Association of Helicobacter pylori infection with Shigella gastroenteritis in young children

Helicobacter pylori infection and risk of salmonella infection

Helicobacter pylori (H pylori) infection is the most frequent infection worldwide and it has been postulated that it predisposes to multiple enteric pathogens and diarrheal diseases. Salmonella infection is common in tropical and under developed communities and is associated with wide range of diseases from gastroenteritis to typhoid fever. This study aimed at detecting the impact of H pylori infection on the incidence of salmonella infections.The study participants were sampled from cohorts of patients in four university hospitals in different Egyptian Governorates. Their age ranged from 20 to 59 years and followed up for a rising Widal test. Case patients (n = 109) were subjects who visited the outpatient clinic because of diarrhea and typhoid like illness. They were either positive for H pylori stool antigen (n = 53) or negative to it (n = 56). All patients were subjected to thorough history taking, clinical examination, routine laboratory investigations, abdominal ultrasonography, H pylori stool antigen detection, and serial Widal test assay.The proportion of salmonella-infected subjects was lower among case patients with H pylori infection (22.6%) than among those negative for H pylori (33.9%) albeit not statistically significant (adjusted odds ratio [OR], 0.57; 95% confidence interval [CI], 0.24-1.33; P = .21). The association persisted nonsignificant after adjusting for sociodemographic variables (adjusted OR, 0.5; 95% CI, 0.18-1.39; P = .18). In a multivariate analysis that adjusted for sex, dietary habits, socioeconomic status, and educational level subjects who eat outdoors were associated with a significantly greater risk of salmonella typhi infection.Our findings suggest that there is no association between H pylori infection and salmonella infection in patients presented with typhoid fever or typhoid like illness.

Use of quantitative molecular diagnostic methods to identify causes of diarrhoea in children: a reanalysis of the GEMS case-control study

BACKGROUND

Diarrhoea is the second leading cause of mortality in children worldwide, but establishing the cause can be complicated by diverse diagnostic approaches and varying test characteristics. We used quantitative molecular diagnostic methods to reassess causes of diarrhoea in the Global Enteric Multicenter Study (GEMS).

METHODS

GEMS was a study of moderate to severe diarrhoea in children younger than 5 years in Africa and Asia. We used quantitative real-time PCR (qPCR) to test for 32 enteropathogens in stool samples from cases and matched asymptomatic controls from GEMS, and compared pathogen-specific attributable incidences with those found with the original GEMS microbiological methods, including culture, EIA, and reverse-transcriptase PCR. We calculated revised pathogen-specific burdens of disease and assessed causes in individual children.

FINDINGS

We analysed 5304 sample pairs. For most pathogens, incidence was greater with qPCR than with the original methods, particularly for adenovirus 40/41 (around five times), Shigella spp or enteroinvasive Escherichia coli (EIEC) and Campylobactor jejuni o C coli (around two times), and heat-stable enterotoxin-producing E coli ([ST-ETEC] around 1·5 times). The six most attributable pathogens became, in descending order, Shigella spp, rotavirus, adenovirus 40/41, ST-ETEC, Cryptosporidium spp, and Campylobacter spp. Pathogen-attributable diarrhoeal burden was 89·3% (95% CI 83·2-96·0) at the population level, compared with 51·5% (48·0-55·0) in the original GEMS analysis. The top six pathogens accounted for 77·8% (74·6-80·9) of all attributable diarrhoea. With use of model-derived quantitative cutoffs to assess individual diarrhoeal cases, 2254 (42·5%) of 5304 cases had one diarrhoea-associated pathogen detected and 2063 (38·9%) had two or more, with Shigella spp and rotavirus being the pathogens most strongly associated with diarrhoea in children with mixed infections.

INTERPRETATION

A quantitative molecular diagnostic approach improved population-level and case-level characterisation of the causes of diarrhoea and indicated a high burden of disease associated with six pathogens, for which targeted treatment should be prioritised.

FUNDING

Bill & Melinda Gates Foundation.

Prevention of Helicobacter pylori infection in childhood

Helicobacter pylori (H. pylori) infection is one of the most common infections worldwide. Although infection rates are falling in the developed and developing countries, H. pylori is still widespread in the world. This article has reviewed the important publications on H. pylori in childhood with a focus on its evolving transmission route and the source of infection and preventive strategies in childhood, PubMed was searched up to identify eligible studies. Relevant publications were searched using the following.

