Use of commonly prescribed antibiotics is not associated with prevalence of Helicobacter pylori infection in adults

Antibiotics taken for other illnesses and spontaneous clearance of Helicobacter pylori infection in children

PURPOSE

Factors that determine persistence of untreated Helicobacter pylori (H. pylori) infection in childhood are not well understood. We estimated risk differences for the effect of incidental antibiotic exposure on the probability of a detected clearance at the next test after an initial detected H. pylori infection.

METHODS

The Pasitos Cohort Study (1998-2005) investigated predictors of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico. Children were screened for infection at 6-month target intervals from 6 to 84 months of age, using the 13C-urea breath test corrected for body-size-dependent variation in CO2 production. Exposure was defined as courses of any systemic antibiotic (systemic) or those with anti-H. pylori action (HP-effective) reported for the interval between initial detected infection and next test. Binomial regression models included country of residence, mother's education, adequacy of prenatal care, age at infection, and interval between tests.

RESULTS

Of 205 children with a test result and antibiotic data following a detected infection, the number of children who took > or =1 course in the interval between tests was 74 for systemic and 33 for HP-effective. The proportion testing negative at the next test was 66% for 0 courses, 72% for > or =1 systemic course, and 79% for > or =1 HP-effective course. Adjusted risk differences (95%CI) for apparent clearance, comparing > or =1 to 0 courses were 10% (1-20%) for systemic and 11% (0-21%) for HP-effective.

CONCLUSIONS

Incidental antibiotic exposure appears to influence the duration of childhood H. pylori infection but seems to explain only a small portion of spontaneous clearance.

Previous antibacterial treatment due to concomitant infections in preschool children is associated with a lower Helicobacter pylori positivity

In 1998 we presented 1 successfully treated case of Listeria monocytogenes prosthetic valve endocarditis and made a review of all the cases that had been published to date. We carry out an up-to-date review through Pub-Med of every case of Listeria monocytogenes prosthetic valve endocarditis; mortality rate is calculated and data from several clinical and therapeutical variables are collected; Fisher's exact test is used to identify those variables significantly associated with mortality. Four out of 23 patients died in hospital (17%); among all the variables included, only peripheral embolism (p=0.024), onset on a mechanical prosthesis (p=0.035) and having used only 1 antibiotic instead of a combination of drugs (p=0.026) were independently associated with mortality. Although the overall number of cases is too low to draw definite conclusions (n=23), mortality rate is lower than previously believed. Some variables that have traditionally been associated with a poor prognosis for endocarditides are not for the case of Listeria monocytogenes on valvular prostheses. It seems prudent to treat affected patients with a combination of ampicillin -- or vancomycin, if there is a history of beta-lactam allergy and ampicillin desensitization is not possible -- plus an aminoglycoside.

Respiratory symptoms/diseases, impaired lung function, and drug use in two Italian general population samples

BACKGROUND

Research and practice indicate that a sizeable amount of prescribed drugs is never used.

AIM

To assess the habitual up-take of medicines in subjects with respiratory symptoms/diseases or impaired lung function in general population samples.

METHODS

Data regard 4010 subjects (8-88 years) from the rural area of Po River Delta (North Italy) and the urban area of Pisa (North-Central Italy). Analyses concern the habitual use of any or specific medicines (broncho-pulmonary, anti-allergic, cardio-vascular, diuretic) in subjects with asthma, chronic bronchitis/emphysema (COPD), COPD or chronic cough/phlegm (COPDsx), and airways obstruction (AO, FEV(1)/FVC<70%).

RESULTS

Asthma, COPD, COPDsx, and AO were present in 6%, 5%, 21%, and 13% of cases, respectively. Only 37% and 21% of subjects with respiratory symptoms/diseases used any or specific medicines, respectively. The subjects with COPD exhibited the highest prevalence of assumption (59% for any drug, 38% for specific medicines), followed by asthmatics (42% and 30%), and subjects with AO (40% and 25%). After accounting for sex, age, residence area, smoking habit, education, and presence of comorbidity, the conditions significantly related to any medicine up-take were COPD (OR 1.65, 95% CI 1.08-2.53) and asthma (OR 1.47, 95% CI 1.01-2.12). Only asthma resulted significantly associated with the use of specific drugs (OR 3.11, 95% CI 1.94-4.97). Drug use was higher in the urban than in the rural area.

