Helicobacter pylori risk associated with sibship size and family history of gastric diseases in Japanese adults

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

Association of Helicobacter Pylori With Development of Peptic Ulcer Disease Among Cirrhotic Patients: An Evidence From Population-Based Study

BACKGROUND

 Helicobacter pylori (H. pylori) plays an important role in causing peptic ulcer disease (PUD) in the general population. However, the role of H. pylori in cirrhotic patients for causing PUD is obscure. There are various studies evaluating H. pylori association with PUD in cirrhotic patients, but the results have been controversial. We sought to analyze the association of H. pylori with the development of PUD in cirrhotic patients from the largest United States population-based database.

METHODS

 We analyzed Nationwide Inpatient Sample (NIS) and Healthcare Cost and Utilization Project (HCUP) data from 2017. Adult hospitalizations due to cirrhosis were identified by previously validated ICD-10-CM codes. PUD and H. pylori were identified with the presence of ICD-10-CM codes in primary and secondary diagnosis fields, respectively. We performed weighted analyses using Chi-Square and paired Student's t-test to compare the groups. Multivariable survey logistic regression was performed to find an association of H. pylori with PUD in cirrhotic patients.

RESULTS

 Our study showed that the prevalence of H. pylori infection was 2.2% in cirrhotic patients with PUD. In regression analysis, H. pylori was found to be associated with PUD in cirrhotic patients (OR 15.1; 95% CI: 13.9-16.4; p <0.001) and non-cirrhotic patients (OR 48.8; 95% CI: 47.5-50.1; p <0.001). In the studied population, H. pylori was more commonly seen in the age between 50 and 64 years (49.4% vs 44.1%; p <0.0001), male (63.4% vs 59.9%; p <0.0413), African American (16.3% vs 10.6%; p <0.0001), and Hispanic (26.2% vs 14.9%; p <0.0001). H. pylori is more likely to be associated with complicated PUD hospitalizations (51.2% vs 44.2%; p <0.0067). Alcoholism and smoking were more common in H. pylori group compared to those without (43.6% vs 35.8%; p <0.0001 and 33.7% vs 24.8% p <0.0001, respectively). Factors associated with increased odds of H. pylori infection include African American (OR 2.3, 95% CI: 1.5-3.6), Hispanic (OR 2.6, 95% CI: 1.7-4.0), and smoking (OR 1.5, 95% CI: 1.1-2.2).

CONCLUSION

 H. pylori are associated with PUD and concurrent cirrhosis, although it is less prevalent than general population. African American, Hispanic, and smoking were independently associated with increased odds of H. pylori infection. Further studies are required to better understand the epidemiology and confirm our findings.

Epidemiology, Diagnosis and Risk Factors of Helicobacter pylori Infection

Helicobacter pylori is a human-specific pathogen, which leads to gastric pathologies including gastric cancer. It is a highly unique bacterium considered as a carcinogenic agent. H. pylori remains a major human health problem, responsible for ~90% of the gastric cancer cases. Approximately four billion individuals have been detected for H. pylori infection worldwide in 2015. At the turn of the twenty-first century, the prevalence of H. pylori has been declining in highly industrialized countries of the Western world, whereas prevalence has plateaued at a high level in developing and newly industrialized countries. However, the infection status remains high in immigrants coming from countries with high prevalence of H. pylori infection. H. pylori can be diagnosed both by invasive and non-invasive methods. Urea breath test and stool antigens detection are among the most commonly used non-invasive ones. Although the way H. pylori is transmitted remains still not fully clear, the level of contamination is strongly dependent on the familial and environmental context, with a drastic impact of living conditions with poor hygiene and sanitation. However, familial socioeconomic status is the main risk factor for H. pylori infection among children. In addition, food and water source have a high impact on the prevalence of H. pylori infection worldwide. This chapter highlights the latest knowledge in the epidemiology of H. pylori infection, its diagnosis and critical risk factors responsible for its high prevalence in some populations and geographic areas.

