Surveillance of Legionnaires’ disease in Austria

Seven foreign cases of travel-associated Legionnaires' disease were associated with two neighbouring tourist villages in Austria between 1992 and 2004. The seven foreigners stayed in four hotels located in a geographical diameter of less than 10 km. Two cases were diagnosed in The Netherlands and five in the UK. The first case occurred in 1992, while the remaining cases clustered between August 2000 and April 2004. None of these cases was reported officially as part of a hotel-associated cluster, thereby highlighting several weaknesses of the infectious disease control systems involved.

Cefazolin concentrations in serum during cardiopulmonary bypass surgery

The objective of the study was to investigate possible changes in cefazolin serum levels induced by cardiopulmonary bypass (CPB). Six cardiac male patients who underwent cardiac surgery requiring CPB took part in the study. Cefazolin 2 g was intravenously infused over 60 min before anesthesia and blood samples were taken at appropriate times after drug administration (0, 0.25, 0.5, 1, 4, 6, 8 h), 2 min before and 5 min after the beginning and 2 min before and 5 min after the end of CPB. Drug serum concentrations were determined by means of a microbiological method. Five minutes after the start of CPB, cefazolin serum levels decreased on average by 46.6% and remained steadily low until 5 min after the end of CPB. Then, they rose on average by 37.3% at 4 h and then declined slowly until the last sampling at 8 h. Cefazolin serum concentrations were low during CPB but remained in a potentially effective range for antimicrobial prophylaxis for this surgery.

The training curriculum in hospital infection control

Standardised training curricula for infection control nurses (ICNs) and recognition of the specialty exist in many European countries, but infection control physician (ICP) is not a specialty recognised by the UEMS. To gather information on curricula for ICPs, members of the ESCMID Study Group on Nosocomial Infections received a questionnaire. There is discussion about which 'professions' should be included in an infection control team. Within the 12 countries included, the average full-time equivalents (FTEs) for ICPs and ICNs per 1000 beds were 1.2 and 3.4, respectively. In addition to ICNs and ICPs, an infection control team should also include a data manager, an epidemiologist, secretarial/administrative support, and possibly, surveillance technicians. Overall, the composition of an ideal infection control team was estimated to be 9.3 FTE per 1000 beds. The background of ICPs can be clinical microbiology or infectious diseases. Among the participants, it was predominantly clinical microbiology. The ideal training curriculum for the ICP should include 6 years of postgraduate training. Of these, at least 2 years should be 'clinical training' (e.g., internal medicine) to acquire experience in the management of high-risk patients. Furthermore, training with regard to infection control and hospital epidemiology should be offered as a 'common trunk' for those being trained in clinical microbiology or infectious diseases. Important issues that remain are: implementation/standardisation of training curricula for doctors, recognition of ICP as a separate specialty or sub-specialty of clinical microbiology and/or infectious diseases, validation of on-the-job training facilities in terms of the number of doctors and nurses who can give training and the category of patients/problems present, and mandatory postgraduate education/continuing medical education specific for infection control for doctors and nurses in the field.

Occurrence of Salmonella Enteritidis phage type 29 in Austria: an opportunity to assess the relevance of chicken meat as source of human Salmonella infections

Assuming that the various phage types of Salmonella Enteritidis (S. Enteritidis) are largely equally virulent, the importance of certain foods as sources of infection for human salmonellosis can be deduced from differences in the distribution of phage types in human and non-human samples. In 2002, S. Enteritidis phage type 29 (PT29) was first isolated from non-human test samples in Austria. S. Enteritidis PT29 accounted for 44 (27.7%) of 159 S. Enteritidis strains, derived from veterinary samples of chicken (e.g. meat, giblets) or chicken habitations (e.g. swabs from the coop and excrement). At the food retail level (chicken meat, chicken liver), five (13.1%) of 38 S. Enteritidis isolates were PT29. The proportion of S. Enteritidis PT29 in human samples was much lower. Only 0.4% (30 human primary isolates) of all S. Enteritidis isolates in the year 2002, and 0.33% (23 human primary isolates) of all human S. Enteritidis strains in 2003 were PT29. In our opinion, the discrepancy between the high prevalence of S. Enteritidis PT29 in broilers and chicken meat and the low number of PT29 cases in humans indicates that chicken meat of Austrian origin is currently only a minor source of human S. Enteritidis infections.

