Relation between infection with Helicobacter pylori and living conditions in childhood: evidence for person to person transmission in early life

Does maternal smoking hinder mother-child transmission of Helicobacter pylori infection?

Evidence for early childhood as the critical period of Helicobacter pylori infection and for clustering of the infection within families suggests a major role of intrafamilial transmission. In a previous study, we found a strong inverse relation between maternal smoking and H. pylori infection among preschool children, suggesting the possibility that mother-child transmission of the infection may be less efficient if the mother smokes. To evaluate this hypothesis further, we carried out a subsequent population-based study in which H. pylori infection was measured by 13C-urea breath test in 947 preschool children and their mothers. We obtained detailed information on potential risk factors for infection, including maternal smoking, by standardized questionnaires. Overall, 9.8% (93 of 947) of the children and 34.7% (329 of 947) of the mothers were infected. Prevalence of infection was much lower among children of uninfected mothers (1.9%) than among children of infected mothers (24.7%). There was a strong inverse relation of children's infection with maternal smoking (adjusted odds ratio = 0.24; 95% confidence interval = 0.12-0.49) among children of infected mothers, but not among children of uninfected mothers. These results support the hypothesis of a predominant role for mother-child transmission of H. pylori infection, which may be less efficient if the mother smokes.

Seroepidemiology of Helicobacter pylori infection in a Jamaican community

We researched epidemiologic associations between environmental and demographic factors and prevalence of Helicobacter pylori infection in a suburban Jamaican community. Using a clustered sampling technique, 22 domestic yards enclosing 60 separate households were randomly selected from a local community. All household members (n = 346) were invited to participate following informed consent; the overall compliance rate was 58.9%. A commercial enzyme immunoassay (HMáCAP) was used to detect IgG antibodies raised against H. pylori. Environmental and demographic information was obtained by questionnaire. The seroprevalence of H. pylori was 69.9% (n = 202). Analysis of the independent variables revealed three major components: Component 1 described, collectively, good personal hygiene and sanitation, indoor water supply and absence of straying animals in the peridomestic area; Component 2 included older age, good personal hygiene and large yard size; Component 3 the presence of domestic animals (cats and dogs) and, again, large yard size. These three complexes explained 42.2% of the variability in the data set. Logistic regression showed that Components 2 and 3 were independently associated with H. pylori seropositivity, indicating that a combination of demographic, environmental and zoonotic factors is involved in the spread of H. pylori infections at the tropical community level.

Effect of cagA status on the sensitivity of enzyme immunoassay in diagnosing Helicobacter pylori-infected children

BACKGROUND

The aims of our study were twofold. First, we sought to evaluate in symptomatic children the influence of the Helicobacter pylori genotype on gastritis, abdominal pain, and circulating anti-H. pylori IgG antibodies (anti-H. pylori IgG) or pepsinogen A (PGA) and C (PGC). Additionally, we sought to assess anti-H. pylori IgG, PGA, and PGC patterns in a large cohort (N = 921) of asymptomatic children.

MATERIALS AND METHODS

In 183 symptomatic children, H. pylori infection and the presence of gastritis were evaluated by histology. In a subgroup of 20 H. pylori-positive children, the H. pylori genotype was evaluated also by polymerase chain reaction. Nine hundred and twenty-one asymptomatic children, aged 11 to 14 years, were studied by anti-H. pylori IgG, PGA, and PGC serum determination.

RESULTS

The infection was found in 33 of 183 symptomatic children; among the 20 H. pylori-positive children for which the H. pylori genotype was available, cagA was present or absent in equal percentages. H. pylori infection was associated with more severe gastritis and higher serum levels of anti-H. pylori IgG and PGC but not with abdominal pain. In infected children, higher levels of anti-H. pylori IgG and the presence of abdominal pain were associated with infections caused by cagA-positive strains. In the cohort of 921 asymptomatic children, raised levels of anti-H. pylori IgG, PGA, and PGC were found in approximately 5% of the cases.

CONCLUSIONS

Infection with cagA-positive H. pylori strains can be associated with increased frequency of reported abdominal pain and higher circulating levels of anti-H. pylori IgG. The serological assessment of H. pylori IgG using H. pylori antigens containing significant amounts of cagA protein may, therefore, underestimate the true prevalence of infection.

Influence of Helicobacter pylori infection on the phenotype of Crohn's disease

OBJECTIVE

Very little is known about the impact of Helicobacter pylori (H. pylori) infection on Crohn's disease. In this study we investigated a possible influence of H. pylori on the phenotype of Crohn's disease.

METHODS

Patients with Crohn's disease who had gastric biopsy between 1990 and 1994 and a clinical follow-up in our outpatient clinic for at least 2 yr were included in the study. The mean number of flare-ups per year of follow-up, the mean numbers of intestinal resections per year of disease duration, and primary disease location were compared in H. pylori-positive and -negative patients. Various regression models were calculated to test the influence of H. pylori status on these parameters, correcting for smoking habits and disease duration.

RESULTS

Of 131 patients, 50 (38.2%) were H. pylori positive and 62 (47.3%) were smokers. Due to a significant interaction between smoking habits and H. pylori infection, regression models were calculated separately for smokers and nonsmokers. Nonsmokers without H. pylori infection had more flare-ups than nonsmokers with H. pylori infection (0.77 [0.57-0.97] vs 0.29 [0.16-0.42]; p < 0.01; mean [95% confidence interval]). In contrast, nonsmokers without H. pylori infection had less intestinal resections than nonsmokers infected with H. pylori (0.08 [0.04-0.12] vs 0.11 [0.07-0.15]; p < 0.05). These differences were not significant for smokers (p < 0.41 and p < 0.07). There was a predominance of small bowel disease in H. pylori-positive patients, which did not reach statistical significance.

CONCLUSIONS

Our data indicate that H. pylori influences the phenotype of Crohn's disease, especially in nonsmokers.

