Epidemiology of neonatal sepsis in two neonatal intensive care units in Krakow, Poland in 2016-2017 years.

BACKGROUND: Sepsis in low-birth-weight neonates remains one of the most significant causes of neonatal morbidity and mortality. Approximately 3 million newborns suffer from sepsis globally every year. The aim of this study was to compare demographic and clinical features, as well as etiology and antibiotic susceptibility, of the main pathogens related to neonatal sepsis in two neonatal intensive units during a two-year period. METHODS: We observed early-onset (EO-BSI) and late-onset bloodstream infections (LO-BSI) cases in two high-reference neonatal intensive care units (NICU) over a 24-month period (2016-2017). Samples of patients' blood were tested for the presence of the microorganisms. All bacterial isolates were tested for susceptibility to antibiotics. RESULTS: The majority of sepsis cases weighed above 1000 g and were born by cesarean section. About 10% of the EO-BSI group died. There were differences in the EO-BSI /LO-BSI ratio in the compared wards due to differences among the admitted children. The most common pathogens isolated from blood were coagulase-negative staphylococci (CoNS) were represented by two dominating species: S. epidermidis and S. haemolyticus, followed by Klebsiella spp. strains and E.coli, which were mostly found in EO-BSI cases. No single S. agalactiae (GBS) strain was isolated. The majority of CoNS strains were resistant to methicillin, half were resistant to aminoglycosides, and one-third were resistant to macrolides and lincosamides. Half of the Gram-negative rods were resistant to beta-lactams. CONCLUSIONS: The epidemiology of sepsis in two observed NICUs is comparable to data obtained from other studies with a predominance of methicillin-resistant CoNS in LO-BSI and beta-lactam resistant E. coli in EO-BSI. It is of importance that the campaign for controlling GBS carriage in pregnant women in Poland resulted in the disappearance of GBS as a cause of sepsis. Unfortunately, there are no such measures to control E.coli related sepsis.

Secondary bacterial infections & extensively drug-resistant bacteria among COVID-19 hospitalized patients at the University Hospital in Kraków.

INTRODUCTION: Healthcare-associated infections (HAI) and bacterial antimicrobial resistance posed a therapeutic risk during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to analyze the HAIs in COVID-19 patients in the Intensive Care Unit (ICU) and non-ICU at the University Hospital in Krakow (UHK) with an emphasis on the susceptibility of the most frequently isolated pathogens and the prevalence of extensively drug resistant (XDR) microorganisms. METHODS: This laboratory-based study was carried out at the University Hospital in Krakow in the ICU and non-ICUs dedicated to COVID-19 patients between May 2021 and January 2022. All isolates of Klebsiella pneumoniae were analyzed using PFGE protocol. RESULTS: 292 independent HAI cases were identified, with the predominance of urinary tract infections (UTI), especially in the non-ICU setting. The most common ICU syndrome was pneumonia (PNA). The prevalence of XDR organisms was 22.6% in the ICU and 14.8% in non-ICUs among all isolates. The incidence of carbapenem-resistant Enterobacteriaceae infection was 24.8 cases per 10,000 hospitalizations and the carbapenem-resistant A. baumannii infection incidence was 208.8 cases per 10,000 hospitalizations. The prevalence of XDR strains was highest in Acinetobacter spp, in PNA cases. The PFGE typing demonstrated that almost all XDR strains varied widely from each other. CONCLUSIONS: In this study, there was a high incidence of HAI in COVID-19 patients, especially when compared to Western Europe and the United States. Similarly, the prevalence of XDR microorganisms, especially XDR-A.baumannii, was also high. PFGE did not confirm the horizontal spread of any organism strains.

Antibiotic consumption in laboratory confirmed vs. non-confirmed bloodstream infections among very low birth weight neonates in Poland.

