Community-based study of the incidence of gastrointestinal diseases in The Netherlands

'We don't use the same ways to treat the illness:' A qualitative study of heterogeneity in health-seeking behaviour for acute gastrointestinal illness among the Ugandan Batwa

The Batwa (Twa), an Indigenous People of southwest Uganda, were evicted from their ancestral forest lands in 1991 due to establishment of the Bwindi Impenetrable Forest. This land dispossession forced Batwa to transition from a semi-nomadic, hunting-gathering livelihood to an agricultural livelihood; eliminated access to Indigenous food, medicines, and shelter; and shifted their healthcare options. Therefore, this exploratory study investigated why Batwa choose Indigenous or biomedical treatment, or no treatment, when experiencing acute gastrointestinal illness. Ten gender-stratified focus groups were conducted in five Batwa settlements in Kanungu District, Uganda (n = 63 participants), alongside eleven semi-structured interviews (2014). Qualitative data were analysed thematically, using a constant comparative method. Batwa emphasised that health-seeking behaviour for acute gastrointestinal illness was diverse: some Batwa used only Indigenous or biomedical healthcare, while others preferred a combination, or no healthcare. Physical and economic access to care, and also perceived efficacy and quality of care, influenced their healthcare decisions. This study provides insight into the Kanungu District Batwa's perceptions of biomedical and Indigenous healthcare, and barriers they experience to accessing either. This study is intended to inform public health interventions to reduce their burden of acute gastrointestinal illness and ensure adequate healthcare, biomedical or Indigenous, for Batwa.

The health and economic impact of acute gastroenteritis in Belgium, 2010-2014

Acute gastroenteritis (AGE) remains a common condition in both low- and high-income countries. In Belgium, however, there is currently a lack of information on the societal health and economic impact of AGE. We conducted a retrospective study using mortality and cause-of-death data, hospital data, primary care data, health interview survey data and other published data. We estimated the burden of illness during a 5-year period (2010–2014) in Belgium in terms of deaths, patients admitted to hospitals, patients consulting their general practitioner (GP) and cases occurring in the community. We further quantified the health impact in terms of disability-adjusted life years (DALYs) and the economic impact in terms of cost-of-illness estimates. We estimated 343 deaths, 27 707 hospitalised patients, 464 222 GP consultations and 10 058 741 episodes occurring in the community (0.91 cases/person) on average per year. AGE was associated with 11 855 DALYs per year (107 DALY per 100 000 persons). The economic burden was estimated to represent direct costs of €112 million, indirect costs of €927 million (90% of the total costs) and an average total cost of €103 per case and €94 per person. AGE results in a substantial health and economic impact in Belgium, justifying continued mitigation efforts.

Magnitude, distribution, risk factors and care-seeking behaviour of acute, self-reported gastrointestinal illness among US Army Soldiers: 2015

Throughout history, acute gastrointestinal illness (AGI) has been a significant cause of morbidity and mortality among US service members. We estimated the magnitude, distribution, risk factors and care seeking behaviour of AGI among the active duty US Army service members using a web-based survey. The survey asked about sociodemographic characteristics, dining and food procurement history and any experience of diarrhoea in the past 30 days. If respondents reported diarrhoea, additional questions about concurrent symptoms, duration of illness, medical care seeking and stool sample submission were asked. Univariable and multivariable logistic regression were used to identify the factors associated with AGI and factors associated with seeking care and submitting a stool sample. The 30-day prevalence of AGI was 18.5% (95% CI 16.66-20.25), the incidence rate was 2.24 AGI episodes per person-year (95% CI 2.04-2.49). Risk factors included a region of residence, eating at the dining facility and eating at other on-post establishments. Individuals with AGI missed 2.7-3.7 days of work, which costs approximately $ 847 451 629 in paid wages. Results indicate there are more than 1 million cases of AGI per year among US Army Soldiers, which can have a major impact on readiness. We found that care-seeking behaviours for AGI are different among US Army Service Members than the general population. Army Service Members with AGI report seeking care and having a stool sample submitted less often, especially for severe (bloody) diarrhoea. Factors associated with seeking care included rank, experiencing respiratory symptoms (sore throat, cough), experiencing vomiting and missing work for their illness. Factors associated with submitting a stool sample including experiencing more than five loose stools in 24 h and not experiencing respiratory symptoms. US Army laboratory-based surveillance under-estimates service members with both bloody and non-bloody diarrhoea. To our knowledge, this is the first study to estimate the magnitude, distribution, risk factors and care-seeking behaviour of AGI among Army members. We determined Army service members care-seeking behaviours, AGI risk factors and stool sample submission rates are different than the general population, so when estimating burden of AGI caused by specific foodborne pathogens using methods like Scallan et al. (2011), unique multipliers must be used for this subset of the population. The study legitimises not only the importance of AGI in the active duty Army population but also highlights opportunities for public health leaders to engage in simple strategies to better capture AGI impact so more modern intervention strategies can be implemented to reduce burden and indirectly improve operational readiness across the Enterprise.

