Antimicrobial stewardship

The aim of antimicrobial management or stewardship programmes is to ensure proper use of antimicrobial agents in order to provide the best treatment outcomes, to lessen the risk of adverse effects (including antimicrobial resistance), and to promote cost-effectiveness. Increasingly, long-term sustainability is found to be the major focus of antimicrobial stewardship. Implementing structural measures in healthcare institutions is therefore a major, but not the sole, focus of attention in promoting prudent use of antibiotics. The problem of antimicrobial resistance requires common strategies at all levels--for the prescribers and at ward, departmental, hospital, national and international levels.

AURES - the first Austrian report on antimicrobial resistance - perspective of the human sector

The first epidemiological report on communicable diseases in Europe published by the European Centre for Disease Prevention and Control (ECDC) identified antibiotic resistance and nosocomial infections as one of the major threats in public health in the future.

Occurrence of the USA300 community-acquired Staphylococcus aureus clone in Austria

Methicillin-resistant Staphylococcus aureus isolates are emerging as significant pathogens in the community.

A Foodborne Norovirus Outbreak Due To Manually Prepared Salad, Austria 2006

BACKGROUND

Norovirus is increasingly being recognized as a leading cause of foodborne disease. Nevertheless, well documented foodborne outbreaks due to norovirus are rarely found in the literature.

MATERIAL AND METHODS

A retrospective cohort study was conducted for identifying the source of a gastroenteritis outbreak. A total of 325 persons were identified as the at risk group.

RESULTS

The overall attack rate was 56% (182/325). Of the four working days of possible foodborne exposure to norovirus (Monday till Thursday), Wednesday (risk ratio [RR]: 18.82; 95%CI 11.82-29.96) and Thursday (RR 2.14; 95%CI 1.65-2.79) turned out to be the most likely days on which infections with norovirus occurred. The day-by-day food specific cohort analyses yielded consumption of salad on Wednesday (adjusted RR 2.82; 95%CI 1.0-7.94) to be associated with highest risk of illness. The most likely source of food contamination is a kitchen assistant having prepared salad manually. She fell ill with symptoms of gastroenteritis on Wednesday during the early working hours and continued working. Human stool samples obtained from five out of six outbreak cases, including the sick kitchen assistant, were RT-PCR positive for norovirus genotype GGII.7 (Leeds-like).

CONCLUSION

This foodborne norovirus outbreak underlines the drastic consequences of neglecting the rules of basic kitchen hygiene. Food handlers working despite manifest diarrhea or vomiting--often in fear of job loss--are a common cause of foodborne norovirus outbreaks.

Update of Clostridium difficile-associated disease due to PCR ribotype 027 in Europe

Recent outbreaks of Clostridium difficile-associated diarrhoea (CDAD) with increased severity, high relapse rate and significant mortality have been related to the emergence of a new, hypervirulent C. difficile strain in North America, Japan and Europe. Definitions have been proposed by the European Centre of Disease Prevention and Control (ECDC) to identify severe cases of CDAD and to differentiate community-acquired cases from nosocomial CDAD (http://www.ecdc.europa.eu/documents/pdf/Cl_dif_v2.pdf). CDAD is mainly known as a healthcare-associated disease, but it is also increasingly recognised as a community-associated disease. The emerging strain is referred to as North American pulsed-field type 1 (NAP1) and PCR ribotype 027. Since 2005, individual countries have developed surveillance studies to monitor the spread of this strain. C. difficile type 027 has caused outbreaks in England and Wales, Ireland, the Netherlands, Belgium, Luxembourg, and France, and has also been detected in Austria, Scotland, Switzerland, Poland and Denmark. Preliminary data indicated that type 027 was already present in historical isolates collected in Sweden between 1997 and 2001.

MLST-v, multilocus sequence typing based on virulence genes, for molecular typing of Salmonella enterica subsp. enterica serovars

Salmonella enterica subsp. enterica is one of the main causative agents of food-borne disease in man, and can also be the cause of serious systemic illness. Organisms belonging to this genus have traditionally been classified on the basis of the antigenic properties of the cell-surface lipopolysaccharide and of the phase 1 and phase 2 flagellar proteins. Primary isolation, biochemical identification, and serotyping are laborious and time consuming. Molecular identification based on suitable marker genes could be an attractive alternative to conventional bacteriological and serological methods. We have assessed the applicability of two housekeeping genes, gyrB, atpD, in combination with the flagellin genes fliC and fljB in multilocus sequence typing of Salmonella. Sequencing and comparative analysis of sequence data was performed on multiple strains from Austria, the United Kingdom, and Switzerland, representing all subspecies and 22 of the more prevalent non-typhoid S. enterica subsp. enterica serovars. A combination of these four marker genes allowed for a clear differentiation of all the strains analysed, indicating their applicability in molecular typing. The term MLST-v, for multilocus sequence typing based on virulence genes, is proposed to distinguish this approach from MLST based solely on housekeeping genes. An assortative recombination of the fliC gene was found in seven of the analysed serovars indicating multiple phylogenetic origin of these serovars.