BACKGROUND: Newborns are a population in which antibiotic consumption is extremely high. Targeted antibiotic therapy should help to reduce antibiotics consumption. The aim of this study was an assessment of antibiotic usage in bloodstream infections treatment in the Polish Neonatology Surveillance Network (PNSN) and determining the possibility of applying this kind of data in infection control, especially for the evaluation of standard methods of microbiological diagnostics. METHODS: Data were collected between 01.01.2009 and 31.12.2013 in five teaching NICUs from the PNSN. The duration of treatment in days (DOT) and the defined daily doses (DDD) were used for the assessment of antibiotics consumption. RESULTS: The median DOT for a single case of BSI amounted to 8.0 days; whereas the median consumption expressed in DDD was 0.130. In the case of laboratory confirmed BSI, median DOT was 8 days, and consumption-0.120 DDD. Median length of therapy was shorter for unconfirmed cases: 7 days, while the consumption of antibiotics was higher-0.140 DDD (p < 0.0001). High consumption of glycopeptides expressed in DOTs was observed in studied population, taking into account etiology of infection. CONCLUSIONS: Even application of classical methods of microbiological diagnostics significantly reduces the consumption of antibiotics expressed by DDD. However, the high consumption of glycopeptides indicates the necessity of applying rapid diagnostic assays. Nevertheless, the assessment of antibiotic consumption in neonatal units represents a methodological challenge and requires the use of different measurement tools.

Infection control: point prevalence study versus incidence study in Polish long-term care facilities in 2009-2010 in the Malopolska Region.

OBJECTIVE: The objective of this study was to evaluate the epidemiology of infection in Polish long-term care facilities (LTCFs) and to analyse the capabilities and legitimacy of implementing continuous targeted surveillance. METHODS: The study investigated the relationship between the presence of infection and health status, tested using a point prevalence study (PPS) and incidence study. A 1-day PPS was carried out in October 2009, with prospective continuous surveillance between December 2009 and November 2010. Infections were defined according to McGeer's criteria. RESULTS: The surveillance encompassed 193 people. The prevalence was 14.0 % in residential homes (RHs) and 18.7 % in the nursing home (NH). Various types of infections (in the PPS) were observed significantly more frequently in patients with asthma, wounds, atherosclerosis of lower extremities, tracheotomy tubes and conditions in patients hospitalised in intensive care units (ICUs) up to 1 year before the PPS day. The incidence rate was 2.7/1,000 patient days (pds). CONCLUSIONS: The factors determined to be important for the risk of infection (in the continuous study) include the general status of patients, expressed using Barthel, abbreviated mental and Katz scales, as well as limited physical activity, stool incontinence and urinary catheterisation. In the PPS study, only a slight relationship was shown between the general status of residents and the risk of infection. None of the general status scales used clinically were shown to be helpful in estimating that risk, similarly to the five-point physical activity scale. Prospective continuous surveillance shows a possibility of limiting the range of infection control in the LTCFs within targeted surveillance in a population of patients that requires intensive nursing procedures. As a marker, one could point to the low score in the Barthel or Katz scales or low physical activity/bedridden persons.

Antimicrobial Resistance in Enterobacterales Bacilli Isolated from Bloodstream Infection in Surgical Patients of Polish Hospitals.

BACKGROUND AND AIMS: Bloodstream infections (BSIs) are one of the most frequently observed hospital-acquired infections (HAIs). We sought to describe the epidemiology and drug resistance secondary Enterobacterales BSIs in surgical patients and check for any correlation with the type of hospital ward. MATERIALS AND METHODS: This multicenter (13 hospitals in southern Poland) laboratory-based retrospective study evaluated adults diagnosed with BSI secondary to surgical site infection (SSI) hospitalized in 2015-2018; 121 Enterobacterales strains were collected. The drug resistance was tested according to the EUCAST recommendations. Tests confirming the presence of extended-spectrum ß-lactamases (ESBLs) and bla resistance genes were carried out. The occurrence of possible clonal epidemics among K. pneumoniae strains was examined. RESULTS: The prevalence of Enterobacterales in secondary BSI was 12.1%; the most common strains were E. coli (n = 74, 61.2%) and Klebsiella spp. (n = 33, 27.2%). High resistance involved ampicillin and ampicillin/sulbactam (92, 8-100%), fluoroquinolones (48-73%), and most cephalosporins (29-50%). Carbapenems were the antimicrobials with the susceptibility at 98%. The prevalence of ESBL strains was 37.2% (n = 45). All the ESBL strains had bla CTX-M gene, 26.7% had the bla SHV gene, and 24.4% had bla TEM gene. The diversity of Klebsiella strains was relatively high. Only 4 strains belonged to one clone. CONCLUSIONS: What is particularly worrying is the high prevalence of Enterobacterales in BSI, as well as the high resistance to antimicrobial agents often used in the empirical therapy. To improve the effectiveness of empirical treatment in surgical departments, we need to know the epidemiology of both surgical site infection and BSI, secondary to SSI. We were surprised to note high heterogeneity among K. pneumoniae strains, which was different from our previous experience.