Changing trends in the prevalence of H. pylori infection in Japan (1908-2003): a systematic review and meta-regression analysis of 170,752 individuals

Changing trends in the prevalence of H. pylori infection in the general population over time are thought to be the main driving force behind the declining gastric cancer mortality in Japan. However, whether the prevalence of H. pylori infection itself shows a birth-cohort pattern needs to be corroborated. We performed a systematic review of studies that reported the prevalence of H. pylori infection among Japanese individuals. Meta-regression was conducted in the framework of a generalized additive mixed model (GAMM) to account for heterogeneity in the prevalence of H. pylori infection as a function of birth year. The prevalence of H. pylori infection confirmed a clear birth cohort pattern: the predicted prevalence (%, 95% CI) was 60.9 (56.3–65.4), 65.9 (63.9–67.9), 67.4 (66.0–68.7), 64.1 (63.1–65.1), 59.1 (58.2–60.0), 49.1 (49.0–49.2), 34.9 (34.0–35.8), 24.6 (23.5–25.8), 15.6 (14.0–17.3), and 6.6 (4.8–8.9) among those who were born in the year 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, and 2000, respectively. The present study demonstrated a clear birth-cohort pattern of H. pylori infection in the Japanese population. The decreased prevalence of H. pylori infection in successive generations should be weighed in future gastric cancer control programs.

Risk Factors and Prevalence of Helicobacter pylori Infection in Persistent High Incidence Area of Gastric Carcinoma in Yangzhong City

Aim. The aim of this study was to investigate the prevalence and risk factors of H. pylori infection in areas with high prevalence of gastric cancer in Jiangsu Province, China. Methods. A prospective epidemiologic survey of H. pylori infection was accomplished in a natural population of 5417 individuals in Yangzhong city. Questionnaires and 13C-urea breath test for H. pylori infection were performed. Results. Among 5417 subjects who completed questionnaires and 13C-urea breath test, 3435 (63.41%) were H. pylori positive. The prevalence reached a peak at the age of 30–39 years (90.82%). There was significant difference between sexes and women had a higher infection rate than men. The prevalence of H. pylori infection was also associated with eating kipper food and fried food. No association between H. pylori prevalence and smoking or drinking was found. Compared to healthy individuals, people with dyspeptic diseases (peptic ulcer, gastroenteritis) presented a high prevalence of H. pylori infection. Using multivariate logistic regression analysis, age and history of peptic ulcer and gastroenteritis were the independent predictors for H. pylori infection. Conclusions. Yangzhong city had a high prevalence of H. pylori infection and was related to several risk factors. The underlying mechanisms are needed to be further investigated.

Helicobacter pylori: a poor man's gut pathogen?

Helicobacter pylori is one of the human pathogens with highest prevalence around the world; yet, its principal mode of transmission remains largely unknown. The role of H. pylori in gastric disease and cancer has not been established until the end of the 20^th century. Since then, its epidemiology has been extensively studied, and an accruing body of literature suggests that not all humans are equally at risk of infection by this gut pathogen. Here, we briefly review the different epidemiological aspects of H. pylori infection with emphasis on those factors related to human poverty. The epidemiology of H. pylori infection is characterized by marked differences between developing and developed countries, notably among children. In addition, congruent lines of evidence point out to socioeconomic factors and living standards as main determinants of the age-dependent acquisition rate of H. pylori, and consequently its prevalence. These data are alarming in the light of the changing global climate and birth rate, which are expected to change the demography of our planet, putting more children at risk of H. pylori and its complications for years to come.

Helicobacter pylori: a poor man's gut pathogen?

Helicobacter pylori is one of the human pathogens with highest prevalence around the world; yet, its principal mode of transmission remains largely unknown. The role of H. pylori in gastric disease and cancer has not been established until the end of the 20th century. Since then, its epidemiology has been extensively studied, and an accruing body of literature suggests that not all humans are equally at risk of infection by this gut pathogen. Here, we briefly review the different epidemiological aspects of H. pylori infection with emphasis on those factors related to human poverty. The epidemiology of H. pylori infection is characterized by marked differences between developing and developed countries, notably among children. In addition, congruent lines of evidence point out to socioeconomic factors and living standards as main determinants of the age-dependent acquisition rate of H. pylori, and consequently its prevalence. These data are alarming in the light of the changing global climate and birth rate, which are expected to change the demography of our planet, putting more children at risk of H. pylori and its complications for years to come.

