Seroprevalence of Helicobacter pylori in school-aged Chinese in Taipei City and relationship between ABO blood groups

Declining trends of prevalence of Helicobacter pylori infection and incidence of gastric cancer in Taiwan: An updated cross-sectional survey and meta-analysis

BACKGROUND

We aimed to assess the latest prevalence and secular trend of Helicobacter pylori infection and its association with the incidence and mortality of gastric cancer in Taiwan.

MATERIALS AND METHODS

Adults naive to H. pylori eradication received ¹³ C-urea breath test (¹³ C-UBT), H. pylori stool antigen test, and serology test during 2019-2020 in this prospective screening program. Children and adolescent aged between 7 and 19 years received ¹³ C-UBT for H. pylori screening. We also conducted a systematic review and meta-analysis to assess the secular trend of prevalence of H. pylori from 1990 to 2020 in Taiwan. The secular trends of age-standardized incidence and mortality of gastric cancer were obtained from the Taiwan Cancer Registry.

RESULTS

A total of 1494 participants were enrolled, including 294 children or adolescents and 1200 adults. The overall prevalence of active H. pylori infection by ¹³ C-UBT was 26.6% (397/1494), which was 30.8% in adults and 9.5% in adolescents/children. The age-standardized prevalence of active H. pylori infection was 32.3% in adults after adjustment of the population structure in Taiwan. Of the 29 studies including 38,597 subjects eligible for the meta-analysis, the pooled prevalence of H. pylori infection decreased from 63.8% (95% CI: 55.9%-71%) in 1990-2000 to 28.2% (95% CI:21.8%-35.6%) in 2016-2020. The age-standardized incidence and mortality of gastric cancer have also declined from 15.2 to 10.75 per 100,000, respectively, in 1999 to 9.29 and 5.4 per 100,000, respectively, in 2019.

CONCLUSIONS

The prevalence of H. pylori infection has declined in Taiwan, which correlates with the declining trends of age-standardized incidence and mortality of gastric cancer in Taiwan.

Urolithin A Attenuates Helicobacter pylori-Induced Damage In Vivo

Urolithin A (UA) is a metabolite produced in the gut following the consumption of ellagic acid (EA) rich foods. EA has shown anti-inflammatory, antioxidant, and anticancer properties. Because EA is poorly absorbed in the gastrointestinal tract, urolithins are considered to play a major role in bioactivity. Helicobacter pylori (H. pylori) infection is the most common chronic bacterial infection all over the world. It is potentially hazardous to humans because of its relationship to various gastrointestinal diseases. In this study, we investigated the effect of UA on inflammation by H. pylori. The results indicated that UA attenuated H. pylori-induced inflammation in vitro and in vivo. UA also reduced the secretion of H. pylori virulence factors and tissue injuries in mice. Furthermore, UA decreased the relative abundance of Helicobacteraceae in feces of H. pylori-infected mice. In summary, taking UA effectively inhibited the injury caused by H. pylori.

Association Between Helicobacter pylori Infection and Serum Iron Profile

Introduction: Helicobacter pylori (H. pylori) infection is reported to be the most frequent cause of morbidity and mortality in cases of upper gastrointestinal (GI) diseases. There is paucity of research between the possible association of H. pylori and iron stores and iron deficiency anemia (IDA). In this study, we will determine if there is an association between serum total iron-binding capacity (TIBC), serum iron and ferritin levels, and H. pylori infection.

Methods: This case-control study was conducted in the gastroenterology ward of a major hospital in Pakistan from December 2020 to April 2021. Three hundred patients diagnosed with H. pylori were enrolled along with 300 participants in the control group. H. pylori was confirmed or excluded with the help of Giemsa stained gastric biopsy specimens. Blood was sent to the laboratory to test for ferritin, serum iron, and TIBC. Each sample was drawn in the morning to avoid any fluctuations.

Results: The mean serum iron level was significantly lower in participants with H. pylori infection compared to those who did not have H. pylori infection (110.72 ± 28.38 ug/dL vs. 162.5 ± 21.18 ug/dL; p-value: <0.0001). Serum ferritin level was significantly higher in participants with H. pylori infection (536.82 ± 117.0 ng/dL vs. 391.31 ± 101.54 ng/dL; p-value: <0.0001).

Conclusion: In comparison with the control group, TIBC and serum iron levels were found to be lower in the case group.

