MRSA diversity and the emergence of LA-MRSA in a large teaching hospital in Slovenia

The methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of a variety of infections in hospitals and the community. One of the most prominent changes in the MRSA epidemiology is the emergence of livestock-associated MRSA (LA-MRSA) strains in the human population. The aim of this study was to follow the MRSA epidemiology in a large teaching hospital during an 8-year time period (2006–2013). Altogether 519 MRSA, cultured from screening or clinical samples, were distributed into 77 spa types, of which three (t003 and t001, associated with CC5; and t015; associated with CC45) were the most common. LA-MRSA-associated spa types (t011, t034, t108, t899; associated with CC398) started to emerge in the year 2009 and continued to be found annually at a frequency from 3.9% to 12.7% of all MRSA strains examined. Only 6 of 27 LA-MRSA strains were associated with infections

False-Positive Result of a Confirmatory Human Immunodeficiency Virus Line Immuno Assay in an Apparently Healthy Individual – A Case Report

A case of a false-positive result of human immunodeficiency virus (HIV) confirmatory immunoblot-based assay is described. Repeatedly borderline reactive anti-HIV screening enzyme immunoassay result obtained in a local hospital resulted in directing the sample to the Slovenian HIV/AIDS Reference Laboratory. In the Reference Laboratory, both anti- HIV screening assays and confirmatory Western blot were negative, while a confirmatory test INNO-LIA HIV I/II Score (Innogenetics, Ghent, Belgium) was anti-HIV-1 positive due to sgp120 and gp41 reactivity. The results of serological testing of the second sample obtained three weeks later were completely identical, while in the third sample obtained 5 months later, seroreversion was observed. Due to a negative dynamics in anti-HIV serological profile and repeatedly negative results of the molecular tests for HIV-1 and HIV-2, HIV infection was excluded and the results of test INNO-LIA HIV I/II Score were finally interpreted as false positive

