Staphylococcus aureus is a commensal colonizing the skin and mucous membranes. It can also act as a pathogen, and is the most common microorganism isolated from prosthetic joint infections (PJIs). The aim of this study was to explore the genomic relatedness between commensal and PJI S. aureus strains as well as microbial traits and host-related risk factors for treatment failure. Whole-genome sequencing (WGS) was performed on S. aureus isolates obtained from PJIs (n = 100) and control isolates from nares (n = 101). Corresponding clinical data for the PJI patients were extracted from medical records. No PJI-specific clusters were found in the WGS phylogeny, and the distribution of the various clonal complexes and prevalence of virulence genes among isolates from PJIs and nares was almost equal. Isolates from patients with treatment success and failure were genetically very similar, while the presence of an antibiotic-resistant phenotype and the use of non-biofilm-active antimicrobial treatment were both associated with failure.In conclusion, commensal and PJI isolates of S. aureus in arthroplasty patients were genetically indistinguishable, suggesting that commensal S. aureus clones are capable of causing PJIs. Furthermore, no association between genetic traits and outcome could be demonstrated, stressing the importance of patient-related factors in the treatment of S. aureus PJIs.

Background: Inflammatory bowel disease (IBD) places a significant burden on health-care systems because of its chronicity and need for expensive therapies and surgery. With increasing use of biological therapies, contemporary data on IBD health-care costs are important for those responsible for allocating resources in Europe. To our knowledge, no prospective long-term analysis of the health-care costs of patients with IBD in the era of biologicals has been done in Europe. We aimed to investigate cost profiles of a pan-European, community-based inception cohort during 5 years of follow-up.

Methods: The Epi-IBD cohort is a community-based, prospective inception cohort of unselected patients with IBD diagnosed in 2010 at centres in 20 European countries plus Israel. Incident patients who were diagnosed with IBD according to the Copenhagen Diagnostic Criteria between Jan 1, and Dec 31,2010, and were aged 15 years or older the time of diagnosis were prospectively included. Data on clinical characteristics and direct costs (investigations and outpatient visits, blood tests, treatments, hospitalisations, and surgeries) were collected prospectively using electronic case-report forms. Patient-level costs incorporated procedures leading to the initial diagnosis of IBD and costs of IBD management during the 5-year follow-up period. Costs incurred by comorbidities and unrelated to IBD were excluded. We grouped direct costs into the following five categories: investigations (including outpatient visits and blood tests), conventional medical treatment, biological therapy, hospitalisation, and surgery.

Findings: The study population consisted of 1289 patients with IBD, with 1073 (83%) patients from western Europe and 216 (17%) from eastern Europe. 488 (38%) patients had Crohn's disease, 717 (56%) had ulcerative colitis, and 84 (6%) had IBD unclassified. The mean cost per patient-year during follow-up for patients with IBD was (sic)2609 (SD 7389; median (sic)446 [IQR 164-1849]). The mean cost per patient-year during follow-up was (sic)3542 (8058; median (sic)717 [214-3512]) for patients with Crohn's disease, (sic)2088 (7058; median (sic)408 [133-1161]) for patients with ulcerative colitis, and (sic)1609 (5010; median (sic)415 [92-1228]) for patients with IBD unclassified (p<0.0001). Costs were highest in the first year and then decreased significantly during follow-up. Hospitalisations and diagnostic procedures accounted for more than 50% of costs during the first year. However, in subsequent years there was a steady increase in expenditure on biologicals, which accounted for 73% of costs in Crohn's disease and 48% in ulcerative colitis, in year 5. The mean annual cost per patient-year for biologicals was (sic)866 (SD 3056). The mean yearly costs of biological therapy were higher in patients with Crohn's disease ((sic)1782 [SD 4370]) than in patients with ulcerative colitis ((sic)286 [1427]) or IBD unclassified ((sic)521 [2807]; p<0.0001).

Interpretation: Overall direct expenditure on health care decreased over a 5-year follow-up period. This period was characterised by increasing expenditure on biologicals and decreasing expenditure on conventional medical treatments, hospitalisations, and surgeries. In light of the expenditures associated with biological therapy, cost-effective treatment strategies are needed to reduce the economic burden of inflammatory bowel disease.

Background: Women with inflammatory bowel diseases (IBD) often receive biologicals during pregnancy to maintain disease remission. Data on outcome of vedolizumab-exposed pregnancies (VDZE) are sparse.

Aims: The aim was to assess pregnancy and child outcomes of VDZE pregnancies and to compare these results to anti-TNF exposed (TNFE) or both immunomodulatory and biologic unexposed (CON IBD) pregnancies.

Methods: A retrospective multicentre case-control observational study was performed.

Results: VDZE group included 79 pregnancies in 73 IBD women. The TNFE and CON IBD group included 186 pregnancies (162 live births) in 164 IBD women and 184 pregnancies (163 live births) in 155 IBD women, respectively. At conception, cases more often had active disease ([VDZE: 36% vs TNFE: 17%, P = .002] and [VDZE: 36% vs CON IBD: 24%, P = .063]). No significant difference in miscarriage rates were found between groups (VDZE and TNFE: 16% vs 13%, P = .567; VDZE and CON IBD: 16% vs 10%, P = .216). In live-born infants, median gestational age and birthweight were similar between groups. Median Apgar score at birth was numerically equal. Prematurity was similar in the VDZE group compared to the control groups, even when correcting for disease activity during pregnancy. The frequency of congenital anomalies was comparable between groups as were the percentages of breastfed babies. During the first year of life, no malignancies were reported and infants' infection risk did not significantly differ between groups.

