Since 1996 Salmonella Typhimurium DT104 salmonellosis has increased in The Netherlands. This prompted a case-control study of risk factors for salmonellosis to inform transmission routes for this ...phage type. Cases were laboratory-confirmed patients with a Salmonella infection and controls were selected from population registries by frequency matching for age, sex, degree of urbanization and season. Cases and controls received a questionnaire on risk factors. Of the 1171 cases, 573 (49%) responded: 245 S. Enteritidis and 232 S. Typhimurium cases (both DT104 and non-DT104), of which 58 were DT104. Of the 10250 controls, 3409 (33%) responded. Use of H2 antagonists odds ratio (OR) 4·4, 95% CI 1·6–12·2 and proton pump inhibitors (OR 4·2, 95% CI 2·2–7·9), consumption of raw eggs (OR 3·1, 95% CI 1·3–7·4) and products containing raw eggs (OR 1·8, 95% CI 1·1–3·0) were associated with endemic S. Enteritidis infection. Risk factors for endemic S. Typhimurium infection were use of proton pump inhibitors (OR 8·3, 95% CI 4·3–15·9), occupational exposure to raw meat (OR 3·0, 95% CI 1·1–7·9), playing in a sandbox (for children aged 4–12 years) (OR 2·4, 95% CI 1·6–3·7), consumption of undercooked meat (OR 2·2, 95% CI 1·1–4·1) and use of antibiotics (OR 1·9, 95% CI 1·0–3·4). Use of proton pump inhibitors (OR 11·2, 95% CI 3·9–31·9) and playing in a sandbox (OR 4·4, 95% CI 1·8–10·7) were the only risk factors for S. Typhimurium DT104 salmonellosis. This study confirms known risk factors for salmonellosis. However, playing in a sandbox was a predominant new risk factor for S. Typhimurium salmonellosis in children population attributable risk (PAR) 14%, and especially for S. Typhimurium DT104 (PAR 32%).
A case-control study comprising 1315 Campylobacter jejuni cases, 121 Campylobacter coli cases and 3409 frequency-matched controls was conducted in The Netherlands in 2002–2003. Risk factors for both ...C. jejuni and C. coli enteritis were consumption of undercooked meat and barbecued meat, ownership of cats and use of proton pump inhibitors. Consumption of chicken was a predominant risk factor for C. jejuni enteritis, but many additional risk factors were identified. Unique risk factors for C. coli infections were consumption of game and tripe, and swimming. Contact with farm animals and persons with gastroenteritis were predominant risk factors for C. jejuni enteritis in young children (0–4 years). Important risk factors for the elderly (⩾60 years) were eating in a restaurant, use of proton pump inhibitors and having a chronic intestinal illness. Consumption of chicken in spring, steak tartare in autumn and winter and barbecued meat in rural areas showed strong associations with C. jejuni infections. This study illustrates that important differences in risk factors exist for different Campylobacter spp. and these may differ dependent on age, season or degree of urbanization.
Infectious gastroenteritis causes a considerable burden of disease worldwide. Costs due to gastroenteritis are dominated by the hospitalized cases. Effective control of gastroenteritis should be ...targeted at the diseases with the highest burden and costs. For that, an accurate understanding of the relative importance of the different bacterial, viral, and parasitic pathogens is needed. The objective of the present study was to determine the incidence and etiology of gastroenteritis requiring hospital admission in the Netherlands. Six hospitals enrolled patients admitted with gastroenteritis for approximately one year over the period May 2008 to November 2009. Participants provided questionnaires and a fecal sample, and the hospital filled out a clinical questionnaire. In total, 143 children hospitalized for gastroenteritis and 64 matched controls were included in the study. Overall incidence of gastroenteritis requiring hospitalization was estimated at 2.92 per 1,000 children aged 0–17 years per year, with the highest incidence in children under the age of 5 years. The full diagnostic panel of pathogens could be studied in fecal samples of 96 cases. One or more pathogens were found in 98% of these cases. Co-infections were observed relatively often (40%). Viruses were detected in 82% of the samples, with rotavirus being most common (56%), bacteria in 32% and parasites in 10%. The present study emphasizes the importance of viral pathogens, especially rotavirus, in hospitalizations of children with gastroenteritis. Policies to reduce (costs of) hospitalizations due to gastroenteritis should therefore be first targeted at rotavirus.
