Sources of sporadic Yersinia enterocolitica infection in children in Sweden, 2004: a case-control study

Young children account for a large proportion of reported Yersinia enterocolitica infections in Sweden with a high incidence compared with other gastrointestinal infections, such as salmonellosis and campylobacteriosis. A case-control study was conducted to investigate selected risk factors for domestic sporadic yersiniosis in children aged 0-6 years in Sweden. In total, 117 cases and 339 controls were included in the study. To minimize exclusion of observations due to missing data a multiple non-parametric imputation technique was used. The following risk factors were identified in the multivariate analysis: eating food prepared from raw pork products (OR 3.0, 95% CI 1.8-5.1) or treated sausage (OR 1.9, 95% CI 1.1-3.3), use of a baby's dummy (OR 1.9, 95% CI 1.1-3.2) and contact with domestic animals (OR 2.0, 95% CI 1.2-3.4). We believe that the importance of Y. enterocolitica infection in children has been neglected and that results from this study can be used to develop preventive recommendations.     

A case-control study of Yersinia enterocolitica infections in Auckland

OBJECTIVE: To identify major risk factors for Yersinia enterocolitica (YE) and identify measures to reduce YE infections. METHODS: A prospective case control study, group age matched, using 186 cases of YE identified by community pathology laboratories and 379 randomly selected controls. Conducted between April 1995 and June 1996 in Auckland, New Zealand. Face-to-face interviews used a standardised questionnaire examining exposures to factors potentially associated with YE infections including untreated water, unreticulated sewerage, consumption of selected foods, selected food handling practices and socio-demographic factors. Multivariate logistic regression was used to calculate adjusted odds ratios for the potential risk factors. Population attributable risk (PAR) was calculated for significant exposures. RESULTS: Having more than two people living in the home was more common among cases than controls (OR = 2.2). Town supply water (OR = 0.2), reticulated sewerage (OR = 0.34) and looking after a young child (OR = 0.51) were significantly less common. Of the meats, only pork (OR = 1.34) had a higher consumption rate, while bacon (OR = 0.75) and smallgoods (OR = 0.73) were consumed less frequently by cases than controls. Eating food from a sandwich bar was more frequent among cases (OR = 1.18). Fruit and vegetable consumption was marginally less (OR = 0.98). The population attributable risk of these factors was 0.89, implying that 89% of YE would be eliminated if adverse exposures were removed. CONCLUSIONS: The risk of YE illness is increased by contact with untreated water, unreticulated sewerage and consumption of pork. Investigation of non-town water supply, informal sewerage systems and methods of preparation and consumption of pork are recommended to determine how YE enters the human food chain.     

Risk factors for sporadic Campylobacter jejuni infections in rural michigan: a prospective case-control study

OBJECTIVES: This case-control study investigated risk factors for campylobacteriosis in a rural population. Exposure to live farm animals was hypothesized to increase the risk for Campylobacter jejuni enteritis. METHODS: Incident cases from rural counties reported to the Michigan Department of Community Health and matched controls completed a self-administered postal questionnaire. RESULTS: Persons engaged in poultry husbandry had increased odds of campylobacteriosis (odds ratio = 6.884; 95% confidence interval (CI) = 1.438, 32.954). There was evidence for a dose-response relationship between the number of types of poultry contact and campylobacteriosis. CONCLUSIONS: We estimate that 18% (95% CI = 6%, 30%) of Campylobacter cases occurring in rural populations are attributable to poultry husbandry. Cases occurred in individuals who were not poultry farmers by occupation.     