Conclusion: No new safety signal was detected in VDZE pregnancies although larger, prospective studies are required for confirmation.

Introduction: Whether data on International Classification of Diseases (ICD)-codes from the Swedish National Patient Register (NPR) correctly correspond to subtypes of inflammatory bowel disease (IBD) and phenotypes of the Montreal classification scheme among patients with prevalent disease is unknown.

Materials and methods: We obtained information on IBD subtypes and phenotypes from the medical records of 1403 patients with known IBD who underwent biological treatment at ten Swedish hospitals and retrieved information on their IBD-associated diagnostic codes from the NPR. We used previously described algorithms to define IBD subtypes and phenotypes. Finally, we compared these register-generated subtypes and phenotypes with the corresponding information from the medical records and calculated positive predictive values (PPV) with 95% confidence intervals.

Results: Among patients with clinically confirmed disease and diagnostic listings of IBD in the NPR (N = 1401), the PPV was 97 (96-99)% for Crohn's disease, 98 (97-100)% for ulcerative colitis, and 8 (4-11)% for IBD-unclassified. The overall accuracy for age at diagnosis was 95% (when defined as A1, A2, or A3). Examining the validity of codes representing disease phenotype, the PPV was 36 (32-40)% for colonic Crohn's disease (L2), 61 (56-65)% for non-stricturing/non-penetrating Crohn's disease behaviour (B1) and 83 (78-87)% for perianal disease. Correspondingly, the PPV was 80 (71-89)% for proctitis (E1)/left-sided colitis (E2) in ulcerative colitis.

Conclusions: Among people with known IBD, the NPR is a reliable source of data to classify most subtypes of prevalent IBD, even though misclassification commonly occurred in Crohn's disease location and behaviour and also among IBD-unclassified patients.

BACKGROUND: A definitive diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) is not always possible and a proportion of patients will be diagnosed as inflammatory bowel disease unclassified (IBDU). The aim of the study was to investigate the prognosis of patients initially diagnosed with IBDU and the disease course during the following five years.

METHODS: The Epi-IBD study is a prospective population-based cohort of 1,289 IBD patients diagnosed in centres across Europe. Clinical data were captured prospectively throughout the follow-up period.

RESULTS: Overall, 476 (37%) patients were initially diagnosed with CD, 701 (54%) with UC, and 112 (9%) with IBDU. During follow-up, 28 (25%) IBDU patients were changed diagnoses to either UC (n=20, 71%) or CD (n=8, 29%) after a median of six months (IQR: 4-12), while 84 (7% of the total cohort) remained IBDU. A total of 17 (15%) IBDU patients were hospitalized for their IBD during follow-up, while 8 (7%) patients underwent surgery. Most surgeries (n=6, 75%) were performed on patients whose diagnosis was later changed to UC; three of these colectomies led to a definitive diagnosis of UC. Most patients (n=107, 96%) received 5-aminosalicylic acid, while 11 (10%) patients received biologicals, of whom five remained classified as IBDU.

CONCLUSIONS: In a population-based inception cohort, 7% of IBD patients were not given a definitive diagnosis of IBD after five years of follow-up. One in four patients with IBDU eventually were classified as CD or UC. Overall, the disease course and medication burden in IBDU patients were mild.

OBJECTIVE: Thiopurines are used as maintenance therapy in ulcerative colitis (UC), but whether these drugs influence the natural history of the disease is unknown. We aimed to assess the effect of thiopurines in terms of colectomy, hospital admission, progression in disease extent and anti-tumour necrosis factor (TNF) therapy within 10 years from initiation.

DESIGN: Patients diagnosed with UC within the Örebro University Hospital catchment area, during 1963-2010, who initiated thiopurines (n=253) were included. To overcome the risk of confounding by indication, we compared patients who stopped treatment within 12 months because of an adverse reaction (n=76) with patients who continued therapy or discontinued due to other reasons (n=177) and assessed long-term outcomes using Cox regression with adjustment for potential confounding factors.

RESULTS: The cumulative probability of colectomy within 10 years was 19.5% in tolerant patients compared with 29.0% in intolerant (adjusted HR 0.49; 95% CI 0.21 to 0.73). The probability of hospital admission was 34.0% in tolerant versus 56.2% in intolerant patients (adjusted HR 0.36; 95% CI 0.23 to 0.56). The risk for progression in disease extent was 20.4% in tolerant patients compared with 48.8% in intolerant (adjusted HR 0.47; 95% CI 0.21 to 1.06). Within 10 years, 16.1% of tolerant and 27.5% of intolerant patients received anti-TNF therapy (adjusted HR 0.49; 95% CI 0.26 to 0.92).

CONCLUSION: Based on the novel approach of comparing patients tolerant and intolerant to thiopurines, we reveal that thiopurines have a profound beneficial impact of the natural history and long-term colectomy rates of UC.