Prevalence of Helicobacter pylori in Sri Lanka as determined by PCR

Pepsinogen and Serum IgG Detection Is a Valuable Diagnostic Method for Helicobacter pylori Infection in a Low-Prevalence Country: A Report from Sri Lanka

The use of serum anti-Helicobacter pylori IgG and pepsinogen (PG) detection as a diagnostic method was evaluated in Sri Lanka. Gastric biopsies were performed (353 patients), and the prevalence of H. pylori infection was 1.7% (culture) and 2.0% (histology). IgG serology testing showed an area under the curve (AUC) of 0.922 (cut-off, 2.95 U/mL; specificity, 91.56%; sensitivity, 88.89%). Histological evaluation showed mild atrophy (34.3%), moderate atrophy (1.7%), metaplasia (1.7%), chronic gastritis (6.2%), and normal tissue (56%). The PGI/PGII ratio was significantly higher in H. pylori-negative patients (p < 0.01). PGII and PGI/PGII levels were lower in patients with metaplasia than in those with normal mucosa (p = 0.049 and p < 0.001, respectively). The PGI/PGII ratio best discriminated metaplasia and moderate atrophy (AUC 0.88 and 0.76, respectively). PGI and PGII alone showed poor discriminative ability, especially in mild atrophy (0.55 and 0.53, respectively) and chronic gastritis (0.55 and 0.53, respectively). The best cut-off to discriminate metaplasia was 3.25 U/mL (95.19% specificity, 83.33% sensitivity). Anti-H. pylori IgG and PG assessment (ABC method) was performed (group B, 2.0%; group A, 92.1%). The new cut-off more accurately identified patients with metaplasia requiring follow-up (group B, 5.4%). Assessment of anti-H. pylori IgG and PG is valuable in countries with a low prevalence of H. pylori infection.

The incidence and patterns of gastric cancers in Sri Lanka from 2001 to 2012: Analysis of National Cancer Registry Data

OBJECTIVES

Varying patterns in incidence of gastric cancer (GC) have been reported globally. We aimed to examine the trends of GC incidence in Sri Lanka.

METHODS

All newly diagnosed patients with GC in Sri Lanka during 2001-2012 included in the National Cancer Registry were analyzed. Joinpoint regression analysis was used to determine the trends in incidence by age and gender. The minimum number of joinpoints were added to the model and statistical significance was checked using the Monte-Carlo permutation method.

RESULTS

Overall, 3353 (male : female = 2.7:1, mean age: 59.5 years) GCs were included in the analysis. Histology findings were available in 2835 patients. Of those, 14.3% (n = 404) were classified as nonspecified neoplasm/carcinoma. Of the remaining 2431 patients, majority (84.1%, n = 2044) were adenocarcinoma/its variants and 9.4% (n = 228) were squamous cell carcinoma. The WHO age-standardized incidence of GC was found to have significantly increased from 1.06 in 2001 (95% CI = 0.9-1.21) to 2.41/100 000 population in 2012 (95% CI = 2.2-2.61); with an estimated annual percentage change (EAPC) of 7.7 (95% CI = 6.1-9.4). Highest incidence of GC was seen in 65-69 year age group (8.2/100 000). The proportional rise in incidence was higher for females (from 0.5 to 1.36, EAPC: 9.0 [95% CI = 6.4-11.8], P < .05 for trend) compared with males (from 1.71 to 3.66, EAPC: 7.5 [95% CI = 5.5-9.6], P < .05 for trend).

CONCLUSIONS

A rise in the incidence of GC was noted in Sri Lanka during the period 2001-2012, which was predominately observed in females. A combination of true increase in incidence and improved reporting may have contributed to this increase. Future studies analyzing tumor characteristics and mortality would enable better understand the burden of GC and potential underlying reasons.

Probiotics in 14-day triple therapy for Asian pediatric patients with Helicobacter pylori infection: a network meta-analysis

Although 14-day triple therapy has been widely administrated for eradicating Helicobacter pylori (H. pylori) in Asia, its antibiotic-associated side effects restrict the effectivity of eradication therapy in pediatric patients. Therefore, a network meta-analysis (NMA) was conducted to compare the efficacy and safety of probiotics supplemented in 14-day triple therapy in Asian pediatric patients.