Low rates of Helicobacter pylori reinfection in children

BACKGROUND & AIMS

Reinfection after treatment for Helicobacter pylori is uncommon in adults. It is more likely to occur in children because they acquire primary infection. The aim of this study was to determine whether children are likely to become reinfected with H. pylori and if there are any risk factors for reinfection.

METHODS

A prospective study of children who had documented evidence of successful treatment for H. pylori infection was performed. Sixty children were eligible for inclusion; results for 52 are presented. Children, parents, and siblings underwent [(13)C]urea breath tests. Details of family size and socioeconomic status were documented. Cox logistic regression analysis was used to determine the risk factors for reinfection.

RESULTS

The duration of follow-up was 103.8 patient-years (mean +/- SD, 24 +/-14.0 months). Forty-six (88.5%) of the index children remained clear of infection, and 6 (11.5%) children were reinfected. The mean age of those who became reinfected was 5.8 +/- 5.6 years compared with 12.3 +/- 3.0 years for those who remained clear of infection (P = 0.00001). Only 2 of 46 (4.3%) children older than 5 years of age were reinfected, although 80.8% had 1 infected parent and 65% of siblings were infected. Reinfection rate was 2.0% per person per year in children older than 5 years. Living with infected parents and siblings and low socioeconomic status were not risk factors for reinfection. In logistic regression analysis, age was the only risk factor for reinfection.

CONCLUSIONS

Reinfection with H. pylori occurs rarely in children older than 5 years of age regardless of socioeconomic group or number of infected family members. These findings also indicate that it is not necessary to treat all family members to achieve long-term eradication of H. pylori.

Helicobacter pylori in the Canadian arctic: seroprevalence and detection in community water samples

OBJECTIVE

Many North American arctic communities are characterized by risk markers associated with Helicobacter pylori (H. pylori) infection, including overcrowded housing and inadequate water supply and sanitation systems. Our aim was to determine the seroprevalence of H. pylori infection in two traditional Inuit communities in the central Canadian arctic and to test for the presence of H. pylori, by polymerase chain reaction (PCR), in local water supplies.

METHODS

Samples of venous whole blood from adults and capillary blood from children were collected and analyzed by enzyme immunoassay and Helisal Rapid Test, respectively, for IgG antibody to H. pylori. Antibodies to CagA were detected by enzyme immunoassay, and ABO and Lewis antigens were also determined. Demographic and clinical information were collected by questionnaire. Water samples from each community were tested for H. pylori by PCR.

RESULTS

One hundred-thirty (50.8%) of 256 subjects from the two communities were positive for H. pylori IgG antibodies. Seropositive subjects were more likely to be male, compared with seronegative individuals (p = 0.01). Antibody status did not differ with respect to age, community, alcohol or cigarette use, number of persons per household, gastrointestinal complaints or previous investigations, medications, or presence of blood group O, Lewis a-b+. CagA antibodies were detected in 78 (61.9%) of 126 H. pylori-seropositive subjects tested; however, 41 (35.3%) of 116 H. pylori-seronegative subjects were also CagA positive. Water samples taken from the water delivery truck in Chesterfield Inlet and two lakes near Repulse Bay were positive for H. pylori.

CONCLUSION

The seroprevalence of H. pylori in the study group was higher than rates in southern Canadian populations, but lower than the seroprevalence previously documented in a Canadian subarctic Indian (First Nations) community. The detection of H. pylori in local water supplies may indicate a natural reservoir for the organism or possible contamination from human sewage.

Seroprevalence of Helicobacter pylori and length of stay in a nursing home

BACKGROUND

Helicobacter pylori infection appears to be contracted mainly in childhood, and it is associated with disadvantaged socioeconomic conditions, overcrowding, and living in institutions. In this study we determined the seroprevalence of H. pylori among elderly patients (age > or = 70 years) admitted to a major medical center in Israel, and studied the relationship between seroprevalence of H. pylori and the duration of stay in a nursing home prior to the admission.

PATIENTS AND METHODS

Whole blood from 182 consecutive patients hospitalized at the Rabin Medical Center was tested for the presence of anti-H. pylori IgG using Helisal Rapid Blood Test kit (Cortecs Diagnostics). Multivariate logistic regression analysis was used to study the relation between H. pylori seropositivity and possible predictive factors such as age, gender and duration of stay in a nursing home.

RESULTS

Of the 182 patients included in the study, 80 (44%) were living in nursing homes (NH) and 102 (56%) were living in their own homes (H) prior to admission. Subjects that stayed in nursing homes for more than 15 months were significantly more likely to be seropositive than subjects with a shorter duration of stay (84% and 63% respectively, p = 0.03). Using a multivariate logistic regression analysis on both the NH group and the whole group, seropositivity was found to be significantly associated with duration of stay in a nursing home (p = 0.03 and p = 0.01 respectively). Seropositivity was not associated with age in either group.

CONCLUSIONS

Living in a nursing home is associated with increased risk for H. pylori infection in the elderly. There is a strong correlation between the duration of stay in a nursing home and the prevalence of H. pylori infection.

Transmission of Helicobacter pylori

Helicobacter pylori is found predominantly in human gastric mucosa. Transfer of the bacterium remains an open topic, but it is likely that infection is usually acquired at a young age, particularly where lower socio-economic conditions prevail. Transmission via an external source such as water supply is a possibility but, in general, infection is probably passed from person to person. Arguments for and against faecal-oral, oral-oral and gastric-oral transmission have been presented, but the dominance of one of these routes is still to be determined.