Infections following surgical patent ductus arteriosus ligation in very-low-birthweight neonates.

BACKGROUND: Very-low-birthweight (VLBW) neonates (<1500g) comprise approximately 1% of liveborn infants in Poland. Patent ductus arteriosus (PDA) is a common complication of prematurity. This study aimed to determine how many VLBW neonates treated in the participating units needed surgical correction of PDA, and to evaluate the incidence of various types of postoperative infections and their microbiology. METHODS: Observational study in five neonatology departments by the Polish Neonatology Surveillance Network, involving 2039 VLBW newborns of whom 103 (5.1%) required surgical PDA ligation. Continuous infection surveillance was conducted between 2009 and 2013; infections were defined based on Gastmeier's criteria. RESULTS: PDA surgery was required significantly more frequently in infants from multiple pregnancies, and where labour was complicated by amnionitis. Surgical PDA correction was performed, on average, at 19 days of life. The incidence of infection was 48.5% (N = 50), and the most common infections were bloodstream infection (26.2%) and pneumonia (22.3%). A correlation was observed between the day on which the procedure was performed and the time of infection: the earlier the neonate underwent PDA surgery, the earlier the infection manifested (P = 0.032). A high CRIB score and chorioamnionitis contributed significantly to the presence of infection. CONCLUSION: The later the PDA surgery was performed, the later the infection occurred. The incidence of infection after correction of PDA among VLBW neonates was comparable with the incidence of infection among all hospitalized VLBW neonates.

Nail microbial colonization following hand disinfection: a qualitative pilot study.

Effective hand hygiene among healthcare workers is one of the basic principles of preventing nosocomial infections. The aim of the study was a qualitative examination of microbial colonization of nails following hand hygiene. The results were stratified by nail length: short versus long and the presence of a varnish coating: natural versus varnished. The presence of potentially pathogenic micro-organisms was correlated with nail length (odds ratio: 7.1; 95% confidence interval: 1.83-27.39; P < 0.001) and the presence of ultraviolet (UV)-cured nail polish (7.2; 1.25-40.91; P < 0.05). There is a high probability of ineffective hand hygiene when keeping long nails and when UV-cured nail polish is present on them.

Molecular analysis of meticillin-resistant Staphylococcus aureus strains isolated from different types of infections from patients hospitalized in 12 regional, non-teaching hospitals in southern Poland.

BACKGROUND: Accumulated data indicate that meticillin-resistant Staphylococcus aureus (MRSA) infections are associated with a worse prognosis than methicillin-susceptible S. aureus infections. AIM: To assess the epidemiological profile of S. aureus infections and the genetic diversity of clinical strains of MRSA in 12 hospitals in southern Poland. METHODS: Samples from bloodstream infections, pneumonia, and skin and soft tissue infections from adult patients were examined. S. aureus isolates were tested for MRSA and macrolide-lincosamide-streptogramin B (MLSB) phenotypes. Staphylococcal cassette chromosome mec (SCCmec) typing and S. aureus protein A (spa) typing were performed. Analysis of the genetic similarity was performed by pulsed-field gel electrophoresis. RESULTS: This study included 555 patients. An MRSA phenotype was detected in 15.1% of strains. The prevalence of MRSA infection was higher in patients aged >80 years. An MLSB phenotype was detected in 18.2% of strains. Analysis of SmaI profiles did not reveal a dominant clone. Spa typing showed 25 different spa types, and spa type t003 was the most common (49% of strains). Among MRSA strains, SCCmecII (49%) and SCCmecIV (27.4%) were predominant. CONCLUSION: The characteristics of MRSA showed considerable heterogeneity. The results demonstrate the need for caution when drawing conclusions on direct epidemiological relationships between isolates based on a single typing method. As the cases of infection in this study were not associated with the hospital environment and horizontal transfer, a focus on screening at hospital admission, and appropriate infection control, may help to reduce the risk of MRSA infections.

Urinary tract infections caused by Pseudomonas aeruginosa among children in Southern Poland: Virulence factors and antibiotic resistance.