Outbreak of acute gastroenteritis in an Austrian boarding school, September 2006

An outbreak of acute gastroenteritis occurred in September 2006 in a boarding school in eastern Austria. Of 113 cases, 101 were hospitalised. In order to identify the outbreak source, a retrospective cohort study on the group at risk was performed, including 222 pupils and 30 staff members. Food exposure in the canteen of the school was identified as the most relevant common link among the cases in the case series investigation. Although the preliminary microbiological investigation made Norovirus infections possible, an in-depth descriptive epidemiological investigation later pointed to food intoxication rather than a viral infection as the cause of the outbreak. The analytical epidemiological investigation implicated boiled rice and chicken wings served in the canteen as the most likely source of the outbreak. Staphylococcus aureus was identified as the causative agent. Further molecular characterisation revealed that the predominant S. aureus type in this outbreak was a new spa type, t2046. The same spa type was isolated from stool specimens of the majority of the cases investigated, from samples of the incriminated boiled rice, and also from a swab of a palmar skin lesion of one of the healthy kitchen workers, who is therefore the most likely source of contamination. This outbreak underlines again the importance of compliance with the basic guidelines for kitchen hygiene.

Outbreak of acute gastroenteritis in an Austrian boarding school, September 2006

An outbreak of acute gastroenteritis occurred in September 2006 in a boarding school in eastern Austria. Of 113 cases, 101 were hospitalised. In order to identify the outbreak source, a retrospective cohort study on the group at risk was performed, including 222 pupils and 30 staff members. Food exposure in the canteen of the school was identified as the most relevant common link among the cases in the case series investigation. Although the preliminary microbiological investigation made Norovirus infections possible, an in-depth descriptive epidemiological investigation later pointed to food intoxication rather than a viral infection as the cause of the outbreak. The analytical epidemiological investigation implicated boiled rice and chicken wings served in the canteen as the most likely source of the outbreak. Staphylococcus aureus was identified as the causative agent. Further molecular characterisation revealed that the predominant S. aureus type in this outbreak was a new spa type, t2046. The same spa type was isolated from stool specimens of the majority of the cases investigated, from samples of the incriminated boiled rice, and also from a swab of a palmar skin lesion of one of the healthy kitchen workers, who is therefore the most likely source of contamination. This outbreak underlines again the importance of compliance with the basic guidelines for kitchen hygiene.

Outbreak of foodborne botulism linked to barbecue, Austria, 2006

On 3 July 2006, public health authorities in northern Austria were informed by a local hospital of a possible botulism outbreak affecting four people who had been admitted two days earlier.

First isolation of Clostridium difficile PCR ribotype 027 in Austria

We report the first isolate of C. difficile 027 documented in Austria. On 9 March 2006, in a local hospital in Tyrol, west Austria, a 69 year old British woman was admitted to hospital

Mumps outbreak affecting adolescents and young adults in Austria, 2006: update

Recently, we reported on a mumps outbreak in Austria [1]. By 3 July 2006, the outbreak is estimated to include at least 150 cases

Characterization of Listeria monocytogenes isolates from 50 small-scale Austrian cheese factories

One hundred eighty-one small-scale cheese factories (annual production < 100,000 kg) were tested for the presence of Listeria monocytogenes in cheese and smear samples from 1997 to 2000. In total, 2615 samples were drawn. Fifty (27.6%) of 181 enterprises yielded L. monocytogenes. From 14 of the cheese-making facilities, we obtained more than four L. monocytogenes isolates. A total of 182 mostly cheese- and smear-borne L. monocytogenes strains were characterized by serotyping and pulsed-field gel electrophoresis. In 12 of 14 cheese factories, over half of the L. monocytogenes isolates were genetically indistinguishable by pulsetype. On average, genetically indistinguishable isolates were recovered for 11.9 months. Regarding serotypes, 27.3% of the isolates were of serovar 4b. Inadequate personal hygiene could explain the high prevalence of serovar 4b isolates in small-scale cheesemaking facilities. Forty-two percent of the serovar 4b isolates recovered from epidemiologically unlinked facilities (in comparison to 40 and 29% of the 1/2a and 1/2b isolates, respectively) were genetically indistinguishable from at least one other isolate. Indistinguishable serovar 1/2a and 1/2b isolates belonged to five and six different pulsetypes, respectively, whereas serovar 4b isolates belonged to only two pulsetypes. This finding suggested a wide distribution of genetically homologous serovar 4b isolates among the facilities tested in our study.