Seroprevalence of Helicobacter pylori, incidence of gastric cancer, and peptic ulcer-associated hospitalizations in a Canadian Indian population

The living conditions of many aboriginal communities in Canada may place their residents at risk for H. pylori infection. Our aims were to determine: (1) the seroprevalence of H. pylori in a traditional Indian community, (2) the clinical relevance of H. pylori infection in this population, and (3) if H. pylori could be identified by polymerase chain reaction from the local water. A demographic questionnaire was administered, and blood was collected from subjects in an Indian community in northwestern Manitoba. The serum was analyzed by ELISA for IgG to H. pylori and to CagA. ABO and Lewis antigens were tested. Age-adjusted incidence of gastric cancer and of hospitalizations associated with diagnoses of peptic ulcer were determined for the Indian and non-Indian Manitoba population in the years 1989-1993. Nested PCR was performed on lake water using H. pylori-specific primers and the amplicons probed with an internal Dig-labeled probe. Three hundred six (59%) of approximately 518 individuals who were resident in the community at the time of the study were enrolled. The ELISA for H. pylori was positive in 291 (95%). There was no association between H. pylori seropositivity and age, sex, gastrointestinal complaints, medications, housing characteristics, and ABO or Lewis antigen status. CagA was positive in 84.5% of infected subjects. The average annual age-adjusted incidence of hospitalizations associated with diagnoses of peptic ulcer disease in Manitoba was higher for treaty-status Indians (394.3/100,000) than for non-Indians (203.8/100,000), but gastric cancer rates were similar (11.2/100,000 vs 11.6/100,000). No H. pylori DNA was detected in the lake water. In conclusion, the seroprevalence of CagA-positive H. pylori is high in this representative Manitoban Indian community. This may be associated with an increased risk for peptic ulcer disease but is not associated with an increased risk for gastric cancer.

Helicobacter pylori seropositivity in patients with severe neurologic impairment

The objective of this study was to assess the prevalence of Helicobacter pylori seropositivity in institutionalized patients with severe neurologic impairment. Anti-H. pylori immunoglobulin G antibody in serum was measured in 196 institutionalized Japanese patients using enzyme linked immunosorbent assay, taking an antibody level >50 units/ml as evidence of H. pylori seropositivity. Patient age pattern and duration of institutionalization were examined for the relationships with H. pylori seropositivity. We also examined for seroconversion indicating new H. pylori infection in initially negative patients 1 year later. Positivity for H pylori infection among institutionalized patients was also compared with positivity among patients living at home. H. pylori seropositivity was present in 81.1% of subjects. Prevalence of H. pylori seropositivity increased with both age and duration of institutionalization. The serum level of anti-H. pylori immunoglobulin G antibody in patients over 20 years old was consistently high, approximately twice that of subjects less than 10 years of age. Of 38 patients initially negative for H. pylori infection, 18 (47.4%) had become positive at 1 year. H. pylori seropositivity was significantly more prevalent among institutionalized patients than among patients living at home (P < 0.0001). This study confirms that high H. pylori seropositivity rates are found among institutionalized patients with severe neurologic impairment. Our observations suggest person to person transmission, with fecal to oral, salivary secretion and respiratory droplet routes possibly being important pathways.

Non-invasive testing for Helicobacter pylori

Confirmed and potential benefits of eradicating Helicobacter pylori have led to the development of a range of diagnostic tests. As well as techniques using biopsy tissue obtained during endoscopy, a number of non-invasive tests are now available. These may be appropriate for pre-endoscopy screening of younger dyspeptics, for use in research, particularly epidemiological surveys, to confirm successful eradication after treatment, and possibly in the future for screening in asymptomatic populations. Serology requiring laboratory analysis is likely to be the least expensive option, particularly suitable for testing large numbers, while urea breath tests should yield the most accurate results and are appropriate for confirming successful eradication since only current infection is detected. The performance of near-patient tests can lack consistency, but these may be useful for small numbers and where other non-invasive testing is unavailable. Tests should be used with an awareness of their potential limitations in terms of accuracy.

A role for Helicobacter pylori in the gastrointestinal complaints of eating disorder patients?

Eating disorder patients frequently present with gastrointestinal complaints. Helicobacter pylori is an etiologic factor in type B gastritis, gastric and duodenal ulcers, and may cause nausea and anorexia.

OBJECTIVE

To determine whether or not there is an increased prevalence of H. pylori infection in patients with eating disorders.

METHOD

Serum H. pylori IgG antibody and gastrointestinal symptoms were assessed in 32 patients admitted for inpatient treatment of anorexia nervosa and/or bulimia nervosa.

RESULTS

Eating disorder patients did not have an increased rate of detectable serum H. pylori IgG antibody.

DISCUSSION

There is not an increased prevalence of H. pylori infection in eating disorder patients. Thus, the increased frequency of gastrointestinal complaints in eating disorder patients cannot be attributed to H. pylori infection.

Peptic ulcer disease and exposure to domestic pets

OBJECTIVES

This study assessed whether an association exists between household pets and peptic ulcer disease.

METHODS

Canadian adults (n = 15,779) were asked about cats or dogs in their household and about history of peptic ulcer disease. Logistic regression was used to assess the association between pet ownership and a history of peptic ulcer disease, after adjustment for sociodemographic differences.

RESULTS

No relationship was observed between report of household pets and a history of peptic ulcer disease (adjusted odds ratio = 1.14, 95% confidence interval = 0.95, 1.36).

CONCLUSIONS

In a large sample of Canadian adults, no association was observed between pet ownership and a history of peptic ulcer disease.

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

Helicobacter pylori is thought to be a cause of gastric cancer. Risk factors of H. pylori positivity were investigated among 4,361 public service workers in Japan. Sera and information on family history and lifestyle were collected, and H. pylori antibody was measured using the sera. Sex- and age-adjusted odds ratios of factors expected to influence H. pylori seropositivity were calculated. The factors with a significant influence were included in a logistic regression model and the final model was obtained by backward elimination. Sibship size (4 and more vs. 1), smoking habit (current vs. never), and paternal and siblings' histories of gastric diseases showed significant relationships to H. pylori seropositivity, with odds ratios (95% confidence intervals) of 1.5 (1.0-2.1), 0.8 (0.7-0.9), 1.5 (1.3-1.8) and 1.7 (1.1-2.6) respectively. However, spouse's history was not related. In the final model, sibship size and paternal history remained as positive factors, and smoking as a negative one. Contradictory results on the relationship between H. pylori status and smoking among recent studies indicate the existence of hidden confounding factors. It is suggested that infection from family members in childhood considerably affects the H. pylori status of Japanese adults, whereas infection between adults is rare.

