Incidence and risk factors for community-acquired acute gastroenteritis in north-west Germany in 2004.

In developed countries, acute gastroenteritis (AGE) is a major source of morbidity. However, only a few studies have estimated its incidence and the associated medical burden. This population-based study determined the incidence of community-acquired AGE patients seeking medical care and the relative role of various pathogens. Stool samples from patients with AGE presenting to a general practitioner (GP), pediatrician, or specialist in internal medicine for that reason were screened for various bacterial and viral enteropathogens. A control group was established as well. Incidences were calculated by the number of positive patients divided by the general population. The study was performed in north-west Germany in 2004. The incidence of AGE patients requiring medical consultation was 4,020/100,000 inhabitants. Children (<5 years of age) were at the highest risk (13,810/100,000 inhabitants). Of the patients, 6.6% were tested positive for an enteropathogenic bacteria and 17.7% for a viral agent. The predominant pathogens were norovirus (626/100,000) and rotavirus (270/100,000). Salmonella was the most frequently detected bacteria (162/100,000). The results presented confirm AGE and, specifically, AGE of viral origin as a major public health burden in developed countries.

[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.

Molecular epidemiology of Salmonella enterica serovar Agona: characterization of a diffuse outbreak caused by aniseed-fennel-caraway infusion.

During 2002-2003 increased numbers of notified salmonellosis due to S. enterica serovar Agona were observed in Germany. In order to understand the recent spread of this serovar and to trace the route of infection to its source, a new phage-typing scheme and pulsed field gel electrophoresis (PFGE) were used to analyse these isolates. By using 14 bacteriophages, 52 phage types were distinguished among the S. Agona strains. PFGE also differentiated 52 different patterns. A combination of both methods generated 94 clonal types among 165 S. Agona strains originating from Germany and other countries including the United States, United Arab Emirates, Turkey, India, Austria and Finland, indicating a great biological diversity within this serovar. However, 36 recent S. Agona isolates from infantile gastroenteritis in Germany, from an untreated batch of aniseed imported from Turkey and from fennel-aniseed-caraway infusion (packed in tea bags) revealed clonal identity indicating their epidemiological relatedness as a new source of infection. It is suggested that strains of S. Agona will continue to be of public health concern, and that phage typing together with PFGE typing should be applied as reliable and rapid tools for epidemiological subtyping and future monitoring.

[Intestinal yersiniosis. Clinical importance, epidemiology, diagnosis, and prevention]. / Enterale Yersiniosen. Klinische Bedeutung, Epidemiologie, Diagnostik und Prävention.

Yersinia enterocolitica and Y. pseudotuberculosis are causative agents of yersiniosis in humans and animals that have to be separated from Y. pestis, the causative agent of plague, representing a separate clinical and epidemiological entity. Intestinal yersiniosis may manifest in humans as (1) enteritis, (2) terminal ileitis, mesenteric lymphadenitis, or pseudoappendicitis, and (3) septicemia leading to focal abscesses in spleen and liver. The intestinal infection may be followed by reactive arthritis in a number of cases. Y. enterocolitica and Y. pseudotuberculosis are distributed worldwide but occur mainly in moderate or subtropical climates. The most important reservoirs are rodents, lagomorphs, and birds for Y. pseudotuberculosis and domestic animals, especially pigs, for Y. enterocolitica. All Y. pseudotuberculosis isolates may be considered as pathogenic whereas Y. enterocolitica strains can be subdivided into pathotypes of different virulence. The differentiation of pathotypes by determination of the biovar and demonstration of the 75-kb virulence plasmid is therefore of diagnostic importance. Preventive measures include avoidance of direct infection by contact with infected reservoir animals and practice of good hygiene during slaughtering as well as in food production and preparation of meals.

A long-term study on the prevalence of shiga toxin-producing Escherichia coli (STEC) on four German cattle farms.

