17 patients with OD and 149 with FD were diagnosed via gastroscopy. OD cases presented as reflux esophagitis (RE), ESCC, and duodenal ulcer. Heartburn (52.94%) and reflux (29.41%) were common in OD, but no symptomatic differences were found between FD and OD. Male sex, low education level, and liquid food were the risk factors for OD, while frequent fresh vegetable consumption was a protective factor. FD included 56 (37.58%) cases of postprandial distress syndrome (PDS), 52 (34.89%) of epigastric pain syndrome (EPS), nine (6.04%) of PDS + EPS, and 32 (21.48%) of FD + functional esophageal disorders. The Helicobacter pylori infection rate in FD patients was not higher than that in the control group (34.23% vs. 42.26%, P = 0.240). Frequent spicy food consumption was associated with PDS (odds ratio [OR]: 2.088, 95% confidence interval [CI]: 1.028-4.243), while consumption of deep well water was protective for PDS (OR: 0.431, 95% CI: 0.251-0.741). CONCLUSIONS: The prevalence of FD was 5.11% in the studied population. Gastroscopy should be prescribed for dyspepsia patients in case that ESCC and RE would be missed in UID cases diagnosed solely by the Rome III questionnaire. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01688908; https://clinicaltrials.gov/ct2/show/record/NCT01688908.

[A case report of collagenous gastritis in a young Chinese woman and literatures review].

OBJECTIVE: Collagenous gastritis is a rare entity, characterized by the deposition of a subepithelial collagen band with an inflammatory infiltrate in the mucosa. This report describes the first case of collagenous gastritis occurring in a young Chinese woman and reviews the literatures. METHODS: The patient underwent the gastroscopy screening, and the biopsy specimens were treated with HE staining, Masson staining, Congo red staining and Warthin-Starry staining.Patients' clinical data was discussed and followed up. RESULTS: A twenty-year-old girl had intermittent epigastric pain for 4 years, abdominal distention, hiccup and weight loss for two months. The gastric endoscopy revealed diffuse white nodular appearance of the mucosa in angular incisura and antrum. Pathologic examination of the gastric biopsies from the antrum and angular showed a subepithelial collagen deposition with moderate infiltrates of lymph plasma cells and eosinophils of the lamina propria. The collagen band measured up to 120.3 µm (mean 43.8 µm). Prednisone 20 mg/d for 4 weeks led to clinical remission and weight gain. CONCLUSION: There are about 40 cases in literatures to date, and the cause and pathogenesis of collagenous gastritis remain unknown. According to the clinical and pathological characteristics, the patient in this article is the subtype of collagenous gastritis that occurring in children and young adults. Specific therapy has not been established, the gluten-free diet and glucocorticosteroid may be helpful to relieve symptoms in collagenous gastritis patients.

[A study on the light microscopic measurement of intercellular space of squamous epithelium in lower-esophagus to diagnose gastroesophageal reflux disease].

OBJECTIVE: To evaluate the significance of dilated intercellular space (DIS) of squamous epithelium in lower-esophagus which was measured at light microscopy (LM) in the diagnosis of gastroesophageal reflux disease (GERD). METHODS: This study was divided into two parts. The first part consists of 133 GERD patients with typical symptoms, including 75 erosive esophagitis (EE) and 58 non-erosive reflux disease (NERD); the second part consists of 25 healthy volunteers as control; ambulatory 24-hr esophageal pH monitoring, endoscopy and biopsies which were taken in lower esophagus were performed in all individuals. NERD patients with negative ambulatory 24-hr esophageal pH monitoring were undertaken PPI test. We selected 43 individuals randomly (4 control, 11 NERD and 28 EE) to measure the intercellular space diameter with LM and transmission electronic microscopy (TEM) simultaneously. All the samples were observed at immersion objective, taken pictures and make the scale at the same time; all the pictures were measured by the computer-assisted morphometry and in the samples for one case should be measured 100 points and then calculate the mean intercellular space diameter, while the TEM has the same procedures. RESULTS: A total of 158 individuals (90 male, 68 female) were enrolled in this study. The mean intercellular space diameter with LM of the controls, the NERD and the EE patients were (0.61 +/- 0.10) microm, (1.12 +/- 0.61) microm and (1.30 +/- 0.19) microm, respectively, with significant differences between the control and NERD group, the control and EE group, the EE and NERD group (P < 0.05); the mean intercellular space diameter with LM of EE subgroup of LA-A, LA-B, LA-C, LA-D were (1.31 +/- 0.23) microm, (1.27 +/- 0.17) microm, (1.31 +/- 0.14) microm, (1.33 +/- 0.11) microm, respectively, without significant differences among every two subgroups (P > 0.05); NERD patients with positive and negative 24-hr ambulatory pH monitoring were 40 and 17 cases, and the mean intercellular space diameter with LM were (1.12 +/- 0.16) microm, (1.11 +/- 0.31) microm, respectively, without significant differences between them (P > 0.05); the cut-off value of mean intercellular space diameter with LM was 0.85 microm, if combination the clinical GERD symptom, endoscopy and 24-hr ambulatory pH monitoring as gold standard, its sensitivity was 95.5% and specificity was 100%; the intercellular space diameter of the controls, the NERD patients and the EE patients with TEM were (0.30 +/- 0.14) microm, (1.33 +/- 0.28) microm, (1.40 +/- 0.22) microm, respectively, with significant differences between the control and NERD group, the control and EE group (P < 0.05). It was significant correlation in intercellular space diameter between LM and TEM (r = 0.737, P = 0.000). CONCLUSIONS: The intercellular space diameter of squamous epithelium in lower esophagus of GERD patients can make quantitative study with LM. It is significant correlation with TEM. DIS with LM is one of sensitive, specific and objective marker of GERD.

