Incidence and risk factors for community-acquired acute gastroenteritis in north-west Germany in 2004

A scoping review of modifiable and behavioural drivers of infectious gastroenteritis among children in high-income countries

BACKGROUND

Globally, gastroenteritis (GE) significantly impacts children's health and contributes to societal, economic, and health burdens. Previous studies reporting risk factors of GE in children in high-income settings mainly rely on outbreak investigations, which inherently capture only a fractional representation of the overall spectrum of GE occurrences. In addition, there is paucity of comprehensive information pertaining to modifiable risk factors of GE. This scoping review aims to synthesize existing evidence concerning modifiable and behavioural risk factors associated with GE among children in high-income countries.

METHODS

PubMed, Embase, CINAHL, and Scopus were the databases from which articles were retrieved. A descriptive synthesis of the evidence was performed, following the Arksey and O'Malley scoping studies framework and enhanced by the Preferred Reporting Items for Systematic Reviews and Meta-analysis extension for Scoping Reviews checklist (PRISMA-ScR).

RESULTS

The systematic search identified 13,395 journal articles, which were subsequently screened, and duplicates removed, resulting in 19 articles for inclusion in the review. The majority of these studies (63.2%) employed a case-control design and were predominantly conducted in community settings (68.4%). Factors such as parental literacy, contact with individuals exhibiting gastrointestinal symptoms, and nappy-wearing were identified as significantly associated with childhood GE within domestic environments. Childcare-related variables, including enrolment size, mixing of personnel between child groups, the presence of central cleaning stations, and the implementation of hygiene and disease prevention policies, showed significant association with GE. In addition, the presence of sand pits, paddling pools, and animals in childcare centers correlated with increased incidences of GE among attending children.

CONCLUSIONS

The scoping review reveals a complex and varied research landscape on factors influencing gastroenteritis (GE) for children in high-income countries. The findings suggest that while some variables are closely linked to specific pathogens, others may not be, highlighting variability across GE aetiology. The significant association between various household level and childcare-related factors and childhood GE points to a valuable direction for future research and public health intervention.

Descriptive study of foodborne disease using disease monitoring data in Zhejiang Province, China, 2016-2020

Background

This study aimed to identify the epidemiology, seasonality, aetiology and clinical characteristics of sporadic foodborne diseases in Zhejiang province during 2016–2020.

Methods

Descriptive statistical methods were used to analyze the data from surveillance network established by the Zhejiang Provincial Center for Disease Control and Prevention. There were 31 designated hospitals in all 11 cities which were selected using probability proportionate to size sampling method.

Results

During the study period, the surveillance system received 75,124 cases with 4826 (6.42%) hospitalizations from 31 hospitals. The most common cause was Norovirus, 6120 cases (42.56%), followed by Salmonella, 3351 cases (23.30%). A significant seasonal trend was observed for the V. parahaemolyticus, with the highest rates over the summer period, peaking in August, 1171 cases (38.75%), a similar trend was also observed with Salmonella and Diarrheagenic E. coli. Norovirus infections showed the highest rate in November (904, 14.77%) and March (660,10.78%), the lowest in August, 215 cases (3.51%). Patients between 19 ~ 40 years were more likely to infected by Norovirus, V. parahaemolyticus and Diarrheagenic E. coli, patients below 1 year were the highest among patients with Salmonella infection, 881 cases (26.3%). The Norovirus, V. parahaemolyticus and Diarrheagenic E. coli infection with the highest positive detection rates among the workers were observed. The largest number cases of food categories were from aquatic product infection. The private home was the most common exposure setting.

Conclusion

Our study highlighted the necessity for conducting an active, comprehensive surveillance for pathogens in all age groups, to monitor the changing dynamics in the epidemiology and aetiology of foodborne diseases to guide policies that would reduce related illnesses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14226-1.

Risk Factors for Acute Gastroenteritis Among Patients Hospitalized in 5 Veterans Affairs Medical Centers, 2016-2019

BACKGROUND

In the United States, ∼179 million acute gastroenteritis (AGE) episodes occur annually. We aimed to identify risk factors for all-cause AGE, norovirus-associated vs non-norovirus AGE, and severe vs mild/moderate AGE among hospitalized adults.

METHODS

We enrolled 1029 AGE cases and 624 non-AGE controls from December 1, 2016, to November 30, 2019, at 5 Veterans Affairs Medical Centers. Patient interviews and medical chart abstractions were conducted, and participant stool samples were tested using the BioFire Gastrointestinal Panel. Severe AGE was defined as a modified Vesikari score of ≥11. Multivariate logistic regression was performed to assess associations between potential risk factors and outcomes; univariate analysis was conducted for norovirus-associated AGE due to limited sample size.

RESULTS

Among 1029 AGE cases, 551 (54%) had severe AGE and 44 (4%) were norovirus positive. Risk factors for all-cause AGE included immunosuppressive therapy (adjusted odds ratio [aOR], 5.6; 95% CI, 2.7-11.7), HIV infection (aOR, 3.9; 95% CI, 1.8-8.5), severe renal disease (aOR, 3.1; 95% CI, 1.8-5.2), and household contact with a person with AGE (aOR, 2.9; 95% CI, 1.3-6.7). Household (OR, 4.4; 95% CI, 1.6-12.0) and non-household contact (OR, 5.0; 95% CI, 2.2-11.5) with AGE was associated with norovirus-associated AGE. Norovirus positivity (aOR, 3.4; 95% CI, 1.3-8.8) was significantly associated with severe AGE.

CONCLUSIONS

Patients with immunosuppressive therapy, HIV, and severe renal disease should be monitored for AGE and may benefit from targeted public health messaging regarding AGE prevention. These results may also direct future public health interventions, such as norovirus vaccines, to specific high-risk populations.

Global Prevalence of Yersinia enterocolitica in Cases of Gastroenteritis: A Systematic Review and Meta-Analysis

The prevalence of Yersinia enterocolitica in gastroenteritis is often underestimated. It relates considerably to morbidity and medical expenses around the world. Understanding the cause of gastroenteritis leads to making the appropriate treatment decisions. We systematically searched PubMed, Science Direct, Embase, and Scopus to identify all published studies between Jan. 1, 2000, and Dec. 31, 2019, to assess the prevalence of Y. enterocolitica in gastroenteritis patients. A total of 5039 articles were identified that lead to the extraction of data from 47 of them. The pooled prevalence of Y. enterocolitica in cases of gastroenteritis was estimated as 1.97% (1.32–2.74%) in the culture method and 2.41% (1.07–4.22%) in the molecular method. Among the biotypes of Y. enterocolitica, 1A (62.48%) and 1B (2.14%) had the most and least prevalence, respectively. Serotype O3 Y. enterocolitica with 39.46% had the highest and O5,27 with 0.0% had the least prevalence in gastroenteritis cases. In conclusion, the findings of this systematic review show that Y. enterocolitica is prevalent in gastroenteritis in all age groups. Serotypes O3 and O9 of Y. enterocolitica had the highest prevalence and O5,27 had the least prevalence in diarrheal patients. The prevalence of Y. enterocolitica was similar in both gender and different seasons. It should be noted that to determine the role of the organism, more studies are needed especially in food-borne diseases.

Heavy weather events, water quality and gastroenteritis in Norway

Climate change will lead to more extreme weather events in Europe. In Norway, little is known about how this will affect drinking water quality and population's health due to waterborne diseases. The aim of our work was to generate new knowledge on the effect of extreme weather conditions and climate change on drinking water and waterborne disease. In this respect we studied the relationship between temperature, precipitation and runoff events, raw and treated water quality, and gastroenteritis consultations in Norway in 2006–2014 to anticipate the risk with changing climate conditions. The main findings are positive associations between extreme weather events and raw water quality, but only few with treated drinking water. Increase in maximum temperature was associated with an increase in risk of disease among all ages and 15–64 years olds for the whole year. Heavy rain and high runoff were associated with a decrease in risk of gastroenteritis for different age groups and time periods throughout the year. No evidence was found that increase in precipitation and runoff trigger increased gastroenteritis outbreaks. Large waterworks in Norway currently seem to manage extreme weather events in preventing waterborne disease. However, with more extreme weather in the future, this may change. Therefore, modelling future climate scenarios is necessary to assess the need for improved water treatment capacity in a future climate.