The occurrence of Shiga toxin-producing Escherichia coli (STEC) was studied on four cattle farms. STEC were detected in 29-82% of the cattle. STEC with additional EHEC markers were detected on all farms. The occurrence of the complete virulence marker pattern (stx1 and/or stx2, eae, EHEC(hlyA), katP, espP) was correlated with the presence of known STEC serotypes. STEC O26:H11 and O165:H25 with the complete pattern of virulence markers were the most prevalent. STEC O157 (H7/H-) STEC O103:H2 and STEC O145:H- were found sporadically. Five clonal subgroups of the STEC O26:H11 isolates were identified by pulsed-field gel electrophoresis. STEC O26:H11 were present in three groups of cattle. This serotype was detected in a single group over the entire fattening period. Most STEC O26:H11 with the complete pattern of potential virulence markers were found in clinically healthy cattle. These animals may represent a risk factor for farmers and consumers.

[Not Available]. / Infektionen des Menschen durch enterohämorrhagische Escherichia coli (EHEC) in der Bundesrepublik Deutschland von 1998 bis 2001 Prävalenz und Typenspektrum : Prävalenz und Typenspektrum.

Intestinal infections in Germany due to enterohemorrhagic E. coli bacteria (EHEC) between 1998 and 2001 reveal a large scale of biological diversity of their pathogens. However, no dramatic increase of their clinical importance and public health implications has been observed. As strains of serovar O157:H7 have continuously declined as causative agents, other serovars such as O26:H11 and O103:H2 have replaced them. The great diversity of the EHEC pathogens might point to a great number of various infection routes and sources. Since recently new pathogenic factors of EHEC bacteria have been detected (especially by the sequencing of the genome of EHEC), it is currently not possible to define a clear-cut difference between human pathogens and nonhuman pathogens. The enhanced surveillance of EHEC pathogens with respect to their biological diversity and dynamics, their epidemic spread, and their infection routes and sources remain an essential task of the public health authorities.

Supplement 2000 (no. 44) to the Kauffmann-White scheme.

This supplement reports the characterization of 12 new Salmonella serovars recognized in 2000 by the WHO Collaborating Centre for Reference and Research on Salmonella: nine were assigned to S. enterica subsp. enterica, two to subspecies salamae, and one to subspecies diarizonae.

Clonal diversity of Shiga toxin-producing Escherichia coli O157:H7/H- in Germany--a ten-year study.

Two hundred and ten E. coli O157:H7/H- strains isolated from single cases and outbreaks of diarrhoea and haemolytic uraemic syndrome (HUS) in Germany between 1988 and 1998 were characterised by a range of molecular subtyping methods and phage typing in order to analyse their clonal nature. A high clonal heterogeneity, together with a considerable clonal stability, has been identified among the bacterial isolates and no single clonal type appeared to be geographically dominant. It is recommended to apply pulsed-field gel electrophoresis (PFGE) together with P gene profile determination (number and genomic positions of lambdoid bacteriophages) as laboratory tools for an extended epidemiological surveillance of E. coli OOFF phage typing will remain helpful as a first line of analysis, particularly in outbreak situations.

Molecular analysis of H antigens reveals that human diarrheagenic Escherichia coli O26 strains that carry the eae gene belong to the H11 clonal complex.

Fifty-seven Escherichia coli O26 strains isolated from patients in six countries were investigated by PCR restriction fragment length polymorphism (RFLP) analysis of the flagellin-encoding (fliC) gene (fliC RFLP analysis). The strains were determined by serotyping to belong to five different H types or were nonmotile. The fliC RFLP analysis revealed only two different patterns among the 57 strains. One fliC RFLP pattern was displayed by 54 strains and was identical to that of E. coli H11 reference strain Su4321-41. The other fliC RFLP pattern was observed for three strains and was identical to that for E. coli H32 reference strain K10. The 54 strains with the H11 fliC RFLP pattern included 22 strains of serotype O26:H11, 23 nonmotile strains, and 9 strains that were initially serotyped as H2, H8, H21, and H32 but that were confirmed to express H11 by repeat serotyping. All 54 strains with the H11 fliC RFLP pattern contained the attaching-and-effacing (eae) gene. The three strains with the H32 fliC RFLP pattern belonged to serotype O26:H32, and all were eae negative. The fliC genes of 14 selected E. coli O26:H11 strains isolated between 1964 and 1999 had identical nucleotide sequences. Our results demonstrate that E. coli O26 strains that carry the eae gene belong exclusively to the H11 clonal complex. Since there were no H11 fliC allelic variations among the O26 strains tested, E. coli O26:H11 may have emerged recently. The fliC PCR-RFLP test is a reliable, easy-to-perform, and rapid method for determination of the H types of E. coli O26 isolates.