Occurrence of Salmonella Enteritidis phage type 29 in Austria : an opportunity to assess the relevance of chicken meat as source of human salmonella infections

Assuming that the various phage types of Salmonella Enteritidis (S. Enteritidis) are largely equally virulent, the importance of certain foods as sources of infection for human salmonellosis can be deduced from differences in the distribution of phage types in human and non-human samples. In 2002, S. Enteritidis phage type 29 (PT29) was first isolated from non-human test samples in Austria. S. Enteritidis PT29 accounted for 44 (27.7%) of 159 S. Enteritidis strains, derived from veterinary samples of chicken (e.g. meat, giblets) or chicken habitations (e.g. swabs from the coop and excrement). At the food retail level (chicken meat, chicken liver), five (13.1%) of 38 S. Enteritidis isolates were PT29. The proportion of S. Enteritidis PT29 in human samples was much lower. Only 0.4% (30 human primary isolates) of all S. Enteritidis isolates in the year 2002, and 0.33% (23 human primary isolates) of all human S. Enteritidis strains in 2003 were PT29. In our opinion, the discrepancy between the high prevalence of S. Enteritidis PT29 in broilers and chicken meat and the low number of PT29 cases in humans indicates that chicken meat of Austrian origin is currently only a minor source of human S. Enteritidis infections.

Characterization of Pathogenic Escherichia coli Isolated from Humans in Austria: Phenotypes, Toxin Gene Types and Epidemiology

One hundred and ten clinical Escherichia coli isolates of serovar O157 (n = 102) and O26 (n = 8) were characterized for the presence of putative virulence genes by PCR. All but one of these isolates contained the eae gene. The EHEC-hly gene could be detected in all E. coli O157 and in 50% of E. coli O26 isolates. Forty-five (40.9%) of the 110 E. coli were positive for both stx(1) and stx(2) genes, 2 (1.8%) isolates were positive for stx(1) and 57 isolates (51.8%) were positive for stx(2) only. Among the 102 stx(2) positive isolates, 14 (13.7%) E. coli O157 contained also the stx(2c) variant gene. No other stx(2) variant was identified. Six clinical isolates (five E. coli O157:H7 and one E. coli O26) did not contain stx genes. Ten non-pathogenic E. coli isolates which were amplified as controls didn't contain any stx and eae gene but two of the ten strains contained the EHEC-hly gene. By their growth on chromogenic media, all but two of 50 E. coli O157 could be differentiated from eight E. coli O26 and 10 non-pathogenic E. coli. Sixty-one of the O157:H7 isolates were further subjected to pulsed-field gel electrophoresis (PFGE) which identified 49 distinguishable patterns. In five cases where contact infection among family members was suspected, indistinguishable PFGE patterns confirmed the epidemiological relatedness of the isolates. Moreover, two PFGE clusters were identified which comprised five and three strains, respectively. These findings indicate the occurrence of both family and diffuse outbreaks of E. coli O157 infections in Austria during recent years and demonstrate the need for molecular subtyping of these pathogens.

Characterization of Listeria monocytogenes recovered from 41 cases of sporadic listeriosis in Austria by serotyping and pulsed-field gel electrophoresis

41 clinical Listeria monocytogenes strains recovered from seven feto-maternal and 34 non-pregnancy associated cases of human listeriosis documented between 1997 and 2000 underwent serotyping and typing by pulsed-field gel electrophoresis (PFGE) applying the enzymes AscI, ApaI and SmaI. The pulsotypes of the clinical strains were compared to the pulsotypes of three L. monocytogenes strains isolated from healthy fecal carriers and nine reference strains isolated from seven outbreaks in Europe and the USA. The 41 clinical strains of Austrian provenance showed 37 pulsotypes. Five sets of two Austrian strains each were indistinguishable by PFGE typing. Epidemiological links were absent between these indistinguishable isolates. One unique pulsotype (AB) was found in three fecal isolates. Five pulsotypes (A, Q, R, AC and AD) were distinguished among the strains associated with outbreaks. Clusters consisting of two, five and six Austrian strains each were indistinguishable from the outbreak-associated pulsotypes A, Q and R, respectively, after PFGE analysis with AscI. Three strains of AscI pulsotype Q and five strains of AscI pulsotype R could be further differentiated by restriction with ApaI and SmaI. One strain each from sporadic cases shared a combined pulsotype with the outbreak strains of pulsotypes A and R, respectively. These PFGE data suggest that a similar genetic background can be found in strains which have been contributing to outbreaks world-wide and in isolates associated with sporadic listeriosis in Austria.