[Epidemiology of Helicobacter pylori infection in Shandong and Beijing areas.].

OBJECTIVES: To study the current prevalence and recent epidemiological changes of Helicobacter pylori (H. pylori) infection among children and adults residing in regions with high (Muping, Shandong) and low (Yanqing, Beijing) incidence of gastric cancer in China. METHODS: A total of 2065 asymptomatic children aged 8 - 15 years and adults aged 40 - 79 years in the above two regions were examined from May to July 2006. The data obtained in early 1990s in the same two areas and those of 11 656 patients undergoing endoscopy in our hospital in 1991 and 2006 were also collected and studied. RESULTS: The prevalence of H. pylori infection in Muping was significantly higher than that in Yanqing among both children (37.69% vs 25.58%, P < 0.001) and adults (50.95% vs 41.35%, P < 0.01). From 1991 to 2006 H. pylori prevalence among children aged 8 - 10 years decreased in Muping (60.00% vs 32.07%, P < 0.001), but not in Yanqing (24.06% vs 19.10%, P > 0.05). A significant decrease in H. pylori prevalence among adults in both regions was observed when the results of 2006 were compared with the data obtained in 1990 in Muping (50.95% vs 73.78%, P < 0.001) and in 1992 in Yanqing (41.35% vs 55.35%, P < 0.01). The detected rate of H. pylori infection in patients undergoing endoscopy in our hospital decreased from 51.88% in 1991 to 33.59% in 2006 (P < 0.001). CONCLUSIONS: The prevalence of H. pylori infection is significantly higher in areas with a high incidence of gastric cancer in China as compared with that in areas with a low incidence of gastric cancer among both children and adults. H. pylori infection may be a risk factor in gastric carcinogenesis. In the past decade or more, H. pylori infection rates have decreased in Chinese population.

[The risk factors of reflux esophagitis in Shandong farmers].

OBJECTIVE: To investigate the risk factors of reflux esophagitis (RE) in farmers of Shandong province. METHODS: Five hundred and fifty six peasants (aged from 34 to 90 years old) were randomly selected from the rural general population in Yantai area, Shandong province. All participants received a face to face interview for relating clinical symptoms. Upper gastrointestinal endoscopic and histopathologic examination were carried out. RESULTS: 101 (18.2%) patients were diagnosed endoscopically as RE. According to Los Angeles Classification system, the distribution of types was as follows: A: 36.6% (37/101), B: 56.4% (57/101), C: 3.0% (3/101), D: 4.0% (4/101). The gender (P < 0.001), age (P = 0.041), time engaged in farming (P = 0.040) of the subjects and the length from Z line to fore-tooth (P = 0.001) were correlated with the occurrence of RE. Smoking (OR 1.894, 95% CI 1.207 - 2.974), drinking strong tea (OR 2.900, 95% CI 1.651 - 5.092), using non-steroidal anti-inflammatory drugs (NSAIDs) (OR 2.159, 95% CI 1.166 - 3.997) and loose cardia (OR 13.630, 95% CI 7.37 - 25.19) were risk factors of RE. But there was no relationship between RE and the height, body weight, abdominal circumference, body mass index (BMI), alcohol drinking, special food habit and the history of diabetes, previous abdominal operation, peptic ulcer and atrophic gastritis of the subjects. H.pylori infection rate in the population was 51.3% (273/532). 37.1% (36/97) of RE patients and 54.5% (237/435) of non-RE patients were H.pylori positive (P = 0.002), OR 0.492 (95% CI 0.313 - 0.776). CONCLUSIONS: Male gender, aging, shorter length from Z line to fore tooth, loose cardia and absence of H.pylori infection were correlated with RE. Smoking, drinking strong tea, NSAIDs and long time engaged in farming were risk factors of RE.