Presence of high numbers of transcriptionally active Helicobacter pylori in vomitus from Bangladeshi patients suffering from acute gastroenteritis

BACKGROUND

Helicobacter pylori is one of the most prevalent human bacterial pathogens; however, its transmission pathways remain unknown. New infections of H. pylori during outbreaks of gastroenteritis have been suggested previously, and to explore this transmission route further H. pylori was quantified in vomitus and diarrheal stool of patients suffering from acute gastroenteritis in Dhaka, Bangladesh.

MATERIALS AND METHODS

Vomitus and stool samples from 28 patients seeking care at the International Centre for Diarrhoeal Disease Research hospital were analyzed for presence of H. pylori and other pathogens using quantitative culturing, real-time polymerase chain reaction (PCR), and H. pylori stool antigen test. Bacterial gene expression was analyzed using reverse transcriptase real-time PCR.

RESULTS

The results of real-time PCR show that 23 (88%) of the 26 vomitus samples and 17 (74%) of the 23 stool samples were H. pylori positive, while stool antigen test show that 14 (67%) of the 21 stool samples were H. pylori positive. H. pylori could not be isolated by culture. Analysis using quantitative culture and real-time PCR to detect Vibrio cholerae showed strong correlation between these methods, and validating real-time PCR. Analysis of H. pylori virulence gene transcription in vomitus, diarrheal stool, antral and duodenal biopsy specimens, and in vitro cultures showed that cagA, flaA, and ureA were highly transcribed in vomitus, biopsy specimens, and cultures, whereas hpaA and vacA were expressed at lower levels. No H. pylori gene expression was detected in diarrheal stool.

CONCLUSIONS

We conclude that high numbers of transcriptionally active H. pylori are shed in vomitus, which indicates that new infections may be disseminated through vomiting.

The decreasing burden of gastric cancer in Japan

Gastric cancer in Japan, previously the top killer cancer, has recently shown decreased incidence and mortality rates. Epidemiological studies have demonstrated that environmental factors are closely associated with stomach oncogenesis, as evident from the geographical differences seen throughout Japan in both incidence and mortality. Moreover, Japanese immigrant populations gradually exhibit the lower incidence and mortality rates of gastric cancer in their chosen country. Likewise, younger generations in Japan have lower mortality rates than older generations at the same age, which may be accounted by the dramatic lifestyle changes in Japan after World War II. In addition to exploring and learning from the impact of these environmental factors, deliberate strategies to further lower the incidence and mortality rates of gastric cancer must include aggressive eradication programs for Helicobacter pylori and dietary education in both school curricula and for the general adult population to lower the intake of causative agents such as salt and increase the intake of beneficial agents such as fruits, vegetables and seaweeds. The dietary education should be coupled with better motivation for the general population to undergo regular screening with improved techniques. In the future, changes in these environmental factors and progresses in the diagnosis of and therapeutic strategies for gastric cancer will lead to further decrease in the incidence and mortality rates of this disease in Japan.

Tobacco smoking and gastric cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

BACKGROUND

We evaluated the association between tobacco smoking and gastric cancer risk among the Japanese population based on a systematic review of epidemiologic evidence.

METHODS

Original data were collected by searches of MEDLINE using PubMed, complemented with manual searches. Evaluation of associations was based on the strength of evidence and the magnitude of association, together with biological plausibility, as evaluated previously by the International Agency for Research on Cancer.

RESULTS

Ten cohort studies and 16 case-control studies were identified. In men, most studies reported moderate or strong positive associations between smoking and gastric cancer. In women, the positive association was weaker than in men. Of eight studies (three cohort studies and five case-case control studies), two cohort and three case control studies reported a weakly to strongly increased risk of gastric cancer. The summary relative risk for current smokers was estimated to be 1.56 (95% confidence intervals 1.36-1.80), 1.79 (1.51-2.12), 1.22 (1.07-1.38) for the total population, men and women, respectively.

CONCLUSION

We conclude that there is convincing evidence that tobacco smoking moderately increases the risk of gastric cancer among the Japanese population.

Community-based familial study of Helicobacter pylori infection among healthy Japanese Brazilians

BACKGROUND

The present study of Helicobacter pylori infection was conducted in family units of Japanese Brazilians living in São Paulo city. The authors attempted to determine the seroprevalence of H. pylori infection within family units of Japanese Brazilians and to identify risk factors associated with intrafamilial transmission.

