Sporadic salmonellosis in Lower Saxony, Germany, 2011-2013: raw ground pork consumption is associated with Salmonella Typhimurium infections and foreign travel with Salmonella Enteritidis infections.

To investigate risk factors for sporadic salmonellosis, for each notified case four randomly selected population controls matched for age, sex and geographical region were interviewed via self-administered questionnaire. Conditional logistic regression analysis of 285 matched pairs revealed significant associations for raw ground pork consumption [odds ratio (OR) 6·0, 95% confidence interval (CI) 1·8-20·1], taking antacids (OR 5·8, 95% CI 1·4-24·5), eating meat outside the home (OR 5·7, 95% CI 2·2-14·6) and daily changing or cleaning of dishcloth (OR 2·1, 95% CI 1·2-3·9). Animal contact and ice cream consumption were negatively associated with salmonellosis (OR 0·5, 95% CI 0·2-1 and OR 0·3, 95% CI 0·1-0·6, respectively). S. Typhimurium infections were significantly associated with raw ground pork consumption (OR 16·7, 95% CI 1·4-194·4) and S. Enteritidis infections with having travelled abroad (OR 9·7, 95% CI 2·0-47·3). Raw egg consumption was not a risk factor, substantiating the success of recently implemented national control programmes in the poultry industry. Unexpectedly, hygienic behaviour was more frequently reported by cases, probably because they overestimated their hygiene precautions retrospectively. Although animal contact might enhance human immunocompetence, underreporting of salmonellosis by pet owners could have occurred. Eating raw pork products is the major risk factor for sporadic human S. Typhimurium infections in Lower Saxony.

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.

[The EHEC O104:H4 outbreak in Germany 2011 - lessons learned?!]. / Der EHEC O104:H4 Ausbruch 2011 in Deutschland - Lektion gelernt?!

The EHEC O104:H4 outbreak 2011 in Germany provided numerous insights into the recognition and control of such epidemic situations. Food-borne outbreaks and their related dynamics may lead to a critical burden of disease and an eventual capacity overload of the medical care system. Possible difficulties in the microbiological diagnostics of new or significantly altered infectious agents may result in a delayed detection of the outbreak as well as the launching of interventional measures. Besides an early notification of the local public health office by the affected institutions, in which a complete electronic procedure and additional sentinel or surveillance instruments (e. g., in emergency departments of hospitals) may be of great help, an interdisciplinary cooperation of the local public health and food safety agencies is the key to an effective outbreak control. Corresponding organizations on the state and federal level should support the investigation process by microbiological diagnostics and advanced epidemiological analysis as well as examination of the food chains. Finally, successful crisis communication relies on "speaking with one voice" (not necessarily one person). Immediate, transparent, appropriate and honest information of the general public concerning the reasons, consequences and (counter-) measures of a crisis are the best means to keep the trust of the population and to counteract the otherwise inevitable speculations.

Subtype specific risk factor analyses for sporadic human salmonellosis: a case-case comparison in Lower Saxony, Germany.

With the intention to deepen the knowledge of the vertical transmission of particular subtypes of Salmonella enterica from "the stable to the table" a case1-case2 analysis in Lower Saxony, Germany, was conducted. The data collection was based on standardised telephone interviews with 1741 Salmonella case persons. Single-factor-analyses revealed statistically significant associations between S. Typhimurium infections and animal keeping (odds ratio (OR): 1.4; 95%-Confidence-interval (CI): 1.2-1.7), especially rodents (OR 1.5; CI 1.2-2.1), and with consumption of meat (OR 1.9; CI 1.3-2.8), raw ground pork (OR 3.0; CI 2.1-4.2) and uncooked pork sausage (OR 2.1; CI 1.6-2.9). The S. Typhimurium phage type DT 104 was associated most with consumption of uncooked pork sausage (OR 3.6; CI 1.3-8.5). Multiple logistic regression analyses confirmed the associations between S. Typhimurium infection and consumption of raw ground pork and with animal contact. The results circumstantiate the assumption of raw pork products still being a relevant source for S. Typhimurium infections in Germany. Therefore, it is recommended to intensify efforts to reduce salmonella infections caused by raw pork products. S. Enteritidis infection was associated statistically significantly with travelling abroad (OR 2.1; CI 1.6-3.3), consumption of raw tomatoes (OR 1.8; CI 1.5-2.1), dried herbs (OR 2.1; CI 1.0-1.8), and undercooked eggs (OR 1.3; CI 1.1-1.6) compared with other serovars. These results were confirmed in multiple logistic regression analyses, as well.