CONCLUSION

The results indicate that most people in the general population do not use drugs, in spite of reported respiratory disorders. The underuse of medicines seems lower in the urban area.

Recent developments in the epidemiology of Helicobacter pylori

Prevalence determinations have been performed around the world, and regardless of how exotic a location, H. pylori is found in a substantial proportion of the population. H. pylori remains among the most universal of infections. Understanding of some features of infection has changed. Infection can be gained and lost at rates higher than previously realized. Oral-oral and oral-fecal transmission account for most, if not nearly all, cases of infection. H. pylori infection has declined rapidly in developed countries, which probably has contributed to declines in duodenal ulcer disease and gastric cancer. The full health implications of the potential elimination of infection are unknown.

Seroconversion and seroreversion in IgG antibodies to Helicobacter pylori: a serology based prospective cohort study

STUDY OBJECTIVES

To assess the incidence of seroconversion and seroreversion in IgG antibodies to Helicobacter pylori within a 11 year observation period using these events as markers for acquisition and loss of the infection, respectively.

DESIGN

Population based prospective cohort study.

SETTING

Northern part of Copenhagen County, Denmark.

PARTICIPANTS AND METHODS

A random sample of 2527 Danish adults were examined and blood obtained in 1983 and in 1994. Matching pairs of sera were analysed for the presence of IgG and IgM antibodies to H pylori with an in house enzyme linked immunosorbent assay. Participants who were seronegative at study entry and seropositive at follow up and had a fourfold increase in baseline IgG antibody levels were categorised as seroconverters and regarded as having acquired H pylori infection. Participants who were seropositive at study entry and had at least a fourfold decrease in baseline IgG antibody levels at follow up were assumed to have lost the infection (seroreverters).

RESULTS

The seroprevalence of H pylori infection was 24.7 (95% confidence intervals (95% CI) 23.0, 26.4) % in 1983 and 24.5 (95% CI 22.8, 26. 2) % in 1994. A total of 14 participants seroconverted within the observation period (cumulative 11 year incidence proportion: 1.0 (95% CI 0.5, 1.5) %). Having increased IgM antibody levels at study entry significantly increased the likelihood of IgG seroconversion (relative risk 6.4 (95% CI 2.1, 19.6). Seroreversion was seen in 48 participants (cumulative 11 year incidence proportion: 7.7 (95% CI 5. 6, 9.8) %).

CONCLUSIONS

Changes in H pylori infection status with time are rare in Danish adults. Few adults become infected with H pylori in Denmark.

Does maternal smoking hinder mother-child transmission of Helicobacter pylori infection?

Evidence for early childhood as the critical period of Helicobacter pylori infection and for clustering of the infection within families suggests a major role of intrafamilial transmission. In a previous study, we found a strong inverse relation between maternal smoking and H. pylori infection among preschool children, suggesting the possibility that mother-child transmission of the infection may be less efficient if the mother smokes. To evaluate this hypothesis further, we carried out a subsequent population-based study in which H. pylori infection was measured by 13C-urea breath test in 947 preschool children and their mothers. We obtained detailed information on potential risk factors for infection, including maternal smoking, by standardized questionnaires. Overall, 9.8% (93 of 947) of the children and 34.7% (329 of 947) of the mothers were infected. Prevalence of infection was much lower among children of uninfected mothers (1.9%) than among children of infected mothers (24.7%). There was a strong inverse relation of children's infection with maternal smoking (adjusted odds ratio = 0.24; 95% confidence interval = 0.12-0.49) among children of infected mothers, but not among children of uninfected mothers. These results support the hypothesis of a predominant role for mother-child transmission of H. pylori infection, which may be less efficient if the mother smokes.