Prevalence of Helicobacter pylori infection, chronic gastritis, and intestinal metaplasia in Mozambican dyspeptic patients. Virchows Arch. 2009;454:153-160. [PMID: 19101725 DOI: 10.1007/s00428-008-0713-7]

Global prevalence of gastric intestinal metaplasia: a systematic review and meta-analysis

BACKGROUND

Gastric intestinal metaplasia (GIM) is a precancerous lesion that increases the risk of gastric cancer. Several preliminary studies have examined the prevalence of GIM. The present systematic review and meta-analysis were conducted aimed estimating the global prevalence of GIM.

METHODS

The present systematic review and meta-analysis was conducted based on the PRISMA reporting guidelines in the range of 1988-2022. Articles related to the purpose of the study were obtained from Embase, PubMed, Scopus, Web of Science (WOS), MagIran, SID databases, and Google Scholar search engine using relevant and validated keywords in MeSH/Emtree. Inclusion criteria were observational articles, access to the full text of the article, and articles that reported prevalence. Heterogeneity among studies was examined using the I2 index. The random effects model was used in this review due to the high heterogeneity between the results of the studies. Data were statistically analyzed using the Comprehensive Meta-Analysis (CMA) software.

RESULTS

In the initial search, 4946 studies were found, of which 20 articles with a sample size of 57,263 met all the criteria for inclusion in the study. The global prevalence of GIM was 17.5% (95% confidence interval: 14.6-20.8%). The highest percentage of prevalence of GIM belonged to American continent with 18.6% (95% confidence interval: 13.8-24.6%) and patients with gastroesophageal reflux with 22.9% (95% confidence interval: 9.9-44.6%).

CONCLUSION

The results of this study showed that the prevalence of GIM in the world is high and needs further investigation. Therefore, it is recommended to be given more attention by experts, officials, and health policymakers.

Prevalence of Gastric Precursor Lesions in Countries With Differential Gastric Cancer Burden: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The prevalence of precursor lesions for gastric cancer (GC) and the differential burden between countries of varying GC risk is not well-understood. We conducted a systematic review and meta-analysis to estimate the global prevalence of precursor lesions.

METHODS

We estimated the prevalence of atrophic gastritis (AG), gastric intestinal metaplasia (IM), and dysplasia in regions with low, medium, and high GC incidence. Because IM is an advanced manifestation of AG, we assessed the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. Prevalence was sub-stratified by Helicobacter pylori infection, symptomatology, and period (<2000, 2000-2010, and >2010).

RESULTS

Among the 582 articles that underwent full-text review, 166 studies met inclusion criteria. The global prevalence estimates of AG, IM, and dysplasia were 25.4%, 16.2%, and 2.0%, respectively, on the basis of 126 studies that reported the prevalence of less advanced precursors, regardless of the presence of more advanced lesions. The prevalence of all precursor lesions was higher in high and medium compared with low GC incidence countries (P < .01). Prevalence of AG and IM was significantly higher among H pylori-infected individuals (P < .01) but not statistically different between symptomatic and asymptomatic individuals (P > .17). All precursors demonstrated a secular decrease in prevalence over time.

CONCLUSIONS

Gastric precursor lesions have differences in prevalence in regions with differential GC incidence and are associated with H pylori infection. Because of the substantial prevalence of precursor lesions in both symptomatic and asymptomatic individuals, symptomatic evaluation may not be sufficient to identify individuals at risk. These estimates provide important insights for tailoring GC prevention strategies.

Prevalence and associated risk factors of Helicobacter pylori infection in East Africa: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is the main cause of chronic gastritis, peptic ulcer, lymphoma, and gastric cancer in humans. The prevalence and factors associated with H. pylori infection are varied across countries. Thus, a comprehensive review has not been done on prevalence and associated factors in East Africa. Therefore, this systematic review and meta-analysis aimed to estimate the pooled prevalence and identify factors associated with H. pylori infection in East Africa.

METHODS

Articles written in English language were retrieved from PubMed, Scopus, and Science Direct. Relevant articles were selected and screened using Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Publication bias was assessed qualitatively and qualitatively using funnel plot symmetry and Egger's test, respectively. Heterogeneity was assessed using the I2 measure. Data were analyzed using Stata software, version 14, and the "metan" command.

RESULTS

A total of 231 articles were retrieved from nineteen countries in East Africa. Of these, 70 articles were eligible for the review. The pooled prevalence of H. pylori in East Africa was 50.98% (95% CI: 45.05-56.90). The prevalence of H. pylori infection ranged from 7.7 to 94.5% in East African countries. The highest pooled prevalence was from Sudan (61.3%, 95% CI: 52.6-69.9), and the lowest prevalence was reported from Uganda (40.7%, 95% CI: 33-48.3). Persons with no formal education (OR: 2.03; 95% CI: 1.22-2.83), lack of hand washing habit after toilet (OR: 2.24; 95% CI: 1.45-3.02), having a history of dyspepsia (OR: 2.25; 95% CI: 1.31-3.18), living in rural areas (OR = 1.80; 95% CI: 0.38-3.23), and having unclean water source (OR = 1.5; 95% CI:0.45-3.45) were all associated with higher risk for H. pylori infection.