Risk factors associated with sporadic salmonellosis in adults: a case-control study.

In order to identify and assess recent risk factors for sporadic human infections with Salmonella enterica, we conducted a case-control study in Lower Saxony, Germany. The data collection was based on standardized telephone interviews with 1017 cases and 346 controls aged >14 years. Odds ratios were calculated in single-factor and multi-factor analyses for Salmonella cases and two different control groups, i.e. population controls and controls with rotavirus infection. Multi-factor analysis revealed associations between sporadic Salmonella infections for two exposures by both sets of controls: consumption of raw ground pork [adjusted odds ratio (aOR) 2·38, 95% confidence interval (CI) 1·27-4·44] and foreign travel (aOR 2·12, 95% CI 1·00-4·52). Other exposures included consumption of food items containing eggs (aOR 1·43, 95% CI 0·80-2·54), consumption of chicken meat (aOR 1·77, 95% CI 1·26-2·50), outdoor meals/barbecues (aOR 3·96, 95% CI 1·41-11·12) and taking gastric acidity inhibitors (aOR 2·42, 95% CI 1·19-4·92), all were significantly associated with respect to one of the two control groups. The impact of consuming food items containing eggs or chicken meat was lower than expected from the literature. This might be a consequence of Salmonella control programmes as well as increased public awareness of eggs and chicken products being a risk factor for salmonellosis. Efforts to reduce Salmonella infections due to raw pork products should be intensified.

MRSA-ST398 in livestock farmers and neighbouring residents in a rural area in Germany.

Prevalence of and risk factors associated with MRSA-ST398 carriage in 1872 (response 70%) farmers and neighbouring residents in a pig- and poultry-dense area in Germany were investigated using a cross-sectional study and self-sampling nasal swabs. In the population, 1% without occupational livestock contact and 24% with occupational livestock contact tested positive for MRSA-ST398. The group without occupational livestock contact was 3·8 times [95% confidence interval (CI) 1·5-9·3] more likely to be colonized if a household member had livestock contact and 3·2 times (95% CI 1·4-7·4) more likely if they regularly made private farm visits (e.g. to buy eggs or milk). In the group with occupational livestock contact, pig contact had an odds ratio of 7·1 (95% CI 2·9-17·2) for MRSA-ST398 acquisition. This is the first study to associate private farm visits with acquisition of MRSA; more research to explore the exact transmission routes is necessary.

[Antimicrobial resistance monitoring in Lower Saxony (ARMIN): first trends for MRSA, ESBL-producing Escherichia coli and VRE from 2006 to 2010]. / Antibiotika-Resistenz-Monitoring in Niedersachsen (ARMIN): Erste Trends für MRSA, ESBL-bildende Escherichia coli und VRE in den Jahren 2006-2010.

Antimicrobial resistance is one of the most important health topics of the past few years. To identify regional trends of antimicrobial resistance in inpatient and outpatient care, the Governmental Institute of Public Health of Lower Saxony (Germany) launched the sentinel system ARMIN (Antimicrobial Resistance Monitoring in Lower Saxony). Currently 9 laboratories participate as sentinel sites and contribute single case data of their microbiological results. Data are presented by an interactive data query in the internet. From 2006 to 2010 laboratories reported about 800 000 diagnostic test results. The proportion of MRSA (methicillin-resistant Staphylococcus aureus) among all Staphylococcus aureus increased from 19.5% in 2006 to 23.4% in 2010 for inpatient care in Lower Saxony. During the same period Escherichia coli resistance to cefotaxime for inpatient care increased from 3.0% to 8.8%. Enterococcus faecium resistance to vancomycin decreased from 13.6% to 5.6%. Currently the emphasis of ARMIN is on the description of trends and on the information of prescribing physicians. A quality circle was established to improve standardisation.

