Are there susceptible hosts to Helicobacter pylori infection?

Helicobacter pylori: Perturbation and restoration of gut microbiome

Alternate remedies with natural products provides unlimited opportunities for new drug development. These can be either as pure compounds or as standardized set of compounds. The phytochemicals and secondary metabolites are in great demand for screening bioactive compounds and plays an important role towards drug development. Natural products have many advantages over to synthetic chemical drugs. Helicobacter pylori (H. pylori) a Gram-negative bacteria has been classified as Class I carcinogen by World Health Organization in 1994. Current treatment regimens for H. pylori is ‘triple therapy’ administrated for two weeks which includes a combination of two antibiotics like Amoxicillin and Clarithromycin and a proton pump inhibitor (PPI) like Lansoprazole, and for ‘quadruple therapy’ in addition to antibiotics and a PPI, Bismuth is used. Antibiotic resistance can be named as the main factor for failure of treatment of H. pylori infection. The need of the hour is to develop a herbal remedy that could combat the growth of H. pylori. Probiotics can also be used as ‘feasible’ tool for H. pylori infection management. Present review is an attempt to briefly discuss about the pathogenicity, genetic predisposition, perturbation of gut microbiota due to antibiotic treatment and restoration of healthy gut microbiota with phytochemicals and probiotics.

Helicobacter Pylori "Test-and-Treat" Strategy for Management of Dyspepsia: A Comprehensive Review

OBJECTIVES:

Deciding on whether the Helicobacter pylori test-and-treat strategy is an appropriate diagnostic–therapeutic approach for patients with dyspepsia invites a series of questions. The aim present article addresses the test-and-treat strategy and attempts to provide practical conclusions for the clinician who diagnoses and treats patients with dyspepsia.

METHODS:

Bibliographical searches were performed in MEDLINE using the keywords Helicobacter pylori, test-and-treat, and dyspepsia. We focused mainly on data from randomized controlled trials (RCTs), systematic reviews, meta-analyses, cost-effectiveness analyses, and decision analyses.

RESULTS:

Several prospective studies and decision analyses support the use of the test-and-treat strategy, although we must be cautious when extrapolating the results from one geographical area to another. Many factors determine whether this strategy is appropriate in each particular area. The test-and-treat strategy will cure most cases of underlying peptic ulcer disease, prevent most potential cases of gastroduodenal disease, and yield symptomatic benefit in a minority of patients with functional dyspepsia. Future studies should be able to stratify dyspeptic patients according to their likelihood of improving after treatment of infection by H. pylori.

CONCLUSIONS:

The test-and-treat strategy will cure most cases of underlying peptic ulcer disease and prevent most potential cases of gastroduodenal disease. In addition, a minority of infected patients with functional dyspepsia will gain symptomatic benefit. Several prospective studies and decision analyses support the use of the test-and-treat strategy. The test-and-treat strategy is being reinforced by the accumulating data that support the increasingly accepted idea that “the only good H. pylori is a dead H. pylori”.

Prevalence of Helicobacter pylori genotypes (vacA, cagA, cagE and virB11) in gastric cancer in Brazilian's patients: an association with histopathological parameters

PURPOSE

To investigate the frequency and the association of vacA alleles, cagA, cagE and virB11 genes of Helicobacter pylori from patients with gastric cancer, considering the clinic histopathological parameters.

METHODS

One hundred and one gastric adenocarcinoma tissues were assessed by PCR to detect H. pylori and vacA alleles, cagA, cagE and virB11.

RESULTS

The distribution of cases according to the presence of the genes studied showed that the group containing vacA s1m1, cagA, cagE and virB11 H. pylori genes was significantly more frequent, followed by the group with at least one marker on the right side and left of the island. They were also present in the early stages and were the most frequent in nearly all histopathological grades.

CONCLUSIONS

This study verified that vacAs1m1 and cag-PAI genes, cagA, cagE and virB11 are important H. pylori markers for gastric cancer development. Also, this study corroborates the importance of cagE and cagA together as cag-PAI marker.