Seroprevalence of Helicobacter pylori in a longitudinal study of New Zealanders at ages 11 and 21

BACKGROUND

Helicobacter pylori seroprevalence increases with age in adult life but spontaneous reversion may occur in childhood and adolescence.

AIMS

To determine the seroprevalence of H. pylori in a longitudinal study of New Zealanders at ages 11 and 21.

METHODS

Serum from members of the Dunedin Multidisciplinary Health and Development Study (DMHDS) at age 11 (n = 561; 303 males, 258 females) and 21 (n = 785; 413 males, 372 females) was tested for H. pylori antibodies. A large proportion of those tested at age 11 was retested at age 21 (n = 465; 262 males, 203 females). Serological status was examined in terms of gender, socioeconomic status (SES) and self-reported use of antibiotics.

RESULTS

The seroprevalence of H. pylori decreased by 38% from 6.6% (37/561) at age 11 to 4.1% (32/785) at age 21. Seroprevalence at age 11 was not associated with gender or SES. For those tested at both ages, the drop in seroprevalence from 6.7% to 4.1% was statistically significant (t = 2.57, p < 0.01, paired t-test) and was much greater in females (71%) than males (12%). Of the 31 seropositive individuals at age 11, 17 (six males, 11 females) seroreverted and self-reported antibiotic use in the year preceeding age 21 was more common in females (eight/11) than males (zero/six). Of the 434 seronegative individuals at age 11, only five (four males, one female) had seroconverted at age 21.

CONCLUSIONS

Seroprevalence in the DMHDS declined from age 11 to 21 predominantly in females. The decline involved a greater rate of seroreversion and lower rate of seroconversion in females than males.

Pets are not a risk factor for Helicobacter pylori infection in young children: results of a population-based study in Southern Germany

BACKGROUND

Helicobacter pylori may have multiple routes of transmission. It is unclear, however, whether the agent is also zoonotic and therefore transmitted from an animal reservoir.

AIMS

The aim of this population-based study was to assess the relationship of exposure to pets and H. pylori infection among children in a population-based sample in Ulm, a city in the South of Germany.

SUBJECTS AND METHODS

All children of German nationality who were to attend first grade in the school year 1996/1997 were included in the study. The 13C-urea breath test was used to determine active infection status. In addition the parents filled out a questionnaire to provide information about pets in the household as well as living conditions and socioeconomic factors of the family.

RESULTS

Of 927 eligible preschool children 685 (74%) participated in the study. Prevalence of infection was 6.3%. Infection with H. pylori was not positively associated with contact with pets in general (p = 0.720) or to a specific kind of animal in bivariate and multivariable analyses as evaluated by means of logistic regression.

CONCLUSIONS

These results suggest that pets in the household are not a risk factor for H. pylori infection among children in this population.

Suggestion against an oral-oral route of transmission for Helicobacter pylori infection: a seroepidemiological study in a rural area

In this study the seroepidemiology of H. pylori and Epstein-Barr virus was compared in the same setting. A sample of 705 subjects completed a structured questionnaire. A serum sample was drawn from each subject and assayed for H. pylori IgG. Antibodies to Epstein-Barr virus were determined in a subgroup of 466 subjects. Cross-tabulation of data showed that 274 (58.8%) subjects were seropositive and 20 (4.3%) were seronegative for both infections, 17 (3.6%) were seropositive for H. pylori, and 155 (33.3%) were seropositive for Epstein-Barr virus (odds ratio=2.08, 95% confidence interval: 1.008-4.3). Nevertheless, the agreement between H. pylori and Epstein-Barr virus seropositivity was no better than chance (kappa=0.067) and the age-related seroprevalence curve of Epstein-Barr virus was similar in H. pylori seropositive and seronegative subjects. Furthermore, multiple logistic regression analysis did not show any risk factor shared by both infections. The findings of this study do not support the hypothesis that H. pylori and Epstein-Barr virus share a common mode of transmission. It can be speculated that the oral cavity may not be an important reservoir for H. pylori.

Why is mortality higher in poorer areas and in more northern areas of England and Wales?

STUDY OBJECTIVE

To identify and quantify the factors responsible for the differences in mortality between affluent and deprived areas, the north and the south, and urban and rural areas in England and Wales.

DESIGN

A multiple Poisson regression analysis of cause specific mortality in the 403 local authority districts, each classified by deprivation (using the Jarman Index), latitude (from 50 degrees to 55 degrees north) and urbanisation, adjusting for age, sex, and proportion of ethnic minorities.

SETTING

England and Wales 1992.

MAIN RESULTS

All cause mortality was 15% higher in the districts comprising the most compared with the least deprived tenth of the population, 23% higher in the most northern (55 degrees) than in the most southern (50 degrees) districts, and 4% higher in metropolitan (within large cities) than rural districts. Nationally these differences were associated with 40,000, 65,000, and 15,000 excess deaths respectively. More than two thirds of the overall excess mortality with deprivation, latitude, and urbanisation was from three diseases--ischaemic heart disease, lung cancer, and chronic bronchitis and emphysema. The excess mortality from these and other diseases closely matched that predicted from differences according to deprivation and latitude in smoking, heavy alcohol consumption, Helicobacter pylori infection, and temperature, and thus could be attributed to these causes. About 85% of the overall excess mortality with deprivation was attributable to heavier smoking and 6% to heavier alcohol consumption, but diet varied little. Deaths more directly related to deprivation (such as those caused by H pylori infection, drug misuse, psychoses) accounted for an estimated 12% of the excess deaths, but variation in provision and uptake of healthcare services only 1%. The direct effects of deprivation are more strongly related to morbidity than mortality. Of the difference in mortality with latitude, about 45% was attributable to differences in smoking, and 25% to climate (mainly the association of cardiovascular and respiratory disease with cold). The differences with urbanisation were mainly because of smoking.

CONCLUSIONS

Differences in the prevalence of smoking account for much of the variation in mortality between areas. Alcohol accounts for some, diet little. The more direct material effect of deprivation contributes to the variation in mortality but is particularly important with respect to differences in morbidity.