Biologic roles of the ABH and Lewis histo-blood group antigens Part I: infection and immunity

The ABH and Lewis antigens were among the first of the human red blood cell polymorphisms to be identified and, in the case of the former, play a dominant role in transfusion and transplantation. But these two therapies are largely twentieth century innovations, and the ABH and related carbohydrate antigens are not only expressed on a very wide range of human tissues, but were present in primates long before modern humans evolved. Although we have learned a great deal about the biochemistry and genetics of these structures, the biological roles that they play in human health and disease are incompletely understood. This review and its companion, to appear in a later issue of Vox Sanguinis, will focus on a few of the biologic and pathologic processes which appear to be affected by histo-blood group phenotype. The first of the two reviews will explore the interactions of two bacteria with the ABH and Lewis glycoconjugates of their human host cells, and describe the possible connections between the immune response of the human host to infection and the development of the AB-isoagglutinins. The second review will describe the relationship between ABO phenotype and thromboembolic disease, cardio-vascular disease states, and general metabolism.

Potential Association of IL1B Polymorphism With Iron Deficiency Risk in Childhood Helicobacter pylori Infection

OBJECTIVE

Helicobacter pylori infection occurs predominantly in childhood. Host immune response gene polymorphism is reported to affect the susceptibility to H pylori infection and the outcome of H pylori-related gastric cancer. Not all H pylori-infected patients, however, exhibit iron deficiency (ID). The relationship between host genetic polymorphisms and ID mediated by H pylori infection is not well understood.

METHODS

Subjects (n = 644) from the general population of age 10 to 18 years were divided into 2 groups based on serology testing for anti-H pylori IgG: seropositive study group; and seronegative control group. Five single nucleotide polymorphisms (SNPs) in IL1B (rs1143627 and rs16944), IL8 (rs4073), IL10 (rs1800896), and ABO (rs505922), were genotyped and the iron status of the 2 groups was compared.

RESULTS

The seroprevalence rate for H pylori was 10.7% in this study. Infected subjects were significantly older and had lower serum iron levels than uninfected subjects (P = 0.0195 and 0.0059, respectively). Multivariate analysis revealed a significantly higher frequency of the T allele of rs505922 (odds ratio [OR] = 6.128; P < 0.001) and lower frequency of the T allele of rs1143627 (OR = 0.846; P = 0.014) in seropositive subjects. Among 59 seropositive subjects, the T allele frequency of rs1143627 was significantly higher in those with ID (OR = 3.156; P = 0.043), compared with those without ID.

CONCLUSIONS

ABO (rs505922) and IL1B (rs1143627) may affect H pylori infection susceptibility, and IL1B (rs1143627) may also influence ID risk in infected children.

Blood Groups in Infection and Host Susceptibility

Blood group antigens represent polymorphic traits inherited among individuals and populations. At present, there are 34 recognized human blood groups and hundreds of individual blood group antigens and alleles. Differences in blood group antigen expression can increase or decrease host susceptibility to many infections. Blood groups can play a direct role in infection by serving as receptors and/or coreceptors for microorganisms, parasites, and viruses. In addition, many blood group antigens facilitate intracellular uptake, signal transduction, or adhesion through the organization of membrane microdomains. Several blood groups can modify the innate immune response to infection. Several distinct phenotypes associated with increased host resistance to malaria are overrepresented in populations living in areas where malaria is endemic, as a result of evolutionary pressures. Microorganisms can also stimulate antibodies against blood group antigens, including ABO, T, and Kell. Finally, there is a symbiotic relationship between blood group expression and maturation of the gastrointestinal microbiome.

Clinical factors related with helicobacter pylori infection--is there an association with gastric cancer history in first-degree family members?

BACKGROUND

The aim of this study was to assess clinical factors associated with Helicobacter pylori positivity and to evaluate the incidence of gastric carcinoma in first-degree family members of infected patients. A total of 580 patients (mean age:38±17) with gastrointestinal complaints underwent C-14 urea breath test (UBT). Patients were grouped as: Group-1, untreated patients (n:384); and Group-2, patients who previously treated with eradication triple therapy (n:196). C-14 UBT was performed 1-2 months after the completion of eradication therapy. Associations of H pylori positivity with age, gender, ABO and Rhesus groups, smoking, dietary habits, and history of gastric cancer in first-degree family members were evaluated. The frequency of H pylori positivity was significantly higher in group-1 (58%) compared to group-2 (20%), p=0.001. There were no correlations between H pylori positivity and age, gender, ABO groups, Rhesus subgroups, smoking and dietary habits in both patient groups. The frequency of gastric cancer in family members was significantly higher in patients with H pylori infection among group-1, compared to infected patients among group-2 (56% vs. 28.6% respectively, p=0.03). We observed a significant association between H pylori positivity and the presence of gastric cancer in first-degree relatives of group-1 patients. Our results provide some confirmation of the presence of a link between gastric cancer development and H pylori. C-14 UBT is a sensitive, reliable and a widely recommended test for the detection of H pylori infection and recurrence. We suggest that detection and eradication of H pylori may contribute to a reduced risk of gastric cancer in the family members of infected patients.