Antimicrobial therapy of peptic ulcers

It is now accepted that peptic ulcer disease, whether duodenal or gastric, is one manifestation of infection with the bacterium Helicobacter pylori. This realization has revolutionized the management of peptic ulcer disease and changed the dictum from no acid no ulcer, to no H. pylori, no ulcer. When confronted with a patient with peptic ulcer disease, the physician must now ask whether H. pylori infection is present and if so, attempt to cure it. The gastric milieu is a very difficult environment for effective antimicrobial therapy. Nevertheless, current multi-drug antimicrobial therapy can be expected to cure the infection in more than 80% of patients. Cure of the infection is associated with a very low rate of recurrence. The continued risk of serious disease or disease complications associated with treatment failure and the availability of the urea breath test to non-invasively assess the results of therapy suggest that post therapy assessment should be routine. Because H. pylori infection causes structural and functional damage to the stomach and is associated with a lifetime risk of peptic or gastric cancer of approximately 16 and 1%, respectively, the infection should be treated whenever it is diagnosed. This paper reviews the current approach to therapy of patients with H. pylori infection, the effective antimicrobial drug combinations end the factors that predict treatment failure. Emergence of antimicrobial resistance may soon undermine the effectiveness of current drug regimens and require pretreatment culture and sensitivity testing as well as development of new drugs and drug regimens.

Infection by Helicobacter pylori in Bangladeshi children from birth to two years: relation to blood group, nutritional status, and seasonality

BACKGROUND

A birth cohort of 238 children was followed in an urban slum in Dhaka, Bangladesh, to determine incidence, prevalence, and epidemiologic factors related to Helicobacter pylori infection.

METHODS

H. pylori infection was determined by a specific stool antigen test as well as enzyme-linked immunosorbent assay for detecting specific IgA and IgG antibodies in sera in children who completed 2 years of follow-up.

RESULTS

Using the stool antigen test and serology, 50% and 60% of infants respectively, were positive for H. pylori by 2 years; an increase in the infection rate was seen after 6 months of age. Determination of specific antibodies in sera and detection of H. pylori antigen in stool were comparable. A typical seasonality, peaking in spring and autumn, was observed for acquisition of initial H. pylori infection. Children with blood group "A" were more susceptible to H. pylori infection than those with other ABO blood groups. Malnutrition did not seem to promote colonization by H. pylori. However, H. pylori-infected children were more often infected by multiple enteropathogens, often isolated at different time points.

CONCLUSIONS

This study shows that noninvasive diagnostic methods such as serology and the stool antigen test are suitable for the study of acquisition of H. pylori infections in infants and can be used in field settings as well as in laboratories and clinical setting having less well equipped facilities. The study also shows seasonality for initial H. pylori infection and a relationship between blood group "A" and infection.

Review article: 'true' re-infection of Helicobacter pylori after successful eradication--worldwide annual rates, risk factors and clinical implications

BACKGROUND

The incidence of 'true' re-infection with Helicobacter pylori after successful eradication remains uncertain.

AIM

To determine the worldwide rates, risk factors and clinical implications of 'true' re-infection of Helicobacter pylori. 'True' re-infection of H. pylori is defined as the situation where tests for H. pylori infection, which were negative for 12 months after eradication, become positive again at a later stage.

RESULTS

Thirty six studies were identified through a literature search to be able to produce annual rates of 'true' re-infection, and data from 33 original articles were considered reliable and adequate in the further review. Generally, the reported rates varied from 0% to 23.4% in adults and from 1.9% to 9.6% in children. Most studies from developed countries reported rates of less than 1%, whereas relatively higher rates were reported in most of the developing countries. Small sample sizes included in the studies appeared to be associated with increased re-infection rates. Interfamilial transmission is the major cause of re-infection, although iatrogenic re-infection through contaminated endoscopic equipment has been reported.

CONCLUSION

Helicobacter pylori re-infection is not a concern in a clinical setting, especially in the developed world; however, caution must be exercised in most developing countries.

IL-1B-511 C-->T polymorphism is associated with increased host susceptibility to Helicobacter pylori infection in Chinese

BACKGROUND

The heritability of Helicobacter pylori infection from twin studies has been reported to be 0.66. However, few data were available on the host susceptibility to H. pylori infection in Chinese. We aimed to evaluate the impact of the IL-1B and IL-1RN single-nucleotide polymorphisms (SNP) and ABO blood types on the host susceptibility to H. pylori infection.

METHODS

Individuals who underwent routine health check-up were enrolled. Genotyping was assessed by polymerase chain reaction (PCR) followed by direct sequencing and size fractionation using DNA from peripheral blood samples. Odds ratios (OR) for the susceptibility of H. pylori infection were computed from logistic regression models.