[The effects of sulindac on the pathology of colorectal remnant polyps of familial adenomatous polyposis (FAP) patients].

OBJECTIVE: To evaluate the long-term effectiveness of sulindac on the pathology of colorectal adenomas of familial adenomatous polyposis (FAP) patients. METHODS: FAP patients were treated with sulindac 400 mg per day. The change of colorectal polyps was assessed every 3 months in the first year. After the significant regression of colorectal polyps was achieved, sulindac was used to maintain the effects. The patients received colonoscopy examination regularly. Biopsies of remnant polyps and other lesions were obtained. The type and dysplasia grade of biopsies were evaluated and compared with baseline. RESULTS: Before the study, 90.8% of adenoma biopsies were tubular, while 9.2% was tubulovillous adenoma. The dysplasia of grades I, II and III were 42.1%, 45.6% and 12.3%, respectively. After sulindac treatment, 99.8% of adenoma biopsies were tubular, while 0.2% tubulovillous adenoma. There was significant difference compared with baseline (P<0.01). The dysplasia of grades I, II and III were 55.8%, 41.8% and 2.4% respectively, which had significant difference with baseline (P<0.01). Minor flat elevation and erythema were found during the treatment, in which approximately 65% was adenoma. CONCLUSION: Long-term use of sulindac seems to be effective in reducing dysplasia grade and tubulovillous adenoma of retained colorectal adenoma of FAP patients. Minor flat elevation and erythema may be the lesions appearing during the regression of adenoma.

Accuracy of diagnosing gastroesophageal reflux disease by GerdQ, esophageal impedance monitoring and histology.

OBJECTIVE: To assess the performance of self-assessment gastroesophageal reflux disease questionnaire (GerdQ), 24-h impedance monitoring, proton pump inhibitor (PPI) test and intercellular space of esophageal mucosal epithelial cells in the diagnosis of gastroesophageal reflux disease (GERD). METHODS: Patients with symptoms suspected of GERD were administered the GerdQ and underwent endoscopy (measurement of intercellular space in the biopsy specimen sampling at 2 cm above the Z-line) and 24-h impedance pH monitoring, together with a 2-week experimental treatment with esomeprazole. RESULTS: A total of 636 patients were included for the final analysis, including 352 with GERD. The sensitivity and specificity of GerdQ and 24-h impedance monitoring for diagnosing GERD were 57.7% and 48.9%, and 66.4% and 43.3%, respectively. The sensitivity of 24-h impedance pH monitoring increased to 93.7%. The sensitivity and specificity of dilated intercellular spaces (DIS) (≥0.9 µm) for diagnosing GERD were 61.2% and 56.1%, respectively, whereas those for PPI test were 70.5% and 44.4%. CONCLUSIONS: GerdQ score or PPI test alone cannot accurately diagnose GERD in a Chinese population suspected of GERD. A definitive diagnosis of GERD still depends on endoscopy or 24-h pH monitoring. 24-h impedance pH monitoring may increase the sensitivity for diagnosing GERD by 20%; however, when used alone, it results in poor specificity in patients without acid suppressive therapy.

Changing pattern of adenocarcinoma of the esophagogastric junction in recent 10 years: experience at a large tertiary medical center in China.