METHODS

The seroprevalence was determined in 1037 healthy and asymptomatic volunteer subjects aged 0-69 years (530 adults and 507 children) of 265 families. Demographic data and details of living conditions were obtained from each family.

RESULTS

H. pylori seropositive infection was found in 39.2% of the parents and 9.3% of the children. A reduced risk of H. pylori infection was found for girls (odds ratio [OR] 0.45; 95% confidence interval [CI], 0.23-0.86). The prevalence of infection was 3.5% for children with uninfected parents; 9.9% (OR, 2.51; 95% CI, 0.95-6.61) for those with a seronegative mother and a seropositive father; 14.9% (OR, 4.93; 95% CI, 1.86-13.06) for those with a seropositive mother and a seronegative father; and 16.0% (OR, 5.29; 95% CI, 1.98-14.14) for those with seropositive parents. On multivariate analysis, the use of a pacifier, and mother's symptoms of nausea and vomiting were significantly associated with the risk of H. pylori infection for children, and the child having her/his own room was significantly associated with a reduced risk. Income was not associated with H. pylori infection in children and was inversely associated in parents.

CONCLUSION

The prevalence of H. pylori infection in family units of Japanese Brazilians supports the hypothesis of a predominant role for mother-child transmission of H. pylori infection, mainly through contact with regurgitated gastric juice in the mother's mouth.

Helicobacter pylori Infection among Patients Visiting a Clinic in Kasama City, Ibaraki Prefecture

We examined Helicobacter pylori infection in patients who visited the Iso Clinic (Kasama City, Ibaraki Prefecture) with abdominal complaints, and determined the prevalence of H. pylori infection by age, sex, endoscopic diagnosis, abdominal complaint, gastric mucosa, and living environment. Peptic ulcer disease was observed in 23.2% of the patients examined with endoscopy, but there was no association between abdominal complaints and the prevalence of H. pylori infection. The prevalence of H. pylori infection was high among patients with peptic ulcer disease and atrophic gastritis. The prevalence of H. pylori infection was higher in the generation born before tae start of the period of rapid economic growth (71.5%) than in the generation born afterward (64.8%). No significant difference was observed between males and females. The prevalence of H. pylori infection was high in those who drank well water during childhood and those who were raised in a house with a nonflushing of toilet (67.2% and 67.5%, respectively). There were no associations with river basin of residence, alcohol consumption, or smoking. The prevalence of H. pylori infection among patients who visited Iso Clinic was higher than that among patients seen at Tama-Nagayama Hospital, Nippon Medical School (Tama City, Tokyo). The difference is attributable to the higher prevalence of H. pylori infection in the elderly.

Individual and joint impact of family history and Helicobacter pylori infection on the risk of stomach cancer: a nested case-control study

We used 202 cases of stomach cancer and 394 controls nested within the Japan Collaborative Cohort Study For Evaluation of Cancer Risk (JACC study) to investigate whether family history has an independent effect on the risk of stomach cancer after controlling for the Helicobacter pylori infection. A positive history of stomach cancer in one or more first-degree relatives was associated with an increased risk of the disease in women, but not in men after controlling for H. pylori infection and other confounding variables. Women with both a family history and H. pylori infection were associated with more than five-fold increased risk of the disease (OR 5.10, 95% CI 1.58–16.5) compared to those without these factors. These results suggest the existence of inherited susceptibility to the disease in women, and that measurements of H. pylori infection together with the family history allow meaningful evaluation of risk beyond that provided by either factor alone.

Seroconversion and seroreversion of Helicobacter pylori antibodies over a 9-year period and related factors in Japanese adults

BACKGROUND

There are still insufficient data on the frequency of seroconversion and seroreversion of Helicobacter pylori antibodies. The frequency of serochange and related factors were investigated in this study over 9 years.

SUBJECTS AND METHODS

Using sera from 3104 workers who underwent health checks in 1989 and again in 1998, H. pylori antibodies were measured. Those with intermediate serology were excluded from the study. Information on past history was collected using a questionnaire.