Incidence of fecal carriage of Listeria monocytogenes in three healthy volunteers: a one-year prospective stool survey

The aim of this study was to establish the incidence of fecal carriage of Listeria monocytogenes in healthy adults. A total of 868 stool specimens from three healthy volunteers (1 male and 2 females; ages 44, 39, and 60 years) were collected between 1 October 2000 and 30 September 2001. Culture was performed using Fraser broth and Palcam selective agar plates. Polymerase chain reaction (PCR) was performed using Probelia Listeria monocytogenes (BioRad, France). Overall, Listeria monocytogenes was detected in 31 of the 868 (3.57%) stool specimens using PCR. Sixteen of the 31 positive results were single events, i.e., samples collected from the same patient the day before and the day after the positive result were both negative. Positive results on two consecutive days were found four times, on three consecutive days one time, and on four consecutive days one time. Listeria monocytogenes was cultured from 10 of 868 (1.15%) stool specimens. These culture-positive samples, all positive by PCR as well, accounted for five independent episodes. Using automated ribotyping on up to 40 single colonies per stool specimen, 9 of 10 culture-positive samples yielded more than one strain. There was no obvious seasonal clustering of positive results. None of the documented episodes of Listeria monocytogenes carriage, all of which involved serotypes 1/2a and 1/2b, coincided with overt illness. The results of PCR indicate an incidence of five to nine exposures to Listeria monocytogenes per person per year. On average, the incidence of culture-confirmed fecal carriage in healthy adults is two episodes of Listeria monocytogenes carriage per person per year. Fecal shedding was of short duration (maximum 4 days), which argues against the appropriateness of routine stool screening in dairy workers as a tool for prevention of listeriosis.

Barbecued chicken causing a multi-state outbreak of Campylobacter jejuni enteritis

BACKGROUND

Although the microbiological safety of food has improved, food-borne disease remains a significant cause of morbidity and mortality in Europe.

PATIENTS AND METHODS

We investigated an outbreak of Campylobacter jejuni enteritis attributed to chicken meat, affecting five out of six people attending a private barbecue party in Germany. Patients fell ill in Germany, in Liechtenstein and in Austria. 80% of the cases had been exposed to barbecued chicken; the case that denied having eaten chicken was the party host, who also handled all the food. Three of four patients submitting stool specimens had culture-confirmed C. jejuni infection.

RESULTS

The chicken meat was purchased in the Tyrol (Austria) and originated from a flock of 55600 chickens raised in Carinthia (Austria). Caecal swabs were obtained in 7 weeks later from 22 chicken at the incriminated farm: 18 of the 22 samples yielded C. jejuni. The same day, six carcasses out of 22000 slaughtered animals from the incriminated farm were tested and all six food samples yielded C. jejuni. Outbreak-associated human isolates yielded pulsed-field gel electrophoresis patterns indistinguishable from each other and from the meat isolates, but different from four human control strains and from 13 of 16 isolates from caecal swabs.

CONCLUSION

Our data show that the outbreak clone had been colonizing the slaughterhouse and was cross-contaminating chickens there. The geographic mobility of people and food necessitates proper epidemiologic investigations to avoid overestimation of the proportion of sporadic occurrence of campylobacteriosis.