Outbreak of Yersinia pseudotuberculosis O:1 infection associated with raw milk consumption, Finland, spring 2014

In March 2014, a Yersinia pseudotuberculosis (YP) outbreak was detected by a municipal authority in southern Finland. We conducted epidemiological, microbiological and traceback investigations to identify the source. We defined a case as a person with YP infection notified to the National Infectious Disease Registry between February and April 2014, or their household member, with abdominal pain and fever≥38 °C or erythema nodosum. Healthy household members were used as household-matched controls. We identified 43 cases and 50 controls. The illness was strongly associated with the consumption of raw milk from a single producer. The odds ratio of illness increased with the amount of raw milk consumed. Also previously healthy adults became infected by consuming raw milk. Identical YP strains were identified from cases' stool samples, raw milk sampled from a case's refrigerator and from the milk filter at the producer's farm. The producer fulfilled the legal requirements for raw milk production and voluntarily recalled the raw milk and stopped its production. We advised consumers to heat the raw milk to 72 °C for 15 s. Current legislation for raw milk producers should be reviewed and public awareness of health risks linked to raw milk consumption should be increased.

Design of the PROUD study: PCR faeces testing in outpatients with diarrhoea

Background

Infectious intestinal disease (IID) is an important cause of morbidity in developed countries and a frequent reason for general practitioner (GP) consultation. In recent years polymerase chain reaction (PCR) based techniques have gradually replaced conventional enteropathogen detection techniques like microscopy and culture in primary care patients suspected of IID. PCR features testing of multiple enteropathogens in a single faecal sample with shorter turnaround times and greater sensitivity compared to conventional techniques. However, the associated costs and benefits have not been quantified. Furthermore, primary care incidence and prevalence estimates of enteropathogens associated with IID are sparsely available and predominantly based on conventional techniques. The PROUD-study (PCR diagnostics in Outpatients with Diarrhoea) determines: 1) health (care) effects and 2) cost-effectiveness of PCR introduction in primary care patients suspected of IID; 3) occurrence of major enteropathogens in primary care patients suspected of IID.

Methods

A before-after cohort study will be performed of patients with suspected IID consulting a GP in the Utrecht General Practitioner Network (UGPN), covering the before period (2010–2011) with conventional testing and the after period (2013–2014) with PCR testing. Prospective study data on patient characteristics and primary outcome measures (i.e. healthcare use and disease outcome) will be collected from electronic patient and laboratory records in 2015 and 2016. The effect of PCR introduction is investigated by comparing the primary outcome measures and their associated healthcare costs between the conventional period and the PCR period, and is followed by a cost-effectiveness analysis. To determine the occurrence of enteropathogens associated with IID in primary care, routine care faeces samples from the year 2014 will be screened using PCR.

Discussion

The PROUD-study will quantify the costs and effects of the introduction of PCR techniques for enteropathogens in primary care patients suspected of IID and generate up-to-date and sensitive estimates of enteropathogen occurrence among primary care patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1371-z) contains supplementary material, which is available to authorized users.

Population-based estimate of the burden of acute gastrointestinal illness in Jiangsu province, China, 2010-2011

To determine the burden and distribution of acute gastrointestinal illness (AGI) in the population, a cross-sectional, monthly face-to-face survey of 10 959 residents was conducted in Jiangsu province between July 2010 and June 2011. The adjusted monthly prevalence was 4.7% with 0.63 AGI episodes/person per year. The prevalence was the highest in children aged <5 years and lowest in persons aged ≥ 65 years. A bimodal seasonal distribution was observed with peaks in summer and winter. Regional difference of AGI prevalence was substantial [lowest 0.5% in Taicang, highest 15.1% in Xinqu (Wuxi prefecture)]. Healthcare was sought by 38.4% of the ill respondents. The use of antibiotics was reported by 65·2% of the ill respondents and 38.9% took antidiarrhoeals. In the multivariable model, gender, education, season, sentinel site and travel were significant risk factors of being a case of AGI. These results highlight the substantial burden of AGI and the risk factors associated with AGI in Jiangsu province, China.