Salmonella Enteritidis phage type 21 outbreak in Austria, 2005

We report an outbreak of gastroenteritis due to Salmonella Enteritidis PT 21 associated with attending an annual traditional fair in a small Austrian village on 4 May 2005. The outbreak lasted from 4 to 8 May. Descriptive and analytical epidemiological investigations were conducted in order to determine the extent of the outbreak and to identify outbreak risk factors. Of the 115 persons who visited the fair, 85 persons fulfilled the criteria of an outbreak case (attack rate=73.9%). Stool specimens from 52 patients, including two kitchen staff, were tested for salmonella, and 20 specimens were positive for Salmonella Enteritidis PT 21. The cohort study revealed mixed salad (which included potatoes) as the likely cause of the outbreak (RR: 10.4, 95%CI 2.8 – 39.1; P=&lt;0.001). The causative agent of the outbreak was cultured from the stock of eggs used at the fair and from all three drag swabs and one barn dust sample collected from the responsible egg laying flock. Molecular subtyping by pulsed-field gel electrophoresis of genomic DNA after XbaI digestion showed that isolates from eggs, from the flock and from humans were indistinguishable. We hypothesise that cross contamination from eggs to boiled potatoes occurred in the kitchen area, where raw eggs were handled by village residents preparing a traditional Viennese egg dressing. Unrefrigerated storage of peeled potatoes may have favoured bacterial growth. Eggs from small rural flocks of laying hens kept in a traditional ‘natural’ way should not be assumed to be salmonella-free.

Salmonella Enteritidis phage type 21 outbreak in Austria, 2005

We report an outbreak of gastroenteritis due to Salmonella Enteritidis PT 21 associated with attending an annual traditional fair in a small Austrian village on 4 May 2005. The outbreak lasted from 4 to 8 May. Descriptive and analytical epidemiological investigations were conducted in order to determine the extent of the outbreak and to identify outbreak risk factors. Of the 115 persons who visited the fair, 85 persons fulfilled the criteria of an outbreak case (attack rate = 73.9%). Stool specimens from 52 patients, including two kitchen staff, were tested for salmonella, and 20 specimens were positive for Salmonella Enteritidis PT 21. The cohort study revealed mixed salad (which included potatoes) as the likely cause of the outbreak (RR: 10.4, 95%CI 2.8 - 39.1; P = < 0.001). The causative agent of the outbreak was cultured from the stock of eggs used at the fair and from all three drag swabs and one barn dust sample collected from the responsible egg laying flock. Molecular subtyping by pulsed-field gel electrophoresis of genomic DNA after XbaI digestion showed that isolates from eggs, from the flock and from humans were indistinguishable. We hypothesise that cross contamination from eggs to boiled potatoes occurred in the kitchen area, where raw eggs were handled by village residents preparing a traditional Viennese egg dressing. Unrefrigerated storage of peeled potatoes may have favoured bacterial growth. Eggs from small rural flocks of laying hens kept in a traditional 'natural' way should not be assumed to be salmonella-free.

A human case of travel-related rabies in Austria, September 2004

A young male Austrian tourist, aged 23 years and unvaccinated against rabies, was bitten by a dog in Morocco in July 2004. One month later he was hospitalised in Ceuta with symptoms compatible with rabies. He died on 23 September in an Austrian hospital after a diagnosis of rabies was confirmed by FAT, IHC and RT-PCR (including sequencing) of the neck skin and the RT-PCR (including sequencing) of the pharyngeal swab. This Austrian case of laboratory confirmed rabies highlights the urgent need for reinforcement of the international recommendations for travel vaccinations.

A human case of travel-related rabies in Austria, September 2004

A young male Austrian tourist, aged 23 years and unvaccinated against rabies, was bitten by a dog in Morocco in July 2004. One month later he was hospitalised in Ceuta with symptoms compatible with rabies. He died on 23 September in an Austrian hospital after a diagnosis of rabies was confirmed by FAT, IHC and RT-PCR (including sequencing) of the neck skin and the RT-PCR (including sequencing) of the pharyngeal swab. This Austrian case of laboratory confirmed rabies highlights the urgent need for reinforcement of the international recommendations for travel vaccinations.

Influence of Human Ascitic Fluid on theIn VitroAntibacterial Activity of Moxifloxacin

We investigated the in vitro influence of HAF on the antibacterial activity of moxifloxacin against Escherichia coli ATCC 10798, Escherichia coli K-12, Proteus rettgeri (Sanelli), Staphylococcus aureus ATCC 25923, Staphylococcus aureus NCTC 1808 and Staphylococcus epidermidis ATCC 12228. Human ascitic fluid was obtained from 6 cirrhotic patients by paracentesis. The interaction effect was evaluated by the checkerboard technique. Our results indicate the ability of human ascitic fluid to reduce minimum inhibitory concentrations of moxifloxacin against Gram-negative bacteria, but not against Gram-positives.