[Familial transmission of Helicobacter pylori infection in Podlasie Region]

The purpose of the study was to assess the incidence of Helicobacter pylori infection in members of families in the Podlasie Region. The study included members of 205 families in whom IgG antibodies against H. pylori were determined. The mean number of members examined in a family was 3.07. The mean age was 16.6 years; the mean level of specific IgG antibodies was 67.35 U/ml. Of the families examined 47 (22.0%) had all members with a positive titer of antibodies against H. pylori (> 24 U/ml); in 62 (30.2%) families, all members presented a negative result of IgG antibodies against H. pylori (< 24 U/ml). Of 97 mothers examined, a positive titer of IgG was found in 77.1%. Of 33 fathers (81.8%) were seropositive. In the families with a mother seropositive, the infection in at least one child examined was revealed in 48.6% of the families, whereas in the families with a mother seronegative, all her children were healthy in 63.6% of the families. In case of a father, a positive IgG in at least one child was found in 55.5% of the families, whereas no infection in children was estabilished in 44.4%.

Helicobacter pylori: what do we still need to know?

Helicobacter pylori is a common gastric infection that causes serious complications in a minority of individuals. A great deal is known about the disease, but many unanswered questions remain. Among these, perhaps the most enigmatic is that we do not know how the organism is transmitted. We are uncertain why the prevalence of the disease is falling within the developed population. There is still debate as to its relationship with gastroesophageal reflux disease. It is unclear why there are differences in the international incidence of gastric cancer. Similar uncertainties relate to the reasons why the complications of H. pylori infection have changed over time. In this article, I have hypothesized that a number of these unanswered questions may be related to a putative increase in gastric acid secretion that may have taken place during the past 200 years. To date, there is little confirmatory evidence for this, and it remains a fascinating area that merits more scientific research.

Association between herpes simplex virus type 1 and Helicobacter pylori in US adolescents

OBJECTIVE

To understand how Helicobacter pylori infection is acquired and the role that herpes simplex virus type 1 (HSV-1) may have, we determined whether an association between HSV and H pylori exists at the individual level and for what reason.

STUDY DESIGN

Data were collected from 1,090 participants aged 12-19 years during phase 1 (1988-1991) of the NHANES III. Generalized estimating equations were used to estimate prevalence ratios (PR).

RESULTS

The crude overall PR and 95% CI for H pylori seropositivity comparing HSV+ to HSV- individuals was 2.20 (1.69-2.85). In large urban households the PR adjusted for poverty level and race/ethnicity was twice that in small nonurban households (2.27 versus 1.15, respectively).

CONCLUSIONS

Overall, HSV-1 seropositivity is associated with a higher H pylori seroprevalence. The negligible association found in some strata suggests that shared environmental factors or routes of transmission rather than biologic reasons may be primarily responsible for this association.

Concordance of Helicobacter pylori infection among children in extended-family homes

Helicobacter pylori is transmitted within households and high concordance is observed among siblings. To better understand the contributions of close interpersonal contact and family relatedness to transmission, we compared concordance of H. pylori infection among 241 sibling and non-sibling children aged 2-18 years in 68, predominantly low-income, Hispanic households with at least two nuclear families. Prevalence of H. pylori infection was 24%. Compared to children with no infected siblings or non-siblings and adjusting for age, odds of H. pylori infection were 1.2 (95% CI 0.52-2.9), 3.2 (95% CI 1.14-9.1), and 9.4 (95% CI 3.1-28.5) for children residing with at least one infected non-sibling, one infected sibling, and with at least one infected sibling and non-sibling, respectively. The study further implicates intersibling transmission as a pathway for H. pylori infection in childhood. In addition, living with a non-sibling in extended-family homes may contribute to infection risk but only in households with prevalent H. pylori infection within all family groups.