RESULTS

Of the 912 seronegative and 1286 seropositive subjects in 1989, seroconversion was observed in 57 and seroreversion in 91 subjects. Seroconversion and seroreversion rates over the 9-year period were 6.3% and 7.1%, respectively, giving rates per 1000 person-years (with 95% confidence interval) of 7.0 (5.2-8.7) and 7.9 (6.3-9.4), respectively. Subjects that reported abdominal symptoms or gastric fiberscope use showed significantly higher seroconversion rates than controls (8.7 vs. 4.5 and 9.2 vs. 1.6, respectively), which remained significant after adjustment for age and gender. Those with a history of duodenal ulcers, a smoking habit or a drinking habit showed significantly lower seroreversion rates than controls (3.5 vs. 8.9, 5.4 vs. 9.2 and 5.9 vs. 13.3, respectively). After adjustment, the association between seroreversion and smoking habit disappeared, while the associations with history of duodenal ulcers and drinking habit remained.

CONCLUSIONS

Those with a history of nonspecific abdominal symptoms and those with a history of gastric fiberscope use showed higher seroconversion rates. Alcohol consumption and duodenal ulcers may inhibit the autoeradication of H. pylori, possibly through increased acid secretion.

Relationship of smoking and coffee and alcohol consumption with seroconversion to Helicobacter pylori: a longitudinal study in hospital workers

BACKGROUND AND AIM

There are few data concerning the relationship between Helicobacter pylori seroconversion, and smoking habits and coffee and alcohol consumption. The aim of the present study was to investigate the relationship between smoking habits, coffee and alcohol consumption, and H. pylori seroconversion.

METHODS

The data used were derived from a sample of 238 subjects (hospital employees) who were initially (on 1994) seronegative to H. pylori. These subjects were tested again 5 years later (1999). Information concerning smoking habits and coffee and alcohol consumption was collected by the use of a special questionnaire, which was completed by the same cohort of subjects in two different periods (1994 and 1999). Logistic regression was used to assess the relationship between H. pylori seroconversion and the aforementioned lifestyle factors.

RESULTS

Neither smoking nor coffee consumption was significantly related to H. pylori seroconversion. Adjusted odds ratio for alcohol drinkers as compared with non-/occasional drinkers was 0.59 (95% confidence interval [CI]: 0.31-1.16, P = 0.13). However, the odds ratio was significantly lower (0.26, 95%CI: 0.07-0.95, P = 0.042) in subjects who reported moderate alcohol consumption at first (1994) examination, as compared with non-/occasional drinkers. Small and heavy drinking were not associated with H. pylori seroconversion.

CONCLUSIONS

There is no significant relation between H. pylori seroconversion and smoking and coffee consumption. The present findings suggest that moderate alcohol consumption might be inversely associated with H. pylori seroconversion.

Helicobacter pylori risk associated with childhood home environment

Helicobacter pylori (H. pylori) is considered to be a cause of gastric ulcer, gastric cancer and other diseases. The relationship between infection and the hygiene or housing circumstances of such patients in their childhood was explored. The study subjects were those who applied for a H. pylori antibody test, and were asked to fill out a questionnaire enclosed with a test kit, inquiring as to their hygiene and housing conditions when they were 10 years old. Of 5971 applicants, 5854 agreed to participate in the study. Associations between the six factors in the questionnaire and infection were calculated, and adjusted for sex, age and district. Drinking water, type of toilet, residential area, number of people in the house, and birth order showed significant correlations with H. pylori infection. The odds ratios (95% confidence intervals) were 0.73 (0.55-0.96) for tap water, 0.72 (0.63-0.84) for flush toilets, 0.74 (0.66-0.83) for urban location, 1.34 (1.09-1.64) for 7 or more people in the household, 1.19 (1.00-1.41) for 4th or 5th in birth order, and 1.47 (1.17-1.85) for 6th or more in birth order. No significant association with breast feeding was observed. These results suggest that infection with H. pylori may be associated with water-related sanitary factors in childhood, and that the bacillus may be transmitted within a family.

