Andrea Ammon

Escherichia coli harboring Shiga toxin 2 gene variants: frequency and association with clinical symptoms

Shiga toxin (Stx)-producing Escherichia coli (STEC) from patients with hemolytic-uremic syndrome (HUS), patients with diarrhea without HUS, or asymptomatic subjects were genotyped to assess associations between stx2 variants and clinical manifestations of infection. Neither stx2d nor stx2e was found in 268 STEC isolates from patients with HUS. Of 262 STEC isolates from patients with diarrhea, stx(2d) was found in 41 (15.6%; P<.000001), and stx2e was found in 12 (4.6%; P=.0004). The stx2c genotype frequency was similar among isolates from patients with HUS (3.7%) and diarrhea (5.0%). The frequencies of stx2c, stx2d, and stx2e among 96 STEC isolates from asymptomatic subjects were comparable to those among isolates from patients with diarrhea. None of the 626 STEC isolates contained stx2f. All stx2d-positive or stx2e-positive STEC isolates were eae negative and originated from subjects older than those with STEC isolates with stx2c. stx2c-positive STEC isolates can cause HUS, but the presence of stx2d or stx2e may predict a milder disease with a minimal risk of HUS.

International outbreak of Salmonella Oranienburg due to German chocolate

BackgroundThis report describes a large international chocolate-associated Salmonella outbreak originating from Germany.MethodsWe conducted epidemiologic investigations including a case-control study, and food safety investigations. Salmonella (S.) Oranienburg isolates were subtyped by the use of pulsed-field gel electrophoresis (PFGE).ResultsFrom 1 October 2001 through 24 March 2002, an estimated excess of 439 S. Oranienburg notifications was registered in Germany. Simultaneously, an increase in S. Oranienburg infections was noted in other European countries in the Enter-net surveillance network. In a multistate matched case-control study in Germany, daily consumption of chocolate (matched odds ratio [MOR]: 4.8; 95% confidence interval [CI]: 1.3–26.5), having shopped at a large chain of discount grocery stores (MOR: 4.2; CI: 1.2–23.0), and consumption of chocolate purchased there (MOR: 5.0; CI: 1.1–47.0) were associated with illness. Subsequently, two brands from the same company, one exclusively produced for that chain, tested positive for S. Oranienburg. In two other European countries and in Canada chocolate from company A was ascertained that also contained S. Oranienburg. Isolates from humans and from chocolates had indistinguishable PFGE profiles. No source or point of contamination was identified. Epidemiological identification of chocolate as a vehicle of infections required two months, and was facilitated by proxy measures.ConclusionsDespite the use of improved production technologies, the chocolate industry continues to carry a small risk of manufacturing Salmonella-containing products. Particularly in diffuse outbreak-settings, clear associations with surrogates of exposure should suffice to trigger public health action. Networks such as Enter-net have become invaluable for facilitating rapid and appropriate management of international outbreaks.

A Large Outbreak of Hemolytic Uremic Syndrome Caused by an Unusual Sorbitol-Fermenting Strain of Escherichia coli O157:H—

Escherichia coli O157:H7 does not ferment sorbitol, a factor used to differentiate it from other E. coli. From December 1995 to March 1996, 28 children with hemolytic uremic syndrome in Bavaria, Germany, were identified; many had a sorbitol-fermenting (sf) E. coli O157:H- cultured. A case-control study showed a dose-response relationship between sausage consumption and illness. A second case-control study showed a relationship between mortadella and teewurst consumption and illness, particularly during December (mortadella odds ratio [OR], 10.5, P=.004; teewurst OR, 6.2, P=.02). Twelve sf O157:H- were characterized to determine clonality and virulence traits. The strains possessed the Stx2, eae, and EHEC-hlyA genes but were nonhemolytic on blood agar plates. The O157:H- isolates belonged to phage type 88 and had identical pulsed-field gel electrophoresis patterns. This outbreak was caused by sf E. coli O157:H-, which is not detectable by culture on sorbitol MacConkeys agar. Consumption of two sausages, including a raw beef-containing sausage, was statistically related to illness.

Risk Factors for Alveolar Echinococcosis in Humans

A case-control study of alveolar echinococcosis cases in Germany identifies several risk factors for the disease.

Strong Association Between Shiga Toxin-Producing Escherichia coli O157 and Virulence Genes stx2 and eae as Possible Explanation for Predominance of Serogroup O157 in Patients with Haemolytic Uraemic Syndrome

Abstract The aim of this study was to investigate the association between Shiga toxin-producing Escherichia coli (STEC) O157 and the simultaneous presence of the virulence genes stx2 and eae in STEC from patients with gastroenteritis. In Germany, the proportion of serogroup O157 is substantially higher among STEC isolates from patients with haemolytic uraemic syndrome (HUS) than among STEC isolates from patients with gastroenteritis. The reason for this is unknown. Independent of serogroup, the virulence genes stx2 and eae have been associated with severe disease. Data collected in 2000–2001 from a Germany-wide laboratory-based surveillance system for STEC-associated gastroenteritis in patients <15 years were analysed. Overall, 18% of the STEC isolates belonged to serogroup O157. Compared with non-O157 strains, 0157 isolates were strongly associated with the simultaneous presence of both an stx2 gene and the eae gene (OR, 76; 95%CI, 27–230). Within the subset of STEC isolates that carried both virulence genes, 60% belonged to serogroup O157, a proportion similar to that found in STEC isolates from pediatric patients with HUS in Germany and Austria (67%, P=0.35). These data suggest that the more frequent carriage of both virulence genes, i.e. stx2 and eae, forms the basis of why STEC O157 predominates in patients with HUS.