Prevalence and risk-factors for Helicobacter pylori infection in urban and rural Beninese populations

In total, 446 healthy individuals (240 in urban and 206 in rural environments, respectively) were selected from 96 households, based on cluster sampling of residential location. Demographic, sociological and environmental data were collected by face-to-face interviews using a standard questionnaire. Infection with Helicobacter pylori was assessed by detection of anti-H. pylori IgG serum antibodies. The prevalence of H. pylori antibodies was 75.4% in the urban population and 72.3% in rural (village) residents (p 0.459). No association was found between infection and age, gender, education level, size of household, economic activity or source of drinking water. The infection rate was higher in children whose parents were both infected, and also in children whose mother was infected (p < 0.001). By logistic regression analysis, the density of occupation of sleeping accommodation (more than three persons sharing a room; 95% odds ratio (OR) = 9.82 (4.13-23.31), p < 0.001), and the mother's status within the household (95% OR = 3.85 (1.53-9.67), p 0.003), were independent predictors for H. pylori infection. The 74% seroprevalence of H. pylori infection found in healthy Beninese individuals is similar to that reported previously from other parts of sub-Saharan Africa. Family contact with infected persons and crowded living conditions were associated with increased risk of infection. These findings are consistent with intra-familial H. pylori transmission and suggest that improvement of living conditions should be protective against infection.

[Epidemiology and transmission route of Helicobacter pylori infection]

Helicobacter pylori (H. pylori) infection is a common bacterial infection among humans. Current knowledge implies that acquisition of H. pylori seems to occur predominantly in childhood and a major role of intrafamilial spread is now beyond controversy. However, the major route of transmission remains poorly understood. The prevalence of H. pylori infection continues to vary markedly between developing countries and developed countries, and according to ethnicity, place of birth and socioeconomic factors among people living in the same country. According to the nation-wide seroprevalence study for 5,732 asymptomatic Korean population, which was conducted from March 1998 to October 1998, the seroprevalence of H. pylori infection was 46.6%, showing the transition from a developing country to a developed country. The seroprevalence in children (neonate-15 yr) and adult (16-79 yrs) were 17.2% and 66.9%, respectively. According to multivariate analysis, variables such as sex, age, geographic area, crowding (number of person per room) in childhood, economic status in childhood, and types of housing in childhood were significantly and independently associated with H. pylori seroprevalence of adults. In children, age, geographic area, household income, mother's education, and drinking water source were significant factors of H. pylori infection. As 7 years has already passed since the nation-wide study, well designed study for the seroprevalence of H. pylori infection, by which epidemiological factors and the route of transmission of H. pylori infection could be discovered, is warranted.

Epidemiology of Helicobacter pylori Infection

This review summarizes epidemiologic studies published between April 2004 and March 2005. DNA of Helicobacter pylori was detected in river water, but the culture was unsuccessful. H. pylori infection was associated with Shigella infection. Despite many studies, predominant infection routes of H. pylori have not yet been clearly identified. In some limited populations in developing countries, H. pylori infection was rare or with strange distributions. Trials to reduce the H. pylori infection rate were performed including H. pylori eradication in total family units and fly control. The hypothesis of a causal role of Helicobacter species and H. pylori infection in cancer of the hepatobiliary tract was indeed confirmed.

Helicobacter pylori status in family members as risk factors for infection in children

This study aimed to disentangle the independent contributions of Helicobacter pylori infections in mothers, fathers and siblings to the risk for the infection in the 11-13 years age group. Index children from a cross-sectional Stockholm school survey and their family members completed questionnaires and contributed blood samples. H. pylori serostatus was determined with an enzyme-linked immunosorbent assay and immunoblot. Fifty-four seropositive and 108 seronegative index children were included and 480 out of 548 family members contributed blood. In multivariate logistic regression modelling, having an infected mother (OR 11.6, 95% CI 2.0-67.9) or at least one infected sibling (OR 8.1, 95% CI 1.8-37.3) were risk factors for index child infection, whilst the influence of infected fathers was non-significant. Birth in high-prevalence countries was an independent risk factor (OR 10.4, 95% CI 3.4-31.3). H. pylori infections in mothers and siblings and birth in high-prevalence countries stand out as strong markers of infection risk amongst children in Sweden.