Gastric cancer

The past decade has seen many advances in knowledge about gastric cancer. Notably, tumour biology and lymphatic spread are now better understood, and treatment by surgical and medical oncologists has become more standardised. Since refrigerators have replaced other methods of food conservation, Helicobacter pylori has become a factor in the cause of gastric cancer. Cancers that arise at the oesophagogastric junction might be further examples of wealth-associated disease. To tailor treatment better, the western hemisphere needs to borrow from the East by establishing screening programmes for early diagnosis, through careful surgical resection, and through detailed analysis of tumour spread. In Europe and the USA, most patients reach treatment with cancers already at an advanced stage. For these patients, three important randomised trials are underway that evaluate combined therapy. Cytostatic drugs, especially angiogenesis inhibitors have proved disappointing; however, basic research efforts to detect familial gastric cancers and to assess minimally residual disease look more hopeful.

Long-term effect of smoking on serum pepsinogen values

BACKGROUND

The serum pepsinogen I to II ratio (PG I/II) is related to the risk of stomach cancer. Smoking is an established risk factor for stomach cancer. The effect of smoking on the change in PG I/II over a 7-year span was investigated.

METHODS

Data were from 1889 male subjects who underwent phlebotomy in both 1989 and 1996. The subjects were classified into smoking and non-smoking groups: those who continued smoking, and those who never smoked during the span. The subjects were stratified by Helicobacter pylori status (negative or positive) and age (20-29 or 30-56 years in 1989), and the change in PG I/II was compared between the smoking and the non-smoking groups.

RESULTS

PG I/II increased less (age adjusted mean +/- standard error of the difference was 0.209 +/- 0.069, p < 0.001) and less frequently in the smoking group (65.8% versus 58.9%, p = 0.002), but these differences were not clear among H. pylori-positive subjects.

CONCLUSIONS

The less frequent increase (i.e. a more frequent decline) in PG I/II may be a long-term effect of smoking, although the effect is not clear under H. pylori infection. The decline may be one of the mechanisms through which smoking elevates the risk of stomach cancer.

[Epidemiological aspects of Helicobacter pylori infection in childhood and adolescence]

The scope of the review is to study the epidemiological aspects of Helicobacter pylori infection and its importance during childhood and adolescence, focusing on incidence, prevalence, transmission and risk factors. The study's references included the following databases: LILACS (PAHO/ Bireme), MEDLINE, the US's National Library of Medicine and the thesis developed at University of São Paulo for the period 1983 to 1999. It was noted that Helicobacter pylori infection is mainly acquired during childhood, age-related prevalence, main risk factors are associated to low socioeconomic status, and its transmission mechanism remains unclear.

Helicobacter pylori infection in rural China: demographic, lifestyle and environmental factors

BACKGROUND

Although Helicobacter pylori is one of the most common human bacterial infections worldwide, its mode of transmission is unclear.

METHODS

To investigate possible associations between H. pylori infection and demographic, lifestyle, and environmental factors in a rural Chinese population, a cross-sectional survey was administered to 3288 adults (1994 seropositive, 1019 seronegative, 275 indeterminate) from 13 villages in Linqu County, Shandong Province, China.

RESULTS

Helicobacter pylori prevalence was elevated for: infrequent handwashing before meals (OR = 1.7, 95% CI: 1.0-3.0), crowding (i.e. sharing a bed with >2 people [OR = 2.3, 95% CI: 1.3-4.2]), washing/bathing in a pond or ditch (OR = 1.5, 95% CI: 1.0-2.4), and medium (OR = 1.6, 95% CI: 1.3-2.0) and low (OR = 2.3, 95% CI: 1.9-2.9) compared to high village education level, and reduced for never being married or divorced (OR = 0.4, 95% CI: 0.2-1.0). There was also a suggestion that source of drinking water, especially water from a shallow village well might be related to H. pylori seropositivity. There was no evidence of an association between H. pylori prevalence and alcohol or tobacco use, raw fruit and vegetable intake, or individual social class measures.

CONCLUSIONS

The results of this study suggest that person-to-person transmission is the most plausible route of H. pylori infection in this rural Chinese population, but waterborne exposures deserve further investigation.