Risk factors for sporadic Yersinia enterocolitica infections, Germany 2009-2010

Yersinia enterocolitica is an important cause of acute gastrointestinal disease and post-infectious complications. In Germany, incidence of reported yersiniosis is relatively high compared with other countries of the European Union. Children aged <5 years are most frequently affected. The aim of our study was to identify risk factors for sporadic yersiniosis in Germany. A population-based case-control study was conducted in five federal states of Germany from April 2009 to June 2010. Cases exhibiting gastrointestinal symptoms were notified to the local health department with a Yersinia enterocolitica infection culture-confirmed from stool. Controls were selected from population registries and frequency-matched on age group and state of residency. Cases and controls received a questionnaire on possible risk factors by mail. Multivariable logistic regression modelling was used to identify risk factors and to calculate adjusted odds ratios (aORs). Population attributable fractions (PAFs) were estimated for exposures associated with yersiniosis. We analysed data on 571 case patients and 1798 controls. Consumption of raw minced pork, a dish frequently consumed even by young children in Germany, was the main risk factor for disease (aOR 4·7, 95% confidence interval (CI) 3·5-6·3, PAF 30%). This association varied by age group and, unexpectedly, was strongest for children aged <2 years (aOR 17·5, 95% CI 6·0-51·2). Other independent risk factors included recent preparation of minced pork in the household (aOR 1·4, 95% CI 1·1-1·9, PAF 21%), playing in a sandbox (aOR 1·7, 95% CI 1·3-2·4, PAF 17%), and contact with birds (aOR 1·7, 95% CI 1·1-2·6, PAF 4%). Prevention efforts should specifically target parents and caregivers of young children and focus on the high infection risk associated with consumption of raw minced pork.     

Salmonella infections in Norway: descriptive epidemiology and a case-control study

The epidemiological progression of human salmonellosis in Norway is parallel to trends noted elsewhere in Europe. During the past two decades, the number of reported cases has increased steadily, with a special sharp rise in the early 1980s due to the emergence of Salmonella enteritidis, followed by a levelling off in recent years. However, in contrast to the situation in most other European countries, about 90% of the cases from whom a travel history is available, have acquired their infection abroad. The incidence of indigenous salmonella infections as well as the prevalence of the microorganism in the domestic food chain, are both comparatively low. In 1993-4, a national case-control study of sporadic indigenous salmonella infections was conducted to identify preventable risk factors and guide preventive efforts. Ninety-four case patients and 226 matched population controls were enrolled. The study failed to demonstrate any statistically significant association between salmonellosis and consumption of domestically produced red meat, poultry or eggs. The only factor which remained independently associated with an increased risk in conditional logistic regression analysis, was consumption of poultry purchased abroad during holiday visits to neighbouring countries. A separate analysis of Salmonella typhimurium infections incriminated food from catering establishments and foreign travel among household members, in addition to imported poultry.     

中国小肠结肠炎耶尔森氏菌病研究进展

小肠结肠炎耶尔森氏菌病 (耶氏菌病 )是 80年代才受到重视的一种新的肠道传染病 ,世界各大洲均有发现 ,是欧洲某些国家腹泻的主要病种 ,不少地区耶氏菌引起的胃肠炎和严重腹泻 ,比痢疾还多。除肠道症状外 ,还能引起呼吸道、心血管系统、骨骼、结缔组织和全身疾病 ,出现败血症时病死率达 30 %以上。1981年我国才发现此病 ,引起全国重视 ,并开展了全国性调查和研究 ,分别从人群、动物和外环境分离出病原菌 ,证明耶氏菌病在我国的分布是非常广泛的一、人群流行概况我国耶氏菌病的流行形式多为散发 ,也发现有暴发流行。1.暴发流行 :我国目前已发…     

Clinical findings and diagnosis of Yersinia enterocolitica infections; a retrospective study in Friesland

The clinical data of 97 patients with Yersinia enterocolitica infection during 1989 were evaluated. The diagnosis was made by positive culture, serology and/or detection of Yersinia antigens in biopsies. The enteric form (enteritis, abdominal syndrome, pseudo-appendicitis, ileitis and colitis) occurred in 66% of all patients, 10 (10%) had an extramesenteric form, 22 had arthritis and 6 had erythema nodosum. The mean age was 33.6 (SD 19.4) years. Abdominal pain was the syndrome most frequently observed (in 55%), followed by diarrhoea in 44% and malaise in 41%. The duration of the disease was shorter than four weeks in 37% and longer than eight weeks in 34%. Serotype 03 was most frequently isolated. The agglutination reaction was positive in 25%, false-positive in 7% and false-negative in 68%; 91% had specific IgA and IgG antibodies against two or more virulence proteins (Yops).     