Sex-specific differences in the association between ABO genotype and gastric cancer risk in a Korean population

BACKGROUND

Although previous studies have demonstrated an association between ABO blood group and the risk of gastric cancer (GC), only one study has identified these associations using the ABO genotype; however, that study did not evaluate sex differences in this association. The aim of the present study was to investigate whether there are sex-specific differences in the ABO genotype-associated risk of GC. In addition, we explored the association of the ABO genotype and the clinicopathologic characteristics of GC in a Korean population.

METHODS

We conducted a large-scale case-control study of 3245 GC patients (2204 males, 1041 females) and 1700 controls (821 males, 879 females). The ABO genotype was determined by multicolor real-time polymerase chain reaction (PCR) using displacing probes.

RESULTS

As compared with genotype OO, genotypes AA and AO in females, but not in males, were associated with a significantly increased risk of GC (odds ratio [OR] 1.56 and 95 % confidence interval [CI] 1.08-2.26 for AA; OR 1.57 and 95 % CI 1.21-2.03 for AO). In a subgroup analysis, blood group A had a significantly increased risk of diffuse-type GC (OR 2.00, 95 % CI 1.43-2.78), but not of intestinal-type (OR 1.31, 95 % CI 0.96-1.79) or mixed-type GC (OR 1.43, 95 % CI 0.92-2.24).

CONCLUSION

The ABO genotypes AA and AO were significantly associated with GC only in females and only for diffuse-type GC. These data suggest that the association between ABO blood group and GC risk may differ according to sex and histological type.

Risk of advanced gastric precancerous lesions in Helicobacter pylori infected subjects is influenced by ABO blood group and cagA status

A higher incidence of stomach cancer in ABO blood type A individuals than in those with blood type O has been known for a long time. We studied this association in relation to Helicobacter pylori (Hp) of different cagA status. For our study, we used baseline gastric histopathology data and DNAs from frozen gastric biopsies of 2,077 subjects enrolled in a chemoprevention trial for gastric precancerous lesions in Venezuela. We analyzed six single nucleotide polymorphisms in the ABO gene, and we assessed the presence of the Hp cagA gene. Odds ratios (ORs) for risk of advanced precancerous gastric lesions were calculated using individuals with normal gastric epithelium or non-atrophic gastritis as a reference. Among individuals carrying a cagA negative Hp infection or no Hp infection, those with blood type A had a lower risk of intestinal metaplasia (IM) and dysplasia than those with blood type O (OR=0.60; 95% CI 0.38-0.94). In carriers of cagA positive Hp strains, individuals with blood type A had a higher risk of IM or dysplasia than those with blood type O (OR=1.42, 95% CI 1.09-1.86) and a higher risk if compared to subjects carrying cagA negative strain and non-A blood group (OR=3.82, 95% CI=2.80-5.20). The interaction between Hp cagA status and blood type was statistically significant (p=0.0006). We showed that SNPs in the ABO gene, predictive of ABO blood groups, are associated with risk of advanced precancerous gastric lesions in individuals infected with Hp, but the assessment of the risk is strictly dependent on cagA status.

Agreement rate of rapid urease test, conventional PCR, and scorpion real-time PCR in detecting helicobacter pylori from tonsillar samples of patients with chronic tonsillitis

Background:

Helicobacter pylori is capable of inducing systemic inflammatory reactions through immunological processes. There are several methods to identify the presence of H. pylori in clinical samples including rapid urease test (RUT), conventional polymerase chain reaction (PCR), and the Scorpion real-time PCR.

Aim:

The aim of the present study is to compare the agreement rate of these tests in identifying H. pylori in tonsillar biopsy specimens collected from patients with chronic tonsillitis.