CONCLUSION

More than half of the populations of East African countries were positive for H. pylori infection. Rural residence, source of water, and alcohol consumption were significantly associated with H. pylori infection. Therefore, healthcare workers could provide health education on the aforementioned risk factors, and the government and other stakeholders could improve the source of drinking water in East Africa.

Helicobacter pylori infection-A risk factor for lipid peroxidation and superoxide dismutase over-activity: A cross-sectional study among patients with dyspepsia in Cameroon

Background and Aim

There is an intimate relationship between oxidative stress and inflammation. Helicobacter pylori (H. pylori) infection leads to gastritis in almost all the hosts. So, we hypothesize that gastritis in H. pylori infection may be described as the accumulation of continuous oxidative damage.

Methods

The study was conducted from October 2020 to October 2021 at three reference health facilities in Cameroon. A total of 266 participants (131 males and 135 females) ranging from 15 to 88 years old with 48.28 ± 17.29 years as mean age were enrolled. Each participant gave a written informed consent and ethical committees approved the protocol. Biopsies samples were collected for H. pylori detection using histological examination and rapid urease test. Malondialdehyde (MDA) and glutathione (GSH) content, and catalase (CAT) and superoxide dismutase (SOD) activities were evaluated in serum as biomarkers of oxidative stress.

Results

Helicobacter pylori was detected in 71.80% of our sample population. Low income level was associated with higher GSH level (P = 0.0249) and having family history of gastric cancer to higher SOD activity (P = 0.0156). A significant higher MDA content (P < 0.0001) and SOD activity (P = 0.0235) was recorded among infected individuals compared with noninfected ones. A significantly higher MDA content and SOD activity was recorded among smokers (P = 0.0461) and participants older than 50 years old (P = 0.0491) with H. pylori positivity.

Conclusion

Our findings showed that H. pylori infection is associated with overproduction of reactive oxygen species and oxidative stress. The presence of this pathogen in elderly individuals or in smokers increased their risk for oxidative stress.

Gastro-duodenal disease in Africa: Literature review and clinical data from Accra, Ghana

Gastroduodenal disease (GDD) was initially thought to be uncommon in Africa. Amongst others, lack of access to optimal health infrastructure and suspicion of conventional medicine resulted in the reported prevalence of GDD being significantly lower than that in other areas of the world. Following the increasing availability of flexible upper gastro-intestinal endoscopy, it has now become apparent that GDD, especially peptic ulcer disease (PUD), is prevalent across the continent of Africa. Recognised risk factors for gastric cancer (GCA) include Helicobater pylori (H. pylori), diet, Epstein-Barr virus infection and industrial chemical exposure, while those for PUD are H. pylori, non-steroidal anti-inflammatory drug (NSAID)-use, smoking and alcohol consumption. Of these, H. pylori is generally accepted to be causally related to the development of atrophic gastritis (AG), intestinal metaplasia (IM), PUD and distal GCA. Here, we perform a systematic review of the patterns of GDD across Africa obtained with endoscopy, and complement the analysis with new data obtained on pre-malignant gastric his-topathological lesions in Accra, Ghana which was compared with previous data from Maputo, Mozambique. As there is a general lack of structured cohort studies in Africa, we also considered endoscopy-based hospital or tertiary centre studies of symptomatic individuals. In Africa, there is considerable heterogeneity in the prevalence of PUD with no clear geographical patterns. Furthermore, there are differences in PUD within-country despite universally endemic H. pylori infection. PUD is not uncommon in Africa. Most of the African tertiary-centre studies had higher prevalence of PUD when compared with similar studies in western countries. An additional intriguing observation is a recent, ongoing decline in PUD in some African countries where H. pylori infection is still high. One possible reason for the high, sustained prevalence of PUD may be the significant use of NSAIDs in local or over-the-counter preparations. The prevalence of AG and IM, were similar or modestly higher over rates in western countries but lower than those seen in Asia. . In our new data, sampling of 136 patients in Accra detected evidence of pre-malignant lesions (AG and/or IM) in 20 individuals (14.7%). Likewise, the prevalence of pre-malignant lesions, in a sample of 109 patients from Maputo, were 8.3% AG and 8.3% IM. While H. pylori is endemic in Africa, the observed prevalence for GCA is rather low. However, cancer data is drawn from country cancer registries that are not comprehensive due to considerable variation in the availability of efficient local cancer reporting systems, diagnostic health facilities and expertise. Validation of cases and their source as well as specificity of outcome definitions are not explicit in most studies further contributing to uncertainty about the precise incidence rates of GCA on the continent. We conclude that evidence is still lacking to support (or not) the African enigma theory due to inconsistencies in the data that indicate a particularly low incidence of GDD in African countries.