A case-control study of risk factors for sporadic campylobacter infections in Denmark

A case control study comprising 282 cases and 319 matched controls was conducted in Denmark during 1996-7. Two estimates of the odds ratio (OR) were determined for each risk factor with and without 'protective factors' fitted into the final model. Consumption of undercooked poultry (OR 4.5; 8.2), consumption of red meat at a barbecue (OR 2.3; 4.1), consumption of grapes (OR 1.6; 2.8) and drinking unpasteurized milk (OR 2.3; 11.8) were identified as risk factors in both models. Frequent consumption of pork chops (OR 4.4) and daily contact with domestic animals and pets were identified as risk factors in one of the two models only. Finally, foreign travel was found to be a significant risk factor (OR 2.5). Seasonal and regional interaction was observed for several risk factors and the time elapsed from interviewing of cases to interviewing of controls seemed to influence the effect of certain seasonal dependent risk factors.     

Factors associated with increased and decreased risk of Campylobacter infection: a prospective case-control study in Norway

In 1999-2000, a prospective case-control study of sporadic, domestically acquired campylobacteriosis was conducted in three counties in Norway to identify preventable risk factors and potentially protective factors. A total of 212 cases and 422 population controls matched by age, sex, and geographic area were enrolled. In conditional logistic regression analysis, the following factors were found to be independently associated with an increased risk of Campylobacter infection: drinking undisinfected water, eating at barbecues, eating poultry bought raw, having occupational exposure to animals, and eating undercooked pork. The following factors were independently related to a decreased risk: eating mutton, eating raw fruits or berries, and swimming. Results indicated that infection is more likely to occur as a result of cross-contamination from raw poultry products than because of poultry consumption per se. Drinking undisinfected water, reported by 53% of cases, was a leading risk factor in this study. Drinking water may constitute the common reservoir linking infection in humans and animals, including poultry and wild birds. Insight into the ecology of Campylobacter in freshwater ecosystems may be required to understand the epidemiology of campylobacteriosis. The possibility that certain foods confer protection against campylobacteriosis deserves exploration.     

Outcomes of nosocomial bloodstream infections in adult neutropenic patients: a prospective cohort and matched case-control study.

OBJECTIVE: To examine the clinical and epidemiologic features, excess length of stay, extra costs, and mortality attributable to bloodstream infection (BSI) in neutropenic patients with hematologic malignancies. DESIGN: Prospective cohort and matched case-control study. PATIENTS: All adult neutropenic patients with hematologic malignancies admitted to Cologne University Hospital between May 1, 1997, and April 30, 1998, were prospectively observed. Case-patients were defined as patients with nosocomial BSI; control-patients were selected among patients without BSI. RESULTS: During the study period, the BSI rate in neutropenic patients was 14.3 per 100 neutropenic episodes. Eighty-four case-patients were included. Matching was successful for 96% of the cohort; 81 matched pairs were studied. The mean total length of stay was significantly longer for patients with BSI than for control-patients (37 vs 29 days; P = .002). Extra costs attributable to the infection averaged 3,200 dollars (U.S.) per patient. The crude mortality rates of case-patients and control-patients were 16% and 4%, respectively (P = .013), with an attributable mortality of 12% (odds ratio, 11). Eighty-seven percent of patients met the criteria for sepsis according to the American College of Chest Physicians/Society of Critical Care Medicine. Severe sepsis or septic shock occurred in 13% of patients and was correlated with mortality (55% vs 10% in patients without severe sepsis or septic shock; P = .01). CONCLUSIONS: Nosocomial BSI in neutropenic patients is significantly associated with an excess length of hospital stay, extra costs, and excess mortality. Severe sepsis and septic shock are closely correlated with an adverse outcome.     