Materials and Methods:

A total of 103 tonsil biopsy samples from patients with clinical signs of chronic tonsillitis were examined with RUT, PCR, and Scorpion real-time PCR. The degree of agreement between the three tests was later calculated.

Results:

There was a poor degree of agreement between RUT and PCR and also RUT and Scorpion real-time PCR (Kappa=0.269 and 0.249, respectively). In contrast with RUT, there was a strong degree of agreement between PCR and Scorpion real-time PCR (Kappa=0.970).

Conclusion:

The presence of a strong agreement between the Scorpion real-time PCR and PCR as well as its technical advantage over the conventional PCR assay, made the Scorpion real-time PCR an appropriate laboratory test to investigate the presence of H. pylori in tonsillar biopsy specimens in patients suffering from chronic tonsillitis.

A genome-wide association study identifies two susceptibility loci for duodenal ulcer in the Japanese population

Through a genome-wide association analysis with a total of 7,035 individuals with duodenal ulcer and 25,323 controls from Japan, we identified two susceptibility loci at the PSCA gene (encoding prostate stem cell antigen) at 8q24 and at the ABO blood group locus at 9q34. The C allele of rs2294008 at PSCA was associated with increased risk of duodenal ulcer (odds ratio (OR) = 1.84; P = 3.92 × 10(-33)) in a recessive model but was associated with decreased risk of gastric cancer (OR = 0.79; P = 6.79 × 10(-12)), as reported previously. The T allele of rs2294008 encodes a translation initiation codon upstream of the reported site and changes protein localization from the cytoplasm to the cell surface. rs505922 at ABO was also associated with duodenal ulcer in a recessive model (OR = 1.32; P = 1.15 × 10(-10)). Our findings demonstrate a role for genetic variants in the pathogenesis of duodenal ulcer.

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.

Cost-effectiveness analysis between primary and secondary preventive strategies for gastric cancer

OBJECTIVE

The present study is done to assess the relative cost-effectiveness, optimal initial age, and interscreening interval between primary and secondary prevention strategies for gastric cancer.

METHODS

Base-case estimates, including variables of natural history, efficacy of intervention, and relevant cost, were derived from two preventive programs targeting a high-risk population. Cost-effectiveness was compared between chemoprevention with (13)C urea breath testing followed by Helicobacter pylori (H. pylori) eradication and high-risk surveillance based on serum pepsinogen measurement and confirmed by endoscopy. The main outcome measure was cost per life-year gained with a 3% annual discount rate.

RESULTS

The incremental cost-effectiveness ratio (ICER) for once-only chemoprevention at age 30 years versus no screening was U.S. $17,044 per life-year gained. Eradication of H. pylori at later age or with a periodic scheme yielded a less favorable result. Annual high-risk screening at age of 50 years versus no screening resulted in an ICER of U.S. $29,741 per life-year gained. The ICERs of surveillance did not substantially vary with different initial ages or interscreening intervals. Chemoprevention could be dominated by high-risk surveillance when the initial age was older than 44 years. Otherwise, chemoprevention was more cost-effective than high-risk surveillance, either at ceiling ratios of U.S. $15,762 or up to U.S. $50,000. The relative cost-effectiveness was most sensitive to the infection rate of H. pylori and proportion of early gastric cancer in all detectable cases.

CONCLUSIONS

Early H. pylori eradication once in lifetime seems more cost-effective than surveillance strategy. However, the choice is still subject to the risk of infection, detectability of early gastric cancer, and timing of intervention.

The relationship of Helicobacter pylori positivity with age, sex, and ABO/Rhesus blood groups in patients with gastrointestinal complaints in Turkey

BACKGROUND

To determine the magnitude of Helicobacter pylori infection in patients with gastrointestinal complaints in Turkey.

METHODS

We studied 1680 patients with variable gastrointestinal complaints. The H. pylori infection status was determined using C-14 urea breath test (UBT). Overall, 1567 patients (548 male, 1019 female; age range 4-80 years, mean 29.37 +/- 17.30 years) were included in this study. The relationship between H. pylori positivity and age, sex, sociodemographic characteristic, blood groups, and gastrointestinal diagnosis was determined.

RESULTS

H. pylori positivity was found to be 68%. The difference in positivity rates between age groups 4-9 years and other groups was statistically significant (p = .001). H. pylori positivity was 67.7% in males and 68.2% in females (p = .865). H. pylori positivity was 72.1, 65.1, 70, and 68.4% in blood groups A, B, AB, and O (p = .703), and 68.9% and 76.3% in Rh (+) and Rh (-) blood subgroups, respectively (p = .292). There was no statistically significant difference between H. pylori positivity and gastrointestinal diagnosis (p = .980). There was significant association between increased number of household members and low socioeconomic status, and H. pylori positivity (p < .001). Living in rural and suburban area was significantly associated with H. pylori positivity compared with living in urban.

