Correlation of serum antibody titres with invasive methods for rapid detection of Helicobacter pylori infections in symptomatic children

Prevalence of Helicobacter pylori Infection among Anemic School-Age Children in Egypt: A Cross-Sectional Population-Based Study

Anemia and Helicobacter pylori infection in school-age children are important public health problems. The association between H. pylori infection and the development of anemia, especially iron deficiency anemia, has been previously studied and until now it is still a matter of argument. This study aimed to determine the prevalence of anemia and H. pylori infection among school-age children and to find the association between H. pylori infection and anemia in school-age children. We conducted this population-based cross-sectional study in six Egyptian primary schools over a 12-month-period, including 1,200 students from all grades who fulfilled the inclusion criteria. The study participants were subjected to the following: medical history, clinical examination, and laboratory investigations included complete blood count and H. pylori antigen in stool, and according to the level of hemoglobin (Hb), we divided the students into two groups; the anemic group with Hb level <11.5 g/dL and nonanemic group with Hb level ≥11.5 g/dL, and the serum ferritin levels were measured only for the anemic group as the best indicator for iron status. The overall prevalence of H. pylori infection was 25%. The overall prevalence of anemia was 13.25%, of which hypochromic microcytic anemia represented 87.4% of the anemic group, and the mean ferritin level in the anemic group was 18.56 ± 9.96 ng/mL. The prevalence of anemia among H. pylori-infected patients (62.3%) was significantly (p < 0.001) higher than in noninfected children (37.7%). In the anemic group, the mean ferritin level in H. pylori-infected children was significantly lower than the mean level in the noninfected children (p <0.001). Furthermore, the anemic group had a significantly higher incidence of H. pylori infection and a lower age (p <0.001) in comparison with the nonanemic group. The dominant type of anemia in H. pylori-infected children was the microcytic hypochromic anemia, with a significantly higher incidence in comparison to other types of anemia (p <0.001). The findings of this study demonstrate a significant association between H. pylori infection and anemia in school-aged children, especially iron deficiency anemia, as the incidence of H. pylori infection was greater in anemic children than in non-anemic children.

Helicobacter pylori among symptomatic Egyptian children: prevalence, risk factors, and effect on growth

AIM

This study was carried out to determine the prevalence and predictors of Helicobacter pylori (H. pylori) infection among symptomatic children and the effect on growth.

METHODS

A cross-sectional study was conducted in the Outpatient Clinics of the Gastroenterology Unit of the Pediatric Hospital, Cairo University. A total of 630 children complaining of any symptoms or signs suspicious of H. pylori infection were enrolled. Weight and height were measured for each child, and the standard deviation scores (Z-scores) for weight-for-age (WAZ), weight-for-height (WHZ), and height-for-age (HAZ) were calculated. H. pylori was diagnosed using a stool antigen test.

RESULTS

The overall prevalence of infection was 64.6%. Socio-demographic variables significantly associated with H. pylori were residence in Upper Egypt (P = 0.013) and rural areas (P = 0.004), illiteracy of mothers (P = 0.017), household crowding index ≥ 3 (P = 0.011), absence of pure water supply (P = 0.005), and eating from street vendors (P < 0.001). Values of WAZ [median, interquartile range (IQR) in infected = - 1.3(- 2.7 to - 0.4) and non-infected = - 0.7(- 2.1 to - 0.1), P < 0.001], HAZ (P = 0.036), and WHZ (P = 0.005) were significantly lower in children infected with H. pylori. After performing a backward logistic regression analysis, eating from street vendors (OR = 1.879, 95% CI 1.346-2.625, P < 0.001), absence of pure water supply (OR = 1.725, 95% CI 1.162-2.561, P = 0.007), and overcrowding (OR = 1.547, 95% CI 1.100-2.177, P = 0.012) remained the significant predictors of H. pylori infection.

CONCLUSION

A high prevalence of H. pylori infection among symptomatic children was detected. The extra-digestive effects of H. pylori were revealed in the form of affection of growth parameters and reduced levels of serum hemoglobin, iron, and ferritin.

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

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.

Clinical value of detection of anti-Helicobacter pylori antibody in urine

Helicobacter pylori (H. pylori) is a kind of gram-negative anaerobic bacterium that was first successfully isolated and cultivated from the specimens of the gastric mucosa by Warren and Marshall in 1983. It is one of the risk factors for gastric cancer and is closely related with chronic gastritis, peptic ulcer, gastric cancer and other diseases of the digestive system. There are a variety of detection technologies and diagnostic methods available for H. pylori infection, including direct detection of the bacterium, urease detection, antigen and antibody detection, polymerase chain reaction and so on. Generally, these methods can be divided into two major categories: invasive and non-invasive. However, no single test can be considered the gold standard for the diagnosis of H. pylori infection. In this paper, we will summarize a kind of completely non-invasive detection method - detection of H. pylori antibody in urine, review its use in the diagnosis of ongoing infection, and discuss its value in clinical applications.

Helicobacter pylori in pediatrics

This review concerned the important pediatric studies published between April 2012 and March 2013. Symptomatology in Helicobacter pylori-positive children is nonspecific, except for those suffering from peptic ulcer diseases. Investigation of H. pylori status in children and adolescents with sideropenic anemia is recommended, and it is the aim of several studies worldwide. Associations of H. pylori with plasma ghrelin levels as well as the negative association of H. pylori with atopic disease were interesting objectives for several studies this year. Success rates of sequential therapy tended to be lower in recent studies than in previous trials, which probably reflects the increase in macrolide resistance. A beneficial effect of probiotics was reported although not all trials supported this result in children. Intrafamilial transmission and young age could be major risk factors associated with reinfection in children.

Helicobacter pylori Infection in the general population: A Middle Eastern perspective

Helicobacter pylori (H.pylori) infection is probably the most important factor that has been associated with the development of gastric cancers in human populations. However, there are no reliable data on the prevalence of this infection in the Middle East. In this article, based on a comprehensive literature review, we aimed to evaluate the situation in this region. The literature has been searched for the incidence and prevalence of H.pylori infection by Pubmed and Google Scholar. Search was repeated for each of the Middle Eastern countries, and to empower the method, citations of each found article were searched for the related studies. Seventy seven reports from the countries of the Middle East region had been reviewed and they all indicated a high rate of infection either in the general population or in the dyspeptic patients, the rate seemed to be higher in patients with dyspepsia, in patients with histologically confirmed gastritis and in patients of older age groups.