Helicobacter pylori infection in different generations of Hispanics in the San Francisco Bay Area

To quantify the contributions of household and environmental factors to Helicobacter pylori infection, the authors examined H. pylori infection among several generations of Hispanics in the San Francisco Bay Area. Between 2000 and 2004, household members were tested for H. pylori and interviewed about demographic factors and household pedigree. An immigrant was defined as someone born in Latin America with at least one Latin America-born parent; a first-generation US-born Hispanic was defined as someone born in the United States with at least one Latin America-born parent; and a second-generation US-born Hispanic was defined as someone born in the United States with at least one US-born parent. Prevalences of H. pylori in immigrants and first- and second-generation US-born Hispanics were 31.4% (102/325), 9.1% (98/1,076), and 3.1% (2/64), respectively. Compared with second-generation US-born Hispanics, the age-adjusted odds ratios for H. pylori were 9.70 (95% confidence interval (CI): 1.57, 60.00) for immigrants and 4.32 (95% CI: 0.69, 26.96) for first-generation US-born Hispanics (p(trend) < 0.001). These odds ratios decreased to 6.19 (95% CI: 1.13, 33.77) and 3.24 (95% CI: 0.59, 17.82), respectively, after adjustment for parental infection (odds ratio (OR) = 2.94, 95% CI: 1.59, 4.38), low education (OR = 1.76, 95% CI: 1.20, 2.68), and crowding (OR = 1.23, 95% CI: 0.84, 1.79). Both the household and birth-country environments probably contributed to declining H. pylori prevalence among successive generations of Hispanics.

Five-year follow-up study of mother-to-child transmission of Helicobacter pylori infection detected by a random amplified polymorphic DNA fingerprinting method

Recent studies have speculated on the possible role of the mother in transmitting Helicobacter pylori infection to their children. In an attempt to either prove or disprove this supposition, we investigated the rates of infection of children born to H. pylori-positive mothers from birth to 5 years of age using serology and the stool antigen test. When infection of the children did occur, the strains from the children were compared to those of their mothers using DNA analysis. Sixty-nine of the 350 pregnant mothers (19.7%) had a positive serology for H. pylori. Fifty-one children underwent serological examinations and stool antigen tests at 4 to 6 days after birth, followed by 1, 3, and 6 months. They were continuously given the stool antigen test at 4- to 6-month intervals until the age of 5 years. Gastric juice samples were collected from the infected children and their mothers for culture and DNA analyses using a random amplified polymorphic DNA fingerprinting method. None of the 51 children acquired H. pylori infection during the first year of life. Of the 44 children enrolled in a 5-year follow-up study, five (11%) acquired H. pylori infection. They acquired the infection at the age of 1 year 2 months, 1 year 3 months, 1 year 6 months, 1 year 8 months, and 4 years 4 months. Random amplified polymorphic DNA fingerprinting confirmed that the strains of the five children exhibited DNA fingerprinting patterns identical to those of their mothers. These findings suggest that mother-to-child transmission is the most probable cause of intrafamilial spread of H. pylori.

Direct transmission of H. pylori from challenged to nonchallenged mice in a single cage

To understand whether direct transmission of H. pylori occurs from infected mouse to noninfected mouse, the system using a mouse model we developed previously was tested. Six nude mice were challenged with H. pylori inocula; one group consisted of one challenged nude mouse 1 week after inoculation raised with four nonchallenged nude mice in a single cage. For the single cage, a polycarbonate cage or a mesh-floor cage was used. Then three groups were kept in a polycarbonate cage and the other three groups kept in a mesh-floor cage to avoid H. pylori transmission through stool. After coraising for 1, 2, or 3 weeks, all mice were sacrificed to determine the existence of H. pylori in the stomach, saliva, and stool by culture or PCR and H. pylori-associated gastritis. RAPD fingerprinting patterns using different primers of isolated strains from challenged and nonchallenged mice were compared to understand the origin of transmitted strains. During 3 weeks after coraising of H. pylori challenged and nonchallenged mice, H. pylori was detected in the stomachs in 3 of 12 nonchallenged mice in the polycarbonate cage and in 2 of 12 nonchallenged mice in the cage with a steel mesh floor. H. pylori was detected from saliva or stool in two nonchallenged, infected mice in the polycarbonate cage. Moreover, RAPD fingerprinting using different primers of the total five strains isolated from five nonchallenged, infected mice in both cages showed the same pattern and concordance with that of the challenged strain and the strains isolated from challenged mice. It is demonstrated that intimate interaction is the cause of H. pylori transmission via saliva and stool.

Children of Helicobacter pylori-infected dyspeptic mothers are predisposed to H. pylori acquisition with subsequent iron deficiency and growth retardation

BACKGROUND

We tested whether Helicobacter pylori-infected dyspeptic mothers had a higher rate of H. pylori infection in their children, and whether such H. pylori-infected children were predisposed to iron deficiency or growth retardation.

