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

Relationship between Helicobacter pylori and undifferentiated non-granulomatous anterior uveitis

PURPOSE

The relationship of Helicobacter pylori infection with ocular diseases, including anterior uveitis, has been reported. The objective of this study was to determine the presence of anti-H. pylori IgG antibodies in patients with idiopathic non-granulomatous anterior uveitis and compare the results with a control group.

METHODS

A prospective, comparative, and cross-sectional study was conducted. Patients with idiopathic granulomatous anterior uveitis and a group of control subjects were included. The presence of anti-H. pylori IgG antibodies was determined. The chi-square test was performed for comparative analysis with GraphPad Prism V5.0 software.

RESULTS

Thirty patients with idiopathic non-granulomatous anterior uveitis and 35 control subjects were included. In the determination of anti-H. pylori IgG antibodies, 24 (80%) patients and 19 (54%) control subjects were positive. A significant difference (p = 0.0263) was found between the groups and an odds ratio (OR) of 3.37.

CONCLUSIONS

A direct relationship was found between the presence of anti-H. pylori IgG antibodies and idiopathic non-granulomatous anterior uveitis. An association can be established between idiopathic non-granulomatous anterior uveitis and H. pylori infection, without this being a causal or physiopathogenic relationship.

Epidemiology of stomach cancer

Despite a decline in incidence and mortality during the last decades, stomach cancer is one of the main health challenges worldwide. According to the GLOBOCAN 2020 estimates, stomach cancer caused approximately 800000 deaths (accounting for 7.7% of all cancer deaths), and ranks as the fourth leading cause of cancer deaths in both genders combined. About 1.1 million new cases of stomach cancer were diagnosed in 2020 (accounting for 5.6% of all cancer cases). About 75% of all new cases and all deaths from stomach cancer are reported in Asia. Stomach cancer is one of the most lethal malignant tumors, with a five-year survival rate of around 20%. There are some well-established risk factors for stomach cancer: Helicobacter pylori infection, dietary factors, tobacco, obesity, and radiation. To date, the most important way of preventing stomach cancer is reduced exposure to risk factors, as well as screening and early detection. Further research on risk factors can help identify various opportunities for more effective prevention. Screening programs for stomach cancer have been implemented in a few countries, either as a national or opportunistic screening of high-risk individuals only. Generally, due to its high aggressiveness and heterogeneity, stomach cancer still remains a severe global health problem.

Molecular Phylogenetic Analysis of 16S rRNA Sequences Identified Two Lineages of Helicobacter pylori Strains Detected from Different Regions in Sudan Suggestive of Differential Evolution

Background

Helicobacter pylori (H. pylori) is ubiquitous among humans and one of the best-studied examples of an intimate association between bacteria and humans. Phylogeny and Phylogeography of H. pylori strains are known to mirror human migration patterns and reflect significant demographic events in human prehistory. In this study, we analyzed the molecular evolution of H. pylori strains detected from different tribes and regions of Sudan using 16S rRNA gene and the phylogenetic approach. Materials and methods. A total of 75 gastric biopsies were taken from patients who had been referred for endoscopy from different regions of Sudan. The DNA extraction was performed by using the guanidine chloride method. Two sets of primers (universal and specific for H. pylori) were used to amplify the 16S ribosomal gene. Sanger sequencing was applied, and the resulted sequences were matched with the sequences of the National Center for Biotechnology Information (NCBI) nucleotide database. The evolutionary aspects were analyzed using MEGA7 software.

Results

Molecular detection of H. pylori has shown that 28 (37.33%) of the patients were positive for H. pylori and no significant differences were found in sociodemographic characteristics, endoscopy series, and H. pylori infection. Nucleotide variations were observed at five nucleotide positions (positions 219, 305, 578, 741, and 763-764), and one insertion mutation (750_InsC_751) was present in sixty-seven percent (7/12) of our strains. These six mutations were detected in regions of the 16S rRNA not closely associated with either tetracycline or tRNA binding sites; 66.67% of them were located in the central domain of 16S rRNA. The phylogenetic analysis of 16S rRNA sequences identified two lineages of H. pylori strains detected from different regions in Sudan. The presence of Sudanese H. pylori strains resembling Hungarian H. pylori strains could reflect the migration of Hungarian people to Sudan or vice versa.

Conclusion

This finding emphasizes the significance of studying the phylogeny of H. pylori strains as a discriminatory tool to mirror human migration patterns. In addition, the 16S rRNA gene amplification method was found useful for bacterial identification and phylogeny.

Prevalence of Helicobacter pylori in asymptomatic patients at surgical outpatient department: Harare hospitals

Background

Helicobacter pylori infection is present in more than 50% of the world's population. The estimated life time risk of peptic ulcer disease is 20 percent and of gastric cancer is 1–2 percent.