RESULTS

The overall prevalence of H. pylori was 62% among the 663 healthy individuals, with 54.7, 63.5, and 66.9% in persons genotyped C/C, C/T, and T/T at IL-1B-511, respectively. Age (OR 1.05, 95% CI = 1.03-1.07, p < .001) and T carrier at IL-1B-511 (OR = 1.56, 95% CI = 1.06-2.30, p = .026) were independent factors associated with increased risks of H. pylori infection in the multivariate analysis. The risks of H. pylori infection were not related to IL-1RN SNP and ABO blood types.

CONCLUSIONS

These findings support that a proinflammatory polymorphism at IL-1B promoter gene is associated with increased host susceptibility to H. pylori infection in Chinese.

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Helicobacter pylori status and symptom assessment two years after eradication in pediatric patients from a high prevalence area

OBJECTIVES

To establish the rate of Helicobacter pylori reinfection in children from an H. pylori high prevalence area, possible clinical features predictive of reinfection and the usefulness of re-treatment.

METHODS

65 consecutive children attending the authors' department between 1998 and 2000 who had proven successful H. pylori eradication were enrolled; 52 took part. Patients and family members were invited to undergo C-urea breath testing and to complete a simple questionnaire regarding symptoms and socioeconomic status. Patients with H. pylori reinfection were offered treatment; eradication was assessed by C-urea breath test 8 weeks after completion of treatment.

RESULTS

Of 52 children, 15 (28.8%) were H. pylori positive. Variables predictive of reinfection were age at primary infection and presence of an infected sibling. Although reinfected children were more frequently symptomatic than non-reinfected patients, no specific symptom was associated with reinfection. Of the nine re-treated patients who returned 8 weeks after completing therapy, the bacterium was eradicated in five (56%).

CONCLUSIONS

The 12.8% per year reinfection rate in childhood at 2 years that we observed should prompt a re-evaluation of H. pylori status even after a successful eradication. Living in an H. pylori high prevalence area increases the annual risk of reinfection by approximately fourfold over the annual risk in H. pylori low prevalence areas.

Does Helicobacter pylori infection explain all socio-economic differences in peptic ulcer incidence? Genetic and psychosocial markers for incident peptic ulcer disease in a large cohort of Danish adults

BACKGROUND

Peptic ulcer epidemiology has changed considerably within the past century. The aim of this study was to assess the 11-year cumulative incidence of peptic ulcer disease and examine the relationship between ulcer incidence and psychosocial and genetic factors.

METHODS

A random sample of 2416 Danish adults with no history of peptic ulcer disease residing in Copenhagen County, Denmark, attended a population-based prospective cohort study in 1983 and 1994. All participants reported whether they had had an ulcer diagnosed within the observation period. Information on socio-economic factors, family history of peptic ulcer disease (PUD) and lifestyle practices was obtained from a questionnaire. Lewis blood group antigens were assessed from blood samples and Helicobacter pylori infection status was determined with an in-house IgG ELISA.

RESULTS

The overall 11-year cumulative incidence proportion of PUD was 2.9% (95% CI (2.2; 3.6)), i.e. 1.6% (95% CI (1.1; 2.1)) for duodenal ulcer, and 1.3% (95% CI (0.8; 1.7)) for gastric ulcer. Poor socio-economic status increased the risk of PUD independently of H. pylori infection (odds ratio 2.7, 95% CI (1.1; 6.1)) and accounted for 17% of all ulcer cases. High physical activity at work increased the risk of PUD in people infected with H. pylori (odds ratio 2.6, 95% CI (0.8; 8.0)). Family history of PUD or Lewis blood group antigens did not relate to ulcer incidence.

CONCLUSIONS

Poor socio-economic status is an important risk factor for PUD that exerts its effect independently of H. pylori infection. Strenuous work may increase the risk of PUD in people with H. pylori infection. Genetic factors do not influence the risk of PUD in Danish adults.

Human leukocyte antigen class II genes and Helicobacter pylori infection: does genotype overwhelm environmental exposure?

OBJECTIVE

We investigated associations between human leukocyte antigen class II genes, environmental exposures, and Helicobacter pylori infection.

METHODS

Sixty-eight subjects with histologically confirmed H. pylori and intestinal metaplasia (cases) and 70 healthy subjects without H. pylori (controls) matched for age, sex, and year of birth were included in this study. All patients answered a detailed questionnaire designed to collect sociodemographic characteristics, smoking, alcohol drinking, and dietary habits. Human leukocyte antigen class II genes were typed with genomic DNA. The cytotoxins CagA and VacA were investigated with serology. Odds ratios and corresponding 95% confidence intervals were estimated from multivariate conditional logistic regression. Multiple correspondence analysis was used to represent the interrelationships of a multiple contingency table.

