<i>Helicobacter pylori</i>Reinfection Is Virtually Absent after Successful Eradication

Hulst, R. W. M. Van Der; Rauws, E. A. J.; Koycu, B.; Keller, JJ; Kate, F. J. W. Ten; Dankert, J.; Tytgat, G. N. J.; Ende, A. van den

doi:10.1086/514023

Cited by 76 publications

(46 citation statements)

References 20 publications

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“…Another reason for falsely identifying natural reinfection is that a new strain could be introduced by endoscopic means during the study. Such endoscopic transmission has been noted in previous investigations (14). In summary, reinfection with H pylori appears to occur at a similar rate as primary infection in the same population.…”

Section: Quel Est Le Taux Total De Réinfection à Helicobacter Pylori?supporting

confidence: 84%

What is the Helicobacter pylori Global Reinfection Rate?

Parsonnet

2003

Canadian Journal of Gastroenterology and Hepatology

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Reinfection with any organism is related to the force of infection in the population and on both innate and acquired immunity to infection.Little is yet known about primary immune protection against Helicobacter pylori. Some data suggest that children can be recurrently infected, spontaneously eliminating the organism only to be infected again and again until the organism takes hold. This pattern of recurrent infection is not observed in patients who receive eradication therapy for chronic infection. After eradication of infection, the rate of reinfection is probably slightly lower than the primary infection rate in that age group, suggesting some level of acquired immunity. In developed countries, reinfection of adults in unusual, and recurrence usually repesents failure of primary eradicaton rather than new infection. Some cases of reinfection do occur, however. Given that acquired immunity probably varies little from population to population, reinfections will most likely occur in areas where the force of infecton is high, ie, where both the prevalence of infection and the opportunities for transmission are high.

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Section: Quel Est Le Taux Total De Réinfection à Helicobacter Pylori?supporting

confidence: 84%

What is the Helicobacter pylori Global Reinfection Rate?

Parsonnet

2003

Canadian Journal of Gastroenterology and Hepatology

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“…Reinfection by H. pylori in adults as well as children is generally uncommon (3,12,31,37). This report describes only a single family case; however, such mother-to-child transmission after treatment may be significant in Japan.…”

Section: Discussionmentioning

confidence: 85%

Helicobacter pylori Intrafamilial Infections: Change in Source of Infection of a Child from Father to Mother after Eradication Therapy

Taneike

Tamura

Shimizu

et al. 2001

Clin Diagn Lab Immunol

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Biopsy specimens of the antrum and corpus were obtained from four Helicobacter pylori-infected members of a family and from the same boy (son 1) in whom the infection reappeared after simultaneous successful eradication treatment of three family members, excluding the mother. A total of 18 to 60 H. pylori isolates were obtained from each specimen and subjected to rRNA gene restriction pattern analysis. The father's isolates and the initial isolates from son 1 showed the same HindIII type, which was divided into three HaeIII subtypes. Isolates from the mother and a brother (son 2) and posttreatment isolates from son 1 showed a distinct HindIII type (with one minor subtype), which was divided into six HaeIII subtypes. All subtypes of the initial isolates from son 1 were present in the father's isolates, and all subtypes of the posttreatment isolates from son 1 were present in the mother's isolates but not in son 2's. Electron microscopic analysis of the biopsy specimens demonstrated extremely high levels of H. pylori colonization in the father's gastric mucosa. H. pylori adherence with a ruffle formation was also demonstrated. The findings suggest that son 1 was infected initially with the H. pylori strain of the father and son 2 was infected with the H. pylori strain of the mother and that after eradication therapy son 1 was reinfected with the H. pylori strain of the mother, who did not undergo eradication therapy.Helicobacter pylori colonizes the gastric mucosa via an oral route, and around 60% of individuals worldwide are infected with H. pylori (5). Children are at high risk for H. pylori infections (21, 34). H. pylori infection may persist for years or be lifelong (30,35), although spontaneous clearance is also common in childhood (15,19). H. pylori infection is closely associated with gastritis and peptic ulcers (14, 25), and it is also a bacterial risk factor for gastric cancer (16) and mucosa-associated lymphoid tissue lymphoma (2).The precise mechanisms of H. pylori transmission are not yet known. Previous investigations by Drumm et al. in 1990 (8), Malaty et al. in 1991 (18), and Oderda et al. in 1991 (27) suggested intrafamilial clustering of H. pylori infections. Molecular DNA analyses of familial strains of H. pylori were then performed by Nwokolo et al. in 1992 (26) and by Bamford et al. in 1993 (1), demonstrating intrafamilial infections due to a single H. pylori strain (or a common source of infection within the family). Now, transmission among family members is considered to constitute the main route of H. pylori infection (6).In intrafamilial H. pylori infection, the infected parents, particularly infected mothers, have been considered likely to play a key role in the transmission of H. pylori (4, 28). In contrast, in developing countries, environmental factors may be more important than intrafamilial transmission (29, 32).Those epidemiological studies, however, are not based on molecular biological analysis of H. pylori strains. In this study, we investigated the molecular basis of H. pylor...

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“…The following possible sources of this diversity have been much discussed: general mutation (56), frameshifts in repetitive sequences in contingency genes (47), and recombination within and between strains (24,29,51,52). We suggest that the present level of diversity also reflects several additional features: (i) H. pylori's mode of transmission, which is preferentially intrafamilial and occurs efficiently in early childhood (7,13,23,36); (ii) the tendency of infections to persist for decades; and (iii) the rarity of new infections in adulthood (1,37,55). These three features create a highly fragmented bacterial population and diminish competition among strains from unrelated persons and selection for any one or few potentially most-fit genotypes (selective sweeps [22]).…”

Section: Discussionmentioning

confidence: 90%

The fdxA Ferredoxin Gene Can Down-Regulate frxA Nitroreductase Gene Expression and Is Essential in Many Strains of Helicobacter pylori

et al. 2003

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Very few examples of metabolic regulation are known in the gastric pathogen Helicobacter pylori. An unanticipated case was suggested, however, upon finding two types of metronidazole (Mtz)-susceptible strains: type I, in which frxA (which encodes a nitroreductase that contributes to Mtz susceptibility) is quiescent, and type II, in which frxA is well expressed. Here we report that inactivation of the fdxA ferredoxin gene (hp277) in type I strains resulted in high-level frxA expression (in effect, making them type II). However, fdxA null derivatives were obtained from only 6 of 32 type I strains tested that were readily transformed with an frxA::aphA marker. This suggested that fdxA is often essential. This essentiality was overcome in 4 of 20 strains by inactivating frxA, which suggested both that frxA overexpression is potentially deleterious and also that fdxA has additional, often vital roles. With type II strains, in contrast, fdxA null derivatives were obtained in 20 of 23 cases tested. Thus, fdxA is dispensable in most strains that normally exhibit (and tolerate) strong frxA expression. We propose that restraint of frxA expression helps maintain balanced metabolic networks in most type I strains, that other homeostatic mechanisms predominate in type II strains, and that these complex results constitute a phenotypic manifestation of H. pylori's great genetic diversity.

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Helicobacter pyloriReinfection Is Virtually Absent after Successful Eradication

Cited by 76 publications

References 20 publications

What is the Helicobacter pylori Global Reinfection Rate?

What is the Helicobacter pylori Global Reinfection Rate?

Helicobacter pylori Intrafamilial Infections: Change in Source of Infection of a Child from Father to Mother after Eradication Therapy

The fdxA Ferredoxin Gene Can Down-Regulate frxA Nitroreductase Gene Expression and Is Essential in Many Strains of Helicobacter pylori

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