171株小肠结肠耶尔森菌的病原学特征

目的研究徐州地区分离的171株小肠结肠炎耶尔森菌(Yersinia enterocolitica,Y.e)的病原学特征及其动态变化。方法通过血清学分型,生物分型,毒力基因检测,分析不同时代分离株的致病性。通过脉冲场凝胶电泳(PFGE)分析Y.e的分子流行病学特征。结果不同时代分离株的优势型别始终为O:3血清型。非致病菌型是近年分离的Y.e菌株的优势菌型。O:3血清型菌株其狗源株和人源株的PFGE带型完全相同。结论不同时代分离菌株的毒力分布特征发生了很大的变迁,O:3血清型菌株流行比较稳定,菌株变异较小。     

Outbreak of Yersinia enterocolitica serogroup O:9 infection and processed pork, Norway

An outbreak involving 11 persons infected with Yersinia enterocolitica O:9 was investigated in Norway in February 2006. A case-control study and microbiologic investigation indicated a ready-to-eat pork product as the probable source. Appropriate control measures are needed to address consumer risk associated with this product.     

Aetiology of peptic ulcer: a prospective population study in Norway.

STUDY OBJECTIVE--To analyse simultaneously the effect of several risk factors for peptic ulcer. DESIGN--Cohort study where all patients with new or incident peptic ulcers in a well defined population were registered for a seven year period. The follow up started with a comprehensive health survey including a questionnaire on diet, lifestyle, psychological and social conditions, and health. Relative risks, both sex specific and separate, for gastric and duodenal ulcers were estimated from proportional hazard regression analysis. SETTING--A population based survey conducted in the municipality of Tromsø, northern Norway. PARTICIPANTS--In 1980, a total of 21,440 men and women, aged 20 to 54 years and 20 to 49 years respectively, were invited to participate. A total of 14,667 people attended and returned the questionnaire. MAIN RESULTS--A total of 328 people had their first peptic ulcer in the follow up period. Age, cigarette smoking, first degree relatives with peptic ulcer, and low educational level were shared risk factors for peptic ulcer in both men and women. In men, frequent upper respiratory infections increased the risk of gastric ulcer and drinking a great deal of milk increased the risk of duodenal ulcer. None of the other dietary variables, including coffee and alcohol consumption, contributed significantly to the risk. Use of analgesics was not a risk factor, and none of the psychological indicators analysed carried any significant risk. CONCLUSIONS--Age, inheritance, and cigarette smoking are all important risk factors for peptic ulcer. The increased risk associated with low educational background indicate that social strains, comprising lifestyle and diet habits, are part of the multifactorial aetiology of peptic ulcer. No support was found for the assumption that peptic ulcer disease is a psychosomatic disorder. This study did not support the view that duodenal and gastric ulcers have different aetiologies-rather it showed a similarity in risk patterns.     

171株小肠结肠耶尔森菌的病原学特征

目的研究徐州地区分离的171株小肠结肠炎耶尔森菌(Yersinia enterocolitica,Y.e)的病原学特征及其动态变化。方法通过血清学分型,生物分型,毒力基因检测,分析不同时代分离株的致病性。通过脉冲场凝胶电泳(PFGE)分析Y.e的分子流行病学特征。结果不同时代分离株的优势型别始终为O:3血清型。非致病菌型是近年分离的Y.e菌株的优势菌型。O:3血清型菌株其狗源株和人源株的PFGE带型完全相同。结论不同时代分离菌株的毒力分布特征发生了很大的变迁,O:3血清型菌株流行比较稳定,菌株变异较小。     

Yersinia enterocolitica : a review of its role in food hygiene.