Transmission of canine gastric Helicobacter salomonis infection from dam to offspring and between puppies

H. bizzozeronii CCUG 35045, a new canine gastric Helicobacter spp. was used for experimental infection of four weaned puppies at 7 weeks of age. Controls were four nonchallenged puppies. The puppies originated from two dams which had Helicobacter salomonis infection in biopsy samples taken 3 weeks before the delivery but which had urease, brush cytology and culture-negative biopsy samples taken 7 weeks after antimicrobial treatment (metronidazole, amoxicillin, bismuth subcitrate). Both dams were detected urease- and Helicobacter-positive again three and a half months after therapy. Dam B was shown to be colonised with the similar genotype of H. salomonis for more than 2 years. Unexpectedly, H. salomonis was also cultured from gastric biopsy samples of the nonchallenged puppies three times during 7 months. When H. salomonis isolates of dams and puppies were studied by ribotyping (HaeIII, ClaI or PstI) they were shown to be identical although the HaeIII and PstI REA patterns of dam A differed from the patterns of dam B and nonchallenged group by one fragment. PFGE pattern analysis of NotI digests, however, revealed that the isolates of the puppies were identical with the isolates of dam B, and differed from the isolates of dam A. The isolates of the dams and puppies in the nonchallenged group were metronidazole-resistant. The antimicrobial therapy had merely suppressed, but not eradicated, the infection from dams. These studies suggested that puppies may acquire gastric Helicobacter infection from dams during the lactation period and puppies can infect each other during their early life. PFGE pattern analysis was shown to be a more distinguishing method than ribotyping to study the similarity of the isolates.

Helicobacter pylori

Helicobacter pylori infection causes peptic ulcer disease, gastric adenocarcinoma, gastric lymphoma, and probably nonulcer dyspepsia. Although the prevalence of infection is declining over time, the organism still infects approximately one half of the world's population. Only a minority will ever suffer serious consequences from their infection. This article reviews current knowledge about H. pylori and presents some of the dilemmas surrounding clinical and public health approaches to this widespread pathogen.

The prevalence of Helicobacter pylori in practising dental staff and dental students

Recent studies suggest Helicobacter pylori is spread by faecal-oral or oral-oral transmission. Gastroenterologists who are exposed to gastric secretions and saliva have a high prevalence of H. pylori infection. Venous blood was obtained from 92 dentists, 40 dental nurses, 33 fifth year and 30 first year dental students. An ELISA assay was used to detect H. pylori IgG antibodies. Results were compared with an age and sex matched normal population. The prevalence of H. pylori infection in dentists, dental nurses, fifth year dental students and first year dental students were 23 per cent, 18 per cent, 18 per cent and 16 per cent, respectively. There were no significant differences when compared with the normal population controls. The prevalence of H. pylori antibody was not significantly increased with years of practice or patient contact time in dentists and dental nurses. Helicobacter pylori infection is uncommon in dental professionals working in the oral cavity.

Socioeconomic status and ulcer. A prospective study of contributory risk factors

Peptic ulcer is associated with low socioeconomic status. In this study we used longitudinal population-based data to investigate factors other than Helicobacter pylori that might contribute to this association. Of 4597 Alameda County Study participants, 104 developed ulcers between 1965 and 1974. We examined the impact of baseline risk factors on the association between education and incident ulcer. Among women, high school dropouts had a higher risk of incident ulcer than those who attended college (age-adjusted odds ratio [OR], 3.3; 95% confidence interval [CI], 1.5, 7.3). Adjustment for smoking, alcohol, lack of sleep, skipping breakfast, chronic pain, and liver disease eliminated 21.7% of this excess risk, whereas adjustment for psychological characteristics and life stress eliminated 56.5% of the risk; adjusted for all risk factors, the OR was 1.9. Among men, the risk associated with low education was weaker (OR, 1.9; 95% CI, 0.9, 3.9). Health risk behaviors and poor health had a greater impact (55.5% drop in excess risk with adjustment) and psychosocial factors a lesser impact (33.3% drop) in men than in women. Adjustment for heavy on-the-job labor decreased the risk by 77.8%, whereas the fully adjusted OR was 1.0. We conclude that psychological stress, health risk behaviors, analgesic use, and hard physical labor may contribute to the increased risk of ulcer in low socioeconomic populations.

Salivary immunoglobulin G assay to diagnose Helicobacter pylori infection in children

An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-specific immunoglobulin G (IgG) and IgA in saliva was evaluated by comparison with histopathologic (Giemsa staining) and biochemical (urease quick test) examination of gastric biopsy specimens obtained from 112 children referred for diagnostic gastroscopy. Serum H. pylori IgG was also measured in a subgroup of 50 children by the same ELISA. Salivary H. pylori IgG levels were significantly higher in H. pylori-positive (n = 57) than in H. pylori-negative (n = 55) children (P < 0.001). The sensitivity and specificity of the salivary IgG test were 93 and 82%, respectively; the positive and negative predictive values were 84 and 92%, respectively; and the accuracy was 87.5%. Salivary H. pylori IgA did not distinguish H. pylori-positive from H. pylori-negative children. The performance of serum H. pylori IgG was slightly (3 to 6%) better than that of salivary H. pylori IgG. The salivary IgG test can be considered a useful tool for the screening of H. pylori infection in children.

Can therapy even be denied for Helicobacter pylori infection?