Materials and Methods

Randomized controlled trials (RCTs) were retrieved comprehensively in electronic databases (such as PubMed, Cochrane library, Embase, CNKI, Wan fang database, VIP database and CBM) until April 2017. Additional references were obtained from reviewed articles. NMA was performed using a random-effects model under a frequentist framework.

Results

Seventeen RCTs were included. NMA indicated that Bifidobacterium infantis+Clostridium butyricum was most beneficial for H. pylori eradication rates (P-score = 0.82) and Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis for total side effects (P-score = 0.77). Taken together, Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis was the best one to supplement in 14-day triple therapy due to its efficacy (P-score = 0.72) and safety (P-score = 0.77). Additionally, pairwise meta-analysis indicated that probiotics supplemented 14-day triple therapy significantly increased H. pylori eradication rates (RR: 1.16, 95%CI: 1.07–1.26) and reduced the incidence of total side effects (RR: 0.40, 95%CI: 0.34–0.48) compared with placebo.

Conclusions

Bacillus mesentericus+Clostridium butyricum+Streptococcus faecalis is the optimal probiotic regime of reducing total side effects and improving eradication rates when supplemented 14-day triple therapy. Further direct evidence is needed to warrant it.

Peptic Ulcer Disease and Helicobacter pylori Infection in Different Siberian Ethnicities

BACKGROUND

The high prevalence of Helicobacter pylori (H. pylori) infection in eastern Siberia is consistently established. In the same geographic area, however, fragmentary information is available on the epidemiology of the peptic ulcer disease (PUD).

AIM

To assess the prevalence of H. pylori infection (including CagA status) and PUD in different eastern Siberian ethnicities.

PATIENTS AND METHODS

An endoscopy population of 3149 eastern Siberian dyspeptic patients was considered [1727 Europoids and 1422 Mongoloids (Evenks = 792; Khakases = 630)]. H. pylori status was assessed by urease test and/or serum anti-H. pylori IgG and/or histology. CagA status was serologically assessed (anti-CagA antibodies).

RESULTS

All the Siberian ethnicities featured high rates of H. pylori infection (Europoids = 87.1%, Evenks = 88.6%, Khakases = 85.4%). Among the 1504 H. pylori-positive Europoids, the prevalence of CagA-positive status (68.7%) was significantly higher than that featured by the 1240 H. pylori-positive Mongoloid ethnicities (46.9%; p < .001 for both comparisons). Peptic ulcer disease significantly prevailed among Europoids (prevalence among Europoid Evenks and Khakases: 8.9% and 8.3%, respectively; prevalence among Mongoloid Evenks and Khakases = 1.0% and 4.4%, respectively).

CONCLUSIONS

eastern Siberian populations feature consistent high rates of H. pylori infection, but different prevalence of peptic ulcer disease. In particular, Europoids featured a prevalence of both CagA-positive status and peptic ulcer disease significantly higher than that of the Mongoloid ethnicities. These results suggest that both environmental factors (coexisting with the H. pylori infection) and host-related variables modulate the clinicopathological expression of the H. pylori -associated gastric diseases.

Detection of clarithromycin-resistant Helicobacter pylori strains in a dyspeptic patient population in Sri Lanka by polymerase chain reaction-restriction fragment length polymorphism

AIM

The aim of this study was to investigate the proportion of common clarithromycin-resistant mutation types present in the 23S ribosomal ribonucleic acid (rRNA) gene of H. pylori strains in Sri Lanka.

SETTINGS AND DESIGN

The study was a cross-sectional, descriptive study where 76 dyspeptic patients who were required to undergo endoscopy examination were included. The study was carried out at a Teaching Hospital in Sri Lanka.

SUBJECTS AND METHODS

In-house urease test and polymerase chain reaction (PCR) amplification of the glmM gene of H. pylori was performed to confirm the H. pylori infection. Analysis of point mutations in 23S rRNA gene strains were performed by PCR-restriction fragment length polymorphism (RFLP).

RESULTS

Of the 16 urease-positive biopsies, 94% (n=15) were positive by PCR using the glmM primer. All H. pylori strains yeilded a point mutation at A2142G site of the 23S rRNA gene, while A2143G mutation was not detected.