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Positive associations between extreme weather events and raw water quality.

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Increase in maximum temperature was associated with an increase in risk of disease.

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Heavy rain and high runoff were associated with a decrease in risk of gastroenteritis.

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Larger water works in Norway seem to cope with the extreme weather events in the current climate.

Factors associated with the detection of norovirus among asymptomatic adults

OBJECTIVES

Little is known about asymptomatic norovirus infection and its risk factors in healthy adults. This study investigated detection of norovirus in stool and its associated factors among asymptomatic healthy adults in a high-income country.

METHODS

This prospective cross-sectional study-conducted between February 2016 and January 2017 at a teaching hospital in Japan-included apparently healthy adults aged ≥18 years who underwent voluntary health check-ups. Our primary outcome was detection of norovirus in stool specimens confirmed by real-time RT-PCR. We evaluated descriptive statistics and associated factors, including demographics, social habits, and clinical parameters.

RESULTS

Among 15 532 participants, 4536 (29.2%, mean age 58.0 (standard deviation 11.8) years, male 44.6%) were enrolled, and 112 (2.5%, GI 57, GII 54, GI + GII 1) were norovirus-positive. Monthly prevalence rates of the GI norovirus were consistent throughout the year, while those of GII were high in May. Participants aged <40 and ≥ 80 years had higher rates of GII norovirus detection. Participants who occasionally consume alcohol, especially wine (odds ratio (OR) 0.17, 95% confidence interval (CI) 0.04-0.68), had lower norovirus detection rates than abstainers. Participants with untreated dyslipidaemia and a low high-density lipoprotein (HDL) cholesterol level had higher detection rates than those with treated dyslipidaemia (OR 1.48, 95%CI 1.07-2.05) and a normal HDL cholesterol level (OR 2.60, 95%CI 1.46-4.61). Some gastrointestinal and female genital diseases were associated with norovirus detection.

CONCLUSIONS

The norovirus detection rate in asymptomatic adults was 2.5%. Participants with specific lifestyles or medical histories may have higher risks of asymptomatic norovirus infection.

Acute Infectious Gastroenteritis in Infancy and Childhood

BACKGROUND

Despite the introduction of vaccination against rotavirus, and even though it can often be treated on an outpatient basis, acute infectious gastroenteritis is nevertheless the second most common non-traumatic cause of emergency hospitaliza - tion in children aged 1 to 5 years, accounting for approximately 9% of cases (39 410 cases in 2017). The most common path - ogens are viruses (47% rotavirus, 29% norovirus, and 14% adenovirus).

METHODS

This review is based on publications retrieved by a selective search in PubMed employing the terms "acute gastro - enteritis children" AND "dehydration" OR "rehydration" OR "prevention," and by manual searching (based, for example, on reference lists and expert knowledge), with subsequent evaluation including consideration of the relevant guidelines.

RESULTS

The degree of dehydration can be judged from weight loss and other clinical findings. In 17 randomized controlled trials conducted on a total of 1811 children with mild or moderate dehydration, oral rehydration with oral rehydration solution was just as effective as intravenous rehydration with respect to weight gain, duration of diarrhea, and fluid administration, and was associated with shorter hospital stays (weighted mean difference, -1.2 days; 95% confidence interval [-2.38; -0.02]). Oral rehydration therapy failed in 4% of patients [1; 7]. In children who are vomiting or who refuse oral rehydration solution, continuous nasogastric application is just as effective as intravenous rehydration and is the treatment of first choice.

CONCLUSION

In Germany, children with mild or moderate dehydration are often hospitalized for intravenous rehydration therapy, despite the good evidence supporting ambulatory oral rehydration. Obstacles to intersectoral care, the nursing shortage, and inadequate reimbursement must all be overcome in order to reduce unnecessary hospitalizations and thereby lessen the risk of nosocomial infection.

Clinical characteristics and risk factors for children with norovirus gastroenteritis in Taiwan

BACKGROUND

Norovirus is a common acute gastroenteritis (AGE) pathogen across all age groups worldwide, which is difficult to differentiate from other pathogens. This study aimed to understand the clinical characteristics and risk factors of norovirus gastroenteritis among children in Taiwan.

METHODS

A prospective AGE surveillance study was conducted in children aged ≤5 years who were hospitalized in 10 major hospitals in Taiwan between 2014 and 2017. The non-AGE control group included healthy children who were matched based on age, gender, season, and geographic area.

RESULTS

Overall, 674 norovirus gastroenteritis patients were enrolled. Fever (p < 0.001), mucoid stool (p < 0.001), and bloody stool (p < 0.001) occurred less frequently among norovirus gastroenteritis patients. Norovirus gastroenteritis patients yielded lower CRP values on admission (21.78 ± 36.81 vs. 46.26 ± 58.12 mg/L, p < 0.001) than non-norovirus controls. Norovirus gastroenteritis patients were associated with higher direct contact rates with AGE patients within 1 week (30.5% vs. 0.97%, p < 0.001), lower hand wash rates before meals (21.6% vs. 15.4%, p = 0.001), lower human milk (15.8% vs. 19.8%, p = 0.045) and guava consumption rates (17.8% vs. 24.3%, p = 0.002) than non-AGE participants.

CONCLUSIONS

Body temperature, stool characteristics, and CRP value can help distinguish the norovirus from other pathogens. The major risk factor of norovirus AGE is contact with AGE patient. Higher frequency of hand wash, human milk, and guava intake may be protective against norovirus gastroenteritis.

Norovirus Vaccine: Priorities for Future Research and Development

Soon after its identification, norovirus (NoV) has been indicated as one of the most common causes of outbreaks of acute gastroenteritis (AGE) and sporadic acute diarrhea episodes in subjects of any age. In 2016 the World Health Organization stated that the development of a NoV vaccine should be considered an absolute priority. Unfortunately, the development of an effective NoV vaccine has proven extremely difficult, and only in recent years, some preparations have been tested in humans in advanced clinical trials. In this paper, reasons that justify efforts to develop a NoV vaccine, difficulties encountered during NoV vaccine development, and NoV vaccine candidates will be discussed. In recent years, identification of some NoV antigens that alone or in combination with other viral antigens can induce a potentially protective immune response has led to the development of a large series of preparations that seem capable of coping with the problems related to NoV infection. Epidemiological and immunological studies have shown that multivalent vaccines, including both GI and GII NoV, are the only solution to induce sufficiently broad protection. However, even if the road to formulation of an effective and safe NoV vaccine seems to be definitively traced, many problems still need to be solved before the total burden of NoV infections can be adequately controlled. Whether currently available vaccines are able to protect against all the heterologous NoV strains and the variants of the most common serotypes that frequently emerge and cause outbreaks must be defined. Moreover, as performed clinical trials have mainly enrolled adults, it is mandatory to know whether vaccines are effective in all age groups, including younger children. Finally, we must know the immune response of immunocompromised patients and the duration of protection induced by NoV vaccines. Only when all these problems have been solved will it be possible to establish an effective immunization schedule against NoV infection and calculate whether systematic vaccination can be cost effective.

Impact of Routine Rotavirus Vaccination in Germany: Evaluation Five Years After Its Introduction

BACKGROUND

Routine rotavirus (RV)-vaccination is recommended in Germany since August 2013. Five years later, we evaluated the recommendation by examining vaccine uptake and the impact on RV-gastroenteritis (RVGE) burden in all age groups and on intussusceptions in infants.

METHODS

We estimated RV-vaccine uptake in the 2014-2018 birth cohorts using statutory health insurance prescription data. For impact assessment, we analyzed RVGE-surveillance data of the German infectious diseases notification system. We compared age-specific RVGE-incidences of different severity between pre-vaccination (2005/06-2007/08) and routine vaccination period (2013/14-2017/18) calculating incidence rate ratios (IRR) using Poisson regression. To determine the effect on intussusception, we used hospital discharge data (2006-2017) and compared incidences between pre-vaccination and routine vaccination period using Poisson regression.