Helicobacter pylori infection is a transmissible bacterial infection of the gastric mucosal surface that causes progressive damage with eventual destruction of the stomach. In the United States, the presence of H. pylori infection in patients carries a lifetime risk of developing peptic ulcer of at least 16% and a 1%-3% risk of developing gastric cancer. An infected individual is also a risk to the community because the infection can be transmitted. A review of the data shows that H. pylori is the only treatable infectious disease with such a high rate of morbidity and mortality that is not the subject of an all-out program to eradicate it from the population. The risk of a serious outcome of untreated asymptomatic H. pylori infection is great, or greater, than with asymptomatic syphilis or tuberculosis. H. pylori infection is a serious public health problem, and thus the presence of H. pylori infection justifies treatment. The question is not whom to treat, but whom to test. The gastroenterology community appears to have been unduly influenced by the fact that H. pylori infection is widespread and often asymptomatic, as well as by the costs and complications of current treatment. H. pylori infection is a serious, worldwide infectious disease with tremendous and unacceptable morbidity and mortality. Although there are no emotional reasons to treat H. pylori infection, there are logical and persuasive scientific reasons to treat. If the tools are available, screening the population for the presence of H. pylori infection with the goal of preventing all H. pylori-related diseases is recommended. Our goal should be to totally eliminate H. pylori from the face of the earth, just as we eliminated smallpox.

Helicobacter pylori infection: a seroepidemiological study in Gipuzkoa, Basque Country, Spain

Helicobacter pylori is one of the most common bacterial infections worldwide. To evaluate the prevalence of this infection in Gipuzkoa (Basque Country, Spain) we studied the presence of antibodies against Helicobacter pylori (HPAb) using a second-generation EIA (Cobas Core). The study was performed on two groups of subjects: a middle-class group, 2-78 years-old (n = 1335) and a group of slum dwellers, 2-15 years-old (n = 89). In the middle-class group the prevalence of HPAb in children under 6 was 3.1% (3/96); the prevalence was significantly greater in older compared to younger age groups, reaching 84.3% (102/121) in adults 50-59 years. The geometric mean of the titer in seropositive subjects was also greater in older age groups. By logistic regression analysis the prevalence of HPAb was associated with age, educational level and geographic origin but not with sex, smoking, alcohol consumption, or use of nonsteroid anti-inflammatory drugs. The prevalence of HPAb was much higher in the slum-dwelling group 2-15 years-old (55.5% of children 2-5 years-old). The results indicate that H. pylori infection was more common in adult people from our geographic region than in those from other developed countries and show that socioeconomically deprived children constitute at present a group at high risk of acquiring infection in our region.

Proposed link between Helicobacter pylori and sudden infant death syndrome

Helicobacter pylori may be linked to sudden infant death syndrome (SIDS) through synthesis of inflammatory cytokines, particularly interleukin-1, which can produce fever, activation of the immune system, and increased deep sleep. A relatively minor respiratory or enteric infection, together with overwrapping and prone sleep position could then induce terminal hypoxemia. Alternatively, H. pylori produces large amounts of urease which, if aspirated in gastric juice, could reach the alveolae, react with plasma urea, and produce ammonia toxicity leading to respiratory arrest. Epidemiological similarities between H. pylori and SIDS are presented along with possible transmission mechanisms for H. pylori which support this hypothesis.

Peptic ulcer bleeding in the elderly: relative roles of Helicobacter pylori and non-steroidal anti-inflammatory drugs

BACKGROUND

Most ulcers are caused, one can deduce, by Helicobacter pylori or by use of non-steroidal anti-inflammatory drugs (NSAIDs). Whether both together are worse than one alone is something that is quite unknown.

AIM

To study both factors in order to see wither they interact together positively.

METHOD

A case control study of ulcer bleeding in elderly patients chosen without weeding.

RESULTS

NSAID usage increased risk substantially. So did H pylori infection (but relative risk less than three). Neither seemed to interact. Their actions were discretely intact.

CONCLUSION

H pylori effects ulcer bleeding in an adverse manner but does not make the risk of NSAIDs worse.

Growth in infancy, infant feeding, childhood living conditions, and Helicobacter pylori infection at age 70

AIM

To examine childhood correlates of Helicobacter pylori infection in adults.

DESIGN

Follow up study of men and women whose birth weight, weight at age 1 year, and feeding in infancy were recorded by health visitors. Data on childhood housing conditions were obtained by recall.

SUBJECTS

631 men and 389 women born in Hertfordshire during 1920-30 and still living in the east or northwest districts of the county.

MAIN OUTCOME MEASURES

Serum H pylori IgG antibodies measured by enzyme linked immunosorbent assay.

RESULTS

Independent of their current social class, subjects were more likely to be H pylori seropositive if they had large numbers of siblings (p < 0.0001), and if they had lived in a crowded house (p = 0.001), or shared a bedroom or bed in childhood (p = 0.02). Low weight at 1 year was associated with increased seropositivity rates in men (p = 0.0002), but not women (p = 0.8). Men and women who were breast fed in infancy were less likely to be seropositive than those who were bottle fed (p = 0.08).

CONCLUSIONS

The findings support the current view that H pylori infection is often acquired in childhood by close person to person contact, and persists into adult life. H pylori infection may be a cause of failure to thrive in infancy, especially in boys. Alternatively, small infants may be more susceptible to infection. Breast feeding may prevent early infection.

Recurrence of Helicobacter pylori infection after successful eradication: nature and possible causes

Recurrence of Helicobacter pylori infection after successful eradication occurs and is associated with relapse of gastroduodenal diseases. The aims of this paper were to assess the incidence and identify the nature and possible causes of recurrence of the infection. A broad-based Medline search was performed to identify all related publications addressing recurrence of the infection between 1986 and 1995. The 12-month recurrence rate varied among the different studies from 0 to 41.5%. A few studies showed 18- to 24-month recurrence rates, which ranged between 0 and 21.4%. Limited data, obtained using molecular fingerprinting techniques, have shown that in most cases recurrence is due to recrudescence of the original strain; a few cases appear to be due to reinfection with a new strain. Recrudescence is most likely during the first 12 months after apparent eradication. Despite the high sensitivity and specificity of the available individual tests for detecting H. pylori infection in untreated patients, no technique alone is sensitive enough to monitor eradication when the four-week-rule definition for eradication is used. A combination of two or more techniques increases sensitivity. Sensitivity and specificity are increased when biopsies are taken from both gastric antrum and corpus. The best treatments have the lowest recurrence rates and recurrence is rare when the eradication rate is over 90%. Individual susceptibility and reexposure to H. pylori are suggested as two major causes of reinfection.

