Risk factors for salmonella gastroenteritis in children less than five years of age in Taiwan

Increased non-typhoidal Salmonella hospitalizations in transfusion-naïve thalassemia children: a nationwide population-based cohort study

INTRODUCTION

Although non-typhoidal Salmonella (NTS) infection usually causes self-limited enterocolitis, several risk factors have been found to predispose individuals to more severe NTS infections. However, few studies have discussed the association between NTS infection and pediatric thalassemia populations.

MATERIAL AND METHODS

A nationwide population-based retrospective cohort study was conducted using medical records of the selected children from the Taiwan National Health Insurance Research Database. Immunocompromised individuals or patients with a history of transfusion or splenectomy were excluded. One thalassemia patient was matched with four non-thalassemia patients based on their year of birth, sex, and urbanization level.

RESULTS

In this cohort, 912 patients with thalassemia and 3648 comparison cohort were analyzed. The mean age of NTS hospitalization was 2.0 ± 1.4 in thalassemia cohort and 2.6 ± 2.4 in non-thalassemia cohort. Transfusion-naïve thalassemia children were proved to have a higher rate of NTS hospitalization (6.90 vs 4.11 per 1000 person-year; p = 0.0004) than the non-thalassemia cohort, with an adjusted hazard ratio (HR) of 1.68 (95% confidence interval [CI] = 1.26-2.24).

CONCLUSION

Our research shows that transfusion-naïve thalassemia is associated with an increased risk of NTS hospitalization. Further prospective study comparing the incidence and severity of NTS infection among children with and without thalassemia is needed.

IMPACT

Pediatric transfusion-naïve thalassemia patients have an 1.68-fold increased risk for hospitalization due to non-typhoidal Salmonella (NTS) infection. This is the first nationwide population-based cohort study based on an extremely large database that shows pediatric transfusion-naïve thalassemia patients have an increased risk for NTS hospitalizations. Besides the previously known risk factors such as extremes of age, sickle cell disease, or immunosuppressing conditions, clinicians must also take thalassemia as a possible risk factor for more severe NTS disease.

Risk factors of non-typhoidal Salmonella gastroenteritis in hospitalised young children: a case-control study

OBJECTIVE

To explore risk factors associated with non-typhoidal Salmonella gastroenteritis in young children in Hong Kong.

DESIGN

A case-control study.

SETTING

Paediatrics wards at three public hospitals in Hong Kong.

PARTICIPANTS

Cases were children aged above 30 days to below 5 years hospitalised for gastroenteritis at three public hospitals in Hong Kong with culture confirmed non-typhoidal Salmonella infection. Controls were age-matched (±2 months) children admitted for a reason other than gastroenteritis.

MAIN OUTCOMES MEASURES

A face-to-face interview by using standardised questionnaire on exposures 3 days prior to illness. Adjusted OR (aORs) and 95% CIs were calculated using multivariable logistic regression.

RESULTS

A total of 102 cases and 204 age-matched controls were included in the analysis. Multivariable logistic regression revealed that having food purchased from places other than a supermarket, that is, from wet market/restaurant/farm (aOR, 2.64; 95% CI, 1.03 to 6.77; p=0.044) was a significant risk factor for non-typhoidal Salmonella infection. Having a household member with gastroenteritis symptoms (aOR, 2.03; 95% CI, 0.94 to 4.39; p=0.072) was of borderline significance and playing at a children's indoor playroom was a protective factor (aOR, 0.28; 95% CI, 0.09 to 0.85; p=0.024).

CONCLUSIONS

Consumption of food purchased from places other than a supermarket was the identified determinant factor for non-typhoidal Salmonella gastroenteritis in Hong Kong. Parents/caregivers should be alerted to this risk when choosing foods for their young children. The protective effect of playing in an indoor playroom could be confounded by socioeconomic factors and further investigation is required to better understand its potential implication. There was some support for person-to-person transmission and good family hygiene needs to be emphasised.

Epidemiological characteristics of a salmonella outbreak among infants in Qatar, 2017

Purpose: This study was conducted to investigate the epidemiology behind the increased incidence of infant salmonella cases in Qatar during 2017 and identify the possible risk factors. Methods: This was a cross-sectional study using the notification reports of laboratory-confirmed infant salmonella cases received by the Ministry of Public Health during the year 2017. Furthermore, complementary phone interviews with the infants' mothers using a validated questionnaire were conducted. Results: The infant salmonella attack rate was calculated at approximately 3.23 cases per 1000 infants. Among the 89 confirmed infant salmonella cases, there were more girls (53%) than boys (47%) with a median age of 8 months. The most common type of salmonella species isolated was group B (50.5%). Among the 59 infant cases whose mothers were interviewed, the majority (94.9%) were symptomatic and diarrhea was the main reported symptom (90%), particularly bloody diarrhoea (62%). Regarding their dietary consumption, the majority (69.5%) of the infected infants were formula-fed. Moreover, the majority reported having no pets at home (91.6%) and were not enrolled in a day care center (93.3%). Conclusion: This study revealed a high incidence of salmonella infection among infants in the State of Qatar, which poses a public health concern. Therefore, targeted interventions and health awareness programs are required for outbreak prevention, detection and control.