EPIDEMIOLOGICAL AND MICROBIOLOGICAL APPROACHES FOR HAI SURVEILLANCE AT THE UNIVERSITY MEDICAL CENTER MARIBOR

Bolnišnične okužbe (BO) so okužbe, povezane z zdravstveno oskrbo (OPZ), ki nastanejo v bolnišnici in predstavljajo najpogostejši zaplet zdravljenja v bolnišnici. Spremljanje njihove pogostosti se lahko uporablja kot kazalnik kakovosti za bolnišnice. K spremljanju spreminjanja pogostosti BO lahko pristopimo tudi s ponavljajočimi se presečnimi raziskavami BO. Evropski center za preprečevanje in obvladovanje bolezni (angl. European Centre for Disease Prevention and Control, ECDC) vsakih pet let koordinira izvedbo evropske presečne raziskave BO. Leta 2011 smo v Sloveniji opravili drugo Slovensko nacionalno presečno raziskavo BO (SNPRBO II), prevalenčno presečno raziskavo na dan (angl. point prevalence survey - PPS) v okviru evropske prevalenčne presečne raziskave BO. V raziskavi je sodeloval tudi Univerzitetni klinični center (UKC) Maribor. Visoko usposobljena zdravnica za obvladovanje in preprečevanje BO (ZOBO) je v UKC Maribor opravila vzporedno validacijo metode zbiranja podatkov, ki so jih zbrali anketarji v skladu s standardizirano metodologijo zbiranja podatkov, ki jo priporoča ECDC. Preverila je pravilnost zabeleženih podatkov za vse bolnike, pri katerih so anketarji prepoznali BO, in za vsakega petega bolnika, pri katerem anketarji niso prepoznali BO. Ob spremljanju širjenja mikroorganizmov znotraj bolnišnice in prepoznavanju izbruhov je pomembna tipizacija mikroorganizmov, ki so povzročili BO. V UKC Maribor smo se odločili za tipizacijo proti meticilinu odpornih zlatih stafilokokov (angl. Methicillin resistant Staphylococcus aureus, MRSA), saj je spremljanje MRSA obvezni kazalnik kakovosti v slovenskih bolnišnicah. Tipizirali smo tudi bakterijo Clostridium difficile (CD), saj marsikje v zdravstveno razvitih državah CD predstavlja kazalnik kakovosti in povzroča klinično pomembne okužbe. Za MRSA smo uporabili spa tipizacijo, za CD pa ribotipizacijo. Cilji doktorske naloge so vključevali: razvoj modificirane, delovno intenzivnejše metode za validacijo uporabljene »običajne ECDC metode« za prepoznavanje BO v presečni raziskavi (»modificirana ECDC metoda«)ocenili smo prevalence BO ob uporabi »običajne ECDC metode« in »modificirane ECDC metode«, razvite v okviru doktorske nalogeobčutljivost in specifičnost »običajne ECDC metode« za prepoznavanje BO v primerjavi z »modificirano ECDC metodo« ter potrebo po nadomestitvi »običajne ECDC metodo« z našo »modificirano ECDC metodo«. Opisali smo značilnosti bolnikov, vključenih v presečno raziskavo, izpostavljenost invazivnim postopkom, BO, izolirane mikroorganizme in odpornost nekaterih mikroorganizmov na izbrane antibiotike ali skupine antibiotikov, ter uporabo antibiotikov. Spremljali smo dva izbrana povzročitelja BO, MRSA in CD, v časovnem obdobju enega leta in ocenili pomen molekularnih tipizacij za prepoznavanje in nadzor BO. V PPS smo vključili 991 bolnikov, to je vse bolnike, ki so bili hospitalizirani v UKC Maribor na dan raziskave. O vsakem smo zabeležili številne podatke, tudi o dejavnikih tveganja za BO, zdravljenju s protimikrobnimi sredstvi in BO. Z obema metodama smo prepoznali 52 bolnikov, ki so na dan raziskave imeli vsaj eno BO oziroma so bili na dan raziskave še vedno zdravljeni zaradi BO. Ustrezna ocena prevalence BO je bila 5,2 % (s 95 % intervalom zaupanja 3,9 % - 6,8 %). Največ BO so imeli bolniki v enotah za intenzivno zdravljenje (EIZ) 25,0 %, na kirurških oddelkih je imelo BO 6,2 % bolnikov, na ginekološkem in porodnem oddelku 4,4 %, na internih oddelkih 3,1 % bolnikov. Z univariatnimi in multivariatnimi analizami smo opredelili neodvisne dejavnike tveganja za BO: prisotnost vsadka v zadnjem letu, prisotnost urinskega katetra, operacija v zadnjih 30 dneh in intubacija. Skupno smo prepoznali 66 BO. Najpogostejše so bile okužbe spodnjih dihal (25 %), okužbe kirurške rane in okužbe sečil. 9 % BO je bilo prisotnih že ob sprejemu bolnika v UKC Maribor, 91 % BO pa je bilo pridobljenih v času aktualne hospitalizacije, največ v obdobju 4.–7. dne po sprejemu. VHospital-acquired infections (HAI) are infections occurring in hospital environment. They are associated with medical care and high complications rates. Monitoring their frequency can be used as a quality indicator for hospitals. Repeated cross-sectional HAI surveys can be applied to monitor the changes in the frequency of HAI. Every 5 years the implementation of a cross-sectional HAI survey is coordinated by the European Centre for Disease Prevention and Control (ECDC). In 2011, the second Slovenian National Cross-Sectional point prevalence survey (SNPRBO II) was conducted as part of a European Point Prevalence HAI study. The University Medical Centre Maribor was taking part in this study, where a high-qualified clinician for the management and control of HAI carried out a parallel validation of data, collected by interviewers in line with a standardized methodology for the collection of data as recommended by ECDC. The accuracy of the recorded data for all HAI patients and for every fifth patient without HAI were checked by qualified clinician. Next to surveillance of micro-organisms spreading in the hospital environment and recognizing outbreaks, characterization of microorganisms (typing) causing HAI also plays a crucial role. At the University Medical Centre Maribor (UKC Maribor), methicillin resistant Staphylococcus aureus (MRSA) typing was used because the surveillance of MRSA is a mandatory quality indicator in Slovene hospitals. Clostridium difficile (CD) was chosen for typing because it is a quality indicator in numerous countries and is currently one of the most important health care associated infections. Spa typing was used for MRSA and ribotyping was used for CD. The objectives of the thesis were the following: to develop a modified, work-intensive method of HAI recognition ("modified ECDC method") in order to validate the applied "usual ECDC method" for recognizing HAI in a cross-sectional HAI surveyto evaluate the HAI prevalence by using the "usual" and the "modified ECDC method" developed in the doctoral thesisto assess the sensitivity and specificity of the "usual ECDC method" for identifying HAI compared to the "modified ECDC method" and assess the need to replace the "normal ECDC method" with our "modified ECDC method". We described the characteristics of patients involved in the survey, invasive procedures, HAI, exposure to commonly known risk factors for hospital infections, isolated microorganisms, and the resistance of certain microorganisms to selected antibiotics or groups of antibiotics, as well as the use of antibiotics. MRSA and CD were monitored over a period of at least one year and the importance of molecular typing for the recognition and control of HAI was evaluated. The point prevalence study (PPS) included 991 patients, i.e. every patient that was hospitalized at the UKC Maribor on the day of survey. In addition to general data, HAI risk factors, treatment with antimicrobials, and hospital-acquired infections were also recorded. Using both methods, 52 patients with at least one HAI on the day of study were identified or still receiving treatment for HAI on the day of the study. HAIs prevalence was 5.2% (with a 95% CI 3.9%–6.8%). The prevalence of HAIs in ICUs was the highest (25.0%), followed by patients in surgical wards (6.2%), obstetrics/gynecology (4.4%), and departments of internal medicine (3.1%). By using univariate and multivariate analyses, independent risk factors for HAI were defined: implant surgery in the last year, a urinary catheter, patients undergone surgery in the last 30 days and intubation. 66 HAIs were identified in total. The most common were lower respiratory tract infections (25%), surgical wound infections, and urinary tract infections. 9% of HAIs were already present at hospital admission, 91% were acquired during the current hospital stay and the majority was acquired in the period from day 4 to 7 following admittance. Except of one, all HAIs were acquired a