[Comparison of the tuberculin skin test with the interferon-gamma test in the framework of a surroundings investigation in a prison]. / Vergleich von Tuberkulin-Hauttests und Interferon-Gamma-Tests im Rahmen einer Umgebungsuntersuchung in einer JVA.

After the occurrence of a multidrug-resistant tuberculosis in a prison of Lower Saxony (Germany), 223 contact persons (178 inmates, 45 staff members) were identified. To detect latent tuberculosis infections, all contact persons were tested with the tuberculin skin test (TST) and the interferon-gamma release assay (IGRA). An additional standardised questionnaire on anamnestic information and risk factors was completed by the participants. The statistical analysis included 149 male inmates with a mean age of 39 years. 61.1% of the inmates were born in Germany, 14.8% were born in the USSR or, respectively, its follow-up states. With the TST 29.5% of the inmates were tested positive, whereas with the IGRA the positive rate was 18.1%. For 7 inmates there was a positive IGRA despite a negative TST. The positive predictive value of TST with respect to IGRA was 45.5%, agreement was 79.2% (kappa=0.44). The agreement found in this study is comparable to studies within populations with lower incidence. Numerous investigations outside Europe indicate a high risk of tuberculosis infection among inmates.

[Protracted nosocomial outbreak of Salmonella Enteritidis LT 8/7]. / Protrahiert verlaufender nosokomialer Ausbruch von Salmonella Enteritidis LT 8/7.

INTRODUCTION: In spring 2007a cluster of nosocomial salmonellosis cases, culture confirmed for SALMONELLA Enteritidis lysotype (LT) 8/7, occurred in a Wolfsburg hospital. An outbreak investigation was initiated to determine the epidemiology of the outbreak and to identify and control the possible sources. METHODS: A multidisciplinary outbreak team was formed including members from hospital hygiene and local, state and national health and veterinarian authorities. Active surveillance was set up in the hospital to find new cases. A retrospective case control study was conducted to identify possible risk factors for disease. Hospital workers and food samples were tested for the pathogen and positive isolates were typed. RESULTS: Between calendar weeks 4 and 24 of the year 2007, a total of 28 patients with a median age 66 years had nosocomial salmonellosis culture confirmed for SALMONELLA Enteritidis LT 8/7. In food samples from February, the same Salmonella lysotype was isolated in 4 different food samples. SALMONELLA Enteritidis LT 8/7 was also identified in stool samples from 5 kitchen personnel. The case control study indicated antacida therapy (odds ratio: 5.5, 95 % CI 1.2 - 26.0) as a risk factor for nosocomial salmonellosis among patients. No particular diet was associated with an increased risk of disease. DISCUSSION: This nosocomial salmonellosis outbreak was characterised by prolonged duration and a low infection rate among patients. The epidemiological investigation suggests that the origin of the outbreak was food that was probably associated with a contamination in the hospital kitchen. Furthermore, kitchen staff could, as carriers, have contributed to a low-level contamination of various foods for a long period. The intermittent occurrence of the cases is best explained by a low level of contaminated food which primarily led to clinical symptoms among especially vulnerable persons (older patients with antacida therapy). Considering the unusual progression of this outbreak, hospitals should initiate an intensive epidemiological and microbiological investigation, even if only few nosocomial salmonellosis cases occur.

[Regionally increased incidence of notified cryptosporidiosis cases due to different laboratory methods]. / Regional erhöhte Inzidenz gemeldeter Kryptosporidiosen durch unterschiedliche Laborroutinen.