Relation of Helicobacter pylori infection and lifestyle to the risk of chronic atrophic gastritis: a cross-sectional study in Japan

To examine the mutual association of risk factors for both Helicobacter pylori (H. pylori) infection and chronic atrophic gastritis (CAG), a cross-sectional study on 954 residents of a rural town in Japan was conducted. Using an unconditional logistic model, we calculated the odds ratios (ORs) for H. pylori infection according to each lifestyle, as well as the ORs for CAG according to each lifestyle and H. pylori infection. A significant positive association was observed between H. pylori infection and the risk of CAG (OR = 6.29). On the other hand, a significant negative association was observed between high consumption of light-colored vegetables and the risk of CAG (OR = 0.68). We also used a path analysis to examine the direct relations of gender, age, and lifestyle variables to CAG, as well as the indirect relations of these variables to CAG through H. pylori infection. Aging had a significantly direct positive association with CAG. Although aging also had an indirect positive association with CAG through H. pylori infection, aging had no association with the consumption of light-colored vegetables. The high consumption of light-colored vegetables showed no association with H. pylori infection but had a significantly direct negative association with CAG. The results of this study suggest a possibility that high light-colored vegetables consumption contributes to the prevention of CAG.

Helicobacter pylori seropositivity among 963 Japanese Brazilians according to sex, age, generation, and lifestyle factors

Seropositivity of anti-Helicobacter pylori antibody (HP + ) was examined among Japanese Brazilians. The study was announced through 18 Japanese community culture associations in São Paulo, Curitiba, Mogi das Cruzes, and Mirandopolis in 2001. Among 969 participants, 963 individuals aged 33 - 69 years were analyzed. The overall HP + % was 48.1% (95% confidence interval, 44.9 - 51.3%). There was no difference in HP + % between 399 males and 564 females (49.6% and 47.0%, respectively). The HP + % increased with age; 35.3% for those aged 33 - 39 years, 46.2% for those aged 40 - 49 years, 46.5% for those aged 50 - 59 years, and 56.9% for those aged 60 - 69 years, but no differences were observed among the generations (Issei, Nisei, and Sansei) for each 10-year age group. Mogi das Cruzes, a rural area, showed a higher HP + %. Length of education was inversely associated with the positivity; the odds ratio (OR) relative to those with eight years or less of schooling was 0.61 (0.42 - 0.89) for those with 12 years or more. The associations with smoking and alcohol drinking were not significant. Fruit intake was associated with the HP + %; the OR relative to everyday intake was 1.38 (1.05 - 1.83) for less frequent intake, while intake frequencies of green tea, miso soup, and pickled vegetables (tsukemono) were not. Multivariate analysis including sex, 10-year age group, residence, education, and fruit intake showed that all factors except sex were significant. This is the largest study of HP infection among Japanese Brazilians, and the results indicated a similar pattern of age-specific infection rate to that for Japanese in Japan.

Helicobacter pylori prevalences and risk factors among school beginners in a German urban center and its rural county

In 1998, the Helicobacter pylori [(13)C]urea breath test was offered to all school beginners (birth cohort 1991/1992) in the city of Leipzig and in Leipzig County, Germany, to determine the colonization prevalence and potential transmission pathways of the bacterium. A total of 3,347 school beginners participated in the test, and 2,888 parents completed the detailed, self-administered questionnaire. The H. pylori prevalence was 6.5% [95% confidence interval (CI), 5.3-7.6] in the city and 5.7% (CI, 4.2-7.0) in the county. Using cluster analysis (WARD's method, Euclidean distances), we identified different sets of variables (confirmed by multivariate logistic regression analyses [odds ratios (ORs)] that are signficantly associated with H. pylori positivity. Among city children, the risk is significantly increased with contact to a pet hamster (OR = 2.4; 95% CI, 1.2-4.7; p < 0.015) and travels to Asian countries (OR = 3.7; 95% CI, 1.6-8.7; p < 0.002). Among county children, H. pylori positivity increased significantly with drinking of water from nonmunicipal sources (OR = 16.4; 95% CI, 3.1-88.5; p < 0.001), more than 3 children living in a household (OR = 4.2; 95% CI, 1.2-14.6; p < 0.02), and contact with pet hamsters (OR = 2.4; 95% CI, 1.0-5.7; p < 0.04). These data suggest that, in a general population sample, indirect fecal-oral transmission and living conditions are important risk factors in the spread of H. pylori infection. However, clinical symptoms do not necessarily indicate H. pylori positivity.