Seroepidemiology of Helicobacter pylori infection and hepatitis A in a rural area: evidence against a common mode of transmission

BACKGROUND AND AIMS

Recent studies have shown that the age-specific seroprevalence of H pylori infection parallels hepatitis A (HAV), suggesting similar modes of transmission. The aim of this study was to investigate the seroepidemiology of H pylori and HAV in the same setting.

PATIENTS

A sample of 705 resident subjects (273 men, age range 1-87 years, median 50) who attended the outpatient medical centre of the rural town of Cirò, Southern Italy (11,000 inhabitants) for blood testing were recruited.

METHODS

All subjects completed a structured questionnaire. A serum sample was drawn from each subject and assayed for H pylori IgG by a validated in house enzyme linked immunosorbent assay. Antibodies to HAV were determined in 466 subjects (163 men, age range 1-87 years, median 49). A measure of agreement between H pylori and HAV seropositivity, the kappa statistic, was used.

RESULTS

Overall, 446 (63%) subjects were seropositive for H pylori. Of the 466 subjects screened for both H pylori and HAV, 291 (62%) were seropositive for H pylori and 407 (87%) for HAV. Cross-tabulation of these data showed that 275 (59%) were seropositive and 43 (9%) seronegative for both H pylori and HAV, 16 (3%) were seropositive for H pylori, and 132 (28%) were seropositive for HAV (OR = 5.6, CI 3 to 10). There was a parallel, weakly correlated (r = 0.287) rise in the seroprevalence of the two infections with increasing age. However, the agreement between H pylori and HAV seropositivity was little better than chance (kappa = 0.21) and in those aged less than 20 years it was worse than chance (kappa = -0.064). Furthermore, multiple logistic regression analysis did not show any risk factor shared by both infections.

CONCLUSIONS

The correlation between H pylori and HAV reflects the age-specific seroprevalence of both infections rather than a true association. This study provides evidence against a common mode of transmission of H pylori and HAV.

Helicobacter pylori acquisition in infancy after decline of maternal passive immunity

We evaluated the natural history of Helicobacter pylori infection and the host immune response in 80 infants, and determined seroprevalence of H. pylori infection in their Taiwanese mothers. Decline in passively transferred maternal anti-H. pylori IgG antibodies and subsequent H. pylori infection was assessed in infants over 14 mo. A sensitive and specific, 96-well microtiter ELISA for the detection of H. pylori IgG antibodies was used to evaluate maternal serum (single specimen) and their infants (birth, 1, 2, 3, 6, 12, and 14 mo). Sera were also evaluated by ELISA for the presence of anti-H. pylori IgM antibodies in the infants. Maternal H. pylori IgG seroprevalence was 62.5% [50/80; 95% confidence intervals (CI), 51-73%]. All infants born to the 50 seropositive mothers passively acquired maternal H. pylori IgG. Transplacentally transferred maternal anti-H. pylori IgG lasted until about the 3rd mo of life, and disappeared in nearly all the infants by 6 mo of age. Seven and one-half percent of infants (6/80; 95% CI, 3-16%) acquired H. pylori infection; two were born to H. pylori-negative mothers. Among the six IgG seropositive infants, an IgM response specific for H. pylori antigens was detected and appeared to precede the rise in IgG in five. We conclude that maternal passive transfer of IgG antibodies occurs in the infant and disappears by 6 mo of age. H. pylori infection is acquired in infancy in this population; IgM antibodies against H. pylori are detectable, seem short-lived, and appear to precede IgG antibody development.

Invasive Helicobacter-like organisms in feline gastric mucosa

BACKGROUND

Helicobacter-like organisms (HLOs) usually are present in the stomachs of cats. Although the histopathology of natural (H. felis or H. heilmannii) infections has been reported, their invasion into the lymphoid aggregates has not been described previously.

MATERIALS AND METHODS

Gastric tissues were obtained from 17 adult cats living in a natural urban environment. Biopsy sites were selected by the presence of urease on the mucosal surface stained by Genta stain and periodic acid-Schiff stain.

RESULTS

Spiral organisms morphologically similar to H. felis or to H. heilmannii were detected in all the cats, distributed predominantly over the oxyntic mucosa. Seven cats had prominent lymphoid follicles with germinal centers within the oxyntic mucosa, and in six of these seven cats, extracellular organisms were present within the lymphoid follicles. Scattered organisms also were found over sites of gastric metaplasia in the duodenum of six cats.

CONCLUSIONS

This study extends previous observations by showing that HLO infection in cats is associated with large lymphoid follicles in the stomach. In addition, HLOs were demonstrated submucosally within gastric lymphoid follicles and on patches of gastric metaplasia in the duodenum.

Serum IgG antibodies to Helicobacter pylori in patients with recurrent aphthous stomatitis and other oral disorders

OBJECTIVES

To compare the frequency of serum anti-Helicobacter pylori IgG antibodies in patients with recurrent aphthous stomatitis with patients with other oral ulcerative and nonulcerative disorders.

STUDY DESIGN

Prospective study of serum IgG antibodies to H. pylori in 75 patients with recurrent aphthous ulcers, 15 patients with other oral ulcerative disorders, 41 patients with other oral mucosal lesions, 27 patients with oral dysaesthesia, and 25 healthy control patients without oral lesions.

RESULTS

The frequency of anti-H, pylori seropositivity was not significantly greater in patients with recurrent aphthous stomatitis (30.6%) compared with patients with other ulcerated oral mucosal lesions (33.0%) and controls (24%).

CONCLUSIONS

Helicobacter pylori does not appear to be of etiologic significance in the development of recurrent aphthous stomatitis.

Sociodemographic, hygienic and nutritional correlates of Helicobacter pylori infection of young Bangladeshi children

BACKGROUND

By the age of 10 years most children in developing countries have been infected by Helicobacter pylori Identification of clues to modes of transmission of this organism to children, as well as evaluation of the sequelae of childhood infections, constitute important research priorities for developing countries.

