Seroepidemiology of Helicobacter pylori infection in a Mennonite community in Durango State, Mexico

Seroprevalence of Helicobacter pylori in Hispanics living in Puerto Rico: A population-based study

BACKGROUND

Helicobacter pylori is an important etiologic factor for peptic ulcers and gastric cancer, one of the top ten leading causes of cancer death in Puerto Rico. However, the prevalence of H. pylori infections in this population was previously unknown. The aim of this study was to examine the seroprevalence of H. pylori and its associated risk factors in Puerto Rico.

MATERIALS AND METHODS

A cross-sectional study was designed using an existing population-based biorepository. Seropositivity was determined using the Premier^™ H. pylori immunoassay. Helicobacter pylori seroprevalence was estimated with 95% confidence using marginal standardization following logistic regression. To assess the risk factors associated with H. pylori seropositivity, a multivariable log-binomial model was fitted to estimate the prevalence ratio (PR) and its 95% confidence interval (95% CI).

RESULTS

A total of 528 population-based serum samples were analyzed. The mean age of the study population was 41 ± 12 years, of whom 55.3% were females. The overall seroprevalence of H. pylori was 33.0% (95% CI = 28.3%-38.1%). Increasing age and having <12 years of education were significantly (P < .05) associated with H. pylori seropositivity in the multivariable model; however, residing in counties with low population density reached marginal significance (P = .085).

CONCLUSIONS

We report that H. pylori infection is common among Hispanics living in Puerto Rico. The H. pylori seroprevalence observed in Puerto Rico is similar to the seroprevalence reported in the overall population of the United States. The association between H. pylori seroprevalence and the risk factors analyzed offers insight into the epidemiology of gastric cancer in Puerto Rico and warrants further investigation.

Helicobacter pylori Infection Induces Anemia, Depletes Serum Iron Storage, and Alters Local Iron-Related and Adult Brain Gene Expression in Male INS-GAS Mice

Iron deficiency anemia (IDA) affects > 500 million people worldwide, and is linked to impaired cognitive development and function in children. Helicobacter pylori, a class 1 carcinogen, infects about half of the world’s population, thus creating a high likelihood of overlapping risk. This study determined the effect of H. pylori infection on iron homeostasis in INS-GAS mice. Two replicates of INS-GAS/FVB male mice (n = 9-12/group) were dosed with H. pylori (Hp) strain SS1 or sham dosed at 6–9 weeks of age, and were necropsied at 27–29 weeks of age. Hematologic and serum iron parameters were evaluated, as was gene expression in gastric and brain tissues. Serum ferritin was lower in Hp SS1-infected mice than uninfected mice (p < 0.0001). Infected mice had a lower red blood cell count (p<0.0001), hematocrit (p < 0.001), and hemoglobin concentration (p <0.0001) than uninfected mice. Relative expression of gastric hepcidin antimicrobial peptide (Hamp) was downregulated in mice infected with Hp SS1 compared to sham-dosed controls (p<0.001). Expression of bone morphogenic protein 4 (Bmp4), a growth factor upstream of hepcidin, was downregulated in gastric tissue of Hp SS1-infected mice (p<0.001). Hp SS1-infected mice had downregulated brain expression of tyrosine hydroxylase (Th) (p = 0.02). Expression of iron-responsive genes involved in myelination (myelin basic protein (Mbp) and proteolipid protein 2 (Plp2)) was downregulated in infected mice (p = 0.001 and p = 0.02). Expression of synaptic plasticity markers (brain derived neurotrophic factor 3 (Bdnf3), Psd95 (a membrane associated guanylate kinase), and insulin-like growth factor 1 (Igf1)) was also downregulated in Hp SS1-infected mice (p = 0.09, p = 0.04, p = 0.02 respectively). Infection of male INS-GAS mice with Hp SS1, without concurrent dietary iron deficiency, depleted serum ferritin, deregulated gastric and hepatic expression of iron regulatory genes, and altered iron-dependent neural processes. The use of Hp SS1-infected INS-GAS mice will be an appropriate animal model for further study of the effects of concurrent H. pylori infection and anemia on iron homeostasis and adult iron-dependent brain gene expression.