RESULTS

Vaccination coverage increased from 59% (2014) to 80% (2018). Incidences of RVGE-outpatient cases, RVGE-hospitalization and nosocomial RVGE among <5-year-olds decreased by 74% (IRR = 0.26; 95% CI: 0.26-0.27), 70% (IRR = 0.30; 95% CI: 0.30-0.31) and 70% (IRR = 0.30; 95% CI: 0.30-0.31), respectively. Incidence of RVGE-outpatient cases in age groups ineligible for RV-vaccination decreased by 38% (IRR 0.62; 95% CI: 0.61-0.63). Compared with the pre-vaccination period, incidence of intussusception in the first year of life decreased by 28% (IRR = 0.73; 95% CI: 0.68-0.79) while at age of the first vaccine-dose (7th-12th week of age) increase in incidence of intussusception was non-significant (IRR = 1.29; 95% CI: 0.93-1.78).

CONCLUSIONS

Routine RV-vaccination is well accepted in Germany. Since implementation of routine RV-vaccination, RVGE significantly decreased in <5-year-olds and in non-vaccinated older age groups through herd protection. The decline of intussusceptions in the first life year suggests a potential vaccination-associated protection against gastrointestinal infections that might trigger intussusceptions. These encouraging results should be communicated to doctors and parents for further improvement of vaccine uptake and protection of more infants.

High prevalence of selected viruses and parasites and their predictors in Malawian children

Enteric pathogens have been related to child undernutrition. Whereas there are lots of data on enteric bacterial microbiota and infections, much less is known about the incidence of prevalence of intestinal colonisation with viruses or important parasitic species. This study assessed the presence of selected viruses and parasites in stools of 469, 354, 468 Malawian children at 6, 12 and 18 months. We also assessed environmental predictors of the presence of viruses and parasites among 6-month infants. Microbial presence was documented using real-time polymerase chain reaction (PCR). Enteroviruses were identified in 68%, 80% and 81% of the stool samples at 6, 12 and 18 months children, rhinovirus in 28%, 18% and 31%, norovirus in 24%, 22% and 16%, parechovirus in 23%, 17% and 17%, rotavirus in 3%, 1% and 0.6%, Giardia lamblia in 9.6%, 23.5% and 26%, and Cryptosporidium (spp.) in 6%, 8% and 2% of the 6, 12 and 18 months stool samples. Dry season (May–October) was associated with a low infection rate of enterovirus, norovirus and Cryptosporidium (spp.). Higher father's education level, less number of person in the household and higher sanitation were associated with a low infection rate of enterovirus, norovirus and rotavirus, respectively. The results suggest that the prevalence of asymptomatic viral and parasitic infections is high among Malawian children and that the family's living conditions and seasonality influence the rate of infections.

Epidemiology, aetiology and seasonality of infectious diarrhoea in adult outpatients through active surveillance in Shanghai, China, 2012-2016: a cross-sectional study

OBJECTIVES

This study aimed to identify the epidemiology, clinical characteristics, aetiology and seasonality of sporadic infectious diarrhoea in adults in Shanghai.

SETTING

This study was based on a city-wide, active continuous hospital-based diarrhoea surveillance network established by Shanghai Municipal Center for Disease Control and Prevention. There were 22 sentinel hospitals in all 16 districts (9 primary-level hospitals, 6 secondary-level hospitals and 7 tertiary-level hospitals) which were selected using probability proportionate to size sampling method.

PARTICIPANTS

From 1 May 2012 to 31 May 2016, 90 713 patients were included in this study. Among 8797 patients whose stool samples were collected and detected, 4392 patients were male.

RESULTS

The positive rate was 47.96%. Bacterial and viral infections accounted for 27.19% and 69.07% separately. Norovirus was the most common pathogen (43.10%), followed by rotavirus, Vibrio parahaemolyticus, diarrhoeagenic Escherichia coli (DEC) and Salmonella spp. Patients between 30-44 and 45-59 years were more likely to have infectious diarrhoea and viral diarrhoea. Those aged 30-44 years were the most likely to get infected with V. parahaemolyticus (adjusted OR, aOR vs 60+ years: 2.04, 95% CI 1.47 to 2.78) and norovirus (aOR vs 60+ years: 1.32, 95% CI 1.12 to 1.56). Bacterial (except V. parahaemolyticus) diarrhoea was characterised by fever, abdominal pain and loose stool; while viral diarrhoea was characterised by nausea, vomiting and watery stool. A seasonal distribution of infectious diarrhoea was observed with larger peaks in winter and smaller peaks in summer. Winter peaks were mainly due to norovirus and rotavirus, and summer peaks were due to bacterial infections. An emerging spring peak of norovirus around March was observed in the past 3 years.

CONCLUSION

Viral infections were predominant, and norovirus played a leading role. A seasonal distribution was observed and an emerging spring peak of norovirus was noted. Our findings highlight the necessity for conducting an active, comprehensive surveillance in adults, to monitor changing dynamics in the epidemiology and aetiology of infectious diarrhoea.

Incidence of household transmission of acute gastroenteritis (AGE) in a primary care sentinel network (1992-2017): cross-sectional and retrospective cohort study protocol

INTRODUCTION

Acute gastroenteritis (AGE) is a highly transmissible condition. Determining characteristics of household transmission will facilitate development of prevention strategies and reduce the burden of this disease.We are carrying out this study to describe household transmission of medically attended AGE, and explore whether there is an increased incidence in households with young children.

METHODS AND ANALYSIS

This study used the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) primary care sentinel network, comprising data from 1 750 167 registered patients (August 2017 database). We conducted a novel analysis using a 'household key', to identify patients within the same household (n=811 027, mean 2.16 people). A 25-year repeated cross-sectional study will explore the incidence of medically attended AGE overall and then a 5-year retrospective cohort study will describe household transmission of AGE. The cross-sectional study will include clinical data for a 25-year period-1 January 1992 until the 31 December 2017. We will describe the incidence of AGE by age-band and gender, and trends in incidence. The 5-year study will use Poisson and quasi-Poisson regression to identify characteristics of individuals and households to predict medically attended AGE transmitted in the household. This will include whether the household contained a child under 5 years and the age category of the first index case (whether adult or child under 5 years). If there is overdispersion and zero-inflation we will compare results with negative binomial to handle these issues.

ETHICS AND DISSEMINATION

All RCGP RSC data are pseudonymised at the point of data extraction. No personally identifiable data are required for this investigation. The protocol follows STrengthening the Reporting of OBservational studies in Epidemiology guidelines (STROBE). The study results will be published in a peer-review journal, the dataset will be available to other researchers.

Secular trends in incidence of acute gastroenteritis in general practice, France, 1991 to 2015

We analysed 25 years of general practitioner (GP) visits for acute gastroenteritis (AG) surveillance in France, by the GP Sentinelles network. We searched for time trends of acute gastroenteritis incidence during winter periods. Data from emergency departments and drug reimbursement were additional data sources. A time-series analysis was performed using a generalised additive model for all data sources for the winter period. Virological data were incorporated and compared with the three data sources. The cumulative incidence of GP visits for winter AG exhibited an increasing trend from 1991 until 2008, when it reached 6,466 per 100,000 inhabitants. It decreased thereafter to 3,918 per 100,000 inhabitants in 2015. This decreasing trend was observed for all age groups and confirmed by the generalised additive model. For emergency department visits a decreasing trend was observed from 2004. Drug reimbursement data analyses demonstrated a decreasing trend from when data began in 2009. The incidence reported by GPs and emergency departments was lower following the emergence of norovirus GII.4 2012 (p < 0.0001). Winter AG incidences seem to follow long-term rising and decreasing trends that are important to monitor through continuous surveillance to evaluate the impact of prevention strategies, such as future immunisation against acute viral gastroenteritis.

Incidence of Norovirus-Associated Diarrhea and Vomiting Disease Among Children and Adults in a Community Cohort in the Peruvian Amazon Basin

Background

Data on norovirus epidemiology among all ages in community settings are scarce, especially from tropical settings.

Methods

We implemented active surveillance in 297 households in Peru from October 2012 to August 2015 to assess the burden of diarrhea and acute gastroenteritis (AGE) due to norovirus in a lower-middle-income community. During period 1 (October 2012-May 2013), we used a "traditional" diarrhea case definition (≥3 loose/liquid stools within 24 hours). During period 2 (June 2013-August 2015), we used an expanded case definition of AGE (by adding ≥2 vomiting episodes without diarrhea or 1-2 vomiting episodes plus 1-2 loose/liquid stools within 24 hours). Stool samples were tested for norovirus by reverse-transcription polymerase chain reaction.