Occurrence of Salmonella enterica serovar Dublin in Austria

In Austria, Salmonella enterica subsp. enterica serovar Dublin, a bovine-adapted serovar, rarely causes infections in humans. In 2000, Austria was within the European mean with an incidence of 0.1 per million inhabitants. Our data show that the vast majority of all serovar Dublin infections (human and non-human) can be traced epidemiologically to two districts in the Tyrol. This concentration of cases can be explained by a particularly traditional aspect of cattle farming in this area, the alpine pasture. There is an increased risk of cross infection due to the communal keeping of animals from various farms. Infected cattle are a source of infection for humans, and transmission usually occurs from eating beef and drinking cows milk. Using pulsed field gel electrophoresis and automated ribotyping, three out of five isolates from human infections could be traced to characteristic Tyrolean Dublin clones. Bacteriological screening for faecal carriage before the transfer of cattle from risk-herds to the alpine pastures and before the return from risk-pastures to the farms would be a possible starting point to prevent cross-contamination of large mixed herds and contamination of pasture through latently infected cattle. Appropriate research is necessary.

Necrotizing fasciitis with Clostridium perfringens after laparoscopic cholecystectomy

Necrotizing fasciitis is a rapidly progressive infection of the fascia and subcutaneous tissues accompanied by a high mortality rate approaching 80% to 100%. Factors that predispose patients to this life-threatening complication include obesity, malnutrition, malignancy, chronic alcoholism, drug abuse, peripheral vascular disease, diabetes mellitus, and immunosuppressive therapy. The pathomechanisms for the development of this rare disease still remain unclear. We report a case of necrotizing fasciitis with Clostridium perfringens after laparoscopic cholecystectomy. The patient left the hospital 5 months after admission. Early recognition based on clinical signs (pain, asymmetric abdominal thickening, crepitus) and computed tomography scanning (gas dissection along fascial planes), in conjunction with prompt, aggressive surgical therapy and debridement of all devitalized tissue, high-dose antibiotic therapy, and therapy at the intensive care unit, appears to afford patients the best chance of survival.

Effects of daily oral administration of rifaximin and neomycin on faecal aerobic flora in rats

The aim of this study was to compare the influence of rifaximin and neomycin on faecal flora in rats. The study was performed on 18 Wistar rats (three groups of six male animals). Group 1 received rifaximin (50 mg kg(-1)/day), group 2, neomycin (50 mg kg(-1)/day) and group 3 was used as control. Drugs were administered orally, once daily for 3 days. Faecal specimens, collected from each rat on day 3, were cultured for the quantitative and qualitative determination of aerobic microorganisms. Rifaximin treatment produced a marked reduction in the number of total aerobic bacteria and Salmonellae; neomycin caused reduction in Salmonellae, but did not cause statistically significant changes in total aerobic bacterial count. The binding of neomycin with faeces could explain this limited activity, which does not correlate with the in vitro susceptibility of the organism affected. These results confirm that rifaximin is suitable for topical treatment to reduce selected bacterial load in the gut intestines.

Helminthic infestations in the Tyrol, Austria

At the federal public health laboratory, Innsbruck, 142 426 samples were examined for intestinal helminthosis from 1990 until 2000. Enterobius vermicularis accounted for half (49.7%) of the cases diagnosed, followed by Taenia saginata (28.3%), Ascaris lumbricoides (12.8%), and Trichuris trichiura (3.9%). Of all specimens tested for helminths, 26% had been positive in 1945, and 0.98% in 1985. The proportion of positive findings with respect to the total number of specimens tested was 0.24% in the time span 1990-2000. It appears to us that these numbers fairly reflect the real prevalence of helminthosis in Austria.

Prevalence and characterization of Listeria monocytogenes in the feces of healthy Austrians

The aims of the study were to determine the prevalence of Listeria monocytogenes in the feces of healthy Austrians and to characterize the isolates by various typing methods. Stool specimens from 505 healthy volunteers from the Tyrol were tested for the presence of L. monocytogenes using cold enrichment for 6 months and five different detection methods: conventional plating onto Palcam and Rapid'L.MONO agar, immunomagnetic separation (IMS) followed by conventional plating, enzyme-linked fluorescent immunoassay (ELFA), ELISA, and PCR. L. monocytogenes was isolated by conventional plating from one specimen (0.2%), and a further three were positive on immunomagnetic separation (0.8%). Only one specimen tested positive with ELFA and EIA, although it tested negative by conventional culture, IMS, and PCR. Eighteen of 505 samples were positive by PCR (3.6%), and this included three of the four culture-confirmed specimens. Serotyping, phage-typing, arsenic cadmium, antimicrobial-resistance typing and pulsed-field gel electrophoresis showed that multiple L. monocytogenes isolates from three of the four carriers were indistinguishable. Our data indicate that the Austrian fecal carriage rate is at least 0.8%. In view of a listeriosis incidence of 0.16/100,000 per year, the chances of fecal carriage developing into listeriosis appear to be very low.