Supplement 1998 (no. 42) to the Kauffmann-White scheme.

This supplement reports the characterization of 14 new Salmonella serovars recognized in 1998 by the WHO Collaborating Centre for Reference and Research on Salmonella: 11 were assigned to S. enterica subsp. enterica, one to subspecies salamae, one to subspecies diarizonae, and one to subsp. indica. In addition, the antigenic factor H:z88 is described.

Supplement 1999 (no. 43) to the Kauffmann-White scheme.

This supplement reports the characterization of 26 new Salmonella serovars recognized in 1999 by the WHO Collaborating Centre for Reference and Research on Salmonella: 15 were assigned to S. enterica subsp. enterica, seven to subspecies salamae, two to subspecies diarizonae, and one to subsp. houtenae; and one to S. bongori. In addition, the antigenic factor H:z89 is described.

Typhoid fever due to Salmonella Kapemba infection in an otherwise healthy middle-aged man.

We report the case of a patient with a Salmonella Kapemba infection, who suffered, 3 weeks after a holiday in Israel, occurrences of high fever and lower back pain for 10 days and icterus for 2 days before admission. Laboratory findings revealed a slight cholestasis and elevation of acute phase protein levels. In the blood culture a Salmonella Kapemba-type organism was cultured. The patient was afebrile for 10 days after hospitalization and then suddenly developed a temperature of 40 degrees C again. At the same time leukopenia, thrombocytopenia, and a rise of D-dimer levels were detected. The patient was admitted to the intensive care unit for a few days, because a disseminated intravascular coagulation was suspected. With magnetic resonance imaging and bone scintigraphy no osteomyelitis or abscess formation could be found. A transesophageal ultrasonography of the heart revealed no signs of endocarditis. In multiple stool cultures no salmonellas could be detected. After antibiotic treatment with ciprofloxacin the fever and lower back pain subsided, and the patient was discharged a fortnight later. This is the first reported case of typhoid fever due to the bacterium Salmonella Kapemba.

Supplement 1997 (no. 41) to the Kauffmann-White scheme.

This supplement reports the characterization of 15 new Salmonella serovars recognized in 1997 by the WHO Collaborating Centre for Reference and Research on Salmonella: 8 were assigned to S. enterica subsp. enterica, 4 to subspecies salamae, 2 to subspecies diarizonae, and 1 to subsp. houtenae. In addition, the antigenic factors H:z85 and H:z87 are described and one modification to the Kauffmann-White scheme is reported.

Detection of hemolysin variants of Shiga toxin-producing Escherichia coli by PCR and culture on vancomycin-cefixime-cefsulodin blood agar.

The presence of a hemolysin-encoding gene, elyA or hlyA, from Shiga toxin-producing Escherichia coli (STEC) was detected by PCR in each of 95 strains tested. PCR products of elyA from human STEC isolates of serovars frequently detected in Germany, such as O157:H-, O103:H2, O103:H-, O26:H11, and O26:H-, showed nucleotide sequences identical to previously reported ones for O157:H7 and O111:H- strains. Compared to them, four elyA amplicons derived from human isolates of rare STEC serovars showed identity of about 98% but lacked an AluI restriction site. However, the nucleotide sequence of an amplicon derived from a porcine O138:K81:H- STEC strain was identical to the corresponding region of hlyA, encoding alpha-hemolysin, from E. coli. This hlyA amplicon showed 68% identity with the nucleotide sequence of the corresponding elyA fragment. It differed from the elyA PCR product in restriction fragments generated by AluI, EcoRI, and MluI. Of the 95 representative STEC strains, 88 produced hemolysin on blood agar supplemented with vancomycin (30 mg/liter), cefixime (20 micrograms/liter), and cefsulodin (3 mg/liter) (BVCC). The lowest added numbers of two to six STEC CFU per g of stool or per ml of raw milk were detectable on BVCC plates after seeding of the preenrichment broth, modified tryptic soy broth (mTSB) supplemented with novobiocin (10 mg/liter), with 16 STEC strains. These strains represented the seven prevailing serovars diagnosed from German patients. However, with ground-beef samples, PCR was essential to identify the lowest added numbers of two to six STEC CFU among colonies of hemolyzing Enterobacteriaceae, such as Serratia spp. and alpha-hemolysin-producing E. coli. We conclude that preenrichment of stool and food samples in mTSB for 6 h followed by overnight culturing on BVCC is a simple method for the isolation and presumptive identification of STEC.