The Relation between Helicobacter pylori Infection and Acute Bacterial Diarrhea in Children

Background. H. pylori infection leads to chronic gastritis in both children and adults. But recently, there are arising theories of its protective effect in diarrheal diseases. Aim. To explore the prevalence of H. pylori infection in children with bacterial diarrhea and compare it with healthy controls. Patients and Methods. Two matched groups consisted of 122 consecutive children, aged 24–72 months old, with acute bacterial diarrhea, who had Shigellosis (N = 68) and Salmonellosis (N = 54) as patients group and 204 healthy asymptomatic children as control group enrolled in this study. Results. The prevalence of H. pylori infection in healthy control children was significantly higher than in patients group, (odds ratio = 3.6, 95% CI: 1.33–9.5, P = 0.007). In our study, only 2/54 Salmonella infected patients and 3/68 of Shigellosis had evidence of H. pylori infection, while normal control children had 27/204 infected individuals. Conclusion. H. pylori infection may play a protective role against bacterial diarrhea in children. So it is important to consider all of the positive and negative aspects of H. pylori infection before its eradication.

Unintended consequences of Helicobacter pylori infection in children in developing countries: iron deficiency, diarrhea, and growth retardation

Helicobacter pylori infection is predominantly acquired early in life. The prevalence of the infection in childhood is low in developed countries, whereas in developing countries most children are infected by 10 y of age. In poor resource settings, where malnutrition, parasitic/enteropathogen and H. pylori infection co-exist in young children, H. pylori might have potentially more diverse clinical outcomes. This paper reviews the impact of childhood H. pylori infection in developing countries that should now be the urgent focus of future research. The extra-gastric manifestations in early H. pylori infection in infants in poor resource settings might be a consequence of the infection associated initial hypochlorhydria. The potential role of H. pylori infection on iron deficiency, growth impairment, diarrheal disease, malabsorption and cognitive function is discussed in this review.

The impoverished gut--a triple burden of diarrhoea, stunting and chronic disease

More than one-fifth of the world's population live in extreme poverty, where a lack of safe water and adequate sanitation enables high rates of enteric infections and diarrhoea to continue unabated. Although oral rehydration therapy has greatly reduced diarrhoea-associated mortality, enteric infections still persist, disrupting intestinal absorptive and barrier functions and resulting in up to 43% of stunted growth, affecting one-fifth of children worldwide and one-third of children in developing countries. Diarrhoea in children from impoverished areas during their first 2 years might cause, on average, an 8 cm growth shortfall and 10 IQ point decrement by the time they are 7-9 years old. A child's height at their second birthday is therefore the best predictor of cognitive development or 'human capital'. To this 'double burden' of diarrhoea and malnutrition, data now suggest that children with stunted growth and repeated gut infections are also at increased risk of developing obesity and its associated comorbidities, resulting in a 'triple burden' of the impoverished gut. Here, we Review the growing evidence for this triple burden and potential mechanisms and interventions that must be understood and applied to prevent the loss of human potential and unaffordable societal costs caused by these vicious cycles of poverty.

An inverse and independent association between Helicobacter pylori infection and the incidence of shigellosis and other diarrheal diseases

OBJECTIVES

 We examined the association between Helicobacter pylori infection and the incidence of diarrheal diseases.

METHODS

 In a nested case-control study participants were sampled from cohorts of male Israeli soldiers aged 18-21 years, serving in field units and followed up for diarrheal diseases. Case patients (n = 177) were subjects who visited the base clinic because diarrhea and were positive for Shigella sonnei (n = 66), enterotoxigenic Escherichia coli (ETEC) (n = 31) or negative for bacterial pathogens (n = 80; diarrhea of unknown etiology). Controls (n = 418) were subjects who did not suffer from a diarrheal disease during the follow-up. They were matched to case patients by training unit and period. Serum samples were obtained from participants at the beginning of their field training and were tested for anti-H. pylori immunoglobulin (Ig) G and preexisting Shigella sonnei lipopolysaccharide IgG and IgA antibodies using enzyme-linked immunosorbent assay.

RESULTS

 The proportion of H. pylori-infected subjects was significantly lower among case patients with infection of unknown etiology (36.3%) than among controls (56.0%) (adjusted odds ratio [OR], 0.43; 95% confidence interval [CI], .24-.77; P = .005). The proportion of H. pylori-infected subjects among case patients with S. sonnei shigellosis was also significantly lower than in the control group: 36.3% versus 56.0%. The association persisted after adjusting for sociodemographic variables and preexisting S. sonnei serum IgA antibodies (adjusted OR, 0.37; 95% CI, .14-.95; P = .03) and IgG antibodies (adjusted OR, 0.38; 95% CI, .14-.99; P = .04). The direction of the association between H. pylori infection and ETEC diarrhea was similar, albeit not statistically significant.

CONCLUSIONS

 Our findings suggest an active role of H. pylori in protection against diarrheal diseases.

Childhood Helicobacter pylori infection and growth impairment in developing countries: a vicious cycle?