Escherichia coli O157 infections and unpasteurised milk

We report on two children with Escherichia coli O157 infection, one of whom developed haemolytic uraemic syndrome (HUS). Both had drunk raw cows or goats milk in the week before their illness. Molecular subtyping identified a sorbitol fermenting Escherichia coli O157:H isolate from a dairy cow. This isolate differed from Shiga toxin producing O157:H strains isolated from the 6 year old boy with HUS. This result underlines the need to search for other causes of infection, despite documented consumption of unpasteurised milk. In the second patient, human sorbitol non-fermenting O157:H isolates and animal isolates from goats were indistinguishable. The isolation of indistinguishable sorbitol non-fermenting Escherichia coli O157:H from contact animals supports the association between HUS and consumption of raw goats milk, and re-emphasises the importance of pasteurising milk.

In vitro activity of fosfomycin in combination with various antistaphylococcal substances

Using the chequerboard technique we studied the in vitro activity of the broad spectrum antibiotic fosfomycin in combination with vancomycin, rifampicin, linezolid, quinupristin/ dalfopristin, cefazolin, meropenem and moxifloxacin against two Staphylococcus epidermidis strains (ATCC 12228, DSM 3269) and five Staphylococcus aureus isolates (ATCC 29213, DSM 683, DSM 46320, GISA 323/93, MRSA 3558/00). The phenomena of 'trailing' and 'skipped wells' did not present a problem. Synergy was the most common effect of all drugs tested in combination with fosfomycin; only combination with vancomycin showed antagonism for two of seven isolates. Using a killing-curve technique fosfomycin showed cidal activity, where increasing the drug concentration above the MIC did not enhance killing velocity. Inhibitory concentrations of vancomycin plus fosfomycin against DSM 46320 caused effects identical to those observed with vancomycin alone. The combination of fosfomycin plus linezolid exerted the bacteriostatic effect found with linezolid alone. Fosfomycin plus quinupristin/dalfopristin exhibited the bactericidal effect found with fosfomycin alone (in contrast to the rapidly bactericidal effect of quinupristin/dalfopristin). Electron microscopy showed that fosfomycin given in combination with linezolid, quinupristin/dalfopristin or moxifloxacin (substances that do not cause morphological alterations when given alone) resulted in 'cauliflower-shaped' distortion as caused by fosfomycin alone. Our in vitro data indicate considerable potential for fosfomycin used in combination with other antistaphylococcal antimicrobials, especially linezolid or quinupristin/dalfopristin.

Fleroxacin uptake in ischaemic limb tissue

Antibiotic application to patients with ischaemia of lower limbs may be indicated to avoid or treat infection of soft tissues. Fleroxacin, a fluoroquinolone, active against various Gram-negative and Gram-positive organisms may be used for this purpose. We evaluated the diffusion of fleroxacin into bone, subcutaneous fat, muscle and tendon tissues of lower limb tissue after a 400 mg i.v. dose. Concentrations in ischaemic tissues were similar to those found in non-ischaemic sites. Since the maximum antibiotic levels found were lower than the MICs of various pathogens relevant for infection, we suggest to increase the dose used for this peri-operative prophylaxis to 800 mg.

Hemolytic-uremic syndrome surveillance to monitor trends in infection with Escherichia coli O157 and non-O157 enterohemorrhagic E. coli in Austria

Austrian data underline that relying on the number of enterohemorrhagic Escherichia coli (EHEC) O157 strains isolated from clinical specimens does not allow assessment of the actual incidence of EHEC infections. A hospital-based system for identification of hemolytic-uremic syndrome cases based on voluntary cooperation was established in 1995 and provides information needed to monitor trends in the incidence of O157 and non-O157 EHEC infections.