Supplement 1996 (no. 40) to the Kauffmann-White scheme.

This supplement reports the characterization of 13 new Salmonella serovars recognized in 1996 by the WHO Collaborating Centre for Reference and Research on Salmonella: 8 were assigned to S. enterica subsp. enterica, 3 to subspecies salamae and 2 to subspecies diarizonae.

Human infection caused by Salmonellae of subspecies II to VI in Germany, 1977-1992.

Human infections by Salmonella (S.) are usually caused by S. enterica strains belonging to the subspecies I (subsp.). Strains of subsp. II-VI and S. bongori are mostly isolated from animals or environmental specimens, and they are therefore considered as less pathogenic for humans. Out of 90,201 S. isolates examined at the German National Reference Centre for Enteric Pathogens between 1977 to 1992, 89,798 (99.55%) belonged to S. subsp. I, while 403 (0.45%) of strains belonged to S. subsp. II-VI and S. bongori (formerly called subsp. V). 108 strains belonged to subsp. II, 241 isolates to subsp. IIIa and IIIb (formerly called Arizona), 49 to subsp. IV, 4 to S. bongori and one isolate to subsp. VI. 215 of the 403 isolates (53.4%) were from humans, 101 (25.1%) from reptiles, 52 (12.9%) from various warm-blooded animals, 11 (2.7%) from foodstuffs and 12 (3.0%) from environmental specimens. The origin of 12 (3.0%) strains was unknown. According to the clinical diagnosis reported by the laboratories, intestinal disease was associated with 176 (81.9%) out of 215 strains of human origin. 11 (5.1%) strains had been isolated from extraintestinal infections (sepsis, atypical pneumonia, urinary tract and wound infections), and 28 (13.0%) strains from stool specimens of healthy persons. A slightly higher incidence was observed in children of 0-5 years of age (49 cases; 22.8%). Male persons were twice as often affected than females. The seasonal incidence of infections was highest in October and in February. In 53 cases (24.6%), travel to a foreign country was reported.

Nationwide outbreak of human salmonellosis in Germany due to contaminated paprika and paprika-powdered potato chips.

Between April and September 1993, a nationwide outbreak of salmonellosis occurred in Germany which was traced to contaminated paprika and paprika-powdered potato chips. Of the estimated 1000 cases, children below 14 years were principally affected. Levels of 0.04-0.45 organisms per gram were found in the snacks. The infective dose was estimated at 4-45 organisms with an attack rate of 1 in 10,000 exposed persons. The unique feature of the outbreak was the variety of serovars involved. S. saintpaul, S. rubislaw and S. javiana were isolated during the same time period from paprika powder, spice mixtures, snacks and patients. Their clonal identity was confirmed by molecular typing methods. Furthermore, monophasic and non-motile strains of rare salmonella O-groups were isolated from both paprika products and patients. This is the largest documented outbreak due to contaminated spices which proved that even extremely low numbers of salmonellae adapted to the dry state were able to cause illness.

Supplement 1994 (no. 38) to the Kauffmann-White scheme.

This supplement reports the characterization of 24 new Salmonella serovars recognized in 1994 by the WHO Collaborating Centre for Reference and Research on Salmonella: 11 were assigned to S. enterica subsp. enterica, 6 to subspecies salamae, 6 to subspecies diarizonae and 1 to subspecies houtenae. In addition, the antigenic factor H:z83 is described.