Effect of age on the relationship between gastric cancer and Helicobacter pylori. Tokyo Research Group of Prevention for Gastric Cancer

Helicobacter pylori is thought to be involved in the pathogenesis of gastric cancer, but the time point at which it produces its effects (critical time) is unknown. We measured the serum level of H. pylori antibody in 787 gastric cancer patients and 1007 controls aged 20 to 69. Odds ratios for different gastric cancer types and stages were determined for each 10-year age class. The overall odds ratio for gastric cancer decreased with age, being 7.0 for those aged 20 - 29, 14.5 for those aged 30 - 39, 9.1 for those aged 40 - 49, 3.5 for those aged 50 - 59, and 1.5 for those aged 60 - 69 (trend in odds ratios: P < 0.01). However, there was no such age-dependent trend for early diffuse-type cancer; the odds ratios were 12.6, 4.0, 7.2, 6.5, and 18.5 respectively (P = 0.29). Early cancer tended to show higher seroprevalence than advanced cancer, especially in older subjects. No significant difference in seroprevalence was observed between diffuse and intestinal cancers within each age-class. Seroreversion must have occurred in the time interval between the critical time and the diagnosis of the cancer, especially in older patients. The age-dependent relationship between H. pylori and gastric cancer may be due to seroreversion, which itself may be independent of age. This age-independence indicates that prolonged exposure to H. pylori does not increase the magnitude of its influence on gastric carcinogenesis. Possible mechanisms through which H. pylori exerts pathogenic effects are continuous inflammation in adulthood and / or irreversible damage to gastric mucosa in childhood or the teenage years.

Long-term effect of Helicobacter pylori infection on serum pepsinogens

Serum pepsinogen values are markers of gastric mucosal status and of gastric cancer risk. The effect of Helicobacter pylori infection and sibship size on change of serum pepsinogen values over a seven-year span was investigated. Data from 2584 subjects with phlebotomy were analyzed both in 1989 and in 1996. The subjects were classified by H. pylori serology and sibship size (1 - 3 vs. 4 and more). Pepsinogen I (PG I) to II (PG II) ratio in '96 minus that in '89 was defined as DeltaPG I / II and compared among the groups. DeltaPG I / II was lower and decrease of PG I / II was more frequent among H. pylori-positive subjects than among negative subjects. The difference was owing to a decrease of PG I in all subjects and owing to an increase of PG II in those not younger than 30 years in '89. In H. pylori-positive subjects, those with a larger sibship size showed lower DeltaPG I / II and higher frequency of PG I / II decline. H. pylori infection exerts a reducing effect on PG I / II during the seven-year span. The effect of H. pylori is stronger among those with a larger sibship size, who are expected to have been infected with H. pylori in childhood. Inducing atrophy of gastric mucosa, which is reflected by a decline of PG I / II, may be one of the mechanisms through which H. pylori elevates the risk of gastric cancer.

Relationship between Helicobacter pylori infection and smoking and drinking habits

BACKGROUND

Helicobacter pylori is a major cause of various gastroduodenal diseases. Some risk factors related to H. pylori infection have been reported; however, studies on the relationship between H. pylori infection and smoking or drinking habits have given conflicting results. In the present study, these relationships were investigated by collecting sera and information from 8837 subjects.

METHODS

Serum H. pylori immunoglobulin G antibody was measured by an enzyme-linked immunoassay. In addition to sex and age, information on smoking and drinking habits was collected by questionnaire. Age- and sex-adjusted odds ratios (95% confidence interval) of smoking and alcohol consumption were calculated for H. pylori seropositivity using logistic regression models.

RESULTS

Current smokers had a 0.82 (0.74-0.91)-fold greater risk of H. pylori seropositivity than those who had never smoked. Current cigarette consumption showed a dose-dependently negative association with H. pylori seropositivity, and the association between smoking and H. pylori infection was strong in younger subjects. Current drinkers had a 0.88 (0.79-0.98)-fold greater risk of H. pylori seropositivity than those who had never drunk alcohol. The volume of alcohol consumed showed a negative association with H. pylori seropositivity.

CONCLUSIONS

In the current study, smoking was negatively associated with H. pylori infection. The risk of H. pylori seropositivity decreased linearly with cigarette consumption per day. Increased gastric acidity in the stomach through smoking may be a cause of the dose-dependently negative association between H. pylori and smoking. Drinking was negatively and dose-dependently associated with H. pylori positivity, although the effect of drinking was weaker than that of smoking.