Epidemiology of Helicobacter pylori infection and public health implications

This article summarizes the published literature concerning the epidemiology and public health implications of Helicobacter pylori infection published from April 2009 through March 2010. Prevalence of infection varied between 7 and 87% and was lower in European studies. All retrieved studies examining transmission of infection concluded that spread is from person-to-person. One study collecting stool and vomitus samples from patients with acute gastroenteritis detected H.?pylori DNA in 88% of vomitus and 74% of stool samples. Proposed risk factors for infection included male gender, increasing age, shorter height, tobacco use, lower socioeconomic status, obesity, and lower educational status of the parents in studies conducted among children. Decision analysis models suggest preventing acquisition of H.?pylori, via vaccination in childhood, could be cost-effective and may reduce incidence of gastric cancer by over 40%. As yet, no country has adopted public health measures to treat infected individuals or prevent infection in populations at risk.     

Helicobacter pylori public health implications

Population Helicobacter pylori screening and treatment has the potential to dramatically reduce global gastric cancer mortality. There is overwhelming evidence that the infection is a major cause of distal gastric adenocarcinoma. There is also randomized controlled trial evidence that H. pylori eradication reverses or ameliorates histological changes in the gastric mucosa that are important in carcinogenesis. Preliminary randomized controlled trial data suggest that screening and treatment may reduce the risk of gastric cancer although the number of cancer cases was small. Population H. pylori screening and treatment will also reduce mortality from peptic ulcer complications and reduce the burden of dyspepsia in the community. The reduction in health service dyspepsia costs means that this could be the first programme to pay for itself. From a scientific perspective, we still have insufficient evidence to conclude the benefits of population H. pylori screening are greater than the possible harms and we need more randomized controlled trial data. From a public health perspective however, sometimes screening programmes are developed with imperfect information. The medical community should be consistent and if we are instituting other population screening programmes without randomized controlled trial evidence then H. pylori testing and treatment should also be considered.     

Review: Epidemiology of Helicobacter pylori infection

This review summarizes recent publications on the epidemiology of Helicobacter pylori. Two major systemic analyses, from Malaysia and Ethiopia, were published. The Brazilian Consensus Conference has stated that H pylori infection is an infectious disease with an indication for antimicrobial therapy. A continuous decrease in H pylori prevalence was reported from many regions worldwide, including Korea, China, Iran, and Austria. A cross‐sectional H pylori prevalence study conducted in the United Arab Emirates found 41% prevalence in a group of healthy children and adults. Several studies from Asia addressed H pylori prevalence in adults undergoing regular checkup. The largest of such studies, performed in Korea, involved 24 471 subjects and reported 41.5% seroprevalence. A relatively smaller study from East China on 3252 subjects reported 27.5% prevalence. In contrast, a study from Spain reported 87.2% seroprevalence. A report on the association between smoking and H pylori seropositivity was published on behalf of the Stomach Cancer Pooling (StoP) Project—a consortium of epidemiological studies of gastric cancer. Also, other potential risk factors, including occupational risk factors, water supply, and food were analyzed. Gastroesophageal reflux and sexual partners has been associated with a higher risk for H pylori acquisition, and gut microbiota was suggested to play a role in intrafamilial transmission of H pylori. Finally, in a few studies (from Mexico and Japan), the catalytic model for predicting the potential risk of acquiring H pylori infection in the future was used. As anticipated, a further decline in H pylori‐related disease was demonstrated by applying the modeling.     

Epidemiology of Helicobacter pylori infection in the Czech Republic

BACKGROUND: Prevalence of Helicobacter pylori infection has been estimated to range from 60 to 95% in the former communist countries of Central and Eastern Europe. The aim of this study was to evaluate H. pylori infection prevalence in a representative sample of the Czech population. The second objective was to describe difference of H. pylori prevalence between different social groups of children and adults. MATERIALS AND METHODS: A total of 2509 persons aged 5-100 years, randomly selected out of 30,012 persons of the general population, took part in the study. H. pylori infection was investigated by means of 13C-urea breath test. Breath samples were analyzed by isotope ratio mass spectrometry. Social and demographic characteristics were based on data from self-completed questionnaires. RESULTS: Using the total Czech population as a standard, we estimated the age-standardized prevalence of H. pylori in males aged 5+ years at 41.9% (95% CI 39.0%, 44.8%) and in females aged 5+ years at 41.4% (95% CI 38.6%, 44.3%) in 2001. Prevalence of H. pylori increased with age but was not related to gender. Children of mothers with basic or lower education, living in crowded accommodations, without access to running warm water, and residing in smaller towns appear to be at the highest risk. Low education and heavy smoking are most strongly associated with prevalence of H. pylori positivity in adults and adolescents. CONCLUSIONS: This is a unique study based on a representative sample of the general population in a Central European country. The overall prevalence of H. pylori is lower than previously assumed and could partly reflect a substantial recent decrease in H. pylori prevalence in the Czech Republic. Consistent with earlier studies, H. pylori infection is strongly influenced by socioeconomic conditions and childhood poverty.     