Results

During period 1, overall diarrhea and norovirus-associated diarrhea incidence was 37.2/100 person-years (PY) (95% confidence interval [CI], 33.2-41.7) and 5.7/100 PY (95% CI, 3.9-8.1), respectively. During period 2, overall AGE and norovirus-associated AGE incidence was 51.8/100 PY (95% CI, 48.8-54.9) and 6.5/100 PY (95% CI, 5.4-7.8), respectively. In both periods, children aged <2 years had the highest incidence of norovirus. Vomiting without diarrhea occurred among norovirus cases in participants <15 years old, but with a higher proportion among children <2 years, accounting for 35% (7/20) of all cases in this age group. Noroviruses were identified in 7% (23/335) of controls free of gastroenteric symptoms.

Conclusions

Norovirus was a significant cause of AGE in this community, especially among children <2 years of age. Inclusion of vomiting in the case definition resulted in a 20% improvement for detection of norovirus cases.

Incidence of Norovirus-Associated Diarrhea, Shanghai, China, 2012-2013

We conducted sentinel-based surveillance for norovirus in the Pudong area of Shanghai, China, during 2012–2013, by analyzing 5,324 community surveys, 408,024 medical records, and 771 laboratory-confirmed norovirus infections among 3,877 diarrhea cases. Our analysis indicated an outpatient incidence of 1.5/100 person-years and a community incidence of 8.9/100 person-years for norovirus-associated diarrhea.

Food-borne disease and climate change in the United Kingdom

This review examined the likely impact of climate change upon food-borne disease in the UK using Campylobacter and Salmonella as example organisms. Campylobacter is an important food-borne disease and an increasing public health threat. There is a reasonable evidence base that the environment and weather play a role in its transmission to humans. However, uncertainty as to the precise mechanisms through which weather affects disease, make it difficult to assess the likely impact of climate change. There are strong positive associations between Salmonella cases and ambient temperature, and a clear understanding of the mechanisms behind this. However, because the incidence of Salmonella disease is declining in the UK, any climate change increases are likely to be small. For both Salmonella and Campylobacter the disease incidence is greatest in older adults and young children. There are many pathways through which climate change may affect food but only a few of these have been rigorously examined. This provides a high degree of uncertainty as to what the impacts of climate change will be. Food is highly controlled at the National and EU level. This provides the UK with resilience to climate change as well as potential to adapt to its consequences but it is unknown whether these are sufficient in the context of a changing climate.

Acute gastroenteritis in primary care: a longitudinal study in the Swiss Sentinel Surveillance Network, Sentinella

PURPOSE

Acute gastroenteritis (AG) leads to considerable burden of disease, health care costs and socio-economic impact worldwide. We assessed the frequency of medical consultations and work absenteeism due to AG at primary care level, and physicians' case management using the Swiss Sentinel Surveillance Network "Sentinella".

METHODS

During the 1-year, longitudinal study in 2014, 172 physicians participating in "Sentinella" reported consultations due to AG including information on clinical presentation, stool diagnostics, treatment, and work absenteeism.

RESULTS

An incidence of 2146 first consultations due to AG at primary care level per 100,000 inhabitants in Switzerland was calculated for 2014 based on reported 3.9 thousand cases. Physicians classified patients' general condition at first consultation with a median score of 7 (1 = poor, 10 = good). The majority (92%) of patients received dietary recommendations and/or medical prescriptions; antibiotics were prescribed in 8.5%. Stool testing was initiated in 12.3% of cases; more frequently in patients reporting recent travel. Among employees (15-64 years), 86.3% were on sick leave. Median duration of sick leave was 4 days.

CONCLUSIONS

The burden of AG in primary care is high and comparable with that of influenza-like illness (ILI) in Switzerland. Work absenteeism is substantial, leading to considerable socio-economic impact. Mandatory infectious disease surveillance underestimates the burden of AG considering that stool testing is not conducted routinely. While a national strategy to reduce the burden of ILI exists, similar comprehensive prevention efforts should be considered for AG.

Epidemiology, clinical features, and microbiology of patients with diarrhea in community clinics in Taiwan

OBJECTIVE

To investigate the clinical features and microbiology of patients with diarrheal diseases in Taiwan.

METHODS

From March 2014 to October 2014, patients with diarrheal diseases referred from the community clinics were enrolled into our prospective study. Demographics and clinical features of the participants were acquired. Stool samples were examined by the Luminex Gastrointestinal Pathogen Panel assay. Data were analyzed by SAS version 9.4.

RESULTS

A total of 545 patients were enrolled into this study. Male and adults accounted for 52.3% and 82.6% of patients, respectively. The median age was 36 years. Enteropathogen(s) was identified in 43.3% of patients and 8.5% of them had more than one agent in their stool samples. Viruses, especially norovirus GI/GII, were the predominant agents of gastroenteritis. Moreover, Campylobacter species was the most common bacterial agent. Bloody stool was frequently reported in patients with bacterial diarrhea (P = 0.002); contrarily, watery stool was significantly associated with viral diarrhea (P < 0.0001). Regional variation and seasonality of microbiological distribution were also observed.

CONCLUSION

In Taiwan, viruses were the predominant pathogens among patients with diarrheal diseases who visited community clinics. The therapeutic strategies for diarrheal patients should be based on the epidemiological and clinical characteristics.

Acute Gastroenteritis and Campylobacteriosis in Swiss Primary Care: The Viewpoint of General Practitioners

Acute gastroenteritis (AG) is frequently caused by infectious intestinal diseases (IID) including food- and waterborne pathogens of public health importance. Among these pathogens, Campylobacter spp. plays a major role. Many European countries monitor selected IIDs within disease surveillance systems. In Switzerland, the information on IIDs is restricted to limited surveillance data, while no data is available for AG. We conducted a qualitative study among Swiss general practitioners (GPs) to investigate the case management of AG and campylobacteriosis patients, the associated disease burden and the determinants leading to registration in the National Notification System for Infectious Diseases (NNSID). Interviews were conducted with a semi-structured questionnaire and underwent inductive content analysis based on Grounded Theory. The questionnaire was repeatedly adapted to capture emerging themes until the point of theoretical saturation. GPs perceived AG and campylobacteriosis of little relevance to their daily work and public health in general. According to GP self-estimates each consults about two cases of AG per week and diagnoses a median of five campylobacteriosis cases per year. A large proportion of AG cases receives telephone consultations only and gets medical advice from the practice nurse. Antibiotic therapy is considered useful and stool diagnostics are performed for about a fifth of consulting AG patients. Stool diagnostics ("test") and antibiotic therapy ("treat") are interrelated and follow four strategies: "Wait & See", "Treat & See", "Treat & Test", and "Test & See". AG case management is diverse and includes different triage steps. A small proportion of AG patients have stool diagnostics performed and only positive tested patients are reported to the NNSID. As a result severe cases and cases with a history of travel abroad are overrepresented in the NNSID. The use of multiplex PCR panels in routine diagnostics likely leads to improved case management and higher case numbers in surveillance systems.