RESULTS

Human leukocyte antigen DRB1, DQA1, and DQB1 genotypes were not significantly associated with H. pylori infection and intestinal metaplasia. No significant association with blood group or Lewis antigen system was found. However, multiple correspondence analysis clearly associated H. pylori with environmental exposure: the control group largely consumed olive oil, fresh fruits, and vegetables and histories of never or formerly smoking and the case group (those positive for H. pylori and metaplasia) largely consumed eggs, meat and butter and had histories of smoking cigarettes.

CONCLUSIONS

These findings suggested that H. pylori infection is not influenced by a genetic compound and confirmed the relevance of environmental exposure.

Analysis of the vacA, cagA, cagE, iceA, and babA2 genes in Helicobacter pylori from sixty-one pediatric patients from the Midwestern United States

This study was designed to characterize H. pylori from pediatric gastric biopsy specimens in terms of several genes (vacA, cagA, cagE, iceA1, iceA2, and babA2) proposed to be involved in the pathogenesis of this organism. Many of these genes have been studied in adult H. pylori isolates, however, these genes have not been well characterized in H. pylori from children. Using PCR we observed that 44% of the H. pylori in our biopsies shared two common genotypes (vacA s1b m1, cagA, cagE, iceA2 +/- babA2). While 26% of the H. pylori had unique genotypes. The cag pathogenicity island associated genes, cagA and cagE, were found together in 64% or our H. pylori, while 84% were iceA2 positive. The presence of the babA2 gene has been proposed to be associated with a higher risk of H. pylori related diseases, however, we found that only 36% of our H. pylori contained this gene.

High prevalence of Helicobacter pylori detected by PCR in the oral cavities of periodontitis patients

BACKGROUND

Helicobacter pylori has been associated with the development of peptic ulcers and gastric cancer. Although it may be transmitted through the oral cavity, it is unknown whether the oral cavity acts as a permanent reservoir for this bacterium. The purpose of this study was to use nested polymerase chain reaction (PCR) to clarify whether the oral cavity acts as a reservoir for H. pylori.

METHODS

The existence of H. pylori in the oral cavity was determined by nested PCR in 57 subjects and by culture method in 18 subjects. The presence of periodontopathic bacteria was also determined by 16S rRNA-based PCR method.

RESULTS

Although H. pylori was rarely detected in the oral cavity by culture technique, it was frequently detected (35.1%) by nested PCR in the oral cavity, especially among periodontitis patients who had the bacterium in the gastrointestinal tract (46.4%). Among the subjects who harbored H. pylori in the stomach or duodenum, 41.2% of patients with periodontal pockets > or = 4 mm and 9.1% of subjects without pockets showed H. pylori in dental plaque, although a statistically significant difference was not observed. One patient who had periodontal pockets retained H. pylori in the oral cavity even after eradication of the bacterium from the stomach and duodenum. Most (8/10) of the patients who had H. pylori in dental plaque harbored Bacteroides forsythus in their oral cavities.

CONCLUSION

Close attention should be given to periodontitis patients who harbor H. pylori in the oral cavity.

[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.

Relevance of vacA genotypes of Helicobacter pylori to cagA status and its clinical outcome

BACKGROUND

Determination of vacA mosaicism may be important because specific Helicobacter pylori vacA genotype can be used to predict different clinical outcome. The aim of this study was to assess the relationship of vacA genotypes of Helicobacter pylori to cagA status and its development of peptic ulcer diseases in Korean patients.

METHODS

Gastric biopsy specimens were obtained from 53 patients with gastric ulcer(GU), 57 with duodenal ulcer (DU) and 26 with chronic gastritis(CG) patients; all patients were infected with Helicobacter pylori. Bacterial mRNAs in the gastric mucosa were amplified by RT-PCR, using synthetic oligonucleotide primers specific for the vacA and the cagA gene. Patients with vacA s1 subtype were further examined to determine whether they had s1a or s1b subtype.