We hypothesize that infection with the gastric pathogen Helicobacter pylori in children in developing countries is the initiator of a vicious cycle of events that result ultimately in malnutrition and growth impairment. Acute infection with H. pylori is accompanied by hypochlorhydria, which facilitates the acquisition of other enteropathogens because of removal of the gastric acid barrier, which then results in diarrheal disease and iron-deficiency anemia. This is likely to occur most frequently in developing regions where the prevalence of H. pylori infection is disproportionately high and multiple enteric coinfections are common. The consequent synergistic impact of diarrheal disease and micronutrient deficiency on growth and cognitive function in children has significant public health implications for socioeconomic development in these countries.

Factors related to Helicobacter pylori prevalence in an adult population in Brazil

BACKGROUND

The prevalence of Helicobacter pylori is higher in developing countries. Sanitary facilities, crowding and ethnic group are some of the factors related to H. pylori infection. The aim of this study was to investigate in blood donors, free of dyspeptic symptoms, the prevalence and factors influencing H. pylori infection.

MATERIALS AND METHODS

This study was conducted in São Paulo, a city known to have a mixed population coming from all over the country. A total of 1008 blood donors were initially included in the study. After a final revision of all the questionnaires, 993 were included in the final analysis (746 males). H. pylori status was checked by an ELISA test. The following associations to infection were analyzed: sex, age, ethnic group, previous upper gastrointestinal (GI) endoscopy, smoking, alcoholism, drug addiction, type of drinking water, crowding, sanitary facilities, and family income.

RESULTS

Infection was observed in 496 of 746 male (66.5%) and in 156 of 247 female (63.2%) blood donors. Infection prevalence increased according to age group, regardless of sex. Prevalence was lower in White population than in non-White. No relationship was observed between infection and smoking, drug addiction, and alcohol. A positive relation was observed between infection and previous upper GI endoscopy, and type of drinking water, regardless if currently or during childhood. Crowding and lack of toilet in the house during childhood resulted in a higher infection rate. Lower familial income and educational level showed a positive association to infection.

CONCLUSIONS

Prevalence of H. pylori is higher in non-White population, independent of gender. A positive association was observed in aging, previous upper GI endoscopy, crowding, type of drinking water, lack of toilet during childhood, lower family income, and lower educational level.

Gastroenteritis and transmission of Helicobacter pylori infection in households

The mode of transmission of Helicobacter pylori infection is poorly characterized. In northern California, 2,752 household members were tested for H. pylori infection in serum or stool at a baseline visit and 3 months later. Among 1,752 person considered uninfected at baseline, 30 new infections (7 definite, 7 probable, and 16 possible) occurred, for an annual incidence of 7% overall and 21% in children <2 years of age. Exposure to an infected household member with gastroenteritis was associated with a 4.8-fold (95% confidence interval [CI] 1.4-17.1) increased risk for definite or probable new infection, with vomiting a greater risk factor (adjusted odds ratio [AOR] 6.3, CI 1.6-24.5) than diarrhea only (AOR 3.0, p = 0.65). Of probable or definite new infections, 75% were attributable to exposure to an infected person with gastroenteritis. Exposure to an H. pylori-infected person with gastroenteritis, particularly vomiting, markedly increased risk for new infection.

Bacteria and the gastrointestinal tract: beneficial and harmful effects

Bacteria are unique microorganisms that have a variety of physiological functions which are beneficial to human beings. However, bacteria can also be harmful and cause infections if translocated from the gastrointestinal tract to the epithelial tissue following surgery. The process of translocation can lead to surgical wounds becoming contaminated with gastrointestinal microbes such as Escherichia coli, Proteus or Klebsiella species. Bacteria can also cause severe gastrointestinal infections as a consequence of the ingestion of contaminated food. Food-borne bacterial infections can lead to serious consequences for the patient. Nurses managing the care of surgical patients and older people need to be aware of the physiological role that bacteria play but also the detrimental effects of bacterial translocation or ingestion particularly in older people, infants and people who are immunosuppressed.

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 infection in pediatrics

The diagnosis of Helicobacter pylori infection continues to challenge practicing physicians around the world. In the last year, several reports from Africa tried to examine the epidemiology of H. pylori infection in nursing babies, while others investigated the association between recurrent abdominal pain symptoms and H. pylori. In the diagnostic arena, attempts were made to improve diagnostic accuracy, mainly by using a new monoclonal version of the stool antigen test, and by applying the urea breath test in smaller children. In the current report, the most important studies on H. pylori infection in children published in the last year are also reviewed.

Important bacterial gastrointestinal pathogens in children: a pathogenesis perspective

This article focuses on the five most common bacterial enteropathogens of the developed world--Helicobacter pylori, Escherichia coli, Shigella, Salmonella, and Campylobacter--from the perspective of how they cause disease and how they relate to each other. Basic and recurring themes of bacterial pathogenesis, including mechanisms of entry, methods of adherence, sites of cellular injury, role of toxins, and how pathogens acquire particular virulence traits (and antimicrobial resistance), are discussed.