Materials and methods

A cross sectional study was done at two Central hospitals in Harare, Zimbabwe, with the objective being to estimate the prevalence of Helicobacter pylori infection in asymptomatic individuals. Other objectives were to determine the association of the Helicobacter pylori infection with potential risk factors.

Four hundred and fifty patients visiting the outpatient surgical clinics for other complaints other than upper gastrointestinal symptoms were recruited in the study. Drops of whole blood were obtained by fingertip puncture from each patient. The Onsite H. pylori Combo Rapid Test was used to confirm the presence or absence of antibodies against Helicobacter pylori. A questionnaire was used to record the sociodemographics of the participants.

Results

Three hundred patients, 186 males (62%) and 114 females (38%) participated. The prevalence of Helicobacter pylori infection was 67.7 percent (203/300). The prevalence of H pylori infection was significantly correlated with increasing age (p = 0.012), sharing of a bed with siblings during childhood (p = 0.013) and the mode of sanitation methods (p = 0.023). There was no association found between H pylori infection and other risk factors such as; gender, level of education, employment status or number of rooms in a house.

Conclusion

H. pylori infection prevalence was significantly associated with increasing age, sharing of a bed with siblings during childhood and the mode of sanitation used. Clinicians and the public have to be aware of the important role of H pylori in upper gastrointestinal disease. Use of better sanitation methods, appropriate hygiene, avoidance of over-crowding amongst other measures should be encouraged as a means to reduce the acquisition and transmission of H pylori.

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Prevalence of H. pylori infection is 67.7%.

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The results are from Zimbabwe.

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It is associated with increasing age and the mode of sanitation.

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It is associated with sharing of a bed with siblings during childhood.

The fourth Mexican consensus on Helicobacter pylori

Important advances have been made since the last Mexican consensus on the diagnosis and treatment of Helicobacter pylori (H. pylori) infection was published in 2007. Therefore, the Asociación Mexicana de Gastroenterología summoned 20 experts to produce "The Fourth Mexican Consensus on Helicobacter pylori". From February to June 2017, 4 working groups were organized, a literature review was performed, and 3 voting rounds were carried out, resulting in the formulation of 32 statements for discussion and consensus. From the ensuing recommendations, it was striking that Mexico is a country with an intermediate-to-low risk for gastric cancer, despite having a high prevalence of H. pylori infection. It was also corroborated that peptic ulcer disease, premalignant lesions, and histories of gastric cancer and mucosa-associated lymphoid tissue lymphoma should be considered clear indications for eradication. The relation of H. pylori to dyspeptic symptoms continues to be controversial. Eradication triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor should no longer be considered first-line treatment, with the following 2 options proposed to take its place: quadruple therapy with bismuth (proton pump inhibitor, bismuth subcitrate, tetracycline, and metronidazole) and quadruple therapy without bismuth (proton pump inhibitor, amoxicillin, clarithromycin, and metronidazole). The need for antimicrobial sensitivity testing when 2 eradication treatments have failed was also established. Finally, the promotion of educational campaigns on the diagnosis and treatment of H. pylori for both primary care physicians and the general population were proposed.

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.

Seroepidemiology of helicobacter pylori infection in pregnant women in rural durango, Mexico

The seroepidemiology of Helicobacter pylori infection in pregnant women in Durango, Mexico is largely unknown. The prevalence of anti-H. pylori IgG antibodies was examined in 343 pregnant women living in rural areas in 7 municipalities in Durango State, Mexico, using enzyme-linked immunosorbent assays (ELISA). A correlation of H. pylori seropositivity with socio-demographic, obstetric and behavioral characteristics of pregnant women was also assessed. In total, 179 (52.2%) of the 343 pregnant women (mean age, 24.2 ± 5.9 years) had H. pylori IgG antibodies, 75 (41.9%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. The seroprevalence of H. pylori infection varied from 33.3% to 65% among municipalities. In contrast, the seroprevalence was comparable among women regardless their age, educational level, occupation, socioeconomic status, animal contacts, foreign travel, eating habits, contact with soil, crowding, sanitary conditions at home and educational level of the head of their families. Multivariant analysis of socio-demographic and behavioral variables showed that H. pylori seropositivity was associated with municipality (OR=1.12; 95% CI: 1.01-1.24; P=0.02). Of the obstetric characteristics, the seroprevalence of H. pylori infection increased significantly with the number of pregnancies and deliveries but not with the number of cesarean sections or miscarriages. Rural pregnant women in Durango had a lower seroprevalence of H. pylori infection than those from populations in developing countries. Results support a variability of H. pylori seroprevalence within a region. Further research at a municipal level might help to understand the epidemiology of 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.