Epidemiology of Helicobacter pylori Infection

This review summarizes studies on the epidemiology of Helicobacter pylori published in peer-reviewed journals between April 2007 and March 2008. Infection with H. pylori often occurs in childhood, and once established, can persist lifelong if untreated. Prevalence of H. pylori infection is higher in developing countries when compared to developed countries, and can vary by ethnicity, place of birth, and socioeconomic factors even among persons living in the same country. Prevalence of infection is decreasing in many countries due to improvements in sanitation and living standards and the relatively recent movement of populations from rural to urban settings; however, post-treatment recurrence rates of H. pylori infection remain high in developing countries, and in given populations within developed countries. In addition, a number of recent studies have begun to explore the possible link between childhood infection with H. pylori and protection against asthma and allergy.     

Epidemiology and Diagnosis of Helicobacter pylori Infection

Medline, PubMed and the Cochrane databases were searched on epidemiology and diagnosis of Helicobacter pylori for the period of April 2011-March 2012. Several studies have shown that the prevalence of H.?pylori infection is decreasing in adults and children in many countries. Various diagnostic tests are available, and most of them have high sensitivity and specificity. The Maastricht IV/Florence consensus report states that the urea breath test using (13) C urea remains the best test to diagnose H.?pylori infection. Among the stool antigen tests, the ELISA monoclonal antibody test is recommended. All these tests were used, either as a single diagnostic test or in combination, to investigate H.?pylori infection among different populations throughout the world. Of particular interest, current improvements in high-resolution endoscopic technologies enable increased diagnostic accuracy for the detection of H.?pylori infection, but none of these techniques, at present, are specific enough for obtaining a real-time diagnosis of H.?pylori infection.     

Review: Epidemiology of Helicobacter pylori

This review summarizes the recent knowledge on the epidemiology of Helicobacter pylori and the potential modes of transmission. In addition to English language publications, the authors have included original full‐text publications from Russia and Latin America published in the original languages. High H pylori prevalence has been reported in Russia, Jordan, Iran, China, and Latin American countries as well as in Arctic populations in Canada. Indigenous inhabitants in the Arctic were found to be infected substantially more frequently than non‐indigenous inhabitants. In Amsterdam, the Netherlands, the ethnic minority groups were at a significantly higher risk of being H pylori seropositive compared to the Dutch population. For the first time, data on the prevalence from Armenia have been published indicating 41.5% H pylori prevalence. Convincing evidence on the decline of H pylori prevalence in Southeast Hungary and Taiwan was published. A study from Chile suggested high infection rates in newborns during the first month after birth. Two meta‐analyses covered the potential correlation between H pylori and periodontal diseases, therefore addressing the potential oro‐oral transmission rates. Periodontal disease was found to be more prevalent in H pylori‐infected subjects. Other studies addressed the potential role of drinking water and food products as well as socioeconomic factors in transmitting the infection. Several studies in Asia addressed annual reinfection rates of H pylori, ranging from 1.5% in China to 3.1% in Korea. Finally, a review was published on the current evidence and future perspective of analysing H pylori in ancient human remains by a metagenomic approach.     

Helicobacter pylori infection and childhood

Pediatric-based Helicobacter?pylori research continues to contribute significantly to our understanding of both clinical and pathophysiological aspects of this infection. Here, we review the published pediatric H.?pylori literature from April 2009-March 2010. Analysis of pediatric H.?pylori strains continues to suggest that cagA(+) and cagPAI competent strains are less prevalent than in adult isolates. Studies from the Middle East report a high H.?pylori prevalence and intrafamilial transmission. Data continue to show a lack of association between H.?pylori and recurrent abdominal pain of childhood, gastroesophageal reflux disease, and growth retardation. Recent probiotic trials have not shown a benefit on H.?pylori eradication in children, while sequential therapy remains an attractive therapeutic eradication strategy in children, which requires validation in different geographic regions.     

幽门螺杆菌感染引起的免疫应答及其对疫苗研制的启示

幽门螺杆菌是一种全世界范围的人类感染病原菌,人感染该菌后可以被诱导产生较强的体液免疫应答和一定程度的细胞免疫应答反应;但是,自然感染往往不能使机体产生有效的免疫保护,相反可引起对机体的免疫病理损伤,有效的疫苗应该被设计为能够诱导机体产生非病理损伤的特异的免疫保护反应,以此来预防和治疗幽门螺杆菌相关性疾病。本综述了这些方面的研究进展。     

Epidemiology of a tick‐borne viral infection: theoretical insights and practical implications for public health

The morbidity of tick‐borne encephalitis (TBE) varies yearly by as much as 10‐fold among the people of Western Siberia. This long‐term variation is dependent on many factors such as the density of the tick populations, the prevalence of TBE virus (TBEV) among sub‐adult ticks, the yearly virulence of the TBEV, and prophylactic measures. Here we highlight the role of small mammal hosts in the circulation of TBEV through the ecosystem. Refining classical models of non‐viremic horizontal transmission, we emphasize the recently understood fact that the physiological and immunological status of the small mammal hosts affects the tick and virus‐host interactions. In addition to its theoretical interest, our approach may lead to some practical improvements in the precision of epidemiological forecasts and perhaps in forestalling the severity of outbreaks of TBE, or, at least, in forewarning medical authorities and the general public of impending TBE outbreaks.