Seroepidemiology of Helicobacter pylori infection in elderly people in the Beijing region, China

AIM

To investigate seroepidemiology of cagA(+) and vacA(+) strains of Helicobacter pylori (H. pylori) in an elderly population in Beijing and to determine risk factors for seropositivity.

METHODS

A total of 2006 elderly persons (> 60 years) were selected using a random cluster sampling method in different parts of the Beijing area (urban, suburban and mountainous districts). Structured questionnaires were completed during home visits, including history of H. pylori infection, history of gastrointestinal diseases, diet types, hygiene habits, occupation and economic status. Blood samples (2 mL) were collected from each participant, and serum IgG antibodies to cagA, vacA and H. pylori urease antigens were measured by immunodetection.

RESULTS

The prevalence of H. pylori infection in elderly subjects was 83.4% and the type I H. pylori strain infection rate was 56%. The seroprevalence for type I H. pylori strain infection in urban and suburban districts was higher than that in the mountainous areas (P < 0.001). Elderly subjects who had previously performed manual labor or were in the young-old age group (age < 75 years) had a higher seroprevalence of H. pylori infection than those who had previously performed mental labor or were in the oldest-old age group (age ≥ 75 year) (P < 0.05). The type I H. pylori strain infection rate in the elderly with vegetarian diets was higher than in those eating high-protein foods (P < 0.001). There was no significant difference in the prevalence of H. pylori strains between male and female elderly participants (P > 0.05).

CONCLUSION

Type I H. pylori seroprevalence is higher in elderly people. The distribution of strains of H. pylori is significantly affected by age, area and dietary habits.

High Seroprevalence of Helicobacter Pylori Infection in Inmates: A Case Control Study in a Northern Mexican City

Background

The epidemiology of Helicobacter pylori infection in inmates has not been previously studied. Therefore, we determine the seroepidemiology of H. pylori infection in inmates.

Methods

Through a case-control study, inmates from a state correctional facility in Durango, Mexico and subjects without incarceration of the same city were examined for the presence of anti-H. pylori IgG antibodies using enzyme-linked immunoassays. Seroprevalence association with socio-demographic, incarceration, clinical and behavioral characteristics of the inmates was also investigated.

Results

Antibodies to H. pylori were found in 140 (83.3%) of 168 inmates and in 101 (60.1%) of 168 controls. Seroprevalence of anti-H. pylori IgG antibodies was significantly higher in inmates than in controls (OR = 3.32; 95% CI: 1.93 - 5.71; P = 0.000002). The seroprevalence of H. pylori infection was not influenced by gender, age, or socioeconomic status of inmates. Seropositivity to H. pylori was found in 3 of 3 inmates with peptic ulcer and in 1 of 2 inmates with gastritis. The seroprevalence of H. pylori exposure was high regardless the jail section, duration (years) in incarceration and number of incarcerations. Multivariate analysis revealed that H. pylori exposure was positively associated with having tattoos (OR = 3.34; 95% CI: 1.14 - 9.70; P = 0.02), and negatively associated with drug abuse (OR = 0.28; 95% CI: 0.11 - 0.70; P = 0.007).

Conclusions

Seroprevalence of H. pylori exposure in inmates is higher than those found in non-incarcerated people and other populations in the region. Results indicate that inmates may represent a new risk group for H. pylori exposure. Results warrant for further research on the potential role of incarceration and behavioral features of inmates for H. pylori infection.

Helicobacter Pylori Infection in Waste Pickers: A Case Control Seroprevalence Study

Background

The epidemiology of Helicobacter pylori (H. pylori) infection in waste pickers had not been previously studied. This study aims to determine the association of H. pylori seropositivity and waste picking activity; and to determine socio-demographic, clinical, work, and behavioral characteristics associated with H. pylori seropositivity in waste pickers.