CONCLUSIONS

H. pylori infection positivity rate was 68% in symptomatic subjects in Turkey and the positivity rate was significantly lower at age 4-9 years than the other age groups. It was not related to gender, ABO, and Rh blood groups and gastrointestinal diagnosis. Low socioeconomic conditions and living in rural and suburban area were significantly associated with H. pylori positivity.

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 in the pharynx of patients with chronic pharyngitis detected with TDI-FP and modified Giemsa stain

AIM: To detect whether there is Helicobacter pylori (H pylori) colonization in the pharynx mucous membrane of healthy people and whether chronic pharyngitis is related to H pylori infection.

METHODS: Fifty cases of chronic pharyngitis refractory over three months were prospectively studied from March 2004 to August 2004 in the otolaryngology outpatient department of the Second Hospital of Xi’an Jiaotong University. Template-directed dye-terminator incorporated with fluorescence polarization detection (TDI-FP) and modified Giemsa stain were used to examine pharynx mucous membrane tissue for H pylori colonization in the patients with chronic pharyngitis and the healthy people as a control group.

RESULTS: In the control group, no people were detected to have H pylori in the pharynx. In contrast, in 50 cases with chronic pharyngitis, 19 (38.0%) cases were H pylori positive with a TDI-FP assay and 4 (8%) cases were TDI-FP positive with Giemsa staining in the pharynx. Sixteen of the 50 pharyngitis cases had stomach ailment history, 11 cases (68.8%) of these 16 patients were determined to be H pylori positive in the pharynx with the TDI-FP assay. χ² test showed that this infection rate was remarkably higher (P = 0.0007) than that in the cases without stomach ailment history. Giemsa staining showed that 3 cases (18.8%) of the patients with stomach ailment history were infected with H pylori in the pharynx, which was remarkably higher (P  = 0.042) than that in the patients without stomach ailment history (1 case, which was 2.9%).

CONCLUSION: H pylori may not be detected in the pharynx of healthy people. Chronic pharyngitis may be related to H pylori infection. The infection rate with H pylori in the pharynx is higher in patients with stomach ailment histories than in patients without stomach ailment histories, suggesting that chronic pharyngitis may be related to stomach ailment history.

Prevalence and risk factors of Helicobacter pylori infection in healthy schoolchildren

OBJECTIVE

Data regarding the prevalence of Helicobacter pylori infection and its potential risk factors among schoolchildren from the Middle East is scarce.

METHODS

An enzyme-linked immunosorbent assay was used to investigate H. pylori status in four groups of children: The first and second groups, 50 children each (25 boys, 25 girls) included children from high socioeconomic class (group 1 = 6 years old; group 2 = 9 years old). The third and fourth groups were sex- and age-matched, but from low socioeconomic class. To evaluate the association between the seroprevalence of H. pylori and selected risk factors, odds ratios (crude and adjusted) were calculated using multiple regression analysis.

RESULTS

Overall seroprevalence rate was 55.5%. Seropositivity was 42%, 52%, 60%, and 68% for groups 1, 2, 3, and 4, respectively. Age and sex were not significantly associated with H. pylori seropositivity. In the final logistic regression model, which was adjusted for age and sex, the following risk factors were found to be significantly associated with seropositivity: living in rural areas (P = 0.015), poor sanitation (P < 0.001), overcrowding (P = 0.014), low maternal educational level (P = 0.010) and low socioeconomic status (P = 0.011).

CONCLUSIONS

The prevalence of H. pylori infection in Jordanian schoolchildren is high, suggesting that most acquisition occurs before the age of 6 years. The seroprevalence for H. pylori increases with social deprivation.

Seroconversion of Helicobacter pylori in Korean male employees

OBJECTIVE

Helicobacter pylori infections are acquired primarily during childhood, but also occur in adults. As no published estimates are available on the seroconversion rate of H. pylori in the Korean population, the purpose of this study was to evaluate the incidence and prevalence of H. pylori infection in male Korean employees.