Characterization of consecutive Streptococcus pyogenes isolates from patients with pharyngitis and bacteriological treatment failure: special reference to prtF1 and sic / drs

To analyze bacteriological treatment failure in streptococcal pharyngitis, 40 consecutive Streptococcus pyogenes isolates from 18 patients were characterized. For 17 patients, isolates were indistinguishable with respect to emm type, random amplified polymorphic DNA pattern, and presence of prtF1 encoding the fibronectin-binding protein F1. prtF1 was detected only in the 11 isolates (4 patients) with emm12 and in the single isolate with emm6. Further analysis by vir(mga) regulon typing, sequencing of sic encoding the streptococcal inhibitor of complement from 19 isolates with emm1 (9 patients), and sequencing of drs (distantly related sic) from 11 isolates with emm12 revealed distinct sic alleles with insertions and/or deletions in sic that corresponded to differences in restriction patterns of the vir(mga) regulon only for paired isolates of 2 patients. Among isolates with emm12, 2 novel drs alleles were found. Analysis of these data suggests that neither the presence of prtF1 nor the diversification of sic / drs is required for the persistence of S. pyogenes in pharyngitis.

Salmonella enterica serotype Oranienburg infections associated with consumption of locally produced Tyrolean cheese

Sixteen culture confirmed cases of enteric infection with Salmonella enterica serotype Oranienburg were detected between August 10 and September 29 1999 in Tyrol (Austria). Ten of them suffered bloody diarrhoea and six were asymptomatic carriers. Intervie

Nontoxigenic sorbitol-fermenting Escherichia coli O157:H- associated with a family outbreak of diarrhoea

A recent study from Germany reported the isolation of E. coli O157:H7/H- from patients with non-bloody diarrhoea and hemolytic uremic syndrome, questioning the role of Shiga toxin as the main trait of virulence for human disease. We isolated 6 sorbitol-fermenting E. coli O157:H- strains that do not contain Shiga toxin genes. The isolates originated from an outbreak (3 patients, 3 asymptomatic contacts) of non-bloody diarrhoea affecting two families sharing one household. Two children (age 10 months and 2 years) suffered severe diarrhoea over 30 and 10 days, respectively. Their uncle had moderate diarrhoea for 2 weeks. In contrast to the other isolates, the uncle's strain (EH109) did not harbour a chromosomal eae gene encoding gamma-intimin nor the plasmid gene E-hly; it also showed a PFGE pattern that was different from the unique pattern of the other isolates. Employing PFGE, phage typing, and P-gene typing, five of the six stx negative isolates were indistinguishable from the stx 2 positive "Bavarian outbreak strain". The only human serum tested, obtained from one asymptomatic contact, contained antibodies to the O157 lipopolysaccharide antigen. Our finding of five stx negative sorbitol-fermenting E. coli O157:H- isolates (harbouring eae and E-hly) associated with an outbreak of non-bloody diarrhoea supports the hypothesis that Stx production is not obligatory for the pathogenicity of E. coli O157 for humans.

Spectrum and transferability of beta-lactam resistance in hospital strains of Enterobacter isolated in Bratislava and Innsbruck

The transferability and expression of beta-lactam resistance were compared in multiresistant clinical isolates of Enterobacter spp. collected from different hospitals in Bratislava, Slovakia (n = 15) and Innsbruck, Austria (n = 19) during 1996-1997. The strains from Bratislava were resistant to ampicillin, cefoxitin, cefotaxime, ceftazidime and ceftriaxone. All strains from Innsbruck were resistant to ampicillin and cefoxitin; 17 were also resistant to ceftazidime and aztreonam but the majority remained susceptible to cefotaxime and ceftriaxone. All strains were susceptible to cefepime and imipenem. The majority of the tested strains transferred resistance determinants to E. coli recipient by conjugation. Production of beta-lactamase including ESBL was the major mechanism of beta-lactam resistance. Large plasmids of 77-88 and 91 kb were confirmed in clinical isolates from Bratislava and Innsbruck.