INTRODUCTION: In Lower Saxony, during 2001 to 2005, 744 cases of cryptosporidiosis were reported according to the Protection against Infection Act to the Governmental Institute of Public Health of Lower Saxony. The yearly incidence rate of 1.9 notified cases per 100,000 population exceeded the German mean incidence rate of 1.5. Within Lower Saxony, there was a striking heterogeneity of regional incidences with rates greater than 10.0 in several neighbouring districts. METHODS: A retrospective case control study was conducted in cooperation with the health departments of the 5 mostly affected districts to test the hypothesis that diagnostic effects might have caused this regional cluster. Notified cryptosporidiosis cases of the years 2002 and 2003 were analysed with respect to the notifying physicians and laboratories. Notified cases of salmonellosis and campylobacteriosis were taken as controls. Controls were matched to the cases with respect to age, sex, district, and year of notification. RESULTS: Of the 146 cryptosporidiosis cases included in the case control study, 130 (89%) were diagnosed and reported by only one laboratory. In contrast, of the controls only 31% were reported by this laboratory. The matched odds ratio for this laboratory was 43.5 (95% confidence interval: 10.7-177; p<0.001). DISCUSSION: The case control study revealed a significant association of the cryptosporidiosis notifications with one particular laboratory. Confounding by co-variables like age or district could be excluded due to matching. In this laboratory all stool samples submitted for routine microbiological diagnosis were screened for Cryptosporidium parvum. Diagnostic work was done by valid, specific, CE-certified procedures. We conclude that the increased regional incidence rate caused by the broader diagnostic activity of this laboratory rather reflects the real occurrence of this infection. Hence, in other regions with lower incidence rates of notified cases an underestimation can be presumed.

[Surveillance of infectious foodborne diseases after enactment of the German Protection against Infection Act in 2001. Potentials and requirements]. / Surveillance Lebensmittel-übertragener Infektionserkrankungen durch das Infektionsschutzgesetz: Möglichkeiten und Anforderungen.

The epidemiology of infectious foodborne diseases has changed. Outbreaks more frequently occur geographically dispersed or protractedly over longer periods of time, and they often appear as a scatter of seemingly sporadic cases. This hampers and delays the identification of their epidemiological link. The surveillance of infectious foodborne diseases has to be refined accordingly to be able to detect these diffuse outbreaks. The German Protection against Infection Act, enacted in 2001, offers the potential of increased sensitivity due to timely electronic reporting of individual cases and detailed data accompanying each report. In addition to a timely and comprehensive reporting system, subtyping of pathogens has become an invaluable tool in identifying epidemiologically linked cases, i.e. outbreaks. Still, the sensitivity of foodborne disease surveillance still hinges on the willingness of physicians to order stool testing for enteric pathogens (and to report suspected outbreaks to local health departments). Without the active participation of physicians, the chance of detecting outbreaks and successfully investigating them is markedly reduced. Consequently, the general preventive strategy would be jeopardised, namely to understand the (often new) mechanisms by which contamination and disease transmission occur well enough to interrupt them.

[Surveillance of acute respiratory illnesses (ARI) in Lower Saxony: first experience from the years 2005-2006]. / Surveillance akuter respiratorischer Erkrankungen (ARE) in Niedersachsen: Erste Erfahrungen aus den Jahren 2005-2006.

In the context of influenza pandemic preparedness planning, a surveillance system for influenza and other acute respiratory illnesses was implemented in Lower Saxony at the beginning of the influenza season 2004/2005 and coordinated by the Governmental Institute of Public Health of Lower Saxony. This surveillance system represents an addition to already existing national monitoring systems. The goal of this surveillance system is to have available prompt information on the beginning, course and end of the influenza season and to recognise the spectrum of pathogens and identify outbreaks of other viral acute respiratory illnesses (ARI). For this purpose an all-season surveillance was established consisting of two supplementary modules. The first module is a symptom-oriented surveillance of acute respiratory illnesses in children of pre-school day care facilities. In the second module a virological surveillance in co-operation with selected medical practices was established. While the temporal course and burden of ARI in all Lower Saxony can be assessed by the surveillance of children in the day-care facilities in a sensitive, but less specific way, the virological surveillance provides highly specific information on the prevailing pathogens in ARI patients at a certain time. This information, in return, gives an indication about the responsible pathogens causing ARI in children of the day-care facilities. The first experience with these two complementary surveillance modules shows that in Lower Saxony a well accepted, prompt and meaningful monitoring system is available for the recognition and description of the occurrence of ARI and concomitantly of influenza. An extension of this surveillance to other pathogens or disease scenarios is possible.