MATERIAL AND METHODS

Levels of anti-H. pylori IgG were measured by ELISA, and gastroscopic findings were checked in 588 employees of the Subway Corporation (aged 40-60 years, male) in 1997, 1998, 1999, 2000, and 2003. Questionnaire responses concerning socio-economic state, education level, and type of job were analyzed versus serologic test results.

RESULTS

Out of the 588 subjects, 455 (77.4%) were positive for anti-H. pylori IgG. Multivariate analysis showed that abnormal gastroscopic findings, especially duodenal ulcers, were more frequent in the H. pylori-positive group (17.6) than in the initially H. pylori-negative group (9.0%) (OR: 1.71, 95% CI: 1.07-2.81). Among the multiple questionnaires, only the proportion of white-collar workers was significant; that is, it was lower in the H. pylori-positive group (44/6) than in the initial H. pylori-negative group (57.9%) (OR: 0.62, 95% CI: 0.41-0.92). Seventeen of 133 subjects (12.8%) who were initially seronegative underwent seroconversion during a 6-year follow-up period, a seroconversion rate of 2.13%/annum.

CONCLUSIONS

The seroprevalence of H. pylori infection in this study group was 77.4% and duodenal ulcer was more frequent in H. pylori-positive subjects, thus confirming the relationship between H. pylori infection and duodenal ulcer. Seroconversion of H. pylori infection in the Korean male employees was determined to be 2.13% per year, suggesting that new infections occur continuously even during late adulthood.

Seroprevalence of Helicobacter pylori among children in Sana'a, Yemen

BACKGROUND

Helicobacter pylori infection is primarily acquired in early childhood. Its transmission routes are debated. The aims of this study were to determine the seroprevalence of anti-H. pylori immunoglobulin G (IgG) in Yemeni children under 10 years of age, the potential risk factors for contracting H. pylori infection and co-infection of H. pylori with intestinal parasites.

METHODS

Enzyme-labeled immunosorbent assay was used to determine the H. pylori prevalence rate among 572 healthy volunteers aged less than 10 years. Formalin ether concentration methods were used to test the prevalence of intestinal parasites (intestinal roundworms and tapeworms). In addition, we interviewed participants regarding potential risk factors for contracting H. pylori infection.

RESULTS

The seroprevalence of H. pylori antibodies was 9%. The prevalence according to age varied from 0% in children under 2 years to 12.5% in age group 9-10 years. There was a correlation between the amounts of positive antibodies and increasing age. The prevalence rate of H. pylori antibodies was also significantly associated with the practice of drinking water from reused plastic jerry cans, with poor mouth hygiene and with co-infection by intestinal parasites.

CONCLUSION

The prevalence of H. pylori antibodies in Yemen among children under 10 years of age is higher than that reported from other regions for the same age groups. Yemen shares some but not all potential risk factors for H. pylori infection with countries in which similar socioeconomic conditions are found. A possible way of eliminating H. pylori from the population would be via public health measures, i.e. preventing the reuse of plastic jerry cans, and improving sanitation and the standard of living.

The relationship of ABO blood group, age, gender, smoking, and Helicobacter pylori infection

It is well known that blood group antigens are related to the development of peptic ulcer and gastric carcinoma. This study sought to determine the relationship between H. pylori and ABO/Rhesus blood groups, age, gender, and smoking. Patients (335 women and 205 men; mean age, 51.68 +/- 15.0 years; range, 18-85 years) who attended our outpatient clinic were enrolled in the study. All patients were randomly selected in each age group. Demographic data recorded for each patient included age, gender, and tobacco use. Blood samples were tested for H. pylori antibodies, and ABO/Rhesus blood group antigen typing was performed. Serum antibodies were tested against H. pylori infection. Prevalences of all blood groups were O (29.2%), A (38.2%), B (17.8%), and AB (14.8%). As expected from previous studies, we found that seropositivity for H. pylori increased with age. H. pylori Ig G antibody positivity was detected in 185 of 335 women (60.6%), compared with 88 of 205 men (42.9%), a statistically significant difference (P < 0.05). H. pylori Ig G antibody positivity was detected in 206 of 379 nonsmokers (54.3%) compared with 67 of 161 smokers (41.6%), a statistically significant difference (P < 0.05). Patients in blood groups A and O were more prone to H. pylori infection than were patients in other blood groups (P < 0.05), and patients in the AB blood group were less prone to H. pylori infection compared with patients in other blood groups (P < 0.05). The results of this study demonstrate that H. pylori infection can be related to ABO blood group, age, gender, and smoking.

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