Raznolikost MRSA spa tipov, izoliranih pri bolnikih iz Univerzitetnega kliničnega centra Maribor

Background: Typing of pathogens is an important part in control and preventionof health care-associated infections. For methilcillin-resistant S. aureus (MRSA) a new sequence-based and easily internationally comparable typing method, spa typing, was recently described. We have used this method to analyze the MRSA types present in our hospital and to compare them with types reported elsewhere. Methods: 63 MRSA strains isolated from patients in Maribor University Hospital (MUH) during the year 2006 were spa typed. Typing data were compared to the patient hospitalization data to detect possible spatial and temporal clusters. Results: Sixty-three MRSA strains were distributed into 12 spa types. Seven spa types were represented only by a single isolate. The three most prevalent types (t001, t288, t003) included 80 % of all strains. The most prevalent type, t001, was present in many differentwards and during entire year. This type is also one of the mostly isolated types worldwide. High prevalence of other two types seems to be associated with small scale transmission events. Conclusions: Most of the spa types present in MUH are well known and widespread also elsewhere in Slovenia, in other EU countries and worldwide. Typing has helped us to follow the introduction of different MRSA types to the hospital environment and to detect occasional transmissions.Izhodišča: Tipizacija patogenih mikroorganizmov lahko doprinese k nadzoru in preprečevanju bolnišničnih okužb. Za tipizacijo sevov S. aureus je bila opisana nova metoda, ki temelji na določanju nukleotidnega zaporedja gena spa, ki kodira protein A. Rezultati so zato za razliko od do sedaj uporabljanih metod zelo lahko primerljivi med laboratoriji. Z novo metodo smo zato želeli preiskati seve, izolirane v naši bolnišnici, ugotoviti raznolikost prisotnih tipov ter jih primerjati z drugimi bolnišnicami. Metode: Vsem sevom MRSA, izoliranim pri bolnikih Univerzitetnega kliničnega centra Maribor v letu 2006, smo določili spa tip. Rezultate tipizacije smo nato primerjali s podatki hospitalizacije posameznega bolnika ter tako sledili morebitne časovne in prostorske povezave. Rezultati: Triinšestdeset MRSA sevov smo uvrstili v 12 spa tipov. Sedem spa tipov je imelo le po enega predstavnika. Trije najpogostejši spa tipi (t001, t288, t003) so predstavljali 80 % vseh preiskanih sevov. Najpogostejši tip t001 je bil prisoten na številnih oddelkih v celem letu. Visok delež drugih dveh tipov pa je najverjetneje povezan s prenosi manjšega obsega. Zaključki: Večina MRSA tipov spa, ki so bili prisotni v UKC Maribor v letu 2006, je pogostih tudi drugje v Sloveniji, v Evropi in v svetu. S pomočjo tipizacije smo lahko natančneje sledili vnos MRSA v našo bolnišnico ter prenose znotraj bolnišnice

The prevalence of and risk factors for healthcare-associated infections in Slovenia: results of the second national survey

In the second Slovenian national healthcare-associated infections (HAIs) prevalence survey, conducted within the European point prevalence survey of HAIs and antimicrobial use in acute-care hospitals, we estimated the prevalence of all types of HAIs and identified risk factors