AIMS AND BACKGROUND: To investigate the changing pattern of adenocarcinoma of the esophagogastric junction subtypes and its time trend relationship with that of reflux esophagitis over 10 years at a tertiary medical center in China. METHODS AND STUDY DESIGN: . The medical records of all patients who underwent gastroscopy from 2000 to 2009 were reviewed. Subtypes of adenocarcinoma of the esophagogastric junction according to Siewert's classification, gastric non-cardiac adenocarcinoma, esophageal squamous cell carcinoma, reflux esophagitis and Helicobacter pylori infection were diagnosed according to the results of gastroscopy and mucosal histopathology. All the patients were divided into three cohorts (cohort A [2000-2003], cohort B [2004-2006]), cohort C [2007-2009]), and the proportion of adenocarcinoma of the esophagogastric junction and its subtypes in all upper gastrointestinal tumors (adenocarcinoma of the esophagogastric junction, gastric non-cardiac adenocarcinoma and esophageal squamous cell carcinoma) in each cohort were compared. The annual percentages of adenocarcinoma of the esophagogastric junction, reflux esophagitis and H pylori in all patients were also compared. RESULTS: 70,073 patients (cohort A, n = 20298, cohort B, n = 20443, cohort C, n = 29332) who underwent gastroscopy were reviewed. Totally there were 279 patients with adenocarcinoma of the esophagogastric junction (0.398%, M:F = 5.6:1), 794 gastric non-cardiac adenocarcinoma patients (1.133%, M:F = 2:1), 366 esophageal squamous cell carcinoma patients (0.522%, M:F = 3.4:1) and 4681 reflux esophagitis patients. Among the three subtypes of adenocarcinoma of the esophagogastric junction, only type I adenocarcinoma of the esophagogastric junction in upper GI tumors exhibited increasing trend over time (1.86%, 3.39% and 4.94% for cohort A, B and C, respectively, P = 0.009). According to the WHO classification of histological types, the tubular types of adenocarcinoma of the esophagogastric junction have decreased (P = 0.008), whereas papillary type (P = 0.001) increased. The annual detection rate of type I adenocarcinoma of the esophagogastric junction appeared to be positively correlated with reflux esophagitis (r = 0.846, P = 0.002) and negatively with H pylori infection (r = -0.785, P = 0.007) in time trend. CONCLUSIONS: Over a recent 10-year period, the three subtypes of adenocarcinoma of the esophagogastric junction showed different changing trends, suggesting heterogeneous characteristics of the three Siewert types of adenocarcinoma of the esophagogastric junction.

The intrinsic fluorescence spectrum of dilute gastric juice as a novel diagnostic tool for gastric cancer.

OBJECTIVE: To investigate the intrinsic fluorescence spectrum of gastric juice as a diagnostic method for gastric cancer. METHODS: We collected gastric juice by gastroscopy in 1,870 patients from May 2001 to March 2006, of whom 202 were involved in a preliminary test, 162 in experimental optimization and 1,506 in clinical verification. The best dilution and pH value were chosen in the experimental optimization phase. Clinical verification was based on optimized samples. Intrinsic fluorescence spectra were measured in all samples with a fluorescence spectrophotometer using an excitation wavelength of 288 nm. RESULTS: The first peak of fluorescence intensity (P(1) FI) of the intrinsic fluorescence spectrum was significantly higher in gastric juice from patients with gastric cancer than from those with benign lesions. There was no significant difference in the P(1) FI differences between patients with benign and malignant lesions with samples diluted by 20-fold to 80-fold and from pH 9 to pH 11. Clinical verification in 1,506 patients showed that P(1) FI ≥ 76.5 was the optimal cut-off on the receiver operating characteristic curve for diagnosing gastric cancers: sensitivity was 83.2%, specificity 80.7% and accuracy 82.0%. CONCLUSIONS: P(1) FI of the intrinsic fluorescence at 288 nm is significantly higher in patients with gastric cancers than in individuals with benign lesions. As a clinical indicator of gastric cancer, its sensitivity, specificity and accuracy were high.

Factors influencing intercellular spaces in the rat esophageal epithelium.