OBJECTIVE: The aim of this study was to analyze antibiotic resistance and virulence patterns in Pseudomonas aeruginosa (PAR) isolates from urinary tract infections among children in Southern Poland. MATERIALS AND METHODS: This study comprised consecutive, non-repetitive PAR isolates sent from two collaborative laboratories. The study group consisted of children aged up to 17 years from Southern Poland with culture-proven PAR UTIs. Relevant information about patients with UTIs, such as age, sex, and type of infection (polymicrobial or monomicrobial), was collected. Isolates were screened for major virulence factors found in uropathogenic PAR strains. Multidrug-resistant (MDR) strains were defined as strains not susceptible to one antimicrobial in at least three different antimicrobial classes. Extensively drug resistant (XDR) strains were defined as strains susceptible to no more than two antimicrobial classes. RESULTS: The total prevalence of PAR UTIs was 2.1%, and in children <5 years of age it was 3.0%. A total of 26 isolates was tested: 21 from outpatients and five from inpatients. Most infections (80.8%) occurred in children ≤ 4 years of age. The most prevalent virulence gene was exoY (96.2%). The prevalence of other effector proteins was 88.5% for exoT, 92.3% for exoS, and 19.2% for exoU. The gene for LasB was present in 80.8% of isolates; the gene for AprA in 61.5%; the gene for PilA in 19.2%; and the gene for PilB was not detected. The PAR isolates were generally susceptible to beta-lactam and aminoglycoside antimicrobials. All isolates were also susceptible to colistin. A large proportion of isolates were resistant to carbapenems and fluoroquinolones (Fig. 1). No significant differences were found in antimicrobial resistance between males and females or inpatients and outpatients (p > 0.05 for all tested antimicrobials), or in antimicrobial resistance between younger (≤ 5 years old, n = 21) and older (> 5 years old, n = 5) children (p > 0.05 for all tested antimicrobials). Two isolates were classified as XDR and none as MDR. The EDTA test yielded one MBL-positive isolate (3.8%), from a 17-year-old patient in home care. No isolates with genes for the KPC, IMP, or VIM were identified. CONCLUSION: As data on UTIs in children with Pseudomonas etiology are scarce, this paper provides useful information for clinicians and allows for comparison between Poland and other countries. Our findings have important implications for clinicians treating UTIs empirically, because the success of empiric treatment is based on knowledge of pathogen antimicrobial susceptibility patterns.

Infections and risk-adjusted length of stay and hospital mortality in Polish Neonatology Intensive Care Units.

BACKGROUND: The objectives of this study were to analyze the impact of infections on prolonging hospital stay with consideration of underlying risk factors and determining the mortality rates and its association with infections. METHODS: An electronic database developed from a continuous prospective targeted infection surveillance program was used in the study. Data were collected from 2009 to 2012 in five Polish tertiary academic neonatal intensive care units (NICUs). The length of stay (LOS) of 2,003 very low birth weight (VLBW) neonates was calculated as the sum of the number of days since birth until death or until reaching a weight of 1,800g. RESULTS: The median LOS for neonates with infections was twice as high as for neonates without infection. LOS was significantly affected by the overall general condition of the neonate, as expressed by both gestational age and birth weight as well as by the Clinical Risk Index for Babies (CRIB) score; another independent factor was presence of at least one infection. Risk of in-hospital mortality was significantly increased by male sex and vaginal birth and was lower among breastfed neonates. Deaths were significantly more frequent in neonates without infection. CONCLUSIONS: The general condition of VLBW infants statistically increase both their risk of mortality and LOS; this is in contrast to the presence of infection, which significantly prolonged LOS only.

[Surveillance of hospital infections in Poland--current condition and prospects]. / Nadzór nad zakazeniami szpitalnymi w Polsce--stan aktualny i mozliwosci rozwoju.

This paper outlines the current achievements in the control of hospital acquired infections in modern countries as well as in Poland in recent years. Studies related to the incidence of hospital-acquired infections have been conduced in western Europe, Scandinavia, the United States, and many other countries around the world. Because of these already completed studies, we are able to develop epidemiologic analysis specifically centered upon the incidence and increased costs involved with hospital-acquired infections. In Poland this type of surveillance was unable to be attained until long after its institution. However, over the past few years, the Polish Society of Hospital-Acquired Infection, has worked to bring recognition of the seriousness of this problem to a representative group of Polish hospitals. One of the most important conclusions reached was lack of departmental control which, using standards previously agreed upon by modern countries, could provide the necessary surveillance over hospital-acquired infections. Currently, surveillance is carried out by treating physicians without the help of specially-trained infection control nurses, epidemiologists and medical microbiologists. The basic challenge for the Polish health service is that of the development and realization of a professional infection control team. This professional team would work develop guidelines for the protection of patients and hospital personnel from hospital-acquired infections.

