Is there a link between seropositivity to Helicobacter pylori and hepatitis A virus? A systematic review

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Helicobacter pylori and unignorable extragastric diseases: Mechanism and implications

Considered as the most popular pathogen worldwide, Helicobacter pylori is intensively associated with diverse gastric diseases, including gastric ulcers, chronic progressive gastritis, and gastric cancer. Aside from its pathogenic effect on gastric diseases, growing evidences reveal that H. pylori may be related to numerous extragastric diseases. In this article, we reviewed recent studies and systematically elucidated that H. pylori may interfere with many biological processes outside the stomach and influence the occurrence of various extragastric diseases. Many epidemiological studies have indicated that H. pylori plays a pathogenic role in COVID-19, atherosclerosis, hyperemesis gravidarum and several other extragastric diseases, while the effect of H. pylori is currently under investigation in gastroesophageal reflux disease, asthma, and inflammatory bowel disease. Moreover, we also summarized the possible pathogenic mechanisms of H. pylori that may be related to chronic systemic inflammation and molecular mimicker. Taken together, this review provides a new perspective on the role of H. pylori in extragastric diseases and explores the possible mechanisms, which may help guide clinical treatment.

Seroprevalence and Determinants of Helicobacter pylori Infection in the Hispanic Community Health Study/Study of Latinos

BACKGROUND & AIMS

Helicobacter pylori infection is the primary known risk factor for gastric cancer. Despite the global decline in H. pylori prevalence, this infection remains a major public health concern in developing areas, including Latin America. Our study aimed to determine H. pylori seroprevalence and identified its determinants among Hispanics/Latinos living in the United States (U.S.).

METHODS

The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a population-based sample of self-identified Hispanics/Latinos (n = 16,144) in four U.S. communities, aged 18 to 74 years, recruited from randomly selected households using a stratified two-stage area probability sample design based on sampling households within sampled census block groups weighted for differential response rates. Anti-H. pylori immunoglobulin G antibodies were measured by an enzyme-linked immunosorbent assay using plasma samples. We calculated adjusted seroprevalence (i.e., predicted margins) from multivariable logistic regression models.

RESULTS

The overall weighted H. pylori seroprevalence was 57% among HCHS/SOL participants, with 38% and 62% seropositivity among U.S.-born and non-U.S.-born individuals, respectively. Age-adjusted prevalence varied by self-reported Hispanic/Latino background, ranging from 47% in Puerto Rican to 72% in Central American backgrounds. Adjusted H. pylori seroprevalence was higher in the following groups: older age, male sex, lower education, non-U.S. born status, smoking, greater number of missing teeth, fewer doctor visits, lower ferritin level, and hepatitis A seropositivity.

CONCLUSIONS

H. pylori seroprevalence in Hispanics/Latinos remains high and differed significantly by Hispanic/Latino background. H. pylori seropositivity is strongly associated with poor socioeconomic conditions. These findings highlight the ongoing importance of this bacterial infection in the U.S.

Helicobacter pylori infection: association with dietary habits and socioeconomic conditions

INTRODUCTION

Few studies have investigated factors possibly related to the source of Helicobacter pylori infection in humans.

MATERIALS AND METHODS

This was a retrospective study including a population of 201 H.pylori positive patients and 259 H. pylori negative subjects observed at a tertiary referral center in Apulia. The H. pylori status was assessed by urea breath test. Data on socio-demographic characteristics and the consumption of different foods and beverages in the last year were collected by a questionnaire.

RESULTS

No significant relationship was found between H. pylori infection and gender or age, type of employment, working in direct contact with the public, residence, level of education or exposure to pets. No association between H.pylori status and the consumption of fish, fruits, legumes, honey, spices, meats, milk and milk products including some typical product of our area was found. The same was true for the consumption of several kind of beverage including green tea and wine. Cigarette smoking and living in the same house with H.pylori positive relatives were significantly associated with H. pylori positivity. The intake of uncooked seafood (mussels and other molluscs) as well as some uncooked vegetables such as tomatos,pepper,and chicory,municipal water and the number of cups of coffee consumed per week correlated significantly with H. pylori status. The consumption of raw vegetables purchased from street vendors and the consumption of meals outside home were also associated with H.pylori infection.

CONCLUSIONS

Foods may represent an important route in the transmission of H. pylori among humans.

First nationwide seroepidemiology and risk factors report of Helicobater pylori in Jordan

BACKGROUND AND AIM

Helicobacter pylori inhabits the gastric mucosa of humans and causes 89% of all gastric cancers. This is the first study of the seroprevalence, spatial distribution, and risk factors for H pylori in Jordan.

MATERIALS AND METHODS

This is a cross-sectional study of 460 healthy participants (aged between 15 and 81 years) proportionately sampled across each region of Jordan. Sera samples were tested for H pylori using Enzygnost^® anti-H pylori immunoglobulin G enzyme-linked immunosorbent assay. Participants completed a validated questionnaire about potential risk factors including food consumption habits and environmental and animal exposure. Multivariate generalized linear models identified risk factors for infection.

RESULTS

The results showed a high seroprevalence (88.6%; 95% confidence interval [CI]: 85.3-91.2) of H pylori in the study population. After adjusting for possible confounders, age, consumption of raw milk, and location of residence were significantly associated with seropositivity. Older participants aged 30-49 years had an 11% greater risk of seropositivity compared to participants aged 15-29 years. Participants who consume raw milk and dairy products have a 9% decreased risk in seropositivity (prevalence ratio = 0.92; 95% CI: 0.84-0.99) compared to those who do not consume these products.