RESULTS

There was no correlation in frequency of vacA s1 and/or s1a genotype between CG and either GU or DU, as the vacA s1 and s1a/m1 were present in the majority of strains independent of clinical status(s1; 100.0% versus 94.3% or 93.0% and s1a/m1; 76.9% versus 62.3% or 64.9%, respectively). Likewise, there was no difference in the prevalence of the cagA gene between CG and either GU or DU patients (92.3% versus 90.6% or 98.2%, respectively). In addition, the cagA-negative status did not predict the presence of vacA s2 genotype.

CONCLUSION

These results strongly suggest that either cagA or vacA s1 and/or s1a is not proved to be a useful marker to distinguish disease-specific Helicobacter pylori strains for the development of peptic ulcer diseases in Korean patients.

Helicobacter pylori prevalence in Leipzig's 1998 school entries: methodology and first results

The non-invasive, stable-isotope-aided Helicobacter pylori (H. pylori) tests--breath and equivalent urine tests--were offered on a voluntary basis as part of the mandatory school entry medical examination to the 1998 school entry cohort of the City of Leipzig (480,000 residents). Parents of participating subjects were asked to fill out a detailed epidemiologic questionnaire. The response rate was 94% (n = 2228 of 2369 school starters born in 1991/92). Parent-completed questionnaires were returned by 1890 (80%) children. The overall H. pylori positive prevalence was 7.2%. The prevalence among children with a test and a parent-completed questionnaire was 6.5%. Prevalences among subsequently tested family members of the positive tested children was 65, 60 and 39% for mothers, fathers and siblings respectively. Though studies have shown that the direct transmission of the bacterium (oral-oral and fecal-oral) is a dominant pathway of infection, the questionnaire analyses indicate associations between H. pylori colonisation and living as well as environmental conditions.

The role of the host versus the environment in duodenal ulcer disease

Gastric functions can be understood only in the context of a network including the brain gut axis, neuro-endocrine and paracrine mechanisms and growth factors. These host factors including parietal cell sensitivity (PCS) may well interact with an important environmental factor, Helicobacter pylori (Hp), and help to explain its actions. The aim of this study was to investigate PCS related to Hp status and duodenal ulcer (DU). PCS was assessed by constructing dose-response curves after pentagastrin and calculating the D50. Five groups of patients were studied: I) active DU, Hp pos. (8); II) history of DU, Hp pos. (8); III) asymptomatic Hp pos. (8); IV) asymptomatic Hp neg. (10); V) DU on maintenance H2 blocker therapy, Hp pos. (20). PCS was repeated after Hp eradication. PCS was lowest in group IV, and in Hp pos. groups, was significantly higher, with insignificant differences among them, irrespective of DU. PCS declined significantly after Hp eradication. Group V showed an insignificant decline in PCS during treatment, not preventing recurrence. A higher PCS in Hp infection irrespective of DU, declining after eradication, suggests that this may be a reversible epiphenomena related to Hp infection. This may offer an explanation as to why DU develops only in some subjects with Hp, suggesting the importance of the host in the pathogenesis of DU.

Infection, immunity, and cancer

A significant percentage of human cancers worldwide are associated with infections due to known viruses, including human papillomaviruses (cervical cancer and other skin cancers), human T-lymphotropic viruses (adult T-cell leukemias and lymphomas in endemic areas), hepatitis B virus (liver cancer), and Epstein-Barr virus (Burkitt lymphoma and nasopharyngeal carcinoma). The fraction of human cancers attributable to infection may now need to be revised in light of the fact that new viral associations have been discovered and other nonviral associations have been identified. This article addresses the increasingly recognized role of infectious agents as precipitants of human neoplasia and the possibility that novel diagnostic, therapeutic, and chemopreventive strategies may emanate directly from research directed at identifying and understanding these agents.

Host determinants of Helicobacter pylori infection and its clinical outcome

Greater than one-half of the world's population harbors Helicobacter pylori. The majority of infected individuals, however, remain asymptomatic, with only 10% to 20% developing diseases, including peptic ulcer disease, gastric cancer, and gastric mucosa-associated lymphoid tissue lymphoma. This article reviews host factors that may predispose an individual to both the acquisition of H. pylori infection and subsequent clinical outcome. Individuals with specific blood group antigens and human leukocyte antigen genotypes may be more susceptible to H. pylori infection. Additional factors, such as the age of acquisition, the host immune response, the site of infection, acid secretion, and interactions with nonhost factors (including bacterial virulence factors and environmental influences) may play a role in determining clinical outcome. Further investigation is required to clarify the mechanisms by which these interactions occur and, more critically, to determine their relative importance. This knowledge will enable the identification of individuals at risk of developing clinical disease with H. pylori infection.