Syndromic Surveillance of Norovirus using Over-the-counter Sales of Medications Related to Gastrointestinal Illness

OBJECTIVE

To assess whether over-the-counter (OTC) sales of gastrointestinal illness (GI)-related medications are associated with temporal trends of reportable community viral, bacterial and parasitic infections.

METHODS

The temporal patterns in weekly and seasonal sales of nonprescription products related to GI were compared with those of reportable viral, bacterial and parasitic infections in a Canadian province.

RESULTS

Temporal patterns of OTC product sales and Norovirus activity were similar, both having highest activity in the winter months. In contrast, GI cases from both bacterial and parasitic agents were highest from late spring through to early fall.

CONCLUSIONS

Nonprescription sales of antidiarrheal and antinauseant products are a good predictor of community Norovirus activity. Syndromic surveillance through monitoring of OTC product sales could be useful as an early indicator of the Norovirus season, allowing for appropriate interventions to reduce the number of infections.

Incidence and determinants of acute diarrhoea in Malaysia: a population-based study

Acute diarrhoea is a major health problem in many parts of the world, contributing to about 1.8 million deaths globally. The objectives of the study were to assess the incidence, determinants, and severity of acute diarrhoea in the population. A nation-wide cross-sectional survey involving about 57,000 respondents was conducted via face-to-face interview among eligible respondents of all ages. An acute diarrhoeal episode was defined as having three or more episodes of loose stools in any 24-hour period within the past four weeks before the interview. The severity was measured by duration of acute diarrhoea and associated symptoms. The variables tested as determinants were age, sex, ethnicity, the highest educational level, total monthly household income, and locality. Univariate, bivariate and multivariate procedures meant for complex study design were used in the analyses. The four-week incidence of acute diarrhoea was 5% [95% confidence interval (CI) 4.8-5.2]. The incidence of acute diarrhoea among the estimated population was the highest among young adults aged 20-29 years, Other Bumiputras (the pre-dominant ethnic group in East Malaysia), those with tertiary-level of education, those earning a monthly household income of less than RM 400, and rural dwellers. Only age, ethnicity, the highest level of education attained, and locality were significantly associated with acute diarrhoea in bivariate analysis. In multivariate analysis, these four variables were found to be the determinants of acute diarrhoea. Sex and monthly household income were excluded from the model. The mean duration of acute diarrhoea was 2.0 days (standard deviation 1.3). Forty-six percent of the respondents reported stomach cramps as an associated symptom. The findings revealed that acute diarrhoea is still a major public-health concern in Malaysia and grossly under-notified. There is a need for intensification of public-health intervention efforts to reduce the incidence of acute diarrhoea while improving surveillance and notification of the disease.

Methods for determining disease burden and calibrating national surveillance data in the United Kingdom: the second study of infectious intestinal disease in the community (IID2 study)

Background

Infectious intestinal disease (IID), usually presenting as diarrhoea and vomiting, is frequently preventable. Though often mild and self-limiting, its commonness makes IID an important public health problem. In the mid 1990s around 1 in 5 people in England suffered from IID a year, costing around £0.75 billion. No routine information source describes the UK's current community burden of IID. We present here the methods for a study to determine rates and aetiology of IID in the community, presenting to primary care and recorded in national surveillance statistics. We will also outline methods to determine whether or not incidence has declined since the mid-1990s.

Methods/design

The Second Study of Infectious Intestinal Disease in the Community (IID2 Study) comprises several separate but related studies. We use two methods to describe IID burden in the community - a retrospective telephone survey of self-reported illness and a prospective, all-age, population-based cohort study with weekly follow-up over a calendar year. Results from the two methods will be compared. To determine IID burden presenting to primary care we perform a prospective study of people presenting to their General Practitioner with symptoms of IID, in which we intervene in clinical and laboratory practice, and an audit of routine clinical and laboratory practice in primary care. We determine aetiology of IID using molecular methods for a wide range of gastrointestinal pathogens, in addition to conventional diagnostic microbiological techniques, and characterise isolates further through reference typing. Finally, we combine all our results to calibrate national surveillance data.

Discussion

Researchers disagree about the best method(s) to ascertain disease burden. Our study will allow an evaluation of methods to determine the community burden of IID by comparing the different approaches to estimate IID incidence in its linked components.