Incidence of Norovirus and Other Viral Pathogens That Cause Acute Gastroenteritis (AGE) among Kaiser Permanente Member Populations in the United States, 2012-2013

Noroviruses and other viral pathogens are increasingly recognized as frequent causes of acute gastroenteritis (AGE). However, few laboratory-based data are available on the incidence of AGE caused by viral pathogens in the U.S. This study examined stool specimens submitted for routine clinical diagnostics from patients enrolled in Kaiser Permanente (KP) health plans in metro Portland, OR, and the Maryland, District of Columbia, and northern Virginia geographic areas to estimate the incidence of viral enteropathogens in these populations. Over a one-year study period, participating laboratories randomly selected stools submitted for routine clinical diagnostics for inclusion in the study along with accompanying demographic and clinical data. Selected stools were tested for norovirus, rotavirus, sapovirus, and astrovirus using standardized real-time RT-PCR protocols. Each KP site provided administrative data which were used in conjunction with previously published data on healthcare utilization to extrapolate pathogen detection rates into population-based incidence rates. A total of 1,099 specimens collected during August 2012 to September 2013 were included. Mean age of patients providing stool specimens was 46 years (range: 0-98 years). Noroviruses were the most common viral pathogen identified among patients with AGE (n = 63 specimens, 6% of specimens tested). In addition, 22 (2%) of specimens were positive for rotavirus; 19 (2%) were positive for sapovirus; and 7 (1%) were positive for astrovirus. Incidence of norovirus-associated outpatient visits was 5.6 per 1,000 person-years; incidence of norovirus disease in the community was estimated to be 69.5 per 1,000 person-years. Norovirus incidence was highest among children <5 years of age (outpatient incidence = 25.6 per 1,000 person-years; community incidence = 152.2 per 1,000 person-years), followed by older adults aged >65 years (outpatient incidence = 7.8 per 1,000 person-years; community incidence = 75.8 per 1,000 person-years). Outpatient incidence rates of rotavirus, sapovirus, and astrovirus were 2.0, 1.6, 0.6 per 1,000 person-years, respectively; community incidence rates for these viruses were 23.4, 22.5, and 8.5 per 1,000 person-years, respectively. This study provides the first age-group specific laboratory-based community and outpatient incidence rates for norovirus AGE in the U.S. Norovirus was the most frequently detected viral enteropathogen across the age spectrum with the highest rates of norovirus disease observed among young children and, to a lesser extent, the elderly. These data provide a better understanding of the norovirus disease burden in the United States, including variations within different age groups, which can help inform the development, targeting, and future impacts of interventions, including vaccines.

Incidence of Norovirus-Associated Medical Encounters among Active Duty United States Military Personnel and Their Dependents

Background

Norovirus is a leading cause of gastroenteritis episodes and outbreaks in US military deployments, but estimates of endemic disease burden among military personnel in garrison are lacking.

Methods

Diagnostic codes from gastroenteritis-associated medical encounters of active duty military personnel and their beneficiaries from July 1998–June 2011 were obtained from the Armed Forces Health Surveillance Center. Using time-series regression models, cause-unspecified encounters were modeled as a function of encounters for specific enteropathogens. Model residuals (representing unexplained encounters) were used to estimate norovirus-attributable medical encounters. Incidence rates were calculated using population data for both active duty and beneficiary populations.

Results

The estimated annual mean rate of norovirus-associated medically-attended visits among active duty personnel and their beneficiaries was 292 (95% CI: 258 to 326) and 93 (95% CI: 80 to 105) encounters per 10,000 persons, respectively. Rates were highest among beneficiaries <5 years of age with a median annual rate of 435 (range: 318 to 646) encounters per 10,000 children. Norovirus was estimated to cause 31% and 27% of all-cause gastroenteritis encounters in the active duty and beneficiary populations, respectively, with over 60% occurring between November and April. There was no evidence of any lag effect where norovirus disease occurred in one population before the other, or in one beneficiary age group before the others.

Conclusions

Norovirus is a major cause of medically-attended gastroenteritis among non-deployed US military active duty members as well as in their beneficiaries.

Community-Acquired Rotavirus Gastroenteritis Compared with Adenovirus and Norovirus Gastroenteritis in Italian Children: A Pedianet Study

Background. Rotavirus (RV) is the commonest pathogen in the hospital and primary care settings, followed by Adenovirus (AV) and Norovirus (NV). Only few studies that assess the burden of RV gastroenteritis at the community level have been carried out. Objectives. To estimate incidence, disease characteristics, seasonal distribution, and working days lost by parents of RV, AV, and NV gastroenteritis leading to a family pediatrician (FP) visit among children < 5 years. Methods. 12-month, observational, prospective, FP-based study has been carried out using Pedianet database. Results. RVGE incidence was 1.04 per 100 person-years with the highest incidence in the first 2 years of life. Incidences of AVGEs (1.74) and NVGEs (1.51) were slightly higher with similar characteristics regarding age distribution and symptoms. Risk of hospitalisation, access to emergency room (ER), and workdays lost from parents were not significantly different in RVGEs compared to the other viral infections. Conclusions. Features of RVGE in terms of hospitalisation length and indirect cost are lower than those reported in previous studies. Results of the present study reflect the large variability of data present in the literature. This observation underlines the utility of primary care networks for AGE surveillance and further studies on community-acquired gastroenteritis in children.

Medium- to Long-Term Impact of Rotavirus Vaccination on Hospital Care in Belgium: A 7-Year Follow-Up of the Rotavirus Belgium Impact Study (RotaBIS)

Introduction

Rotavirus (RV) vaccination was introduced in Belgium in 2006. With the high uptake it had (>85%), a sharp decline in hospitalizations was observed during the first years after vaccine introduction. The objective of this study was to investigate whether this decline was maintained and to simulate projections.

Methods

The Rotavirus Belgium Impact Study allowed an analysis of the RV vaccine impact amongst children in 11 hospitals in Belgium over a 9-year period (2005–2013) with 2 years pre- and 7 years post-vaccine introduction. Results were compared by year and by subsequent birth cohort aging up to 5 years. The two different analysis methods helped dismantling the different (direct and indirect) effects of vaccine protection to simulate future hospitalization trends.

Results

During the whole observation period, 40,552 RV detection tests were performed of which 5832 were positive (14.4%). After RV vaccine introduction, a significant reduction in number of tests performed (−38%) was combined with a dramatic drop in numbers of positive tests (−76.6%). The decreases were spectacular during the first two years of vaccine introduction; after that period, the decrease flattened. Cross-sectional comparison with cohort data showed that the initial drop was heavily influenced by the herd effect of the vaccine. Cohort analysis demonstrated a low rate of residual disease over time, suggesting another infection source other than the child population.

Conclusion

The residual disease will be maintained in the community when a same vaccination strategy is continued over time, starting vaccination of children only at 6 weeks’ time.

Funding

GlaxoSmithKline Biologicals SA.

Trial registration

ClinicalTrials.gov identifier, NCT01563146.

Electronic supplementary material

The online version of this article (doi:10.1007/s40121-015-0099-1) contains supplementary material, which is available to authorized users.

Recommendation of rotavirus vaccination and herd effect: a budget impact analysis based on German health insurance data

The objective of this study was to assess the budget impact and health effects of introducing rotavirus (RV) vaccination in Saxony, Germany, from a health insurance perspective. Special emphasis is given to the herd effect. We analyzed direct medical and non-medical costs of RV infection for Social Health Insurance between 2007 and 2010 based on 360,000 routine data observations from the AOK PLUS for children below 5 years of age. We compared the actual annual number of RV cases (vaccination scenario) with the number derived from 2005 (no vaccination, base case scenario). The vaccination coverage rate has increased from 5% to 61% between 2007 and 2010. The number of RV cases decreased by 21% from 32,274 in 2007 to 25,614 in 2010. Based on vaccination coverage, the total cost savings per 1,000 children due to RV vaccination was estimated to be 39,686 Euros. The overall share of outpatient costs was 60%. Mean gross cost savings were expected to be 304 Euros per avoided case. The net cost savings were expected to be 19 Euros per avoided case. About 59% of total savings was due to herd protection resulting from increasing vaccine rates. The herd effect per avoided case increased with increasing vaccine coverage. Incidence of RV cases, vaccination costs and days absent from work were sensitive parameters. This retrospective analysis showed that the increase in RV vaccination coverage in Saxony has been budget neutral if not cost saving for sick funds.

Transmission of Norovirus Within Households in Quininde, Ecuador

We studied the transmission of norovirus infection in households in Quininde, Ecuador. Among household contacts of norovirus positive children with diarrhea, norovirus negative children with diarrhea and asymptomatic controls, infection attack rates were 33%, 8% and 18%, respectively (N = 45, 36, 83). Infection attack rates were higher when index children had a higher viral load.

Possible Hematological Changes Associated with Acute Gastroenteritis among Kindergarten Children in Gaza

Background:

Gastroenteritis is considered one of the leading causes of morbidity and mortality in children especially in developing countries. It is a major childhood problem in Gaza and one of the most common etiologic agents of iron deficiency anemia (IDA).

Aim:

This study was conducted to investigate possible changes in blood parameters that are associated with gastroenteritis infection among kindergarten children in Gaza.