[The epidemiology of human enterohemorrhagic Escherichia coli infections in Lower Saxony]. / Zur Epidemiologie humaner enterohämorrhagischer Escherichia coli-Infektionen in Niedersachsen.

BACKGROUND: In the German federal state Lower Saxony, data on infections with enterohemorrhagic Escherichia coli (EHEC) and hemolytic uremic syndrome (HUS) are collected systematically since 1997 based on reports by physicians and laboratories. Initially the data were collected by means of a specific established surveillance system, since 2001 they are collected as part of the new infectious disease law. RESULTS: From 1997 to 2003, in Lower Saxony 880 EHEC-infections and 112 HUS-cases, 6 of whom died, were notified. This corresponds to an incidence of 1.6 EHEC-infections and 0.2 HUS-cases per 100000 person-years. No secular trend was observ-ed for the yearly number of HUS-cases, but raised numbers were observed for the years 1997 and 2002. There were strong regional differences of the EHEC/HUS-incidence from 0.7 in the district Braunschweig to 3.5 in the district Weser-Ems. For 56% of reported EHEC-cases, serotype information was available. The most frequent serogroup was O157, accounting for 30% of cases with serotype information. Of HUS-cases with known serotype, 86% were caused by O157, 20% by O157:H-. 52% of the EHEC-cases were less than 5 years old (HUS: 77%), and 68% less than 10 years (HUS: 92%). 23% of EHEC/HUS-cases could be identified as part of clusters with a mean number of 2.6 cases per cluster. These clusters almost exclusively affect-ed families. Though the data also contained information on possible sources or routes of infection, for none of the cases a microbiologically assured source was documented. CONCLUSIONS: The incidences of EHEC and HUS were higher in Lower-Saxony than in the whole of Germany. During the study period no significant trends concerning the number of HUS-cases or the distribution of serotypes were observed. More frequent serotyping and more complete information on sources or risks of infection should be achieved.

[Surveillance of gastroenteritic infections in lower Saxony: results and experiences from a regional public-health project over six years]. / Gastroenteritis-Surveillance in Niedersachsen: Ergebnisse und Erfahrungen aus einem sechsjährigen OGD-Regionalprojekt.

In Lower Saxony, a regional public health project on a pathogen-specific surveillance of Enteritis infectiosa was carried out from 1994 to 2000. In a separate reporting procedure thirteen health departments transmitted data on the specific pathogen collected from laboratory reports for a joint analysis. The results were distributed among the participants, providing them with information on the situation and trends in their districts and in addition giving them the possibility to compare their data with those of other districts. The incidence of Enteritis infectiosa was 199 reported cases per 100,000 person years. Salmonella was reported most frequently (51 %; S. enteritidis: 33 %, S. TYPHIMURIUM: 14 %, 111 other serotypes: 4 %), followed by Campylobacter (18 %), Rotavirus (17 %), Yersinia enterocolitica (6 %) and Adenovirus (5 %). The incidences of Salmonella and Yersinia enterocolitica were found to be nearly constant over the project period while the incidences of Campylobacter, Rotavirus and Adenovirus increased. This, however, may be due to intensified diagnostics and better reporting behaviour rather than to a real increase. The incidence rates and their trends differed from other German states. This observation emphasizes the need for a regional analysis of infectious disease surveillance data.

Rapid detection of enterohemorrhagic Escherichia coli by real-time PCR with fluorescent hybridization probes.

In this report, we present a PCR protocol for rapid identification of enterohemorrhagic Escherichia coli on a LightCycler instrument. In a multiplex assay, the genes encoding Shiga toxin 1 and Shiga toxin 2 are detected in a single reaction capillary. A complete analysis of up to 32 samples takes about 45 min.

[Investigation of foodborne outbreak due to Salmonella infantis using epidemiological and microbiological methods]. / Untersuchung einer lebensmittelbedingten Salmonella infantis-Gruppenerkrankung mit Methoden der Epidemiologie und Mikrobiologie.

