Lasten sairaalainfektiot

Healthcare-associated infections (HAIs) are known to increase the risk for patient morbidity and mortality in different healthcare settings and thereby to cause additional costs. HAIs typically affect patients with severe underlying conditions. HAIs are prevalent also among pediatric patients, but the distribution of the types of infection and the causative agents differ from those detected in adults. The aim of this study was to obtain information on pediatric HAIs in Finland through an assessment of the surveillance of bloodstream infections (BSIs), through two outbreak investigations in a neonatal intensive care unit (NICU), and through a study of postoperative HAIs after open-heart surgery. The studies were carried out at the Hospital for Children and Adolescents of Helsinki University Central Hospital. Epidemiological features of pediatric BSIs were assessed. For the outbreak investigations, case definitions were set and data collected from microbiological and clinical records. The antimicrobial susceptibilities of the Serratia marcescens and the Candida parapsilosis isolates were determined and they were genotyped. Patient charts were reviewed for the case-control and cohort studies during the outbreak investigations, as well as for the patients who acquired surgical site infections (SSIs) after having undergone open-heart surgery. Also a prospective postdischarge study was conducted to detect postoperative HAIs in these patients. During 1999-2006, the overall annual BSI rate was 1.6/1,000 patient days (range by year, 1.2–2.1). High rates (average, 4.9 and 3.2 BSIs/1,000 patient days) were detected in hematology and neonatology units. Coagulase-negative staphylococci were the most common pathogens both hospital-wide and in each patient group. The overall mortality was 5%. The genotyping of the 15 S. marcescens isolates revealed three independent clusters. All of the 26 C. parapsilosis isolates studied proved to be indistinguishable. The NICU was overcrowded during the S. marcescens clusters. A negative correlation between C. parapsilosis BSIs and fluconazole use in the NICU was detected, and the isolates derived from a single initially susceptible strain became less susceptible to fluconazole over time. Eighty postoperative HAIs, including all severe infections, were detected during hospitalization after open-heart surgery; 34% of those HAIs were SSIs and 25% were BSIs. The postdischarge study found 65 infections that were likely to be associated with hospitalization. The majority (89%) of them were viral respiratory or gastrointestinal infections, and these often led to rehospitalizations. The annual hospital-wide BSI rates were stable, and the significant variation detected in some units could not be seen in overall rates. Further studies with data adequately adjusted for risk factors are needed to assess BSI rates in the patient groups with the highest rates (hematology, neonatology). The outbreak investigations showed that horizontal transmission was common in the NICU. Overcrowding and lapses in hand hygiene probably contributed to the spreading of the pathogens. Following long-term use of fluconazole in the NICU, resistance to fluconazole developed in C. parapsilosis. Almost one-fourth of the patients who underwent open-heart surgery acquired at least one HAI. All severe HAIs were detected during hospitalization. The postdischarge study found numerous viral infections, which often caused rehospitalization.Hoitoon liittyvät infektiot eli sairaalainfektiot lisäävät potilaiden sairastavuutta ja kuolleisuutta terveydenhuollon laitoksissa. Sairaalainfektioita esiintyy eniten kirurgisia toimenpiteitä tai tehohoitoa tarvitsevilla potilailla sekä potilailla, joiden vastustuskyky on perussairauksien vuoksi heikentynyt. Lasten sairaalainfektioiden aiheuttajat ja infektiotyypit poikkeavat aikuisten infektioista. Tämän tutkimuksen tavoitteena oli selvittää sairaalainfektioiden esiintyvyyttä suomalaisessa lastensairaalassa eri potilasryhmissä ja eri infektiotyyppien osalta. Väitöskirja koostuu neljästä osatyöstä: veriviljelypositiivisten infektioiden seurantatutkimuksesta, kahdesta vastasyntyneiden teho-osastolla tehdystä epidemiaselvityksestä sekä sydänleikattujen lasten sairaalainfektiotutkimuksesta. Tutkimusaineisto kerättiin Helsingin yliopistollisen keskussairaalan Lasten ja nuorten sairaalassa vuosina 1999-2006. Tutkimusaikana todettuja veriviljelypositiivisia sairaalainfektioita tarkasteltiin koko sairaalassa ja eri yksiköissä. Vastasyntyneiden teho-osastolla ilmenneitä Serratia marcescens ja Candida parapsilosis -epidemioita selviteittiin: epidemiakantojen mikrobilääkeherkkyydet määritettiin ja kannat tyypitettiin DNA-pohjaisten menetelmien avulla. Avosydänleikkauksen läpikäyneiden lasten hoitojakson aikana ilmenneet leikkausalueen infektiot sekä muut sairaalainfektiot selvitettiin sairauskertomusten ja sairaalan tietojärjestelmien avulla, kotiutuksen jälkeiset leikkausalueen infektiot sekä todennäköisesti sairaalasyntyiset virusinfektiot kartoitettiin kotiutusvaiheessa jaetun kyselylomakkeen avulla. Tutkimus osoitti, että veriviljelypositiivisten sairaalainfektioiden esiintyvyys pysyi seurantajakson aikana samalla tasolla. Hematologisia potilaita ja sairaita vastasyntyneitä hoitavissa yksiköissä esiintyvyys oli huomattavasti keskimääräistä suurempi, ja näissä yksiköissä ilmeni myös suuria vuosittaisia vaihteluja infektioluvuissa. Epidemiaselvitykset osoittivat, että mikrobitartunnat potilaasta toiseen olivat tavallisia, ja että osaston ylikuormitus sekä siihen liittyvät ongelmat käsihygienian toteutumisessa todennäköisesti edesauttoivat epidemioiden leviämistä. Flukonatsoliestolääkityksen pitkäaikainen käyttö osastolla johti flukonatsolille vastustuskykyisten C. parapsilosis -alatyyppien kehittymiseen. Avosydänleikatuista lapsista jopa joka neljäs sai sairaalainfektion leikkauksen jälkeen. Vakavat infektiot todettiin sairaalajakson aikana, mutta kotiutuksen jälkeen esiintyi runsaasti todennäköisesti sairaalasyntyisiä virusinfektioita, jotka aiheuttivat usein uuden sairaalahoitojakson