MATERIALS AND METHODS

A total of 163 children from 106 dyspeptic mothers (58 with and 48 without H. pylori infection) were enrolled to evaluate body weight, height, hemoglobin, serum ferritin, and H. pylori infection using the 13C-urea breath test. A questionnaire was used to evaluate demographic factors of each child.

RESULTS

The rate of H. pylori infection in children with H. pylori-infected dyspeptic mothers was higher than that of children with noninfected mothers (20.5% vs. 5.3%; p<.01, OR: 4.6, 95% CI: 1.5-14.2). The rate of H. pylori infection in children elevated as the number of their H. pylori-infected siblings increased (p<.01). For children below 10 years of age, H. pylori infection was closely related to low serum ferritin and body weight growth (p<.05).

CONCLUSION

The children of H. pylori-infected dyspeptic mothers had an increased risk for such infection. The risk further increased once their siblings were infected. H. pylori infection in pre-adolescent children may determine iron deficiency and growth retardation.

Association of Helicobacter pylori infection and giardiasis: Results from a study of surrogate markers for fecal exposure among children

AIM: To investigate whether Helicobacter pylori (H pylori) infection is associated with hepatitis A virus (HAV) infection, presence of enteroparasites, and other surrogates of fecal exposure.

METHODS: We conducted a cross-sectional study in 121 children consecutively admitted at a pediatric hospital in Salvador, Brazil. H pylori and HAV infection were identified by the presence of serum antibodies. Stool specimens were examined for the presence of ova and parasites. A structured questionnaire inquiring about sanitary conditions and life style was applied to each subject.

RESULTS: Fifty-one of the 121 children (42.1%) were found to be seropositive for H pylori, and 45 (37.2%) for HAV. The seroprevalence of H pylori and HAV both increased significantly with age. Cross-tabulation of data showed that 26 (21.5%) were seropositive and 51 (42.1%) were negative for both H pylori and HAV antibodies (χ² = 7.18, OR = 2.8, CI 1.30-5.97). The age adjusted OR for an HAV-infected child being H pylori positive was 2.3 (CI 1.02-5.03). The agreement between H pylori and HAV seropositivity was fair (κ = 0.24). After controlling for possible confounding, the variables remaining independently associated with seropositivity to H pylori were age, presence of Giardia lamblia in feces (OR = 3.2, 95%CI, 1.1-9.5) and poor garbage disposal quality (OR = 2.4, 95%CI, 1.1-5.1).

CONCLUSION: Our data suggest that H pylori infection is associated with surrogate markers of fecal exposure. Thus, we conclude that the fecal-oral route is relevant in the transmission of HP among children in an urban setting of a developing country. The association observed between G. lamblia and H pylori infection may have several explanations. Further studies to investigate this relationship are warranted.

[Pathogenesis of Helicobacter pylori infection--bacterium and host relationship]

Helicobacter pylori (H. pylori) colonizes the gastric mucosa of a half of the mankind. Duodenal ulcer is found in 15-25%, gastric ulcer in 13%, while gastric adenocarcinoma develops in 1% of all infected individuals. Pathogenesis of H. pylori infection is related to the virulence factors of the bacterium, environmental (dietary habits, hygiene, stress) and host factors (age, sex, blood type). Colonization of the gastric mucosa is related to the motility of the bacterium, presence of lipopolysaccharide (LPS) and various bacterial enzymes. Gastric mucosal injury is the result of H. pylori LPS, vacuolization cytotoxin (vacA), cytotoxin associated protein (cagA), heat shock proteins and factors responsible for neutrophil chemotaxis and activity. H. pylori colonizes the gastric mucosa and zones of ectopic gastric epithelium. H. pylori infection is transmitted via oral-oral, fecal-oral and iatrogenic way (during endoscopy). Higher prevalence of the infection is associated with lower socioeconomic level, lack of drinking water, and living in a community. Acute H. pylori gastritis is superficial pangastritis progressing into the chronic phase after 7-10 days. Gastric mucosal atrophy and intestinal metaplasia can develop during the course of H. pylori infection. Clearly defined factors that influence the outcome of H. pylori infection include bacterial strain, distribution of gastritis, acid secretion and gastric mucosal atrophy.

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.