Subjects and Methods:

A cross-sectional case–control study was performed including kindergarten children suffering from gastroenteritis and matched healthy control group. Types of etiological agents were identified using standard microbiological and serological procedures. Blood samples were collected for estimation of complete blood count and for determination of serum iron, total iron binding capacity (TIBC), and transferrin saturation. Independent sample t-test was used for comparisons and performed using SPSS software version 17(Chicago Illinois USA).

Results:

The prevalence of enteric pathogens among cases (88.5% [85/96]) was significantly higher than in asymptomatic controls (11.1% [6/54]). The most common enteric pathogens isolated were Entamoeba histolytica (28% [42/91]) and Giardia lamblia (26.7% [40/91]). Blood tests revealed that 21.8% (21/96) of cases and 14.8% (8/54) of controls had IDA, which were not significantly different. Meanwhile, a significant difference was found between the TIBC and hemoglobin in cases compared to controls. Conclusion: This study indicates that gastroenteritis infection could be considered as a common health problem in kindergarten children in Gaza, and it is possibly associated with changes in hemoglobin concentration and TIBC.

Incidence of Medically-Attended Norovirus-Associated Acute Gastroenteritis in Four Veteran's Affairs Medical Center Populations in the United States, 2011-2012

An estimated 179 million acute gastroenteritis (AGE) illnesses occur annually in the United States. The role of noroviruses in hospital-related AGE has not been well-documented in the U. S. We estimated the population incidence of community- acquired outpatient and inpatient norovirus AGE encounters, as well as hospital-acquired inpatient norovirus AGE among inpatients at four Veterans Affairs (VA) Medical Centers (VAMCs). Fifty (4%) of 1,160 stool specimens collected ≤7 days from symptom onset tested positive for norovirus. During a one year period, the estimated incidence of outpatient, community- and hospital-acquired inpatient norovirus AGE was 188 cases, 11 cases, and 54 cases/ 100,000 patients, respectively. This study demonstrates the incidence of outpatient and community- and hospital-acquired inpatient norovirus AGE among the VA population seeking care at these four VAMCs.

The burden of norovirus gastroenteritis: an important foodborne and healthcare-related infection

Human norovirus (NoV) is now recognized as one of the most important causative agents of gastroenteritis in all age groups worldwide. During the course of NoV infection, symptoms are usually mild and disappear within 48 h after onset. The incidence of NoV infection is high, with hundreds of cases per 10 000 of the population, although the number of infections is still underestimated. Epidemiological surveys conducted in Europe and North America have shown that NoV infections constitute a major disease burden, especially for young children and the elderly, in whom NoV infection leads to high rates of hospitalization and mortality. NoV infections are also of concern in hospitals, where viral infections can be persistent in immunocompromised patients. Although the cost of NoV infection in the hospital community has not yet been clearly established, it appears that NoV infections could cost hundreds of thousands of euros in terms of unit closure, and NoV-related sickness in patients and health workers. Besides their clinical burden, NoVs, as foodborne pathogens, also cause to millions of dollars of losses for the healthcare system and the food industry. Recent estimates in the USA showed that, annually, NoV illness cost $2 billion and led to a loss of approximately 5000 quality-adjusted life-years, making NoV one of the top five pathogens causing enteric illnesses. The highest cost among 14 foodborne pathogens is also attributed to human NoV in The Netherlands. This accumulation of evidence underlines the enormous impact of NoV on populations.

Spectrum of enteropathogens detected by the FilmArray GI Panel in a multicentre study of community-acquired gastroenteritis

The European, multicentre, quarterly point-prevalence study of community-acquired diarrhoea (EUCODI) analysed stool samples received at ten participating clinical microbiology laboratories (Austria, Finland, France, Germany, Greece, Ireland, Italy, Portugal, Romania, and the UK) in 2014. On four specified days, each local laboratory submitted samples from ≤20 consecutive patients to the Austrian Study Centre for further testing with the FilmArray GI Panel (BioFire Diagnostics, Salt Lake City, UT, USA). Of the 709 samples from as many patients received, 325 (45.8%) tested negative, 268 (37.8%) yielded only one organism, and 116 (16.4%) yielded multiple organisms. Positivity rates ranged from 41% (30 of 73 samples) in France to 74% (59 of 80 samples) in Romania. With the exception of Entamoeba histolytica and Vibrio cholerae, all of the 22 targeted pathogens were detected at least once. Enteropathogenic Escherichia coli, Campylobacter species, toxigenic Clostridium difficile, enteroaggregative E. coli, norovirus and enterotoxigenic E. coli were the six most commonly detected pathogens. When tested according to local protocols, seven of 128 positive samples (5.5%) yielded multiple organisms. Overall, the FilmArray GI Panel detected at least one organism in 54.2% (384/709) of the samples, as compared with 18.1% (128/709) when testing was performed with conventional techniques locally. This underlines the considerable potential of multiplex PCR to improve routine stool diagnostics in community-acquired diarrhoea. Classic culture methods directed at the isolation of specific pathogens are increasingly becoming second-line tools, being deployed when rapid molecular tests give positive results. This optimizes the yield from stool examinations and dramatically improves the timeliness of diagnosis.

Prevalence of enteric pathogen-associated community gastroenteritis among kindergarten children in Gaza

Gastroenteritis is considered as one of the leading causes of illness and death in children under 5 years age, especially in developing countries. It is one of the major public health problems among childhood in Gaza strip, Palestine. This study was conducted to determine the prevalence of enteric pathogen-associated community gastroenteritis among kindergarten children in Gaza. A total of 150 stool samples were collected and investigated for parasitic, viral and bacterial pathogens at Al Azhar microbiology laboratories by using standard microbiological and serological procedures. Out of the 150 study samples, the overall percentage of positive stool samples with a known enteric pathogen was 60.6%. The prevalence of different enteric pathogens causing community gastroenteritis among symptomatic cases (88.5%) was significantly higher than the prevalence in asymptomatic carriage (11.1%). The most prevalent isolated enteric pathogens were Entamoeba histolytica (28.0%) and Giardia lamblia (26.7%). Rotavirus was found in 3.1% of symptomatic cases but not detected in asymptomatic carriage. However, adenovirus type 40 and 41 were not detected in any of the study samples. The bacterial enteric pathogens Shigella and Enterohemorrhagic Escherichia coli O157:H7 (EHEC) have comparable occurrence as rotavirus (3.1%), meanwhile, Salmonella was not isolated. Mixed infection with more than 1 pathogen was found (11.4%) only among symptomatic cases. Children aged 3-year-old showed the highest prevalence of community gastroenteritis. This study demonstrates a high prevalence of parasitic enteropathogens and a relatively low prevalence of bacterial and viral enteropathogens among kindergarten children living in Gaza city, moreover, children aged 3 years old showed the highest prevalence of isolated enteropathogens.

The burden of norovirus disease in children in the European Union

BACKGROUND

Noroviruses (NoVs) are the leading cause of acute gastroenteritis across all age groups. Because a vaccine is in clinical development, burden of disease data are required to guide the eventual introduction of this vaccine. In this study, we estimate the burden of NoV disease in children less than 5 years of age in the European Union (EU).

METHODS

We carried out a literature search using PubMed to identify studies providing incidence or prevalence data for NoV disease in the EU. We applied the pooled average NoV incidence and prevalence rates to the EU population less than 5 years of age to obtain the annual number of NoV illnesses, medical visits, hospitalizations and deaths occurring in the EU among children younger than 5 years.

RESULTS

Data from 12 studies were included. We estimate that NoV infection may cause up to 5.7 million illnesses in the community, 800,000 medical visits, 53,000 hospitalizations and 102 deaths every year in children younger than 5 years in the EU.

CONCLUSION

The burden of NoV disease in children in the EU is substantial, and will grow in relative importance as rotavirus (RV) vaccines are rolled out in the EU. This burden of disease is comparable with the burden of RV disease in the EU before RV vaccine introduction. More country-specific studies are needed to better assess this burden and guide the potential introduction of a vaccine against NoV at the national level.

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.

Acute diarrhea in adults consulting a general practitioner in France during winter: incidence, clinical characteristics, management and risk factors

Background

Data describing the epidemiology and management of viral acute diarrhea (AD) in adults are scant. The objective of this study was to identify the incidence, clinical characteristics, management and risk factors of winter viral AD in adults.