OBJECTIVES

To evaluate demographic, socioeconomic and hygienic factors associated with acquisition of infection by H. pylori early in childhood among Bangladeshi children ages 2 to 5 years and to assess whether infection by H. pylori was associated with poor nutritional status in these children and in an older group ages 6 to 9 years.

METHODS

A random population-based survey of 257 rural Bangladeshi children ages 2 to 5 years and 312 children ages 6 to 9 years. Seropositivity for H. pylori, as manifested by the presence of serum IgG anti-H. pylori antibodies, was correlated with nutritional status of the sampled children and with sociodemographic features and access to clean water and latrine facilities among families of the children.

RESULTS

Among children ages 2 to 5 years, the 123 (48%) who were infected by H. pylori were similar to the 134 noninfected children with respect to socioeconomic level, family access to tube well water and family ownership of a latrine. However, families of infected children had more persons per sleeping room in the home (3.8 vs. 3.2, P < 0.05) and were more likely to be Hindu (20% vs. 10%, P < 0.05). Infected children did not differ significantly from noninfected children in Z scores for weight-for-age (-2.66 vs. -2.78), weight-for-height (-1.17 vs. -1.28) or height-for-age (-3.58 vs. -3.56). Analysis of survey children ages 6 to 9 years also revealed similar nutritional indexes among infected vs. noninfected children.

CONCLUSIONS

Household crowding and behaviors that differ between Hindus and Muslims, but not lack of access to clean water and latrines, may enhance the transmission of H. pylori to rural Bangladeshi children. Although confirming the high frequency of infections in young Bangladeshi children, our findings do not support the notion that H. pylori is responsible for the high prevalence of malnutrition in this setting.

Socioeconomic factors in Helicobacter pylori infection among Danish adults

OBJECTIVES

This study examined the relationship between housing conditions, educational level, occupational factors, and serologically diagnosed acute and chronic Helicobacter pylori infection.

METHODS

Immunoglobulin G and immunoglobulin M serum antibodies against H. pylori were measured in 3589 Danish adults who participated in a population study.

RESULTS

Low socioeconomic status (odds ratio [OR] = 2.2, 95% confidence interval [CI] = 1.7, 3.0), short duration of schooling (OR = 2.0, 95% CI = 1.3, 2.5), lack of training/education (OR = 1.4, 95% CI = 1.2, 1.7]), unskilled work (OR = 1.7, 95% CI = 1.2, 2.5), and high work-related energy expenditure (OR = 1.4, 95% CI = 1.1, 1.9) increased the likelihood of chronic H. pylori infection. Infection was frequent in people who had lived abroad. Increased levels solely of immunoglobulin M antibodies were found more often in people who were divorced (OR = 2.3, 95% CI = 1.2, 4.4) or unmarried (OR = 2.0, 95% CI = 1.1, 3.8) or who worked long hours (OR = 2.0, 95% CI = 1.1, 4.0).

CONCLUSIONS

Educational and occupational factors relate to the likelihood of chronic H. pylori infection in adults. The rate of acute infection is high in single individuals.

Prevalence of Helicobacter pylori infection in different ethnic groups in New Zealand children and adults

BACKGROUND

Helicobacter pylori infection is a major risk factor for peptic ulcer disease and gastric cancer. A study of patients with dyspepsia attending for gastroscopy showed significant differences in H. pylori seropositivity between ethnic groups.

AIMS

To determine the prevalence of H. pylori in children and adults in the community in different ethnic groups and to identify risk factors for infection.

METHODS

Serum samples (324) were randomly selected from a cross-sectional survey of 11-12 year old school children with a high proportion of Maori and Pacific Island groups. Serum samples (579) were randomly selected from a cross-sectional workforce survey of 5677 participants aged 40-64 years. Serum samples were tested for H.pylori IgG.

RESULTS

The percentage seropositivity in 11-12 year old children was European 7%, Maori/part Maori 21%, all Pacific Island groups 48% and for the workforce survey 35.8%, 57.4% and 73.2% respectively. Compared with Europeans the increased relative risk of seropositivity for H.pylori in Maori and Pacific Island participants was significant after adjusting for age and socio-economic status (1.43 [1.13, 1.80] and 1.76 [1.43, 2.18]) respectively. The relative risk of H.pylori infection significantly increased with age, lower socio-economic status and lower household income, but was not significantly associated with gender, alcohol or cigarette use.

CONCLUSIONS

The high seroprevalence of H.pylori in Maori and Pacific Island groups is consistent with the differences in incidence of gastric cancer. H.pylori continues to be a common infection in Maori and Pacific Island school children. Ethnicity appears to be a risk factor for H.pylori independent of socio-economic status.

Local immune response in Helicobacter pylori-infected cats and identification of H. pylori in saliva, gastric fluid and faeces

Helicobacter pylori-infected cats were screened by culture and polymerase chain reaction (PCR) for the presence of H. pylori in salivary secretions, gastric juice, gastric tissue and faeces. H. pylori was cultured from salivary secretions in six of 12 (50%) cats and from gastric fluid samples in 11 of 12 (91%) cats. A 298 base pair polymerase chain reactions (PCR) product specific for an H. pylori 26000 MW surface protein was amplified from dental plaque samples from five of 12 (42%) cats and from the faeces of four of five (80%) cats studied. Analyses of serum and mucosal secretions by enzyme-linked immunosorbent assay (ELISA) revealed an H. pylori-specific immunoglobulin G (IgG) response, and elevated IgA anti-H. pylori antibody levels in salivary and local gastric secretions. Immunohistochemical analyses of gastric tissue revealed the presence of IgM+ B cells assembled into multiple lymphoid follicles surrounded by clusters of CD4+ and CD8+ T cells. The lamina propria also contained single cells or aggregates of IgA+ and IgM+ B cells. These observations show that H. pylori can be identified in feline mucosal secretions, and that a localized IgA immune response develops in gastric tissue of H. pylori-infected cats. The findings suggest a zoonotic risk from exposure to personnel handling H. pylori-infected cats in vivaria.