[Hospital acquired pneumonia--analysis of frequency and etiology in Polish hospitals in 1998]. / Szpitalne zapalenia pluc--analiza czestosci wystepowania oraz czynników etiologicznych tego zakazenia w Polskich szpitalach w 1998 roku.

Hospital-acquired pneumonia (HAP) is one of the most frequently occurring hospital infections in the world. This study describes the incidence of HAP in Poland, as well as the specific risk factors leading to this type of infection in Polish hospitals; including those of patient age, length of hospitalization, and use of mechanical ventilation. The epidemiology of HAP as well as treatment resistance of various causal organisms was studied. Data for this study was acquired from the Registry of Hospital-acquired Infectious Diseases for the year 1998. Out of 329,608 hospital-acquired infections in all patients except newborns, 920 were found to be HAP. This study showed that of every 1000 hospital admissions three patients developed HAP (0.3%). Death occurred in 260 of 920 HAP cases or 30%; and HAP found to be the direct cause of death in 66 of the 260 cases (25%). The greatest incidence of HAP was found to occur in patients older than 75 years, was directly related to the length of hospital stay, and was higher in patients on mechanical ventilation longer than 10 days. The most frequently isolated causal agents were the Gram-negative rods (Pseudomonas aeruginosa, Acinetobacter sp., Klebsiella sp., Enterobacter sp.), and Staphylococcus aureus. Streptococcus pneumoniae and Haemophilus influenzae were found in only 2% and 4% of cases, respectively, and thus were the least likely causes of HAP in this population. It was found that the percentage of methicillin-resistant strains of Staphylococcus aureus was very high (55% to 60%); vancomycin-resistant enterococci were only found in patients who did not undergo surgery. The isolated strains of Pseudomonas aeruginosa showed marked resistance to chinolones (58-76%) and to imipen (approximately 20%). In the Enterobacteriaceae family, Klebsiella sp. was found to be resistant to third-generation cephalosporins (56-73%) and Enterobacter sp. resistant in 55% to 81% of the isolates.

[Mortality associated with hospital acquired infections. Analysis based upon data from the Polish National Program for Control of Infection in 1998]. / Smiertelnosc zwiazana z zakazeniami szpitalnymi. Analiza oparta na danych uzyskanych w ramach ogólnopolskiego programu kontroli zakazen w 1998 roku.

OBJECTIVE: The purpose of this study was to analyse patient mortality connected with hospital acquired infections in Polish hospitals during the year 1998. METHODS: Data was taken from 96 hospitals involved in the National Programme for the Registration of Hospital-Acquired Infections which was established in 1998. The data concerning the presence or absence of 19 specific infection forms was gathered using the passive method. RESULTS: The mortality of patients during 1998 in which hospital acquired infections were the direct or indirect cause of death was 6.9% Pneumonia and blood stream infections were the most frequent causes of death in patients hospitalised in Intensive Care Units. The most important risk factors for the development of hospital acquired infections, included old age, mechanical ventilation and urinary bladder catheterization. CONCLUSIONS: Selected epidemiological indicators for mortality rate were similar to those reported in countries with high quality infection control. A marked difference, however, was seen when comparing dating involving blood stream infections. The level of morbidity was found to be less in Poland than in developed countries. The authors feel that this low morbidity may be secondary to the decreased frequency of blood culture testing in Poland.

[Dominant etiological factors of urinary tract infections in various hospital departments and their resistance to chemotherapeutic agents]. / Czynniki etiologiczne zakazen ukladu moczowego dominujace na róznych oddzialach szpitalnych i ich opornosc na chemioterapeutyki.