CONCLUSIONS

For the first time in Sri Lanka, we reported predominance of A2142G point mutation associated with claritromycin resistance of H. pylori in a Sri Lankan population.

Prevalence of Helicobacter pylori vacA, cagA, and iceA Genotypes in Cuban Patients with Upper Gastrointestinal Diseases

Virulence factors of Helicobacter pylori can predict the development of different gastroduodenal diseases. There are scarce reports in Cuba about H. pylori isolates genotyping. The aim of the present investigation was to identify allelic variation of the virulence genes vacA, cagA, and iceA in sixty-eight patients diagnosed as H. pylori positive by culture. In seven out of 68 patients, strains from both gastric regions were obtained and considered independent. DNA was extracted from all the H. pylori strains and evaluated by PCR-genotyping. The vacA s1 allele, cagA gene, and iceA2 allele were the most prevalent (72.0%, 56.0%, and 57.3%, respectively). Alleles from m-region showed a similar frequency as s1a and s1b subtypes. The presence of multiple H. pylori genotypes in a single biopsy and two gastric region specimens were found. Significant statistical association was observed between iceA2 allele and patients with non-peptic ulcer dyspepsia (NUD) (P = 0.037) as well as virulence genotypes (s1, s1m2) and patients over 40 years old (P < 0.05). In conclusion, the results demonstrated a high prevalence of H. pylori virulent genotypes in Cuban patients over 40 years old while iceA2 alleles demonstrated a good specificity in patients with NUD.

Presence of Helicobacter pylori in betel chewers and non betel chewers with and without oral cancers

BACKGROUND

Betel chewing has been shown to predispose to periodontal disease and oral cancer. Studies show that people with gum disease are more likely to test positive for Helicobacter pylori (H. pylori). It is not known if the lesions produced by betel quid and the resulting, chemical changes predispose to colonization by H. pylori. Further the role of this organism in oral cancer is not known. Our objective was to determine the presence of H. pylori in oral lesions of thirty oral cancer patients and to determine the presence of IgG antibodies to H. pylori in oral cancer patients who are betel chewers and non betel chewers, healthy betel chewers and healthy non-betel chewers and to compare the presence of H. pylori in these four groups. This case control study was conducted at the Cancer Institute Maharagama and the Department of Microbiology, Faculty of Medical Sciences, University of Sri Jayewardenepura.

METHODS

One hundred and seventy three subjects, of whom fifty three were patients presenting with oral cancer to the Cancer Institute Maharagama, sixty healthy betel chewers and sixty healthy non-betel chewers from the Religious and Welfare Service Centre Maharagama were tested for H. pylori by serology. Thirty oral biopsies from oral cancer patients were cultured under microaerophilic condition to isolate H. pylori. The statistic used was Chi-square test.

RESULTS

Of the fifty-three oral cancer patients, forty-four were betel chewers. Among the 53 oral cancer patients examined, ten of forty-four (10/44 = 22.7%) patients who are betel chewers and four of nine (4/9 = 44.4%) patients who are non-betel chewers were detected positive for IgG antibody against H. pylori. In the healthy group (betel chewers and non betel chewers) ten (16.7%) of the healthy betel chewers tested positive for H. pylori by serology. None of the healthy non-betel chewers tested positive for H. pyloriFourteen [26.4%] of oral cancer patients tested positive for H. pylori by serology, of which two were also culture positive (Only thirty samples were cultured). The presence of H. pylori in betel chewers (with or without cancer) compared to non-betel chewers was statistically significant. (Chi-square test p < 0.05) The use of tobacco and areca nut in betel chewers was significant with the presence of H. pylori (p < 0.05).

CONCLUSION

There is a significant higher proportion of H. pylori in betel chewers compared to non-betel chewers but not between oral cancer patients compared to patients without oral cancer. Hence Betel chewing may predispose to colonisation with H. pylori in the digestive tract through swallowing the quid or during betel chewing.