In 1999, the costs of gastroenteritis in the Netherlands were estimated using data on hospitalizations from national registries, together with data on etiology and self-reported data on health care ...resource use in a community-based study. Now, more information on hospitalizations is available and these data were used to update the total costs of gastroenteritis in the Netherlands. The costs of severe gastroenteritis in the Netherlands were estimated in more depth using a hospital-based study, with patient questionnaires including a follow-up period of 6 months. The overall costs of gastroenteritis were calculated taking direct medical costs, direct non-medical costs, and indirect non-medical costs into account. The costs for severe gastroenteritis in 2009 were estimated at €2,203 per hospitalized child and €6,834 per hospitalized adult. The overall costs of gastroenteritis in 2009 were estimated at €611–695 million, which is €133–151 per gastroenteritis case or €37–42 per inhabitant. The total health care costs for gastroenteritis were about 50% higher in 2009 compared to 1999, which is mostly due to the rise in health care costs. The costs per gastroenteritis episode in adults are higher compared to children, mainly due to differences in the reasons for hospitalization and course of disease, and productivity losses.
During large Q fever outbreaks in the Netherlands between 2007 and 2010, dairy goat farms were implicated as the primary source of human Q fever. The transmission of Coxiella burnetii to humans is ...thought to occur primarily via aerosols, although available data on C. burnetii in aerosols and other environmental matrices are limited. During the outbreak of 2009, 19 dairy goat farms and one dairy sheep farm were selected nationwide to investigate the presence of C. burnetii DNA in vaginal swabs, manure, surface area swabs, milk unit filters, and aerosols. Four of these farms had a positive status during the Coxiella burnetii bulk milk monitoring program in 2009 and additionally reported abortion waves in 2008 or 2009. Eleven farms were reported as having positive bulk milk only, and five selected (control) farms had a bulk milk-negative status in 2009 and no reported Q fever history. Screening by quantitative PCR (qPCR) revealed that on farms with a history of abortions related to C. burnetii and, to a lesser extent, on farms positive by bulk milk monitoring, generally higher proportions of positive samples and higher levels of C. burnetii DNA within positive samples were observed than on the control farms. The relatively high levels of C. burnetii DNA in surface area swabs and aerosols sampled in stables of bulk milk-positive farms, including farms with a Q fever-related abortion history, support the hypothesis that these farms can pose a risk for the transmission of C. burnetii to humans.
A prospective population-based cohort study with a nested case-control study was conducted to estimate the incidence of gastroenteritis and the associated pathogens in the general Dutch population. ...Follow-up of two consecutive cohorts was performed by weekly reporting cards from December 1998 to December 1999. Cases and controls in the case-control study supplied a questionnaire and stool samples. The standardized gastroenteritis incidence was 283 per 1,000 person-years. The incidence rose with increasing level of education and was higher for persons with a history of diarrhea and for young children. Bacterial pathogens accounted for 5% of cases, bacterial toxins for 9%, parasites for 6%, and viral pathogens for 21%, with Norwalk-like virus (NLV) as the leading pathogen in 11% of cases. The gastroenteritis incidence was higher than that reported for England, but lower than for the United States. In community cases, viral pathogens are the leading cause of gastroenteritis, with NLV being the number one cause of illness in all age groups but one. In many countries, preventive measures are implemented to decrease bacterial infections. However, additional prevention of viral infections, especially NLV, might significantly decrease the number of gastroenteritis cases in the community.