High-risk food consumption and food safety practices in a Canadian community

Understanding consumers' high-risk food consumption patterns and food handling in the home is critical in reducing foodborne illness. This study was conducted to determine the prevalence of unsafe food practices of individuals in a Canadian-based population, specifically, high-risk food consumption and home food safety practices. During November 2005 to March 2006, a sample of 2,332 randomly selected residents of the Waterloo Region (Ontario, Canada) participated in a telephone survey of food consumption and food safety. Questions covered consumption of high-risk foods, hand washing practices, safe food handling knowledge, source of food safety education, meat thawing and cooking practices, cross-contamination after raw food preparation, and refrigeration temperatures. Certain high-risk food behaviors were common among respondents and were associated with demographic characteristics. In general, unsafe practices increased with increasing total annual household income level. Males were more likely to report engaging in risky practices than were females. Specific high-risk behaviors of public health concern were reported by elderly individuals (e.g., consuming undercooked eggs), children (e.g., consuming chicken nuggets), and rural residents (e.g., drinking unpasteurized milk). Respondents appeared to know proper food safety practices, but did not put them into practice. Thus, educational programs emphasizing specific practices to improve food safety should be directed to targeted audiences, and they should stress the importance of consumer behavior in the safety of foods prepared at home. Further investigation of consumer perceptions is needed to design such programs to effectively increase the implementation of safe food practices by consumers.

A descriptive analysis of hospitalization due to acute gastrointestinal illness in Canada, 1995-2004

BACKGROUND

Gastrointestinal illness (GI) remains a leading cause of morbidity and mortality worldwide. In Canada, research has already demonstrated a rate in excess of one episode per person-year. National passive surveillance programs may be enhanced by information from hospitalizations for acute gastrointestinal disease. The objective of this report is to explore the incidence of acute GI in hospital administrative data collected by the Canadian Institute for Health Information (CIHI)--specifically the hospital morbidity database (HMDB).

METHODS

Data from acute care facilities and select chronic care and rehabilitation facilities across Canada were analyzed using standardized rates, and age- and sex-adjusted rates for the years 1995-2004.

RESULTS

The results indicate that GI causes at least 92,765 hospital admissions per year in Canada. In the majority (78.3%) of gastrointestinal hospitalizations, no specific etiology was recorded. Of the remaining diagnoses, 11.6% were due to viruses, 9.7% to bacteria and 0.3% to parasites. Age-standardized rates of hospitalizations for acute GI appear to have declined over the 10-year period.

CONCLUSION

Gastrointestinal illness is still present in the Canadian population and presents a significant burden to the health care system. Whereas the HMDB likely underestimates the true rate of GI, it does capture cases that are serious enough to require hospitalization. This is a unique source of data and highlights other pathogen-specific disease data not currently collected through national surveillance tools (e.g., viruses).

A common, symptom-based case definition for gastroenteritis

National studies determining the burden of gastroenteritis have defined gastroenteritis by its clinical picture, using symptoms to classify cases and non-cases. The use of different case definitions has complicated inter-country comparisons. We selected four case definitions from the literature, applied these to population data from Australia, Canada, Ireland, Malta and the United States, and evaluated how the epidemiology of illness varied. Based on the results, we developed a standard case definition. The choice of case definition impacted on the observed incidence of gastroenteritis, with a 1.5-2.1 times difference between definitions in a given country. The proportion of cases with bloody diarrhoea, fever, and the proportion who sought medical care and submitted a stool sample also varied. The mean age of cases varied by <5 years under the four definitions. To ensure comparability of results between studies, we recommend a standard symptom-based case definition, and minimum set of results to be reported.

Demographic determinants of acute gastrointestinal illness in Canada: a population study

Background

Gastrointestinal illness is an important global public health issue, even in developed countries, where the morbidity and economic impact are significant. Our objective was to evaluate the demographic determinants of acute gastrointestinal illness in Canadians.

Methods

We used data from two population-based studies conducted in select communities between 2001 and 2003. Together, the studies comprised 8,108 randomly selected respondents; proxies were used for all respondents under 12 years and for respondents under 19 years at the discretion of the parent or guardian. Using univariate and multivariate logistic regression, we evaluated the following demographic determinants: age, gender, cultural group, and urban/rural status of the respondent, highest education level of the respondent or proxy, number of people in the household, and total annual household income. Two-way interaction terms were included in the multivariate analyses. The final multivariate model included income, age, gender, and the interaction between income and gender.