Since Yersinia enterocolitica, now classified as a member of the Enterobacteriaceae, was recognized as a distinct species in 1964 it has been isolated with increasing frequency from man and animals (including dogs and pigs) and from some human foods. Y. enterocolitica infections are now seen as a cause for some concern in both human and veterinary medicine. The organism is commonly found in specimens from swine slaughterhouses and has been isolated from samples of market meat, vacuum-packed beef, mussels, oysters, and ice-cream. It has also been found in nonchlorinated well water used for drinking purposes. Infections in man therefore probably have an alimentary origin. Only 23 human infections were recorded in 1966 but the number increased to over 4000 in 1974. However, reported incidence is affected by growing awareness about the role of the organism in human and animal disease and by intensive laboratory analyses. While knowledge about the geographical distribution of Y. enterocolitica is still fragmentary it is clear that infections are very frequent in some parts of the world and probably common but unrecognized in many countries. The most common symptoms of Y. enterocolitica infections in man are fever, abdominal pain, and diarrhoea. In the USA most isolations in human infections were made from blood and mesenteric lymph node samples. The pathogenic mechanism is not known. In one experiment involving a human volunteer subject a dose of 3.5 × 10⁹ organisms was required to produce an infection. Only recently has some success been obtained in establishing experimental infections in mice, guinea-pigs, rats, and rabbits. Laboratory cultivation techniques for Y. enterocolitica are described together with a table of minimal tests for characterizing the organism and two biotyping schema. Little is known about methods for controlling this disease, but environmental hygiene and sanitation with regard to food and water should apply.     

An outbreak of Yersinia enterocolitica O:3 infections on an oil tanker

In January 2002, an outbreak of Yersinia enterocolitica O:3 infections occured on 'Asirat', an oil tanker, during its return test voyage from Split, Croatia to Trieste, Italy. Of the 120 crewmembers and workers 22 (18%) suffered from gastrointestinal symptoms. In 17 patients Y. enterocolitica O:3 was isolated from stool samples. All available food and water samples were negative and the source of infection was not determined. Probably a foodborne transmission was involved, although person to person transmission could not be excluded.     

Risk factors for sporadic giardiasis: a case-control study in southwestern England

To investigate risk factors for sporadic infection with Giardia lamblia acquired in the United Kingdom, we conducted a matched case-control study in southwest England in 1998 and 1999. Response rates to a postal questionnaire were 84% (232/276) for cases and 69% (574/828) for controls. In multivariable analysis, swallowing water while swimming (p<0.0001, odds ratio [OR] 6.2, 95% confidence intervals [CI] 2.3 to 16.6), recreational fresh water contact (p=0.001, OR 5.5, 95% CI 1.9 to 15.9), drinking treated tap water (p<0.0001, OR 1.3, 95% CI 1.1 to 1.5 for each additional glass per day), and eating lettuce (p?=0.01, OR 2.2, 95% CI 1.2 to 4.3) had positive and independent associations with infection. Although case-control studies are prone to bias and the risk of Giardia infection is minimized by water treatment processes, the possibility that treated tap water is a source of sporadic giardiasis warrants further investigation.     

Risk factors for the occurrence of sporadic Salmonella enterica serotype enteritidis infections in children in France: a national case-control study

To determine risk factors associated with the occurrence of sporadic cases of Salmonella enteritidis infections among children in France, we conducted a matched case-control study. Cases were identified between 1 March and 30 September 1995. One hundred and five pairs of cases and controls matched for age and place of residence were interviewed. In the 1-5 years age group, illness was associated with the consumption of raw eggs or undercooked egg-containing foods (OR 2.4, 95% CI 1.2-4.8). Storing eggs more than 2 weeks after purchase was associated with Salmonella enteritidis infection (OR 3.8, 95% CI 1.4-10.2), particularly during the summer period (OR 6.0, 95% CI 1.3-26.8). Cases were more likely to report a case of diarrhoea in the household 10-3 days before the onset of symptoms, particularly in the age group < or = 1 year (P = 0.01). This study confirms the link between eggs and the occurrence of sporadic cases of Salmonella enteritidis among children, highlights the potential role of prolonged egg storage and underlines the role of person-to-person transmission in infants.