Potential risk factors and prevalence of Helicobacter pylori infection among adult patients with dyspepsia symptoms in Cameroon

BACKGROUND

Helicobacter pylori is a Gram negative bacterium that colonizes the stomach of approximately two-thirds of the human population and it is involved in the pathogenesis of gastroduodenal diseases. This study sought to determine potential risk factors associated with seroprevalence of H. pylori among dyspepsia patients in Cameroon for a better management of the disease.

METHODS

The study was carried out from August to December 2014 at Laquintinie Hospital and District Hospital of Bonassama in Douala metropolis. 205 patients (127 women and 78 men; mean age, 53.79 ± 11.11 years; range, 35-75 years) were enrolled. Each subject gave a written consent. The study was approved by the local Ethical Committee of Medical Sciences. A structured questionnaire was used to collect information on sociodemographic parameters and predisposing risk factors for Helicobacter pylori infection. For each patient, body mass index (BMI) and direct inquiry about dyspeptic symptoms were done. Blood samples were tested for H. pylori antibodies, and ABO/Rhesus blood group antigen typing was performed.

RESULTS

The overall prevalence was 64.39%. All patients with upper abdominal pains and frequent burping were H. pylori seropositive. We found that infection takes place early in childhood and adolescence, and reaches its peak at adulthood at 35 to 44 years. Sixty-two percent of women over 68 of men were infected. 80.39% of patients with family history of gastric cancer were seropositive, while 19.60% were seronegative (p = 0.001). Prevalence of 79.09 and 47.4% was recorded respectively for subjects with low, middle and high income levels (p = 0.001). H. pylori infection rate was 60.48% in blood group O patients compared with 70.37% in other blood groups (p = 0.203). 73% of infected subjects over 59% of uninfected ones currently take NSAIDs (p = 0.0509). Overcrowded households have a higher rate of 65.32% seropositivity in contrast with a lower rate of 33.33% from norm household (p = 0.197). 69.29% of obese and overweight patients versus 58.24% of subjects with normal weight were seropositive (P = 0.215).

CONCLUSION

The results of this study demonstrate that low income, family history of gastric cancer, clinical symptoms of nausea/vomiting and flatulence/bloating were risk factors of H. pylori infection in this population.

Trends in cancer incidence in Maputo, Mozambique, 1991-2008

Background

Very limited information is available regarding the incidence of cancer in sub-Saharan Africa. We analyzed changes in cancer patterns from 1991 to 2008 in Maputo (Mozambique).

Methods

We calculated the rates of incidence of different cancer sites by sex in the 5-year age-group of the population of Maputo city as well as age-standardized rates (ASRs) and average annual percentage changes (AAPC).

Results

Over the 18-year study period a total of 12,674 cases of cancer (56.9% females) were registered with an overall increase in the risk of cancer in both sexes. In males, the most common cancers were those of the prostate, Kaposi sarcoma (KS) and the liver. Prostate cancer showed the most dramatic increase over the whole study period (AAPC +11.3%; 95% CI: 9.7–13.0), with an ASR of 61.7 per 10⁵ in 2003–2008. In females, the most frequent cancers were of the uterine cervix, the breast and KS, with the former increasing along the whole study period (AAPC + 4.7%; 95% CI: 3.4–6) with an ASR of 62.0 per 10⁵ in 2003–2008 as well as breast cancer (AAPC +6.5%; 95%CI: 4.3–8.7).

Conclusions

Overall, the risk of cancer rose in both sexes during the study period, particularly among cancers associated with westernization of lifestyles (prostate, breast), combined with increasingly rising incidences or limited changes in cancers associated with infection and poverty (uterine cervix, liver). Moreover, the burden of AIDS-associated cancers has shown a marked increase.

Comparison of demographic characteristics and upper gastrointestinal endoscopy findings in HIV-positive, antiretroviral-treated patients with and without Helicobacter pylori coinfection

OBJECTIVES

We evaluated demographic characteristics in HIV-positive patients receiving highly active antiretroviral therapy (HAART) who had upper gastrointestinal (UGI) symptoms requiring UGI endoscopy and compared the findings in patients with and without H. Pylori coinfection.