Results

After adjusting for income, gender, and their interaction, children under 10 years had the highest risk of acute gastrointestinal illness, followed by young adults aged 20 to 24 years. For males, the risk of acute gastrointestinal illness was similar across all income levels, but for females the risk was much higher in the lowest income category. Specifically, in those with total annual household incomes of less than $20,000, the odds of acute gastrointestinal illness were 2.46 times higher in females than in males.

Conclusion

Understanding the demographic determinants of acute gastrointestinal illness is essential in order to identify vulnerable groups to which intervention and prevention efforts can be targeted.

The burden of acute gastrointestinal illness in Ontario, Canada, 2005-2006

A retrospective, cross-sectional telephone survey (n=2090) was conducted in Ontario, Canada, between May 2005 and April 2006, to determine the burden of acute gastrointestinal illness in the population. The 4-week prevalence was 8.56% (95% CI 7.36-9.76); in households with more than one resident, 35% of cases reported someone else in their household had similar symptoms at the same time. The annual adjusted incidence rate was 1.17 (95% CI 0.99-1.35) episodes per person-year, with higher rates in females, rural residents, and in the winter and spring. Health care was sought by 22% of cases, of which 33% were asked to provide a stool sample. Interestingly, 2.2% of cases who did not visit a health-care provider reported self-administering antibiotics. Overall, acute gastrointestinal illness appears to pose a significant burden in the Ontario population. Further research into the specific aetiologies and risk factors is now needed to better target intervention strategies.

The magnitude and distribution of infectious intestinal disease in Malta: a population-based study

Routine sources of information on infectious intestinal disease (IID) capture a fraction of the actual disease burden. Population studies are required to measure the burden of illness. A retrospective age-stratified cross-sectional telephone study was carried out in Malta in order to estimate the magnitude and distribution of IID at population level. A random sample of 3504 persons was interviewed by a structured questionnaire between April 2004 and December 2005. The response rate was 99.7%. From the study, the observed standardized monthly prevalence was 3.18% (95% CI 0.7-5.74) with 0.421 (95% CI 0.092-0.771) episodes of IID per person per year. The monthly prevalence was higher in the <5 years age group and in females aged 31-44 years. The mean duration of illness was 6.8 days and a median duration of 3 days. A bimodal seasonal distribution was observed with peaks in June-July and October-November.

Population distribution and burden of acute gastrointestinal illness in British Columbia, Canada

BACKGROUND

In developed countries, gastrointestinal illness (GI) is typically mild and self-limiting, however, it has considerable economic impact due to high morbidity.

METHODS

The magnitude and distribution of acute GI in British Columbia (BC), Canada was evaluated via a cross-sectional telephone survey of 4,612 randomly selected residents, conducted from June 2002 to June 2003. Respondents were asked if they had experienced vomiting or diarrhoea in the 28 days prior to the interview.

RESULTS

A response rate of 44.3% was achieved. A monthly prevalence of 9.2% (95% CI 8.4-10.0), an incidence rate of 1.3 (95% CI 1.1-1.4) episodes of acute GI per person-year, and an average probability that an individual developed illness in the year of 71.6% (95% CI 68.0-74.8), weighted by population size were observed. The average duration of illness was 3.7 days, translating into 19.2 million days annually of acute GI in BC.

CONCLUSION

The results corroborate those from previous Canadian and international studies, highlighting the substantial burden of acute GI.

Domestic and travel-related foodborne gastrointestinal illness in a population health survey

Routine surveillance data underestimate incidence of foodborne gastrointestinal (FGI) illness and provide little information on illness related to travel. We analysed data from the Welsh Health Survey to estimate population incidence, and to examine risk factors for FGI and factors associated with consulting a doctor. Reported frequency of any FGI in the 3 months before interview was 20.0% [95% confidence interval (CI) 19.5-20.4; equivalent to 0.8 episodes per person-year], and for travel-related FGI was 1.6% (95% CI 1.5-1.8). In the final model, sex, age group, marital status, self-reported health, long-term illness, smoking and alcohol consumption were all independent predictors of FGI. People who consulted a doctor were likely to be older, in poorer health, taking regular medication, or to report mental illness. FGI is common but risk factors for illness and consultation differ and impressions of the epidemiology of the disease based on surveillance data are therefore distorted.

[Morbidity and cost of rotavirus infections in France]

BACKGROUND

Rotavirus is the most common cause of severe diarrhea in children. Morbidity and mortality related to rotavirus infection is not well known in temperate countries in general, and in France in particular.

OBJECTIVES

The aim of this study was estimate the morbidity, mortality, and cost related to the rotavirus infection in France, in order to assess the potential impact of a vaccination program.