Molecular epidemiology of carbapenemase-producing Enterobacterales in Finland, 2012-2018

Carbapenemase-producing Enterobacterales (CPE) pose an increasing threat to patient safety and healthcare systems globally. We present molecular epidemiology of CPE in Finland during 2012-2018 with detailed characteristics of CPE strains causing clusters during the same time period. All Finnish clinical microbiology laboratories send Enterobacterales isolates with reduced susceptibility to carbapenems or isolates producing carbapenemase to the reference laboratory for further characterization by whole genome sequencing (WGS). In total, 231 CPE strains from 202 patients were identified during 2012-2018. Of the strains, 59% were found by screening and 32% from clinical specimens, the latter were most commonly urine. Travel and/or hospitalization history abroad was reported for 108/171 strains (63%). The most common species were Klebsiella pneumoniae (45%), Escherichia coli (40%), and Citrobacter freundii (6%), and the most common carbapenemase genes bla(NDM-like) (35%), bla(OXA-48-like) (33%), and bla(KPC-like) (31%). During 2012-2018, the annual number of CPE strains increased from 9 to 70 and different sequence types from 7 to 33, and bla(OXA-48-like) genes became the most prevalent. Of the clusters, 3/8 were linked to traveling or hospitalization abroad and 5/8 were caused by K. pneumoniae clone clonal complex 258. Most of the clusters were caused by K. pneumoniae producing KPC. High variety among different sequence types indicates that majority of CPE cases detected in Finland are likely imported from foreign countries. Nearly one-third of the cases are not found by screening suggesting that there is hidden transmission occurring in the healthcare settings.Peer reviewe