Coxiella burnetii seroprevalence was assessed on Dutch dairy and non-dairy sheep farms using ELISA. Risk factors for seropositivity on non-dairy sheep farms were identified at farm and sheep level by ...univariate and multivariate multilevel analyses. Based on 953 dairy and 5671 non-dairy serum samples, sheep seroprevalences were 18.7 per cent and 2.0 per cent, respectively, and 78.6 per cent and 30.5 per cent at farm level. Significant risk factors for non-dairy sheep farms were farm location in the south of the country, sheep kept on marginal grounds, one or several supply addresses for ewes during 2007-2009 and wearing farm boots and/or outfit by professional visitors. On sheep level, risk factors included among others farm location in the south of the country, lamb breeding as main farm purpose, goat density within 10 km farm radius, use of windbreak curtain or windshields, and presence of ≥6 stillborn lambs in 2009. Farm location in the south of the country and goat density suggests that infected goats have played a role in the transmission to non-dairy sheep. Other risk factors suggest introduction of the bacterium through sheep supply and professional visitors. Biosecurity measures should be strengthened, including avoiding infection during handling of stillborn lambs and birth products in the lambing period.
To estimate the change in the seroprevalence and risk factors for toxoplasmosis in The Netherlands, a study was conducted in the general population in 2006/2007, similarly designed as a previous ...study in 1995/1996. Testing 5541 sera for IgG antibodies against Toxoplasma gondii showed a marked decrease of the overall seroprevalence to 26·0% 95% confidence interval (CI) 24·0–28·0, compared to 40·5% (95% CI 37·5–43·4) in 1995/1996. In women of reproductive age the seroprevalence decreased from 35·2% (95% CI 32·9–38·6) in 1995/1996 to 18·5% (95% CI 16·2–20·7) in 2006/2007, leaving the majority of pregnant women susceptible to primary infection with T. gondii and their babies to congenital toxoplasmosis. In participants aged ≥20 years, Toxoplasma seropositivity was associated with living in the Northwest, living in urban areas, low educational level, consumption of raw pork, keeping a cat, and not having occupational contact with clients or patients. For younger participants, risk factors were keeping sheep or cattle, consumption of raw unwashed vegetables and putting sand in the mouth.
Data from a general practice-based, case-control study on gastroenteritis and the pathogens related to this disease were used to study the association between specific pathogens and the infected ...patients' ages and symptoms. For comparison, the occurrence of these pathogens in control patients, stratified by age, also is presented. In children with gastroenteritis who were <5 years of age, rotavirus (in 21% of patients) and Norwalk-like virus (NLV; in 15%) were the most common pathogens. Among patients who were 5-14 years of age, Campylobacter species (in 16% of patients) and Giardia lamblia (in 10%) were the most common pathogens. In the older patients, Campylobacter species was also the most common pathogen (8% to 15% of patients). In addition, several symptoms in case patients were associated with specific pathogens. Blood in the stool was associated with infection with Campylobacter species. In patients with fever, Salmonella species, Campylobacter species, and rotavirus were detected relatively often. Vomiting was associated with NLV and rotavirus. This is the first study in The Netherlands and one of the first studies in the world that has investigated a broad range of pathogens recovered from an unselected population of patients who had consulted general practitioners because of gastroenteritis.
Effective infection control measures during norovirus outbreaks are urgently needed in places where vulnerable individuals gather. In the present study, the effect of a number of measures was ...investigated in daily practice. Forty-nine Dutch nursing homes were monitored prospectively for norovirus outbreaks during two winter seasons. A total of 37 norovirus outbreaks were registered. Control measures were most effective when implemented within 3 days after onset of disease of the first patient. Measures targeted at reduced transmission between persons, via aérosols, and via contaminated surfaces reduced illness in staff and in residents. Reducing illness in staff results in fewer costs for sick leave and substitution of staff and less disruption in thè care of residents. The effect of control measures on outbreak duration was limited. This is the first intervention study examining the effect of control measures. Further research is needed to extend and refine the conclusions.
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