CONCLUSION

This study reports a negative association between consumption of raw milk and seropositivity, and this is in line with several studies that report consumption of raw milk may be protective against H pylori. However, because of the risk of other serious pathogens associated with the consumption of raw dairy products, this study recommends pasteurization of raw milk. Future studies on the effect of fermented dairy products on H pylori colorization in gastric mucosa are recommended.

Seroprevalence of Hepatitis A Virus, Hepatitis E Virus, and Helicobacter pylori in Rural Communities of the Bolivian Chaco, 2013

In the Bolivian Chaco, south-east of Bolivia, studies conducted over the past three decades reported hepatitis A virus (HAV) and Helicobacter pylori seroprevalences above 90% and 60%, respectively. Hepatitis E virus (HEV) prevalence was previously found to be 6-7% but is probably an underestimate because of the poor sensitivity of the assays used. In November 2013, we conducted a cross-sectional study of 263 healthy volunteers from two rural communities of the Bolivian Chaco, aiming to reassess HAV, HEV, and H. pylori seroprevalence 10-20 years following the previous surveys. Hepatitis A virus seroprevalence was 95%, with universal exposure after the first decade of life; HEV seroprevalence was considerably higher (31-35%) than that previously reported; H. pylori seroprevalence was 59%, with an age-dependent distribution. The high prevalence of these infections suggests that major efforts are still needed to reduce fecal-oral transmission and to improve human health in the Bolivian Chaco.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

Serologic Evidence for Fecal-Oral Transmission of Helicobacter pylori

Helicobacter pylori infection is among the most prevalent infections in the world and a key cause of gastric diseases; however, its route of transmission remains unclear. This study aimed to assess the potential for fecal-oral transmission of H. pylori by leveraging its association with a disease with known etiology. Utilizing serology data from the National Health and Nutrition Examination Survey (NHANES 1999; N = 6,347), the association between H. pylori and hepatitis A virus (HAV), a sensitive indicator for fecal-oral exposure, was assessed. Survey-weighted kappa and multiple logistic regression were used to quantify the association between H. pylori and HAV after controlling for age, sex, race, poverty, birthplace, crowding, smoking, and alcohol use. Concordant serological results were found among 69.8% of participants (survey-weighted κ = 0.30, 95% confidence interval [CI] = 0.26, 0.35). The adjusted odds of H. pylori seropositivity were over two times higher after adjusting for confounders (odds ratio = 2.27, 95% CI = 1.79, 2.87). Results from this study suggest H. pylori and HAV infections are strongly associated. Since HAV is primarily transmitted through the fecal-oral route, fecal-oral transmission may be an important pathway for H. pylori spread.

Seroprevalence of Helicobacter pylori and Hepatitis A Virus among Children in Rural Central Taiwan

Helicobacter pylori and hepatitis A virus (HAV) are thought to have similar routes of transmission and epidemiology. This study investigated the seroprevalence of these 2 pathogens among children in rural, central Taiwan. Serum samples were collected from 856 children between 2010 and 2012 and levels of anti-HAV and anti-H. pylori antibodies were measured by ELISA. Questionnaires were used to investigate possible risk factors. The overall H. pylori and HAV infection rates were 6% and 0.8%, respectively. There was a significant difference in H. pylori infection rates (P value=0.008), but not HAV infection rates, between different age groups. H. pylori infection rates were significantly higher in children whose mothers had lower education levels. In contrast, HAV infection rates were significantly higher in children whose fathers had lower education levels. The risk of HAV infection was also 14.20-fold higher in children whose family members had traveled to China or Southeast Asia. No significant correlation was found between H. pylori and HAV seropositivity. The seroprevalences of H. pylori and HAV were low in rural central Taiwan. Universal HAV vaccination is highly recommended to prevent outbreak due to low seroprevalence.

Seroprevalence of hepatitis a and associated socioeconomic factors in young healthy korean adults

BACKGROUND/AIMS

An epidemiologic shift of hepatitis A virus (HAV) seroprevalence is expected due to an improvement in socioeconomic status in young adults in Korea. We investigated the age-specific seroprevalence and socioeconomic factors associated with HAV seropositivity in young, healthy Korean adults.

METHODS

Between March 2009 and February 2010, a total of 5,051 persons from 20 to 49 years of age presenting for a health check-up were included and responded to a questionaire. The seroprevalence of HAV was investigated by measuring immunoglobulin G (IgG) anti-HAV. A total of 984 pairs of cases and age- and sex-matched controls were analyzed for associated socioeconomic factors.

RESULTS

The prevalence of seropositive HAV was 6.2% in the 20 to 29 age range, 33.1% in the 30 to 39 range and 82.4% in the 40 to 49 range (p<0.001). There were no significant differences in any group according to gender. A multivariate analysis for paired cases indicated that HAV seropositivity was significantly higher in the low monthly income (below five million won, approximately 4,300 dollars) group and the Helicobacter pylori (H. pylori)-positive group (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.27-2.14; p<0.001; OR, 1.45; 95% CI, 1.19-1.76; p<0.001, respectively).

CONCLUSIONS

HAV seropositivity in young adults presenting for a health checkup appears to be decreasing, and the prevalence was significantly higher in the low monthly income group and the H. pylori-positive group.