SurvNet@RKI--a multistate electronic reporting system for communicable diseases.

In 2001 Germany implemented a new electronic reporting system for surveillance of notifiable infectious diseases (SurvNet@RKI). The system is currently being used in all 431 local health departments (LHD), the 16 state health departments (SHD) and the Robert Koch-Institut (RKI), the national agency for infectious disease epidemiology. The SurvNet@RKI software is written in MS Access 97 and Visual Basic and it supports MS Access as well as MS SQL Server database management systems as a back-end. The database is designed as a distributed, dynamic database for 73 reporting categories with more than 600 fields and about 7000 predefined entry values. An integrated version management system documents deletion, undeletion, completion and correction of cases at any time and entry level and allows reproduction of previously conducted queries. Integrated algorithms and help functions support data quality and the application of case definitions. RKI makes the system available to all LHDs and SHDs free of charge. RKI receives an average of 300 000 case reports and 6240 outbreak reports per year through this system. A public web-based query interface, SurvStat@RKI, assures extensive and timely publication of the data. During the 5 years that SurvNet@RKI has been running in all LHDs and SHDs in Germany it has coped well with a complex federal structure which makes this system particularly attractive to multinational surveillance networks. The system is currently being migrated to Microsoft C#/.NET and transport formats in XML. Based on our experiences, we provide recommendations for the design and implementation of national or international electronic surveillance systems.

SurvNet Electronic Surveillance System for Infectious Disease Outbreaks, Germany

Electronic Surveillance System for Infectious Disease Outbreaks, Germany This system has managed detailed information on 30,578 disease outbreaks.

Cross-Sectional Study on Influenza Vaccination, Germany, 1999-2000

To assess influenza vaccination coverage in Germany, we conducted a nationwide telephone survey in November 1999 in adults (>18 yrs) using random-digit dialing. Overall, 23% of 1,190 survey participants reported having been vaccinated (adjusted 18%) with 16% (adjusted 15%) in former West Germany versus 35% (adjusted 32%) in former East Germany. Immunization rates for vaccination target groups were lower in West Germany (21%) than in East Germany (40%). Seven percent of health-care workers were immunized. Previous influenza vaccination, positive attitudes towards immunization, and having a family physician increased the rate of vaccination; fear of adverse effects lowered the rate. Family physicians performed 93% of the vaccinations, which suggests their key role in improving low vaccination coverage in Germany. The fact that >71% (850/1,190) of participants belonged to at least one of the vaccination target groups recommended by the German Standing Commission on Immunization emphasizes the need to focus the definition of target groups.

Sorbitol-fermenting enterohaemorrhagic Escherichia coli O157:H- causes another outbreak of haemolytic uraemic syndrome in children.

An outbreak of haemolytic uraemic syndrome (HUS) among children caused by infection with sorbitol-fermenting enterohaemorrhagic Escherichia coli O157:H- (SF EHEC O157:H-) occurred in Germany in 2002. This pathogen has caused several outbreaks so far, yet its reservoir and routes of transmission remain unknown. SF EHEC O157:H- is easily missed as most laboratory protocols target the more common sorbitol non-fermenting strains. We performed active case-finding, extensive exploratory interviews and a case-control study. Clinical and environmental samples were screened for SF EHEC O157:H- and the isolates were subtyped by pulsed-field gel electrophoresis. We identified 38 case-patients in 11 federal states. Four case-patients died during the acute phase (case-fatality ratio 11%). The case-control study could not identify a single vehicle or source. Further studies are necessary to identify the pathogens reservoir(s). Stool samples of patients with HUS should be tested with an adequate microbiological set-up to quickly identify SF EHEC O157:H-.

Hepatitis B and C among Berlin dental personnel: incidence, risk factors, and effectiveness of barrier prevention measures.

A study of 215 Berlin dentists and 108 dental assistants recruited at the 1997 Berlin Dental Society meeting assessed their occupational risk of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. HBV vaccine coverage, and barrier prevention methods used. Among dentists, 7% (95% CI 4-11) and 0.5% (95% CI 0-3) had serological evidence of previous HBV and HCV infection, respectively. Similar figures for dental assistants were 1% (95% CI 0-5) and 0% (95% CI 0-4). Only 74% of dentists and 63% of dental assistants reported HBV vaccination. Approximately half always used gloves, eye glasses, or face masks. HBV unvaccinated dentists whose patients had HBV risk factors had a greater risk of HBV infection; those who always wore face masks were at lower risk (OR 0.2, 95% CI 0.02-0.98). These data indicate that among Berlin dentists, the HCV risk was lower than that of HBV and that face masks may have lowered the risk of HBV. The use of eye glasses or gloves did not appear to lower the risk of HBV acquisition in this population.