In foodborne outbreaks, direct microbiological diagnosis is often not possible due to lack of remaining food samples. Therefore, in this investigation of an outbreak of Salmonella infantis at a fair, we chose an epidemiological approach in addition to microbiological testing. In a case control study, fair participants with symptoms of acute gastroenteritis as well as participants showing no signs of disease were interviewed by telephone. Questions concerning what food had been eaten at the fair and the course of disease had priority. Data analysis showed a significantly elevated odds ratio of 144 (p < 0.00001) for the consumption of potato salad. Salmonella infantis was cultured in faeces of symptomatic individuals as well as from left-over potato salad in high concentration. In conclusion, our data show that the cause of a foodborne outbreak can be detected through the application of epidemiologic methods with a high degree of certainty. In order to eliminate memory bias, a structured interview should be carried out as soon as possible after the initial outbreak.

[Environmental studies of asymptomatic kindergarten children as carriers of enterohemorrhagic Escherichia coli (EHEC) in the Ammerland district]. / Umgebungsuntersuchungen bei asymptomatischen Kindergartenkindern als Ausscheider von enterohämorrhagischen Escherichia coli (EHEC) im Landkreis Ammerland.

The increase of serious EHEC diseases in the northwest Lower Saxony in summer 1997 was accompanied by a lively discussion on the hazard represented by this pathogen which gained a large amount of media attention. The Lower Saxony Public Health Department initiated a study of this case in the Weser-Ems government district to investigate the spread of EHEC by children and their supervisors in kindergartens receiving certified raw milk supply. This established that there were ten kindergarten children in the Ammerland rural district who were asymptomatik EHEC carriers. The Local Public Health Department immediately carried out the necessary epidemic hygiene measures. First of all, control investigations were performed on the affected children, including environmental investigations on their families and contracts. The results of these investigations revealed the need to carry out additional environmental investigations in two kindegartens (follow-up investigations) as well as amongst employees in a hospital canteen. Within the families, a mother of an affected child was also identified as another asymptomatic EHEC carrier. However, the strains that were isolated reflected different serotypes. In total, the investigation of 337 people in contact with the eleven asymptomatic EHEC carriers did not confirm any person-to-person transmission--even though three of the kindergarten children shedding the organisms for 6-10 weeks attended the kindergartens for at least 4 weeks. No EHEC disease occurred in the communal facilities, neither were any positive cases identified by additional control investigations. The results indicate a probable lower rate of infectiousness by healthy EHEC carriers than was previously thought to be the case. Further studies are needed to decide if in future one should proceed on a case by case basis when considering the reauthorization of affected children and other people to enter communal facilities.

[Epidemiologic and actual importance of entero-hemorrhagic E. coli in Northern Bavaria (1996)]. / Zur Epidemiologie und aktuellen Bedeutung enterohämorrhagischer Escherichia coli (EHEC) in Nordbayern (1996).

Following an epidemic occurrence of EHEC infections (1995-1996) Bavaria enacted legislation to survey EHEC. In consequence thereof there was an extraordinary increase in examinations for this pathogen at the Landesuntersuchungsamt für das Gesundheitswesen Nordbayern in Erlangen. Of 2712 stool specimens 2% were positive for EHEC. At first an enzyme immunoassay (EIA) was used in screening for Shiga toxin (Stx) 1 and 2. Because this EIA revealed a lack of specificity the PCR for amplification of sequences derived from Stx genes was set as screening test. Among 53 EHEC strains isolated by colony hybridisation 25 different serotypes could be identified. A complete virulence pattern (formation of Shiga toxins and EHEC haemolysin, presence of the eaeA gene) was detected in 3 of 4 strains from HUS patients (75%), in 14 of 17 enteritis cases (82.4%) and in 17 of 32 persons with asymptomatic carriage (53.1%). Besides the serotypes O157H- and O103H2 strains of the serotype 08 were isolated particularly frequently in certain regions of North Bavaria for limited periods. EHEC infections in North Bavaria are related to many serotypes that are mostly different from the O157 serotype. Especially in adults the clinical course is usually asymptomatic.