Helicobacter pylori transmission between a boy with duodenal ulcer and his father

The transmission of Helicobacter pylori: the effects of analysis method and study population on inference

Although much is known about the virulence of Helicobacter pylori, the transmission pathways for this bacterium are still unresolved. Transmission has been addressed through: (1) prevalence within families; (2) detection in fecal/oral environments; (3) detection in the abiotic/biotic environment; and (4) direct inference from strain similarity. Here, we review the molecular and biochemical methods used and discuss the relative merits of each. Furthermore, as there are differences between developing and developed nations, we discuss the results obtained from transmission studies in light of the study population. We conclude that H. pylori is probably transmitted person-to-person, facilitated by fecal-oral transmission during episodes of diarrhea or gastro-oral contact during periods of vomiting. The persistence of H. pylori in abiotic and biotic environments remains unproven but possible reactivation from viable, non-culturable coccoid forms should be further investigated. Finally, we speculate on the effect of host-pathogen interactions in confounding the inference of transmission.

Helicobacter pylori infection with a duodenal ulcer in a 6-year-old boy

A 6-year-old boy was hospitalized because of dark feces and facial pallor of 1 weeks duration. Other gastrointestinal symptoms, including vomiting and abdominal pain, were absent, but he felt dizziness when standing and fatigue on effort. Hematologic studies revealed iron-deficiency anemia, and endoscopy showed gastric erosions and a duodenal ulcer. All test results for Helicobacter pylori infection, including H. pylori antigen in stool, anti-H. pylori IgG immunoassay in serum, and the (13)C-urea breath test, were positive. Because an H. pylori-associated gastric ulcer had been diagnosed with endoscopy in the patients father 3 years earlier, father-son transmission was suspected. The patient was treated with triple-agent eradication therapy (proton pump inhibitor [lansoprazol], amoxicillin, and clarithromycin) for 2 weeks. One month after therapy was completed, eradication of H. pylori was confirmed by negative results on the stool antigen test. Peptic ulcer disease can occur in young children, as in this case. The stool antigen test kit is a useful and reliable method that can be used even in preschool children to diagnose H. pylori infection.

Trends in the prevalence of Helicobacter pylori in symptomatic children in the era of eradication

PURPOSE

Helicobacter pylori infection is common in Asia and is associated with dyspepsia, peptic ulcer, and gastric cancer. Eradication of the organism remains an important goal. Here, we looked at the trends in the prevalence of H pylori in symptomatic children over an 8-year period to assess the impact of an aggressive eradication program.

METHOD

A retrospective review was carried out between 1997 and 2004. All children with a history of dyspepsia or acute gastrointestinal bleeding were included and underwent gastroscopy. Three antral biopsies were taken during endoscopy and sent for histological analysis. Positivity of H pylori was treated aggressively with quadruple therapy under protocol. The demographic data, the histological findings, and the H pylori status were recorded.

RESULTS

There were a total of 159 patients (71 males, 88 females) who underwent gastroscopy in this period. One hundred nineteen patients showed histological evidence of gastritis, and the positive rate of H pylori was 25.6%. The overall prevalence has not decreased (33.3% in 1997, 27.7% in 2004). Increasing age, however, was associated significantly with the higher risk of H pylori infection.

CONCLUSION

H pylori has a high prevalence in Chinese children with increasing age. Eradication efforts seem to be unsuccessful in the reduction of prevalence. We hypothesize that this may be owing to cross-infection at meal times from sharing chopsticks.

Evidence of mother-child transmission of Helicobacter pylori infection

BACKGROUND

Low socioeconomical status is a major risk factor for natural acquisition of Helicobacter pylori (H. pylori) infection in developing countries. Its transmission route is unknown but studies suggest person-to-person transmission.

AIM

To evaluate seropositivity of anti-H. pylori antibodies in family members of infected symptomatic index patients as compared to family members of symptomatic uninfected index patients.

PATIENTS AND METHODS

One hundred and twelve family members of 38 patients who underwent endoscopy to exclude peptic disease were studied. Patients were deemed H. pylori infected or not infected when rapid urease test and histology were both positive or both negative. The family members underwent ELISA serology using the Cobas Core II Kit (Roche) and were classified into three groups: I - 29 family members of 10 H. pylori (+) duodenal ulcer index patients; II - 57 family members of 17 H. pylori (+) index patients without duodenal ulcer; III - 26 family members of 11 H. pylori (-) index patients.

RESULTS

Seropositivity of group I and II (infected patients) was higher than the control group, 83% vs 38%, specially in mothers, 81% vs 18%, and in siblings 76% vs 20%. Differences between fathers' seropositivity was not statistically significant in the three groups: 100% vs 86% vs 70%. Seropositivity of all family members (mother, father and siblings) between infected group (I vs II) was similar.

CONCLUSION

Prevalence of H. pylori infection was higher in family members of infected patients, but was similar among family members of infected patients with and without duodenal ulcer. H. pylori infection is more frequent in mothers and siblings of infected index children. A common source of infection cannot be excluded, but facts suggest that person-to-person transmission occurs, specially from mother to child.

Helicobacter pylori status and symptom assessment two years after eradication in pediatric patients from a high prevalence area

OBJECTIVES

To establish the rate of Helicobacter pylori reinfection in children from an H. pylori high prevalence area, possible clinical features predictive of reinfection and the usefulness of re-treatment.

METHODS

65 consecutive children attending the authors' department between 1998 and 2000 who had proven successful H. pylori eradication were enrolled; 52 took part. Patients and family members were invited to undergo C-urea breath testing and to complete a simple questionnaire regarding symptoms and socioeconomic status. Patients with H. pylori reinfection were offered treatment; eradication was assessed by C-urea breath test 8 weeks after completion of treatment.

RESULTS

Of 52 children, 15 (28.8%) were H. pylori positive. Variables predictive of reinfection were age at primary infection and presence of an infected sibling. Although reinfected children were more frequently symptomatic than non-reinfected patients, no specific symptom was associated with reinfection. Of the nine re-treated patients who returned 8 weeks after completing therapy, the bacterium was eradicated in five (56%).

CONCLUSIONS

The 12.8% per year reinfection rate in childhood at 2 years that we observed should prompt a re-evaluation of H. pylori status even after a successful eradication. Living in an H. pylori high prevalence area increases the annual risk of reinfection by approximately fourfold over the annual risk in H. pylori low prevalence areas.