Association of Helicobacter pylori and protozoal parasites in patients with chronic diarrhoea.

Introduction An association of Helicobacter pylori and common protozoal parasites in patients with abdominal discomfort and chronic diarrhoea is unclear and may be pathological. Materials and methods One hundred and sixty-one patients with diarrhoea were compared to 114 age and sex matched controls. Stool samples were examined by microscopy and DNA extracted for PCR with specific primers for H. pylori and protozoal parasites Blastocystis sp., Entamoeba sp. (Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii) and Giardia duodenalis (G. duodenalis). Results There was a marked difference in the presence of parasites between patients and controls: no parasite 42/75%, one parasite 42/15%, two or more parasites 16/10%, respectively (p < 0.001). Patients with diarrhoea were more likely to be infected with Blastocystis sp (p < 0.001), E. histolytica (p = 0.027) and E moshkovskii (p = 0.003). There was no difference in the frequency of H. pylori (p = 0.528), G duodenalis (p = 0.697) or E dispar (p = 0.425). Thirty-three patients and 27 controls had H. pylori infection. Of these, 22 patients and 6 controls were infected with Blastocystis sp (p = 0.001), 6 patients and no controls were infected with E. histolytica (p = 0.02), whilst 7 patents and 9 controls were infected with E dispar (p = 0.292). Conclusion In this population, diarrhoea is linked to infection with Blastocystis sp, E. histolytica and E moshkoviskii. In H. pylori infection, diarrhoea is linked to Blastocystis sp and E. histolytica infection. These associations may be linked pathogenically.

Elevated prevalence of Helicobacter species and virulence factors in opisthorchiasis and associated hepatobiliary disease.

Recent reports suggest that Opisthorchis viverrini serves as a reservoir of Helicobacter and implicate Helicobacter in pathogenesis of opisthorchiasis-associated cholangiocarcinoma (CCA). Here, 553 age-sex matched cases and controls, 293 and 260 positive and negative for liver fluke O. viverrini eggs, of residents in Northeastern Thailand were investigated for associations among infection with liver fluke, Helicobacter and hepatobiliary fibrosis. The prevalence of H. pylori infection was higher in O. viverrini-infected than uninfected participants. H. pylori bacterial load correlated positively with intensity of O. viverrini infection, and participants with opisthorchiasis exhibited higher frequency of virulent cagA-positive H. pylori than those free of fluke infection. Genotyping of cagA from feces of both infected and uninfected participants revealed that the AB genotype accounted for 78% and Western type 22%. Participants infected with O. viverrini exhibited higher prevalence of typical Western type (EPIYA ABC) and variant AB'C type (EPIYT B) CagA. Multivariate analyses among H. pylori virulence genes and severity of hepatobiliary disease revealed positive correlations between biliary periductal fibrosis during opisthorchiasis and CagA and CagA with CagA multimerization (CM) sequence-positive H. pylori. These findings support the hypothesis that H. pylori contributes to the pathogenesis of chronic opisthorchiasis and specifically to opisthorchiasis-associated CCA.

GIARDIA INTESTINALIS AND HELICOBACTER PYLORI CO-INFECTION: ESTIMATED RISKS AND PREDICTIVE FACTORS IN EGYPT.

Giardia intestinalis (G. intestinalis) and Helicobacter pylori (Hpylori) are two intestinal pathogens sharing the same mode of infection. This study determines the prevalence of G. intestinalis and H pylori co-infection estimated risks and predictive factors for susceptibility to co-infection. Stool samples were collected from 801 patients suffering gastrointestinal symptoms and living in Greater Cairo. They were subjected to coproscopic examination for detection of intestinal parasites and copro PCR-restriction fragment length polymorphism (PCR-RFLP) and sequencing targeting the glutamate dehydrogenase (gdh) gene for Giardia. Positive samples for gidrdiasis were further subjected to copro- immunoassay to detect H pylori coprontigen. Among 63 cases of giardiasis by both microscopy and PCR (84.1 % as-semblage B and 15.9% AII), 52.5% were coinfected with H pylori. Co-infection was more frequent with assemblage B (50.9%) than assemblage A (40%). Among studied variables of assemblage type, gender, or harboring more than one parasite (polyparasitism), only school age children, was signifi-cantly associated (P value: 0.02) with Giardia and H pylori co-infection. Physicians in Egypt must consider G. intestinalis and H pylori as prevailing intestinal pathogens with predominance of Giardia assemblage B. Giardia and H pylori co-infection is common in school aged children and modulates gastrointestinal manifestations. Intestinal parasitism and H pylori association is complex and necessitates further genomic studies for a better understanding of the epidemiological and clinical impact of co-infection, as well as possible strategies for their treatment and control.

Seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients with Helicobacter pylori infection: histological and laboratory findings and clinical significance.

Previous studies have demonstrated a high prevalence of seropositivity to the Ani s 1 protein in dyspeptic patients with Helicobacter pylori infection, but it is not known whether this represents episodes of anisakiasis misdiagnosis or previous exposure to the parasite without clinical relevance. To investigate the clinical significance of seropositivity to the Ani s 1 protein, a cohort study was performed with 87 consecutive dyspeptic patients who were treated for H. pylori infection. Fourteen (16.5%) patients were seropositive for the Ani s 1 protein, which was associated with the consumption of uncooked fish (p 0.0002). There were no differences in histological findings between subjects seropositive or seronegative for Ani s 1, but seropositive patients had increased eosinophil and basophil leukocyte counts (p < 0.05). Anti-Ani s 1 IgE was associated with a lack of improvement in the group of patients with non-ulcer dyspepsia after successful eradication of H. pylori (p 0.016). Thus, in at least a subset of patients with H. pylori infection, seropositivity to Ani s 1 could have clinical relevance. In addition, these data highlight that only anisakiasis associated with severe allergic or gastric symptoms is currently being diagnosed.

Gastric giardiasis.

AIMS: To assess the prevalence of gastric giardiasis in patients undergoing upper gastrointestinal endoscopy, and to define the clinicopathological correlates of gastric Giardia lamblia infection. METHODS: Consecutive gastric biopsy specimens (n = 15,023) from 11,085 patients, taken at Feltre City Hospital (north eastern Italy) from January 1986 to December 1991, were histologically and immunocytochemically examined for the occurrence of G lamblia trophozoites. Three gastric biopsy specimens from patients harbouring G lamblia infection, who repeated endoscopy before treatment, were also examined electron microscopically. RESULTS: Forty one patients (0.37% of the population study) harboured gastric giardiasis. All patients underwent upper gastrointestinal endoscopy because of dyspepsia, epigastric pain, or abdominal distension. Only two patients had diarrhoea at the time of investigation. Giardiasis was clinically unsuspected in all cases, although the nine patients who also had duodenal biopsies performed had concomitant intestinal giardiasis. Gastric giardiasis was invariably associated with chronic atrophic gastritis. Intestinal metaplasia of the gastric mucosa and Helicobacter pylori infection were found in 32 and 37 of the 41 patients with gastric giardiasis, respectively. CONCLUSIONS: The invariable association of gastric giardiasis with chronic atrophic gastritis, most often showing intestinal metaplasia and H pylori infection, indicates that a decreased gastric acidity is a prerequisite for localisation of G lamblia to the gastric mucosa. Though its possible role as a gastric pathogen remains to be elucidated, these findings suggest that trophozoites should be carefully searched for when examining gastric biopsy specimens showing chronic atrophic gastritis.