Helicobacter pylori and hepatitis A virus infection in school-aged children on two isolated neighborhood islands in Taiwan

Seroprevalence of Helicobacter pylori infection among schoolchildren in southern Taiwan-A 20-year longitudinal follow-up

BACKGROUND

Helicobacter pylori infection is primarily acquired in childhood and can lead to peptic ulcer diseases and gastric cancer. The prevalence of H. pylori infection varies widely in different countries. The aim of this study was to explore the change of pediatric H. pylori seroprevalence in the past two decades and to investigate the risk factors for pediatric H. pylori seropositivity in southern Taiwan.

MATERIALS AND METHODS

This study enrolled children aged 7-12 years in Tainan City in 2018 and compared the result with our previous data in 1998, 2005, and 2010. Parents of the participants were invited to fill out questionnaires, including information of personal history, family history of peptic ulcer diseases, annual household income, and source of drinking water. Blood samples were analyzed for anti-H. pylori IgG by enzyme-linked immunosorbent assay.

RESULTS

A total of 391, 629, 618, and 488 elementary school students in Tainan City were enrolled in 1998, 2005, 2010, and 2018, respectively. There was a significant decline in H. pylori seroprevalence from 9.2% in 1998, 7.8% in 2005, 6.2% in 2010 to 4.7% in 2018 (p < 0.001). Neither gender difference nor age difference was found in H. pylori seropositivity in each year of enrollment. Low household income was significantly associated with pediatric H. pylori seropositivity.

CONCLUSIONS

The seroprevalence of H. pylori infection among elementary schoolchildren has remarkably declined in southern Taiwan in the past two decades. Low household income was a risk factor for pediatric H. pylori seropositivity.

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.

The rural - urban divide in ambulatory care of gastrointestinal diseases in Taiwan

BACKGROUND

The utilization of medical care for gastrointestinal diseases increased over the past decade worldwide. The aim of the study was to investigate the difference between rural and urban patients in seeking medical service for gastrointestinal diseases at ambulatory sector in Taiwan.

METHODS

From the one-million-people cohort datasets of the National Health Insurance Research Database, the utilization of ambulatory visits for gastrointestinal diseases in 2009 was analyzed. Rural patients were compared with urban and suburban patients as to diagnosis, locality of visits and choice of specialists.

RESULTS

Among 295,056 patients who had ambulatory visits for gastrointestinal diseases in 2009, rural patients sought medical care for gastrointestinal diseases more frequently than urban and suburban patients (1.60 ± 3.90 vs. 1.17 ± 3.02 and 1.39 ± 3.47). 83.4% of rural patients with gastrointestinal diseases were treated by non-gastroenterologists in rural areas. Rural people had lower accessibility of specialist care, especially for hepatitis, esophageal disorders and gastroduodenal ulcer.

CONCLUSION

The rural-urban disparity of medical care for gastrointestinal diseases in Taiwan highlighted the importance of the well communication between rural physicians and gastroenterologists. Besides the establishment of the referral system, the medical teleconsultation system and the arrangement of specialist outreach clinics in rural areas might be helpful.

Seroprevalence rates of Helicobacter pylori and viral hepatitis A among adolescents in three regions of the Kingdom of Saudi Arabia: is there any correlation?

BACKGROUND

The seroprevalence rate of Helicobacter pylori in the Kingdom of Saudi Arabia (KSA) was reported to be in the range of 50-80% among mostly symptomatic patients in non-community-based studies. However, the seroprevalence of viral hepatitis A (HAV) underwent a marked decline in the last two decades from over 50% in 1989 to 25% in 1997 among Saudi children under the age of 12 years. The aim of this paper was to study seroprevalence rates of H. pylori and HAV among the adolescent population in three regions of KSA and to determine whether there was any correlation between them.

MATERIALS AND METHODS

We randomly selected 1200 16-18-year-old students from three regions around KSA. Demographic data, including socioeconomic status (SES), were recorded, and each student was tested for the presence of H. pylori-IgG antibodies and anti-HAV-IgG.

RESULTS

The results indicate a high H. pylori infection rate (47%) among this age group. Boys had a higher prevalence than girls (p = .03), and the Al-Qaseem region had the highest prevalence (51%, p = .002). SES did not contribute to the high prevalence rates (p = .83). A cross-tabulation of data showed that 88 (8%) of the teenagers were seropositive and that 512 (44%) were negative for both H. pylori and HAV antibodies (χ(2) = 0.03, OR = 0.97, CI = 0.70-1.34). The agreement between H. pylori and HAV seropositivity was lower than would be predicted by chance (κ = -0.03). The variables that were independently associated with seropositivity to H. pylori were being female (OR = 0.75, 95% CI = 0.60-0.95) and living in the Madinah region (OR = 0.72, 95% CI = 0.55-0.94).

CONCLUSION

The prevalence of H. pylori in this group of adolescents was high. However, there was no correlation between H. pylori and HAV infection rates. Hence, factors contributing to the transmission source and route seem to be different.