Clinical relevance of the cagA, vacA, and iceA status of Helicobacter pylori

BACKGROUND & AIMS

Clinical outcome of Helicobacter pylori infection may be associated with specific virulence-associated bacterial genotypes. The aim of this study was to assess the relationships between H. pylori cagA, vacA, and iceA status and severity of disease.

METHODS

Gastric biopsy specimens from 94 patients in The Netherlands were analyzed by polymerase chain reaction and reverse hybridization.

RESULTS

cagA was present in 63 (67%) of 94 cases and was associated with peptic ulcer disease (P = 0.0019). vacA geno-types s1a/m1, s1b/m2, s1b/m1, s1b/m2, and s2/m2 were found in 36.2%, 23.4%, 2.1%, 5.3%, and 20.2%, respectively. Ten isolates (10.6%) contained multiple vacA genotypes. The presence of peptic ulcers was associated with type s1 strains (P = 0.0006) but not with the m type (P = 0.2035). cagA and vacA s1 were strongly associated (P < 10(-5)). iceA1 was found in 53 (56.4%) and iceA2 in 25 (26.6%) of the 94 cases. In 14 isolates (14.9%), both iceA alleles were found, and 2 (2.1%) were negative for both iceA1 and iceA2. iceA1 was also associated with peptic ulcer disease (P = 0.0042). The iceA allelic type was independent of the cagA and vacA status.

CONCLUSIONS

vacA s1, cagA, and iceA1 are markers of H. pylori strains that are more likely to lead to ulcer disease.

Co-existing gastric cancer and duodenal ulcer disease: role of Helicobacter pylori infection

BACKGROUND

The association of gastric cancer and chronic duodenal ulcer disease is considered rare. In fact duodenal ulcer disease is believed to somehow "protect" against the development of gastric cancer. Helicobacter pylori infection is an important factor in the development of gastric cancer. No detailed investigation on the prevalence of H. pylori in coexistence of gastric cancer and duodenal ulcer disease has been performed. We evaluated the frequency of H. pylori infection in the patients with co-existence of gastric cancer and duodenal ulcer disease.

MATERIALS AND METHODS

During the period March 1994 to February 1995, we collected data from 3,652 patients in whom esophagogastroduodenoscopy was done. During this period, when the cancerous or ulcerative lesions in stomach or duodenum were found, rapid urease tests were performed.

RESULTS

Six patients had concurrent gastric carcinoma and duodenal ulcer disease. Three of the cases had early gastric carcinoma; 2 had active duodenal ulcers and one had a duodenal ulcer scar; all 3 had positive rapid urease tests. The patients with early gastric cancer were younger than the individuals with advanced gastric cancer.

CONCLUSIONS

The co-existence of both diseases may be higher than reported from Western countries or from Peru which may either reflect the high prevalence of circulation of H. pylori ulcer and cancer strains in Korea and the co-infection with both types of organism in some individuals.

High seroprevalence of IgG against Helicobacter pylori among endoscopists in Taiwan

A prospective survey to investigate the seroprevalence of IgG against Helicobacter pylori among endoscopists in Taiwan was conducted by analyzing blood samples of 70 study subjects and 64 nonendoscopist physicians with quantitative ELISA. Personal information and the practices of infection control related to gastroscopy examination were obtained by a self-administered questionnaire. Significant differences were detected in the IgG prevalence between study and control subjects (80.0% vs 51.6%; P < 0.05). The serum level of antibody in endoscopists (385.2 +/- 36.1 unit/ml) was significantly higher than that of nonedoscopists (211.8 +/- 33.0 unit/ml; P = 0.018). Endoscopists performing 30 or more sessions of gastroscopy per week had higher seroprevalence than those performing less than 30 sessions (90.9% vs 70.3%; P = 0.0126). In conclusion, endoscopists in Taiwan had a high prevalence of H. pylori infection. The cause might be related to the frequency of gastroscopies performed.

Helicobacter pylori and socioeconomic factors in Russia

BACKGROUND

The factors influencing the acquisition and prevalence of Helicobacter pylori infection remain incompletely understood. In Russia, the demographic and socioeconomic factors are relatively similar, allowing investigation of risk factors that might not be identifiable in a more diverse population.