Methods

The incidence of AD in adults during two consecutive winters (from December 2010 to April 2011 and from December 2011 to April 2012) was estimated from the French Sentinelles network. During these two winters, a subset of Sentinelles general practitioners (GPs) identified and included adult patients who presented with AD and who filled out a questionnaire and returned a stool specimen for virological examination. All stool specimens were tested for astrovirus, group A rotavirus, human enteric adenovirus, and norovirus of genogroup I and genogroup II. Age- and sex-matched controls were included to permit a case–control analysis with the aim of identifying risk factors for viral AD.

Results

During the studied winters, the average incidence of AD in adults was estimated to be 3,158 per 100,000 French adults (95% CI [2,321 – 3,997]). The most reported clinical signs were abdominal pain (91.1%), watery diarrhea (88.5%), and nausea (83.3%). GPs prescribed a treatment in 95% of the patients with AD, and 80% of the working patients with AD could not go to work. Stool examinations were positive for at least one enteric virus in 65% (95% CI [57 – 73]) of patients with AD with a predominance of noroviruses (49%). Having been in contact with a person who has suffered from AD in the last 7 days, whether within or outside the household, and having a job (or being a student) were risk factors significantly associated with acquiring viral AD.

Conclusions

During the winter, AD of viral origin is a frequent disease in adults, and noroviruses are most often the cause. No preventable risk factor was identified other than contact with a person with AD. Thus, at the present time, reinforcement of education related to hand hygiene remains the only way to reduce the burden of disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0574-4) contains supplementary material, which is available to authorized users.

Disease burden of selected gastrointestinal pathogens in Australia, 2010

OBJECTIVE

To estimate and compare disease burden attributable to six gastrointestinal pathogens (norovirus, rotavirus, Campylobacter, non-typhoidal Salmonella, Giardia, and Cryptosporidium) in Australia, 2010.

METHODS

We estimated the number of acute gastroenteritis (AGE) cases and deaths, disability-adjusted life years (DALYs), and DALY/case for each pathogen. We included AGE cases that did not require medical care. Sequelae were included for Campylobacter (Guillain-Barré syndrome, reactive arthritis (ReA), irritable bowel syndrome (IBS)) and Salmonella (ReA, IBS).

RESULTS

We estimated 16626069 AGE cases in Australia in 2010 (population 22 million). Of the pathogens studied, most AGE cases were attributed to norovirus (2180145), Campylobacter (774003), and Giardia (614740). Salmonella caused the fewest AGE cases (71255) but the most AGE deaths (90). The DALY burden was greatest for Campylobacter (18222 DALYs) and Salmonella (3856 DALYs), followed by the viral and protozoal pathogens. The average DALY/case was greatest for Salmonella (54.1 DALY/1000 cases), followed by Campylobacter (23.5 DALY/1000 cases).

CONCLUSIONS

The pathogen causing the greatest disease burden varied according to the metric used, however DALYs are considered most useful given the incorporation of morbidity, mortality, and sequelae. These results can be used to prioritize public health interventions toward Salmonella and Campylobacter infections and to measure the impact of these interventions.

Molecular epidemiology of norovirus from patients with acute gastroenteritis in northwestern Spain

The high incidence of norovirus (NoV) infections seems to be related to the emergence of new variants that evolved by genetic drift of the capsid gene. In this work, that represents a first effort to describe the molecular epidemiology of NoV in the northwest of Spain, a total of eight different NoV genotypes (GII.1, GII.3, GII.4, GII.6, GII.7, GII.12, GII.13, GII.14) were detected. The major genotypes observed were GII.4 (45·42%) and GII.14 (34·9%), being detected in all age groups. In addition, and although most of GII.4 sequences belonged to 2006b (7·2%) and 2010 (50·35%) variants, the presence of new NoV variants was observed. Phylogenetic analysis revealed that a high number of GII.4 sequences (35·24%) could be assigned to the newly emerging Sydney 2012 variant, even during late 2010. The high prevalence of NoV GII.14 observed in this study may indicate the emergence of this genotype in Spain.

Epidemiologic implications of asymptomatic reinfection: a mathematical modeling study of norovirus

The pathogenicity of norovirus is definitively established. However, norovirus is frequently detected in the stool of healthy individuals. To gain understanding of the apparent high prevalence of asymptomatic infection, we analyzed a dynamic transmission model of norovirus infection, disease, and immunity. We simulated norovirus epidemiology in low- and high-transmission settings by varying the basic reproduction number (R0). We predicted annual disease incidence values in children aged 0-4 years of 25% with a low R0 and 29% with a high R0. However, the point prevalence of asymptomatic infection rose sharply from 3% to 48% from the low to high R0 settings. Among older children and adults, the models projected that incidence of disease would rise from 6% to 16% from the low to high R0 settings, whereas asymptomatic infection prevalence was lower in this age group. Asymptomatic prevalence of norovirus can change dramatically with small changes in R0. The ratio of prevalence in cases to controls could be high in a developed country and close to or even less than 1 in a high-exposure setting, despite similar disease incidence. These findings highlight an important limitation of case-control studies for pathogens for which there is suboptimal diagnostic specificity.

Emergency department visit data for rapid detection and monitoring of norovirus activity, United States

Noroviruses are the leading cause of gastroenteritis in the United States, but timely measures of disease are lacking. BioSense, a national-level electronic surveillance system, assigns data on chief complaints (patient symptoms) collected during emergency department (ED) visits to 78 subsyndromes in near real-time. In a series of linear regression models, BioSense visits mapped by chief complaints of diarrhea and nausea/vomiting subsyndromes as a monthly proportion of all visits correlated strongly with reported norovirus outbreaks from 6 states during 2007–2010. Higher correlations were seen for diarrhea (R = 0.828–0.926) than for nausea/vomiting (R = 0.729–0.866) across multiple age groups. Diarrhea ED visit proportions exhibited winter seasonality attributable to norovirus; rotavirus contributed substantially for children <5 years of age. Diarrhea ED visit data estimated the onset, peak, and end of norovirus season within 4 weeks of observed dates and could be reliable, timely indicators of norovirus activity.

Norovirus disease in the United States

Although recognized as the leading cause of epidemic acute gastroenteritis across all age groups, norovirus has remained poorly characterized with respect to its endemic disease incidence. Use of different methods, including attributable proportion extrapolation, population-based surveillance, and indirect modeling, in several recent studies has considerably improved norovirus disease incidence estimates for the United States. Norovirus causes an average of 570–800 deaths, 56,000–71,000 hospitalizations, 400,000 emergency department visits, 1.7–1.9 million outpatient visits, and 19–21 million total illnesses per year. Persons >65 years of age are at greatest risk for norovirus-associated death, and children <5 years of age have the highest rates of norovirus-associated medical care visits. Endemic norovirus disease occurs year round but exhibits a pronounced winter peak and increases by ≤50% during years in which pandemic strains emerge. These findings support continued development and targeting of appropriate interventions, including vaccines, for norovirus disease.

Multiple norovirus infections in a birth cohort in a Peruvian Periurban community

BACKGROUND

Human noroviruses are among the most common enteropathogens globally, and are a leading cause of infant diarrhea in developing countries. However, data measuring the impact of norovirus at the community level are sparse.

METHODS

We followed a birth cohort of children to estimate norovirus infection and diarrhea incidence in a Peruvian community. Stool samples from diarrheal episodes and randomly selected nondiarrheal samples were tested by polymerase chain reaction for norovirus genogroup and genotype. Excretion duration and rotavirus coinfection were evaluated in a subset of episodes.

RESULTS

Two hundred twenty and 189 children were followed to 1 and 2 years of age, respectively. By 1 year, 80% (95% confidence interval [CI], 75%-85%) experienced at least 1 norovirus infection and by 2 years, 71% (95% CI, 65%-77%) had at least 1 episode of norovirus-associated diarrhea. Genogroup II (GII) infections were 3 times more frequent than genogroup 1 (GI) infections. Eighteen genotypes were found; GII genotype 4 accounted for 41%. Median excretion duration was 34.5 days for GII vs 8.5 days for GI infection (P = .0006). Repeat infections by the same genogroup were common, but repeat infections by the same genotype were rare. Mean length-for-age z score at 12 months was lower among children with prior norovirus infection compared to uninfected children (coefficient: -0.33 [95% CI, -.65 to -.01]; P = .04); the effect persisted at 24 months.