Prevalence of Helicobacter pylori infection in high-school students on Lanyu Island, Taiwan: risk factor analysis and effect on growth

BACKGROUND/PURPOSE

The Yami inhabit Lanyu Island and are the smallest and most primitive aboriginal tribe in Taiwan. Lanyu Island is a closed environment and little information is available on the prevalence of Helicobacter pylori infection there. This study aimed to establish the prevalence of H. pylori infection in high-school students on Lanyu Island and its risk factors and effect on growth.

METHODS

A cross-sectional population-based study was conducted among high-school students to determine the prevalence of H. pylori infection by using the 13C urea breath test. A questionnaire was administered to the recruited population. Relevant personal and socioeconomic data for risk factors of infection were collected. Body height and weight of the recruited adolescents in relation to H. pylori infection were analyzed.

RESULTS

A total of 106 high-school students (55 boys and 51 girls), with a mean age of 14.3 +/- 1.4 years were enrolled. The overall prevalence of H. pylori infection was 54.7%. Those residing in Dongcing village had the highest rate of H. pylori infection (73.3%). There was no difference in the prevalence of H. pylori infection according to sex, ethnicity, socioeconomic level or parental education. Sixty-two students (54.8%) were completely asymptomatic and the others had at least one gastrointestinal symptom. H. pylori infection was asymptomatic in 56.8% and symptomatic in 53.2% of students. There was no significant difference between infected and uninfected children with regard to body weight, height and body mass index.

CONCLUSION

The prevalence of H. pylori infection is high among high-school students on Lanyu Island. There is no evidence that infection is related to growth failure.

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

BACKGROUND

Since hepatitis A virus (HAV) is acquired primarily through the fecal-oral pathway, several investigators have used HAV seropositivity as a proxy for exposure to this pathway. This paper is a critical review of the evidence relevant to the association between seropositivity to HAV and Helicobacter pylori, and considers the validity of comparisons for testing the hypothesis that H. pylori spreads by the fecal-oral route.

MATERIALS AND METHODS

A Medline search identified reports of all types published in the English language literature that were linked to the keywords 'Campylobacter pylori', 'hepatitis A', or 'Helicobacter pylori', cross-referenced with 'seroepidemiology', 'seroprevalence', or 'seropositivity'. Studies identified by the search were included in the review if they used specific IgG antibodies to classify the serostatus of subjects for both HAV and H. pylori infection and provided an estimate of the magnitude of the association between HAV and H. pylori or information that permitted calculation of an odds ratio (OR).

RESULTS

Out of the 21 studies identified, 15 met the inclusion criteria. The studies showed ORs for an association of HAV and H. pylori that ranged from 0.81 to 8.4. After adjustment for potential confounders, ORs shifted toward the null. They also showed that HAV seroprevalence is lower than H. pylori seroprevalence in early life and then becomes higher in later life. Thus in most populations, the trends cross over at some point.

CONCLUSION

The observed associations between the two infections are generally overestimated by the confounding effects of age and socio-economic status-related factors, and when these factors are controlled, the association becomes weak. Moreover, HAV infection elicits a long-term antibody response, while H. pylori infection does not. Consequently, serostatus comparison does not constitute a convincing test of the fecal-oral transmission hypothesis for H. pylori.

Long-term follow up of Helicobacter pylori IgG serology after eradication and reinfection rate of H. pylori in South Korea

BACKGROUND

Serology is widely used for epidemiologic research of Helicobacter pylori. However, there is limited information on the long-term follow up of H. pylori titers after eradication. In addition, it is presumed that the reinfection rate decreases as the H. pylori infection rate decreases. The aim of this study was to investigate the long-term follow up of H. pylori IgG, and to evaluate the reinfection rate of H. pylori in Korea.

METHODS

Among 247 patients, who were enrolled during 2003-07, 185 patients with invasive H. pylori test positive received proton pump inhibitor-based triple therapy, and follow-up H. pylori testing, including histology, CLOtest, culture, and serology, were evaluated 2, 10, and 18 months after H. pylori eradication.

RESULTS

The initial H. pylori IgG optical density (OD(450 nm)), 2.06, gradually decreased to 0.63 (67% reduction) at 18 months after H. pylori eradication. The seroreversion rate was 5, 10, and 45% at 2, 10, and 18 months after H. pylori eradication, respectively. The recrudescence of H. pylori was 3.49%, and the annual reinfection rate was 2.94% per year. H. pylori IgG titers abruptly increased in cases with recrudescence and reinfection, and correlated with the results of the invasive H. pylori tests.

CONCLUSION

The results of this study showed that H. pylori IgG serology could be used for the determination of reinfection of H. pylori, but not for the diagnosis of H. pylori eradication. The reinfection rate of H. pylori, in Korea, was found to be very low, 2.94% per year.

Seroprevalence of Helicobacter pylori infection among schoolchildren and teachers in Taiwan

BACKGROUND

Helicobacter pylori are associated with chronic antral gastritis that is related to duodenal ulcer, gastric ulcer, and probably gastric adenocarcinoma. Infection of H. pylori during childhood is considered an important risk factor for gastric carcinoma in adult life.