Methods

Through a case-control study design, we examined 90 waste pickers and 90 age- and gender-matched control subjects for the presence of anti-H. pylori IgG antibodies using enzyme-linked immunoassays. Seroprevalence association with socio-demographic, clinical, work and behavioral characteristics of the waste pickers were also investigated.

Results

Antibodies to H. pylori were found in 60 (66.7%) of the 90 waste pickers and in 51 (56.7%) of the 90 controls (P = 0.16). Stratification by age showed that waste pickers aged 14 -30 years old had significantly higher frequency of H. pylori infection than controls of the same age group (56.5% versus 35.6%, respectively; P = 0.04). The seroprevalence of H. pylori infection was not influenced by gender, age, educational level, socioeconomic status, residence, or housing conditions of waste pickers. The presence of underlying diseases and the frequency of gastritis were similar among H. pylori positive and H. pylori negative waste pickers. Logistic regression analysis showed that the duration (years) in the waste picking activity was positively associated with H. pylori exposure (OR = 2.76; 95% CI: 1.22 - 6.25; P = 0.01). In contrast, consumption of alcohol was negatively associated with H. pylori exposure (OR = 0.27; 95% CI: 0.09 - 0.78; P = 0.01). Other work or behavioral characteristics of waste pickers including washing hands before eating, eating from the garbage, animal contacts, consumption of unpasteurized milk, unwashed raw vegetables, fruits, or untreated water, and contact with soil were not associated with H. pylori exposure.

Conclusions

This is the first report on the seroprevalence of H. pylori infection among waste pickers and the factors contributing to such exposure. Results warrant for further research on the potential role of contact with garbage for H. pylori infection.

Diagnosis and epidemiology of Helicobacter pylori infection

A limited amount of new information was published in the field of diagnosis and epidemiology of Helicobacter pylori this last year. Besides some improvement in current tests, it is interesting to note the attempts to identify severe disease, for example gastric cancer, by breath analysis using nanomaterial-based sensors. In contrast, the predictive value for gastric cancer and atrophy of pepsinogen determinations was found inadequate. Prevalence studies of H. pylori infection have been carried out in adults and children around the world in the general population but also in specific communities. The usual risk factors were found. In addition, a Japanese study highlighted the role of grandmothers in the familial transmission of H. pylori. A study showed that the infection may not always readily establish itself in children, given the number of transient infections observed. It was also noted that after eradication, a first-year relapse is likely to be a recurrence of the previous infection, while later on it is probably a reinfection with a new strain.

Seroepidemiology of Helicobacter pylori Infection in Tepehuanos Aged 15 Years and Older in Durango, Mexico

This study aimed to determine the seroepidemiology of Helicobacter pylori infection in Tepehuanos (an indigenous ethnic group living in rural Mexico). The prevalence of anti-Helicobacter pylori IgG antibodies was examined in 156 Tepehuanos in Durango State, Mexico, using an enzyme-linked immunoassay. In addition, sociodemographic, clinical, and behavioral characteristics of Tepehuanos associated with seropositivity were investigated. In total, 103 (66%) of the 156 participants (mean age 31.03  ±  16.71 years) had Helicobacter pylori IgG antibodies. Fifty-four (52.4%) of the 103 seropositive individuals had Helicobacter pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence of Helicobacter pylori infection and Helicobacter pylori IgG antibody levels. The seroprevalence was significantly higher in women with pregnancies than those without this obstetric characteristic. Logistic regression showed that Helicobacter pylori infection was positively associated with low education (OR = 3.37; 95% CI: 1.13-10.00; P = 0.02) and laborer occupation (OR = 2.71; 95% CI: 1.14-6.42; P = 0.02). This is the first report of seroprevalence and contributing factors for Helicobacter pylori infection in Tepehuanos and of the association of Helicobacter pylori infection with laborer occupation. Results warrants further research.