METHODS

A birth cohort was followed until 5 years of age using a decision tree model. Rotavirus infection incidence rates were modeled according to age, seasons, and breast-feeding status.

RESULTS

Based on estimates from a decision model, we found that in France, rotavirus infection was responsible for 300,000 annual episodes of acute diarrhea, 138,000 visits to general practitioners, 18,000 hospitalizations, and 9 deaths. The annual direct cost related to rotavirus infection care was estimated at 28 million euros.

CONCLUSION

This study demonstrates the high morbidity and cost of care associated with rotavirus infection in France. The decision tree model developed in this study could be used in the future to estimate the potential effectiveness, cost and cost-effectiveness of childhood vaccination strategies using new rotavirus vaccines.

Household transmission of gastroenteritis

Transmission of infectious gastroenteritis was studied in 936 predominately Hispanic households in northern California. Among 3,916 contacts of 1,099 primary case-patients, the secondary attack rate was 8.8% (95% confidence interval 7.9–9.7); children had a 2- to 8-fold greater risk than adults. Bed-sharing among children in crowded homes is a potentially modifiable risk.

Syndromic surveillance of gastrointestinal illness using pharmacy over-the-counter sales. A retrospective study of waterborne outbreaks in Saskatchewan and Ontario

OBJECTIVE

To ascertain if monitoring over-the-counter (OTC) drug sales could provide a timely syndromic surveillance method of detecting outbreaks of gastrointestinal illness.

METHOD

This study evaluated the potential of a syndromic surveillance system by comparing retrospective pharmacy OTC sales of anti-nauseants and anti-diarrheals to emergency room visits and case numbers from two Canadian outbreaks related to water contamination by Cryptosporidium, and E.coli O157:H7 and Campylobacter.

RESULTS

Local sales trends of weekly aggregate OTC products were comparable to the outbreak epidemic curves. Statistical control tests on the sales data indicated the start of the outbreak periods.

CONCLUSIONS

An automated monitoring tool based on spatial and temporal trend analyses of daily OTC sales would provide supplemental community health information for public health officials that is timelier than currently available laboratory-based surveillance systems.

Prevalence of diarrhoea in the community in Australia, Canada, Ireland, and the United States

BACKGROUND

Studies in several countries have estimated the prevalence of diarrhoea in the community. However, the use of different study designs and varying case definitions has made international comparisons difficult.

METHODS

Similar cross-sectional telephone surveys were conducted in Australia, Canada, Ireland (including Northern Ireland), and the United States over 12 month periods between 2000 and 2002. Each survey asked about diarrhoea in the four weeks before the interview. For this comparative analysis, uniform definitions were used.

RESULTS

Questionnaires were completed for 6087 respondents in Australia, 3496 in Canada, 9903 in Ireland, and 14,647 in the United States. In the four weeks prior to interview, at least one episode of diarrhoea was reported by 7.6% of respondents in Canada, 7.6% in the United States, 6.4% in Australia, and 3.4% in Ireland. The prevalence of diarrhoea was consistently higher in females. In all countries, the prevalence of diarrhoea was highest in children <5 years and lowest in persons > or =65 years of age. When diarrhoea and vomiting was considered, the prevalence was almost identical in the four studies (range: 2.0-2.6%). Despite different health care structures, a similar proportion of respondents sought medical care (approximately one in five). Antibiotic usage for the treatment of diarrhoea was reported by 8.3% of respondents in the United States, 5.6% in Ireland, 3.8% in Canada, and 3.6% in Australia.

CONCLUSIONS

Diarrhoea is a common illness among persons in the community in Australia, Canada, Ireland, and the United States. With similar methodologies and a standard case definition, age and sex patterns and health care seeking behaviour were remarkably consistent between countries.

Cost of community gastroenteritis

BACKGROUND AND AIM

Gastroenteritis is a common illness that causes considerable morbidity in developed countries. Endemic gastroenteritis that is not associated with outbreaks causes the greatest number of cases, but information is limited about the burden of this disease, and the resources required to manage its impact on society. In the present study, we estimated the rate of endemic gastroenteritis, the number of visits to the local doctor, use of medication, and the cost of gastroenteritis in Australia.

METHODS

Data from a community-based study of gastroenteritis, a general practice surveillance network, the Australian Bureau of Statistics and the Health Insurance Commission were used to measure endemic gastroenteritis and other study outcomes. The results were then extrapolated to the Australian Community.