AIM: To evaluate the effect of acute stress, hydrochloric acid, ethanol, aspirin, and prednisolone on the intercellular spaces of the esophageal epithelium. METHODS: Part I, male Sprague-Dawley rats were randomly divided into eight groups and treated with the damaging or control factors. The esophagus of each rat was macroscopically inspected. Histological changes in mucosal biopsies were examined by light microscopy, and the widths of intercellular spaces were determined by transmission electron microscopy (TEM). Part II, in part I, we found that acute stress and aspirin induced dilated intercellular spaces (DIS) of the esophageal epithelium. Therefore, the effect of acid suppression pretreatment with esomeprazole on esophageal epithelial DIS induced by water immersion and restraint stress (WRS) and aspirin was further investigated to determine the association of DIS with acid reflux. After administration of 0.9% sodium chloride solution or esomeprazole solution orally for five days, rats underwent WRS or intragastric administration of aspirin solution. Esophageal epithelial intercellular spaces were investigated by TEM. RESULTS: (1) The five damaging factors produced no lesions or inflammation in esophageal mucosa of rats under either gross or routine histological inspections. Esophageal epithelial intercellular space diameters in stress and aspirin groups were significantly greater, nearly three or two-fold respectively, than those in their corresponding control groups (stress model: 0.38 + or - 0.05 microm vs 0.13 + or - 0.02 microm, P < 0.01; aspirin model: 0.32 + or - 0.12 microm vs 0.19 + or - 0.05 microm, P < 0.01). Neither intragastric administration of hydrochloric acid or ethanol, nor hypodermic injection of prednisolone produced DIS compared with their corresponding control groups (hydrochloric acid model: 0.24 + or - 0.03 microm vs 0.19 + or - 0.05 microm, P > 0.05; ethanol model: 0.25 + or - 0.10 microm vs 0.19 + or - 0.05 microm, P > 0.05; prednisolone model: 0.20 + or - 0.03 microm vs 0.14 + or - 0.03 microm, P > 0.05); and (2) No significant difference in the intercellular space diameters was observed between the group pretreated with esomeprazole and the control group, in both the stress and aspirin models (stress model: 0.35 + or - 0.05 microm vs 0.37 + or - 0.05 microm, P > 0.05; aspirin model: 0.24 + or - 0.02 microm vs 0.27 + or - 0.03 microm, P > 0.05). CONCLUSION: Acute stress and aspirin can induce DIS of the esophageal epithelium in rats, and it is not correlated with acid reflux.

Recent changes in the prevalence of Helicobacter pylori infection among children and adults in high- or low-incidence regions of gastric cancer in China.

BACKGROUND: The prevalence of Helicobacter pylori (H. pylori) infection varies by geographic locations. Studies indicate that the infection rate of H. pylori was previously high in China but that rates had been declining worldwide over recent decades. THE AIMS OF OUR STUDY WERE: (1) to determine the current prevalence of H. pylori infection among children and adults residing in areas with high (Muping County, Shandong) and low (Yanqing County, Beijing) incidences of gastric cancer in China, and (2) to compare the prevalence for 2006 with the prevalence for the early 1990s. METHODS: Using Warthin-Starry silver staining of gastric mucosal biopsy specimens and H. pylori stool antigen tests (HpSA), we tested a total of 2065 asymptomatic children aged 8 - 15 years and adults aged 40 - 79 years in the above two regions from May to July 2006. We evaluated 520 children and 526 adults from Muping, and 516 children and 503 adults from Yanqing. Subjects were selected randomly and H. pylori status was determined by HpSA in children and either HpSA or histology of gastric biopsies in adults. Data obtained in the early 1990s in the same two areas of China were also collected and studied. RESULTS: For children, the prevalence of H. pylori infection was significantly higher in Muping (37.69%) than it was in Yanqing (25.58%, P < 0.001). In both regions, the prevalence of H. pylori increased with age but was not related to gender. A significant difference was observed between 8 - 9-years old and 10 - 11-years old (P < 0.05), but not between other adjoining age groups (P > 0.05). From 1991 to 2006 H. pylori prevalence among 8 - 10-year-old children decreased in Muping (60.00% vs 32.07%, P < 0.001), but not Yanqing (24.06% vs 19.10%, P > 0.05). In the adult group, H. pylori prevalence was 50.95% in Muping, which was significantly higher than the 41.35% positive rate in Yanqing (P < 0.01). But there were no statistically significant differences between different age groups of 40 - 49, 50 - 59, and 60 - 79 years, or between males and females. A significant decrease in H. pylori prevalence in both regions was observed when the results of 2006 were compared with the data obtained in 1990 in Muping (50.95% vs 73.78%, P < 0.001) and in 1992 in Yanqing (41.35% vs 55.35%, P < 0.01). CONCLUSIONS: After fifteen years, the prevalence of H. pylori infection among both children and adults remained significantly higher in areas with a high incidence of gastric cancer in China compared with that in areas with a low incidence of gastric cancer. H. pylori infection rates have decreased in the general Chinese population during recent years.