PURPOSE: The purpose of this study was the determination of the incidence of urinary tract infection (UTI) in patients hospitalized in specific wards, and the analysis of the factors influencing the incidence of infection. METHODS: 329,608 hospital infection registration cards taken from the Polish national program for registration of hospital infections were analysed. This programme is based on a unified registration card system and on the definitions of particular types of hospital-acquired infections provided by the CDC (Centers for Disease Control, Atlanta, Georgia, USA). Statistical analysis was performed using the Statistica programme. RESULTS: 1,422 cases of hospital-acquired UTI, making up 21% of total hospital-acquired infections, were found. Six hundred sixty-six microbes were isolated from this total number of cases. The dominant pathogens were: Escherichia coli (31%), followed by Pseudomonas aeruginosa (13%), and Enterococcus sp. (12%). Hospital-acquired UTI occurred most often in maternity wards, gynaecology departments and intensive care units. Microbiological confirmation was obtained for only 45% of the clinically diagnosed cases of UTI. A disquieting increase of Pseudomonas aeruginosa resistant to chinolones was observed as well as extremely high resistance to aminoglycosides in Enterococcus sp. CONCLUSIONS: Urinary tract infections (UTIs) are the second most common form of hospital-acquired infection. Causal agents of hospital-acquired UTIs differed, depending upon the specific ward to which the patient is admitted. The most frequently isolated pathogens were Escherichia coli, Pseudomonas aeruginosa and Enterococcus sp. Microbiological confirmation of the clinically diagnosed cases of urinary tract infection is absolutely necessary, as well as a better cooperation between practicing physicians and microbiologists in the detection of hospital-acquired infection and interpretation of results.

Control of an outbreak of Acinetobacter baumannii infections using vaporized hydrogen peroxide.

BACKGROUND: Multidrug-resistant Acinetobacter baumannii (MRAB) is a serious nosocomial pathogen characterized by its survival on inanimate surfaces for long periods, making control of outbreaks difficult. AIM: To analyse two hospital outbreaks caused by MRAB, determine their epidemiology, carbapenem-resistance mechanisms and assess the effectiveness of surface disinfection by vaporized hydrogen peroxide (VHP). METHODS: MRAB strains were isolated from patients in two intensive care units (ICUs). Antimicrobial susceptibility testing was performed by E-test. Polymerase chain reaction (PCR) was used to detect the presence of the most common A. baumannii carbapenemases. Epidemiological typing was performed by rep-PCR (DiversiLab) and pulsed-field gel electrophoresis. VHP was used to decontaminate the affected ICUs. FINDINGS: MRAB was isolated from 28 patients between January 2009 and September 2010. All isolates were resistant to ciprofloxacin and gentamicin. Twenty-one were also resistant to carbapenems. Carbapenem resistance was associated primarily with the acquired OXA-23-like enzyme. Genotyping revealed three clones; the predominant clone corresponded to the international clone (IC) 2. Typing of the isolates pointed to a multifocal outbreak without a single source of infection, with horizontal spread of the dominating clone among ICU patients. A combination of rigorous infection control measures including strict isolation, education of staff, hand hygiene and surface decontamination using VHP halted the outbreak. CONCLUSION: The results of this study confirm the importance of rigorous infection prevention and control measures, combined with VHP decontamination in controlling an outbreak of MRAB.

Comparison of SSI rates in endoarthroplasty of hip and knee in a Cracow patient population and the importance of postdischarge surveillance.

BACKGROUND: The aim of the study was to analyse the epidemiological and microbiological analysis of surgical site infections in patients that underwent knee or hip endoarthroplasty procedures. MATERIALS AND METHODS: The epidemiological and microbiological surveillance was carried out by the local infection control team in cooperation with the Department of Bacteriology, at the Chair of Microbiology, Jagiellonian University Medical College in Cracow. RESULTS: A total of 651 patients operated in the Department of Orthopedics, Trauma Surgery and Rehabilitation of Cracow Rehabilitation Center in Poland were analyzed. Twenty-three cases of SSI were detected. The cumulative incidence after hip prosthesis (HPRO) procedures was 2.3%, while for knee prosthesis (KPRO) it was 7.0. Standardized risk index, comparing the incidence in our study to German hospitals, shows a statistically significant, higher incidence in patients with knee replacement procedures in our study (p=0.004). Among etiological agents of SSIs, we demonstrated the dominating role of Gram-positive cocci to be 75% (30% methicillin resistant). This resistance was confirmed only in case of coagulasenegative staphylococci (no MRSA were cultured). Gramnegative rods were isolated with a frequency of 25%: 41.6% in SSI after hip endoarthroplasty and 15% after knee endoarthroplasty. Postdischarge surveillance encompassed 59% of operated patients. CONCLUSION: The incidence of SSIs of hip prosthesis in our study was comparable to the incidence in the German KISS program, where surveillance is integrating a highly sensitive postdischarge detection. On the other hand, we observed a higher, statistically significant cumulative incidence in case of knee endoarthroplasty. Our microbiological data show effective control of methicillin-resistant Staphylococcus aureus and are also in agreement with the data found in literature referring to coagulasenegative multi-resistant staphylococci as an important problem in the orthopaedic surgery of the knee joint.