RESULTS

There were an estimated 0.8 cases of gastroenteritis per person per year in Australia. This equated to 15,173,430 cases of gastroenteritis in Australia annually. The age-standardized estimate of the total number of visits to the general practitioner (GP) for gastroenteritis was 1024,214 at a cost of 26,722,691 Australian dollars. The average cost of prescribed medication per visit was 6.83 Australia dollars; the estimated total cost of prescribed medication was 6995,381 Australian dollars. The estimated cost of over-the-counter medication was 14,587,477 Australia dollars. It was estimated that people working full or part-time had 0.13 days-off per person per year because of gastroenteritis, at a cost of 137,924,170 Australian dollars. The estimated total cost of endemic gastroenteritis in Australia was 342,855,616 Australian dollars of which 75,908,274 Australian dollars was direct medical costs and 266,947,342 Australian dollars was time costs and the costs for time off work to care for a sick family member.

CONCLUSIONS

Endemic gastroenteritis is an important illness in both developed and developing countries. Although in developed countries, the majority of individual cases are mild to moderate in their severity; the overall costs are significant. The results highlight the need for ongoing research to identify the main causes of endemic gastroenteritis.

Surface plasmon resonance (BIACORE) detection of serum antibodies against Salmonella enteritidis and Salmonella typhimurium

We have used a surface plasmon resonance biosensor (BIACORE 3000) to detect serum antibodies in chickens having current or recent infections. Three well-defined Salmonella flagellar recombinant DNA antigens reflecting Salmonella enteritidis (H:g,m flagellin) and Salmonella typhimurium (H:i and H:1,2 flagellins) expressed in Escherichia coli were each immobilized in a single flow cell of a biosensor chip. Glutathione-S-transferase was immobilized on the surface of another flow cell to monitor non-specific binding. Sera collected from chickens with no history of Salmonella infection, and from chickens infected with Salmonella serotypes infantis, pullorum, gallinarum were used to test the performance of the system. The sensitivity exhibited to a range up to 900 arbitrary response units (RU) for the most positive S. typhimurium serum at a dilution of 1/40. Sera from Salmonella infantis, Salmonella pullorum and Salmonella gallinarum infected birds gave responses less than the cut-off point, which was determined as the averaged response of sera from specific pathogen-free chickens plus three times the standard deviation. A positive response was obtained when these sera and whole blood were fortified with S. enteritidis and S. typhimurium positive serum. The sensitivity, specificity, precision and reproducibility obtained suggested that this approach could be used for detecting past or present infection with a range of pathogens in animals.

A population-based longitudinal study on the incidence and disease burden of gastroenteritis and Campylobacter and Salmonella infection in four regions of The Netherlands

The aim of this study was to estimate the incidence of gastroenteritis and Campylobacter and Salmonella infection in the Dutch population, the disease burden, and the percentage of patients with gastroenteritis that consults a general practitioner. A sample of 6243 persons was invited to participate in the study, i.e. completing a questionnaire and submitting stool samples. The follow-up period was 17 weeks. In total, 2206 persons participated (= 35%), contributing 660 person years. The incidence (standardised by age and gender) of first episodes of gastroenteritis was 45 per 100 person years. Among patients with gastroenteritis, Salmonella and Campylobacter were cultured in 1.6 and 4.5%, respectively. The standardised incidence of first Campylobacter infections was 9 per 100 person years, of first Salmonella infections 4 per 100 person years. For 22% of the episodes of gastroenteritis, a general practitioner was consulted (either by phone or by practice visit). For 52% of the episodes, medicine were used. For 34% of the episodes, absence from school was reported and for 15%, absence from work was reported. Despite of possible biases, we can conclude that the incidence of gastroenteritis is very high and causes considerable use of medication, consultation of general practitioners and absence from work and school.

Gastroenteritis in sentinel general practices,The Netherlands

From 1996 to 1999, the incidence of gastroenteritis in general practices and the role of a broad range of pathogens in the Netherlands were studied. All patients with gastroenteritis who had visited a general practitioner were reported. All patients who had visited a general practitioner for gastroenteritis (cases) and an equal number of patients visiting for nongastrointestinal symptoms (controls) were invited to participate in a case-control study. The incidence of gastroenteritis was 79.7 per 10,000 person years. Campylobacter was detected most frequently (10% of cases), followed by Giardia lamblia (5%), rotavirus (5%), Norwalk-like viruses (5%) and Salmonella (4%). Our study found that in the Netherlands (population 15.6 million), an estimated 128,000 persons each year consult their general practitioner for gastroenteritis, slightly less than in a comparable study in 1992 to 1993. A pathogen could be detected in almost 40% of patients (bacteria 16%, viruses 15%, parasites 8%).

Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance. The Infectious Intestinal Disease Study Executive

OBJECTIVE

To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance.

DESIGN

Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance.

SETTING

70 general practices throughout England.

PARTICIPANTS

459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients.

MAIN OUTCOME MEASURES

Incidence of infectious intestinal disease in community and reported to general practice.

RESULTS

781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified.

CONCLUSIONS

Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism. Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered.

Impact on human health of Salmonella spp. on pork in The Netherlands and the anticipated effects of some currently proposed control strategies

The impact on human health of Salmonella spp. on pork in The Netherlands is described. Subsequently, the effects of some currently proposed control strategies in the Dutch pork production chain are evaluated and quantified with the aid of a simple mathematical model. The estimated average incidence of cases of salmonellosis in the Netherlands is about 450 cases per 100,000 person years at risk (pyar). Some special risk groups for which the risks could be quantified are (1) persons with underlying diseases, such as neoplasms or diabetes mellitus (1200 cases/100,000 pyar); (2) persons with achlorhydria or who excessively use antacids (1100 cases/100,000 pyar); (3) persons who have recently been treated with antibiotics that disturb the normal gut flora (1700 cases/100,000 pyar); (4) nurses (900 cases/100,000 pyar); (5) caterers (900 cases/100,000 pyar); (6) slaughterline personnel (1800 cases/100,000 pyar). Furthermore, it is estimated that 15% (5-25%) of all cases of salmonellosis in The Netherlands are associated with the consumption of pork. Currently, proposed control measures regarding Salmonella in pigs and on pork in The Netherlands are codes of good manufacturing practices (GMP) that, in fact, formalize recommendations that can be found in many handbooks about pig breeding and pig slaughtering. When evaluated by a mathematical model constructed for this purpose, the proposed GMP codes from farm to cutting/retail could, at best, reduce the current levels of Salmonella-positive pigs and pork by 50-60%. If pigs were bred according to the rather costly specific pathogen-free concept (SPF), the prevalence of contaminated carcasses and pork could in total be reduced by 95% or more. However, implementing GMP codes from the transport phase up to the cutting/retail phase coupled with a decontamination step at the end of the slaughterline would be just as effective as GMP in combination with breeding using the SPF-concept. It is therefore concluded that the most efficient and cost-effective way of reducing the 'Salmonella problem' entailed by the consumption of pork would be to decontaminate carcasses under the precondition that the entire production chain strictly adheres to GMP principles. Therefore, the EU should also allow for more possibilities regarding the decontamination of carcasses than is currently the case. It is also concluded that current EU regulations relying on hazard analysis of critical control points (HACCP)-inspired production in cutting plants will not be effective in reducing the prevalence of Salmonella spp. on pork. This is mainly because (1) there is currently an almost steady stream of Salmonella-positive carcasses that enter the cutting process; (2) when contaminated carcasses are being processed, further cross-contamination during working hours is unavoidable; (3) no steps in the cutting process are intentionally designed to effectively reduce the risks or consequences of cross contamination of cuts and retail-ready products.

The prevalence and aetiology of persistent diarrhoea in adults in urban Zambia

As the AIDS pandemic has spread, diarrhoea in adults has become a major burden on health care institutions in central Africa and on the families of sufferers. In order to assess the magnitude of the problem, we carried out a survey of households in a high population density township of Lusaka to determine the prevalence of persistent diarrhoea in adults. We also carried out a study of the causes of persistent diarrhoea in patients attending the University Teaching Hospital, Lusaka. The community survey assessed 460 households, representing a sample of 1440 adults. 94 adults were reported as having had diarrhoea in the 2 weeks prior to the survey, implying an attack rate of 1.74 per adult per year. Of these 94 cases, six had diarrhoea of between 2 and 4 weeks duration, and ten had diarrhoea of over 4 weeks duration. In the hospital study, 75 (97%) out of 77 patients with diarrhoea of over 1 months' duration were HIV seropositive; potentially pathogenic parasites were found in 61/75 (81%) of seropositives. This information indicates that persistent diarrhoea in adults, mostly related to HIV infection, is likely to be an important and growing reservoir of enteric pathogens and represents a significant burden on hospitals and relatives. This emerging problem in sub-Saharan Africa may foreshadow developments in other continents.