A relatively low prevalence of Helicobacter pylori infection in a healthy paediatric population in Riga, Latvia: a cross-sectional study.

UNLABELLED: The aim of this study was to investigate the prevalence, age of acquisition and risk factors for Helicobacter pylori (H. pylori) among asymptomatic children. 13C-urea breath tests and questionnaires were obtained from 142 children and 40 parents. The prevalence of H. pylori was 19%. H. pylori positivity was higher in children with a positive parent (p=0.003) and independently inversely related to antibiotic treatment during the previous year in preschool children (p = 0.045). CONCLUSION: The prevalence of H. pylori in children in Riga is higher than that in Western countries, but lower than that in Eastern European countries. H. pylori is present during the second year of life and is influenced by parental H. pylori status and previous treatment with antibiotics.

Imported rocket salad partly responsible for increased incidence of hepatitis A cases in Sweden, 2000-2001.

An increased incidence of domestic hepatitis A without any obvious source of infection in Sweden and a small outbreak in late spring 2001 led to the undertaking of a case-control study. Consumption of imported rocket salad was clearly associated with disease (odds ratio 9.1, 95% confidence interval 1.5 to 69). The importation of vegetables from countries where hepatitis A is endemic to countries where this disease is not endemic continues to be a public health problem.

Helicobacter pylori infection in Ethiopian children: a cohort study.

Risk factors for infection with Helicobacter pylori (HP) were investigated in a cohort study of 121 seronegative children in Ethiopia aged 2-4 y, who had previously participated in a case-control study. Blood samples were drawn at inclusion in the cohort study and again after 12 and 30 months. At 12 months the parents were also interviewed about putative risk factors for infection, using a structured questionnaire. Analyses were made by comparing risk factors in seropositive and seronegative children. The seroconversion rate during the first year was 31% (27/87) and during the following 18 months 34% (17/50; corresponding to an annual incidence of 24%). After a period of 30 months, 58% (14/24) of the children who were 24-29 months old at inclusion in the study had seroconverted, compared with 40% (4/10) of those who were 30-35 months old, 73% (22/30) of those who were 36-41 months old and 31% (4/13) of those who were 42 months old or more. These results indicate that peak age for HP infection is below 6 y in this cohort in Ethiopia, and might also reflect a pattern of repeated seroconversion and sero-reversion in early childhood. Independent predictors of HP-seroconversion were the variables 'drinking-water', comparing water from a well with water from rivers or pipes (RR = 1.46, 95% CI 1.0-2.15) and 'antibiotic treatment' (RR = 1.84, 95% CI 1.16-2.92).

Risk factors for infection with Helicobacter pylori--a study of children in rural Ethiopia.

The public health impact of Helicobacter pylori (HP) infection is gradually becoming obvious, the bacterium now being implicated as an aetiologic agent in a variety of gastric diseases. Transmission routes still remain unknown, although single risk factors, such as domestic crowding (especially bed-sharing) in childhood and low parental socioeconomic status, have been pointed out in studies from developed countries. In an attempt to study the risk factors in a developing country, we performed a case control study of 242 randomly selected children aged 2-4 y in Butajira rural area in Ethiopia. Blood samples were drawn and a questionnaire administered. The total prevalence of IgG antibody to HP among the children in the region was 48% (116/242). Several risk factors such as: crowding, water, animals, sanitation, etc. correlated strongly to seropositivity in a univariate analysis. After controlling for possible confounding, independent predictors of seropositivity were: living in town (OR = 2.15, p = 0.001), increasing age (OR = 1.71, p = 0.060), and being a Muslim (OR = 1.54, p = 0.005). It could not be excluded that a bad water supply in town could explain the difference in seroprevalence between town and village. These results indicate that, in developing countries, factors relating to community and religion might be as important risk factors for infection with HP in children as characteristics of the family or the home.

Age at acquisition of Helicobacter pylori infection: comparison of a high and a low prevalence country.

Helicobacter pylori (HP) is now generally accepted as the main aetiological agent in chronic active gastritis and peptic ulcer. Infection with HP is widespread, but the routes of transmission are still unclear. Several studies have shown increasing prevalence of antibodies against HP with age. In developing countries, age at peak incidence of seroconversion is probably considerably lower than in developed countries. We performed a cross-sectional study to determine the age at maximum incidence of seroconversion to HP in a high-prevalence country (Ethiopia) and in a low-prevalence country (Sweden). Sera from 242 Ethiopian children, aged 2-14 years and from 295 Swedish children aged 1-15 years were analysed using an enzyme linked immunosorbent assay (ELISA) for detecting immunoglobulin G (IgG) antibodies. In Ethiopia, a comparison was made of a local and a reference strain for preparation of the antigen, but there was little difference in outcome. A comparison between antigen prepared from the reference strain and the pooled antigen used in the Swedish study also showed little difference. The sharpest rise in seroprevalence was found in the age range 2-4 years. Among 4-year-olds, some 60% had already seroconverted, and among 12-year-olds almost 100% had done so. In Sweden, the sharpest rise appeared between the ages of 9 and 10 years. Above 10 years of age seroprevalence was around 20%. Infection with HP is acquired in early childhood in Ethiopia, but somewhat later, although still before the teens, in Sweden. To determine properly the risk factors for infection with HP, possible exposure must be assessed around the age of seroconversion, since seropositivity may remain for a long time but environmental factors may have changed since primary infection.

Helicobacter pylori infection and foreign travel.

Seroprevalence of antibodies to Helicobacter pylori is generally higher in developing than in developed countries. The route of transmission of H. pylori is unknown but is most commonly assumed to be fecal-oral. Gastroenteritis in a person traveling to developing countries is often a marker of exposure to fecally contaminated food or water. Of 133 initially seronegative young Swedes traveling to developing countries for a total of 16.4 years, of whom 102 reported having had at least one episode of gastroenteritis, not one seroconverted. This rate is lower than in studies of residents in developed countries and casts some doubt on the theory of fecal-oral transmission via a common source as an important mode of transmission of infection with Helicobacter pylori.