CONCLUSIONS

Norovirus infection occurs early in life and children experience serial infections with multiple genotypes, suggesting genotype-specific immunity. An effective vaccine would have a substantial impact on morbidity, but may need to target multiple genotypes.

Multiplex molecular testing for management of infectious gastroenteritis in a hospital setting: a comparative diagnostic and clinical utility study

Laboratory diagnosis and clinical management of inpatients with diarrhoea is complex and time consuming. Tests are often requested sequentially and undertaken in different laboratories. This causes prolonged unnecessary presumptive isolation of patients, because most cases are non-infectious. A molecular multiplex test (Luminex(®) Gastrointestinal Pathogen Panel (GPP)) was compared with conventional testing over 8 months to determine diagnostic accuracy, turnaround times, laboratory costs, use of isolation facilities and user acceptability. A total of 262 (12%) patients had a pathogen detected by conventional methods compared with 483 (22.1%) by GPP. Most additional cases were detected in patients developing symptoms in the first 4 days of admission. Additional cases were detected because of presumed improved diagnostic sensitivity but also because clinicians had not requested the correct pathogen. Turnaround time (41.8 h) was faster than bacterial culture (66.5 h) and parasite investigation (66.5 h) but slower than conventional testing for Clostridium difficile (17.3 h) and viruses (27 h). The test could allow simplified requesting by clinicians and a consolidated laboratory workflow, reducing the overall number of specimens received by the laboratory. A total of 154 isolation days were saved at an estimated cost of £30 800. Consumables and labour were estimated at £150 641 compared with £63 431 for conventional testing. Multiplex molecular testing using a panel of targets allowed enhanced detection and a consolidated laboratory workflow. This is likely to be of greater benefit to cases that present within the first 4 days of hospital admission.

Will vaccination against rotavirus infection with RIX4414 be cost-saving in Germany?

BACKGROUND

Rotavirus gastroenteritis (RVGE) is a frequent disease in young children. The recommended German paediatric immunisation schedule does not currently include rotavirus vaccination. A lack of economic data on the impact of routine vaccination is stated as one of the reasons. As a result, the current coverage rate is low, around 26%. This study investigated whether rotavirus vaccination using the two-dose rotavirus vaccine RIX4414 (Rotarix®, GlaxoSmithKline Vaccines) would be a cost-saving intervention from the perspective of the statutory health insurance (SHI) in Germany.

OBJECTIVE

The objective of the study was to analyse health outcomes (number of RVGE cases and hospitalisations prevented) and the associated cost to the SHI when comparing 100% rotavirus vaccination with no vaccination in Germany.

METHODS

A Markov cohort model simulated the number of RVGE events and related costs in a German birth cohort over the first 60 months of life with current disease management. The model compared an unvaccinated cohort with a fully vaccinated cohort. Vaccine efficacy data from international clinical trials were combined with German-specific epidemiological and cost data. Results were tested using extensive sensitivity analyses.

RESULTS

Full vaccination of a birth cohort against rotavirus disease would be expected to prevent 82% of RVGE cases, reducing RVGE frequency from 28 to 5 events per 100 children in the birth cohort up to age 5 years. The estimated cost reduction with vaccination for that period is predicted to be €9.2 million with 100% coverage (€6.9 million with 75% coverage), mainly due to reductions in SHI reimbursement for productivity losses, hospital stays and visits to office-based physicians due to the vaccine's efficacy against severe disease.

CONCLUSIONS

Routine rotavirus vaccination in Germany would reduce the number of hospitalised and outpatient cases. The associated investment could be fully offset by costs avoided in hospital stays, physician visits and SHI reimbursement of productivity losses. Sensitivity analysis indicated that vaccination would be cost-saving in 95% of simulations. Incremental cost was observed only under extreme conditions, especially when the time spent at home due to rotavirus disease was low or when vaccine efficacy against severe disease was heavily decreased.

Risk factors for community-based reports of gastrointestinal, respiratory, and dermal symptoms: findings from a cohort study in Australia

Background

Although gastrointestinal (GI), respiratory, and dermal symptoms are common, few studies have conducted concurrent and comparative prospective analyses of risk factors for these 3 morbidity outcomes.

Methods

We used data from a community-based randomized controlled trial among 277 South Australian families to analyze GI (diarrhea, vomiting), respiratory (sore throat, runny nose, cough) and dermal (rash, generalized itch, dermal infection) symptoms.

Results

Log-binomial regression analysis revealed similar risks of GI (adjusted risk ratio [RR], 1.65; 95% CI, 1.05–2.58) and respiratory (RR, 1.68; 95% CI, 1.31–2.15) symptoms among childcare/kindergarten attendees. Swimming in public pools/spas in the current or previous week was associated with all 3 symptom complexes, conferring similar risk for each (RR for GI: 1.33; 95% CI, 0.99–1.77; respiratory: 1.20; 95% CI, 1.04–1.38; dermal: 1.41; 95% CI, 1.08–1.85). Pet ownership was not associated with symptoms. Household clustering of GI and respiratory symptoms was common, and clustering of respiratory symptoms correlated with number of individuals per household.

Conclusions

This simultaneous examination of risk factors for 3 health outcomes yielded new comparative data that are useful for developing prevention strategies.

Endemic norovirus infections in children, Ho Chi Minh City, Vietnam, 2009-2010

We performed a case–control investigation to identify risk factors for norovirus infections among children in Vietnam. Of samples from 1,419 children who had diarrhea and 609 who were asymptomatic, 20.6% and 2.8%, respectively, were norovirus positive. Risk factors included residential crowding and symptomatic contacts, indicating person-to-person transmission of norovirus.

Characterising the aetiology of severe acute gastroenteritis among patients visiting a hospital in Qatar using real-time polymerase chain reaction

Background

Acute gastroenteritis (AGE) remains a common cause of clinic visits and hospitalizations, though its aetiology has not been determined in Qatar.

Methods

We performed a prospective, emergency department–based study of 288 children and adults with AGE. Stool specimens were collected at presentation from June to November 2009. Faecal specimens were tested, using real-time PCR, for a panel of four viral (norovirus, adenovirus, astrovirus and rotavirus) and bacterial pathogens.

Results

Viral and bacterial pathogens were detected in 131 (45.5%) and 34 (12.2%) of the 288 patients recruited. The most commonly detected pathogens were norovirus (28.5%), rotavirus (10.4%), followed by adenovirus (6.25%) and astrovirus (0.30%). Norovirus was the most commonly detected viral pathogen amongst all the age groups with an almost even distribution in all age groups. Rotavirus and adenovirus were more common in children under 5 yr of age. Astrovirus was found in only one person.

Conclusions

Viruses, especially noroviruses, are associated with severe diarrhoea in children and adults in Qatar. Further studies to confirm the findings and to explore the causes of illness among patients from whom a pathogen cannot be determined are needed.

Role of norovirus in acute gastroenteritis in the Northwest of Spain during 2010-2011

A total of 2,643 samples from patients with gastroenteritis in Galicia (NW Spain) were tested for the presence of Norovirus (NoV). NoV genogroup GI was detected in 416 (15.7%) samples, while NoV genogroup GII was detected in 278 (10.5%) samples. Mixed infections of NoV GI and GII were observed in 53 (2%) samples. Total prevalence of NoV in the analyzed samples was 28.3%. Besides NoV diagnosis assay, all the specimens were also submitted to routine clinical bacteriology tests. Cryptosporidium spp. as well as adenovirus (AdV) and rotavirus (RV) were determined on some samples after specific request by hospital units. The results obtained allowed to determine the disease etiology in 14.4% of the patients. Taking into account all the microorganisms studied, the etiological agent was determined for 39.5% of the cases. The results indicated that NoVs are the leading cause of acute gastroenteritis in all age-groups in Northwestern Spain, and that the lack of routine NoV diagnosis contributes to the underestimation of the importance of this virus, not only in outbreaks, but also in sporadic cases of acute gastroenteritis.