MATERIALS AND METHODS

To examine the epidemiologic characteristics of H. pylori infection among schoolchildren in central Taiwan, a community-based survey was carried out using stratified sampling in 10 elementary schools and three junior high schools including students and theirs teachers. Serum specimens of 1950 healthy schoolchildren (aged 9-15 years old) and 253 teachers who were randomly sampled were screened for the H. pylori antibodies by enzyme-linked immunosorbent assay. Statistical analysis was performed by using the SPSS for Windows statistical software system.

RESULTS

A total of 332 subjects were H. pylori antibodies positive, giving an overall prevalence of 15.1%. The age-specific seropositive rates were 11.0% in 9-12 years age group, 12.3% in 13-15 years age group, and 45.1% in the teacher group. The older the age, the higher the seroprevalence (OR = 11.53; 95% CI = 6.73-19.74; p < .001 for children vs. teachers). There was no difference in the seroprevalence of H. pylori infection by gender, ethnicity, geographical area, socioeconomic level, parental education, sibship size, family members, and source of drinking water.

CONCLUSION

The teachers had a much higher prevalence of H. pylori antibodies. The finding suggests that these teachers (adults) might be infected in their early childhood and implies that the poor environmental and hygienic conditions might be responsible for it. It seemed that poor water supply system, sewage disposal, and other environmental hygiene in adult might play some roles in H. pylori infection in Taiwan (before early 1980s).

Helicobacter pylori infection: further evidence for the role of feco-oral transmission

BACKGROUND

Helicobacter pylori infection is recognized as a major cause of chronic digestive diseases with a major public health impact, yet the knowledge of transmission pathways is limited. We studied the transmission in employees taking care of institutionalized persons with mental disabilities with a documented high prevalence of H. pylori.

MATERIALS AND METHODS

Six hundred and seventy-one health-care workers were screened for H. pylori serology. For each employee, information was collected on age, sex, father's and mother's education level, number of household members and number of children sleeping in the same bedroom during childhood, as well as lifestyle factors such as smoking and tropical journeys and occupational exposure data such as type of contact with inhabitants (changing napkins with stools, washing inhabitants, feeding inhabitants, personal contact) and seniority in the institution.

RESULTS

Seroprevalence for H. pylori increased significantly with age. In univariate analysis, risk factors for H. pylori positivity were (age-adjusted): father's education, mean length of employment, smoking, contact with fecal materials of inhabitants, washing and feeding of inhabitants. Controlling for confounders, in multiple logistic regression analysis, only fecal contact remained as a significant risk factor for H. pylori infection.

CONCLUSIONS

In health-care workers caring for a population with a high prevalence of H. pylori infection, there is an association with fecal transmission. This, however, does not rule out the possibility of other ways of transmission.

A seroepidemiology survey on Helicobacter pylori infection in rural families

AIM: To estimate the prevalence of H. pylori infection in rural families, and to investigate the transmission route of H. pyloriinfection.

METHODS: A cross-sectional study was carried out among 263 villagers from 71 families in September 2004 in Zunhua city, Hebei province. Each subject was interviewed using a unified questionnaire. Blood sample of 5 mL was collected for the antibody examination by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was performed to distinguish the infected strains, and compared with two standard strains NCTC 11637 and CAPM N111, respectively. Similarity analysis was then carried out with Quantity one 4.1.1 software, which is special for photographs of electrophoresis.

RESULTS: The seroprevalence of H. pylori infection in residents of this area was of medium level in our country, and it was not associated with gender. In this area, the risk factors of infection were bad living conditions, overcrowding and possession of pigs during childhood, as well as several generations eating together, less vinegar and fruit intake. The overall prevalence and serum level of anti-H. pylori antibodies in 263 subjects was 57.41% and 0.911 ± 0.810 mg/L, respectively. In males, they were 60.50% and 0.948 ± 0.843 mg/L, while 54.86% and 0.880 ± 0.748 mg/L in females, respectively (P > 0.05). Infection clustered within families, and 60% and 51.35% of the children with two or at least one infected parent were H. pylori-positive, while the prevalence rate in the children with both parents uninfected was only 11.11% (P < 0.05). Western blot showed that the antibodies of the residents living in the area were similar in bands (F = 1.22, P > 0.05).

CONCLUSION: The prevalence of H. pylori in residents of this area was of medium level in our country. Infection clusters within families, and the status of parents' infection can affect that of the children.

Epidemiology of Helicobacter pylori infection

This review summarizes key results of epidemiologic studies published in peer-reviewed journals between April 2003 and March 2004. The prevalence of H. pylori infection continues to vary strongly between developing countries and developed countries, and according to ethnicity, place of birth and socioeconomic factors among people living in the same country. Intrafamilial spread appears to play a central role in transmission of the infection in both developing and developed countries. The role of H. pylori infection in development of noncardia gastric cancer appears to be even much stronger than previously assumed, whereas the lack of an association with cardia cancer and an inverse association with adenocarcinoma of the esophagus could be confirmed. Suggestions for an inverse association of the infection with atopic diseases have recently received further support, whereas evidence concerning the role of the infection (or its eradication) in GERD and a large variety of other extragastric diseases, including cardiovascular disease, remains inconclusive.