MATERIALS AND METHODS

Sero-prevalence of H. pylori infection was studied in 520 asymptomatic individuals between the ages of 1 and 75 years, residing in St. Petersburg, Russia. Forty-four children lived in orphanages or communal apartments. Demographic information and socioeconomic factors were evaluated, including educational level, income, and living conditions. Helicobacter pylori status was evaluated by using an enzyme-linked immunosorbent assay for anti-H. pylori IgG.

RESULTS

The prevalence of H. pylori infection was 44% in children and 88% in adults (P < .001). In adults, H. pylori prevalence was independent of socioeconomic factors. The crude and the age-adjusted odds ratios (ORs) in children showed an inverse correlation between the mother's educational level and H. pylori seropositivity [e.g., OR, 1.8; (95% confidence interval (CI) = 1-3.2] for children whose mothers completed only 8 to 10 years of school compared to children whose mothers completed university. Overcrowding in childhood also was associated with increased H. pylori prevalence. Children from orphanages and communal apartments had the highest crowding index and also were at the greatest risk for H. pylori acquisition (age-adjusted OR, 2.1; 95% CI = 1.2-2.5).

CONCLUSIONS

The prevalence of H. pylori infection in Russia correlated with socioeconomic factors, suggesting there are differences sufficient to affect H. pylori transmission. The prevalence of H. pylori infection during childhood forms the basis for the variances in prevalence among populations.

Helicobacter pylori and ulcerogenesis

The dictum "no acid-no ulcer" had, in the past, summarized the thinking concerning the pathogenesis of peptic ulcer disease. It is now recognized that infection with Helicobacter pylori is the major causal factor leading to both duodenal and gastric ulceration. Infection is associated with many of the acid secretory abnormalities that have traditionally characterized peptic ulcer disease; indeed, acid secretory physiology returns to normal following bacterial eradication. Since not all individuals infected with H. pylori develop ulcers, host susceptibility, bacterial virulence, and/or specific environmental factors must determine the response to infection and the ultimate clinical outcome. The relative importance of these factors and their complex interactions remain to be determined. H. pylori infection produces tissue damage indirectly because the organism does not directly invade gastroduodenal tissue. A variety of bacterial enzymes, toxins, and inflammatory mediators produced in response to bacterial colonization challenge the integrity of host mucosal defenses. In a susceptible host, breached defenses render epithelium more vulnerable to acid injury and ulcer development. Eradication of H. pylori leads to rapid ulcer healing and reversal of tissue injury, thereby obviating ulcer recurrence.

Presentation and management of Helicobacter pylori infection in childhood

Helicobacter pylori is responsible for one of the most frequently encountered infectious diseases worldwide. Helicobacter pylori infection can lead to the development of gastritis and peptic ulcer disease. The presence of Helicobacter pylori in the human stomach also represents an increased risk of gastric cancer and gastric lymphoma. Epidemiological data obtained in adults suggest that the actual colonization with Helicobacter pylori is in fact determined by childhood factors. Therefore, the pediatric age group represents the ideal target population for studies concerning the pathogenesis and epidemiology of Helicobacter pylori infection. The present work reflects our experience with regard to the diagnosis, epidemiology and pathogenesis of Helicobacter pylori infection in childhood.

Helicobacter pylori disease in childhood

Helicobacter pylori (H. pylori) is responsible for one of the most frequently encountered infectious diseases worldwide. H. pylori infection can lead to the development of gastritis and peptic ulcer disease. The presence of H. pylori in the human stomach also represents an increased risk for gastric cancer and gastric lymphoma. Epidemiologic data obtained in adults suggest that the actual colonization with H. pylori is in fact determined by childhood factors. Therefore, the pediatric age group represents the ideal target population for studies concerning the pathogenesis and epidemiology of H. pylori infection.

Helicobacter pylori in the oral cavity. A critical review of the literature

Helicobacter pylori is now generally accepted as a key etiologic agent in peptic ulcer disease as well as in gastric cancer. Dental plaque has been implicated as a possible source of H. pylori by studies that used culture, biochemical, nucleic acid, and immunologic analyses. Variation in the sensitivities of detection by these different reported assays may reflect the methods used, technical difficulties, microbiota complexes, geographic distribution, and host response. The finding of H. pylori in dental plaque also suggested that dental workers may be at increased risk of acquiring H. pylori infection from occupational exposure. We review the available data concerning the presence of this important pathogen in the oral cavity and its potential to be acquired by dental workers. Knowledge of this organism's route of transmission may aid in the development of therapeutic procedures to stop its potential spread.