Causal role of Helicobacter pylori infection in gastric cancer: An Asian enigma

Helicobacter pylori (H pylori) has been etiologically linked to gastric cancer. H pylori infection is more frequent in less developed Asian countries like India, Bangladesh, Pakistan, and Thailand and is acquired at early age than in more developed Asian countries like Japan and China. Frequency of gastric cancer, however, is very low in India, Bangladesh, Pakistan and Thailand compared to that in Japan and China. Similar enigma has been reported from Africa as compared to the West. Seroprevalence of H pylori infection in adult populations of India, Bangladesh, Pakistan and Thailand varies from 55% to 92%. In contrast, seroprevalence of H pylori in Chinese and Japanese adults is 44% and 55%, respectively. Annual incidence rate of gastric cancer in India, Bangladesh, and Thailand is 10.6, 1.3, 7.1 per 100 000 populations, respectively; in contrast, that in China and Japan is 32-59 and 80-115 per 100 000 populations, respectively. Several studies from India failed to show higher frequency of H pylori infection in patients with gastric cancer than controls. Available evidences did not support difference in H pylori strains as an explanation for this enigma. Despite established etiological role of H pylori, situation is somewhat enigmatic in Asian countries because in countries with higher frequency of infection, there is lower rate of gastric cancer. Host’s genetic make-up and dietary and environmental factors might explain this enigma. Studies are urgently needed to solve this issue.

Helicobacter pylori virulence factors in duodenal ulceration: A primary cause or a secondary infection causing chronicity

Reports from countries with a high prevalence of Helicobacter pylori (H pylori) infection do not show a proportionately high prevalence of duodenal ulceration, suggesting the possibility that H pylori cannot be a primary cause of duodenal ulceration. It has been mooted that this discrepancy might be explained by variations in the prevalence of virulence factors in different populations. The aim of this paper is to determine whether the published literature gives support to this possibility. The relevant literature was reviewed and analyzed separately for countries with a high and low prevalence of H pylori infection and virulence factors. Although virulent strains of H pylori were significantly more often present in patients with duodenal ulcer than without the disease in countries with a low prevalence of H pylori infection in the population, there was no difference in the prevalence of virulence factors between duodenal ulcer, non - ulcer dyspepsia or normal subjects in many countries, where the prevalence of both H pylori infection and of virulence factors was high. In these countries, the presence of virulence factors was not predictive the clinical outcome. To explain the association between virulence factors and duodenal ulcer in countries where H pylori prevalence is low, only two papers were found that give little support to the usual model proposed, namely that organisms with the virulence factors are more likely than those without them to initiate a duodenal ulcer. We offer an alternative hypothesis that suggests virulence factors are more likely to interfere with the healing of a previously produced ulcer. The presence of virulence factors only correlates with the prevalence of duodenal ulcer in countries where the prevalence of H pylori is low. There is very little evidence that virulence factors initiate duodenal ulceration, but they may be related to failure of the ulcer to heal.

Prevalence of Helicobacter pylori vacA and cagA genotypes in Ethiopian dyspeptic patients

A total of 300 gastric biopsy samples and 50 Helicobacter pylori isolates were collected from Ethiopian adult dyspeptic patients. The vacA and cagA genes were detected in 90 and 79% of biopsy specimens, respectively, and in 100 and 87% of clinical isolates, respectively. Both genes were detected in 84% of the gastric biopsy samples and in 87% of the clinical isolates. Among vacA genotypes, the s1/m1 genotype was the most common in gastric biopsy samples (48%). The vacA and cagA positive H. pylori strains were detected to a higher degree in patients with chronic active gastritis (71%) than patients with other histopathological findings (29%) (P < 0.05).

Helicobacter in the developing world

Helicobacter pylori in the developing world is associated with many unique challenges not encountered in an industrialized setting. The 20% prevalence of infection with H. pylori among adolescents in the United States pales in comparison to infection rates exceeding 90% by 5 years of age in parts of the developing world. While H. pylori within the developed world is associated with gastritis, which may lead to peptic ulcer and gastric carcinoma, the infection in the developing world appears to also be linked with chronic diarrhea, malnutrition and growth faltering as well as predisposition to other enteric infections, including typhoid fever and cholera. Once identified, treatment of H. pylori within the developing world presents increased difficulties due to the frequency of antibiotic resistance as well as the frequency of recurrence after successful treatment. Control, and possibly eradication, of H. pylori could likely be achieved through increased standards of living and improved public health, as it has in the industrialized world. However, these measures are distant objectives for most developing countries, making long-term control of the organism dependent on the development and administration of an effective vaccine.