METHODS

We prospectively observed all HIV-infected patients treated with antiretroviral therapy who underwent UGI endoscopy for the first time and were tested for H. pylori from January 2004 to December 2008. Data collected included the following: demographics (age, gender, ethnicity, body mass index [BMI], tobacco use, alcohol intake, and HIV risk behavior); comorbidity (viral hepatitis B or C, any organ dysfunction, or opportunistic disease); medication, including antibiotics, H2 blockers, proton pump inhibitors, and NSAIDs; CD4 cell counts, viral load; symptoms; and endoscopic and histologic diagnoses (H. pylori determined by Giemsa staining). Patients were compared according to H. pylori status (presence vs absence).

RESULTS

One hundred and forty-five patients were evaluated. Compared to patients without H. pylori infection (n = 97), those with H. pylori infection (n = 48) had a significantly higher CD4 cell count (p = .008), were more likely to be heterosexual (p = .047), had a higher BMI (p = .027), had a greater incidence of duodenal ulcers (p = .005), had lower viral loads (p < .01), were less likely to have received macrolide antibiotics in the last 3 months (p = .00), and had less comorbidity (p = .03). They were also more frequently of Black African than Caucasians. In multivariate analysis, being heterosexual and having a low viral load were independently associated with an increased risk of having H. Pylori coinfection.

CONCLUSION

In the antiretroviral therapy era, HIV-H. pylori coinfection is associated with a greater incidence of duodenal ulcers and higher CD4 counts, higher BMI, less comorbidity, and less frequent use of macrolides.

Association between cytokine gene polymorphisms and gastric precancerous lesions: systematic review and meta-analysis

Polymorphisms within interleukin-1 (IL1) and tumor necrosis factor alpha (TNFA) gene clusters are associated with an increased risk of gastric cancer. However, their role in gastric precancerous lesions remains poorly understood. Our objective was to perform a meta-analysis of studies addressing the association between IL1B-511, IL1RN variable number of tandem repeat, and TNFA-308 gene polymorphisms and gastric precancerous lesions, including original data from Portugal and Mozambique. Published studies on the association between these cytokine gene polymorphisms and gastric precancerous lesions were identified by systematic review, and estimates of the association were combined using random-effects meta-analysis taking into account new data obtained from Portuguese volunteer shipyard workers (n = 215) and Mozambican dyspeptic patients (n = 96) who underwent endoscopic and pathologic evaluation following the same protocol. Odds ratio (OR) estimates for intestinal metaplasia were 2.83 [95% confidence interval (95% CI), 1.15-6.96] for the IL1RN*22 genotype, 1.86 (95% CI, 1.03-3.36) for IL1B-511 T carriers, and 0.59 (95% CI, 0.12-3.04) for the TNFA-308*AA genotype in the Portuguese sample. All Mozambican subjects with intestinal metaplasia were T carriers for IL1B-511 and none had the 2 allele for IL1RN. In meta-analysis, IL1RN*22 genotype was associated with an increased risk of gastric precancerous lesions (22 versus LL: OR, 2.27; 95% CI, 1.40-3.70; I(2) = 26.4%; 12 studies). No such association was found for the IL1B-511 (TT versus CC: OR, 1.34; 95% CI, 0.87-2.07; I(2) = 65.7%; 13 studies) or TNFA-308 genotypes (AA versus GG: OR, 0.93; 95% CI, 0.35-2.43; I(2) = 0.0%; 7 studies). The IL1RN*22 genotype seems to consistently increase the risk of gastric precancerous lesions, supporting a role for this polymorphism in the early stages of gastric carcinogenesis.

Sensitivity is not an intrinsic property of a diagnostic test: empirical evidence from histological diagnosis of Helicobacter pylori infection

Background

We aimed to provide empirical evidence of how spectrum effects can affect the sensitivity of histological assessment of Helicobacter pylori infection, which may contribute to explain the heterogeneity in prevalence estimates across populations with expectedly similar prevalence.

Methods

Cross-sectional evaluation of dyspeptic subjects undergoing upper digestive endoscopy, including collection of biopsy specimens from the greater curvature of the antrum for assessment of H. pylori infection by histopathological study and polymerase chain reaction (PCR), from Portugal (n = 106) and Mozambique (n = 102) following the same standardized protocol.

Results

In the Portuguese sample the prevalence of infection was 95.3% by histological assessment and 98.1% by PCR. In the Mozambican sample the prevalence was 63.7% and 93.1%, respectively. Among those classified as infected by PCR, the sensitivity of histological assessment was 96.2% among the Portuguese and 66.3% among the Mozambican. Among those testing positive by both methods, 5.0% of the Portuguese and 20.6% of the Mozambican had mild density of colonization.

Conclusions

This study shows a lower sensitivity of histological assessment of H. pylori infection in Mozambican dyspeptic patients compared to the Portuguese, which may be explained by differences in the density of colonization, and may contribute to explain the heterogeneity in prevalence estimates across African settings.