Salmonella and the changing environment: systematic review using New York State as a model

Salmonella is a public health concern, for which a complex interplay between host, agent, and environment exists. An improved understanding of causal processes can be used to better gauge the causes and trajectory of Salmonella in a changing environment. This would be useful in determining the impact of climate change on the New York State (NYS) environment, the effect of climate change on Salmonella in NYS, factors contributing to Salmonella vulnerability in humans, and aspects of climate change and Salmonella which necessitate further research. A systematic review was conducted to study associations between Salmonella and the environment. Using the search criteria, a total of 91 relevant articles were identified from four electronic databases. Key information was abstracted, organized, and synthesized to identify causal processes and linkages between climate change, the environment of NYS, and Salmonella-related outcomes, as well as risk factors to characterize Salmonella vulnerabilities. Three inter-related domains were identified for consideration and application to epidemiological research to confirm and extrapolate disease patterns using climate change scenarios: improved quantification of causal relationships, inclusion of factors linked to sectors not immediately associated with the exposure and outcome, and increased capacity to validate models in diverse settings.

A Hospital-based Case-control Study of Diarrhea in Children in Shanghai

BACKGROUND

Prevention and control of childhood diarrhea is a global priority. We conducted a case-control study of childhood diarrhea in Shanghai.

METHODS

We prospectively recruited diarrheal children in an outpatient setting. Nondiarrheal controls were individually matched to cases. Rotavirus, norovirus and bacterial pathogens were examined. Clinical and epidemiologic data were obtained at enrollment and follow-up.

RESULTS

Potential pathogens identified in 680 diarrheal cases and 680 controls were rotavirus (19.0% vs. 1.3%), norovirus (13.4% vs. 4.7%), nontyphoidal Salmonella (9.3% vs. 1.9%), enteropathogenic Escherichia coli (8.4% vs. 6.9%) and enteroaggregative Escherichia coli (7.2% vs. 6.2%) and Campylobacter (5.1% vs. 1.2%), enterotoxigenic Escherichia coli (1.2% vs. 0.6%), enterohemorrhagic Escherichia coli (0.3% vs. 0%) and Shigella (0.15% vs. 0%), respectively. The specificity and sensitivity of fecal leukocytes >5 per high-power field for the diagnosis of bacterial diarrhea were 94.2% and 22.8%. Salmonella were susceptible to ciprofloxacin, ceftriaxone and amoxicillin-clavulanate and showed low frequency of resistance to azithromycin. Campylobacter showed low frequency of resistance to azithromycin and high frequency of resistance to ciprofloxacin. Diarrheagenic Escherichia coli was highly susceptible to ciprofloxacin and amoxicillin-clavulanate. Contact with diarrheal patients was a risk factor for rotavirus [adjusted odds ratio (aOR): 11.7], norovirus (aOR: 7.5) and Campylobacter (aOR: 27.1) infections. Mother's education was positively associated with Salmonella infection (aOR: 2.1). Good hand hygiene was protective against rotavirus (aOR: 0.6), norovirus (aOR: 0.5) and Salmonella (aOR: 0.3) infections.

CONCLUSIONS

Rotavirus, norovirus, nontyphoidal Salmonella and Campylobacter are significantly associated with diarrhea in Chinese children. Fecal leukocytes >5 per high-power field can predict bacterial diarrhea. Target prevention and appropriate treatment of diarrhea should consider the potential pathogen and resistance pattern.

Risk factors associated with sporadic salmonellosis in children: a case-control study in Lower Saxony, Germany, 2008-2011

We conducted a case-control study based on 884 laboratory-confirmed sporadic Salmonella cases reported to the German infectious disease notification system. For controls, we recruited 510 rotavirus cases via the same system. Univariable and multivariable logistic regression analyses were performed separately for children aged 0-3 years and 4-14 years. In both age groups, the highest odds ratios (OR) were found for raw ground pork consumption [0-3 years: OR 8·6, 95% confidence interval (CI) 2·4-30·8; 4-14 years: OR 4·5, 95% CI 1·1-19]. Further risk factors were exposure to animals (OR 1·6, 95% CI 1·1-2·1), consumption of poultry (OR 1·5, 95% CI 1·1-2·1), food items containing eggs (OR 1·5, 95% CI 1·1-2) and black pepper (OR 1·7, 95% CI 1·1-3·5) in children aged 0-3 years, and consumption of uncooked pork sausage (OR 3·6, 95% CI 1·4-9·3) in children aged 4-14 years. This study highlights the significance of raw pork products ('Mett' in German) as risk factors for sporadic salmonellosis in children in Germany.