Evaluation of rectal swab use for the determination of enteric pathogens: a prospective study of diarrhoea in adults.

OBJECTIVES: A stool sample is the sample of choice for microbiological testing of enteric pathogens causing diarrhoea, but a rectal swab can be a more practical alternative. A prospective observational study was performed to evaluate the diagnostic performance of flocked rectal swab specimens using the syndromic molecular approach to determine the aetiology of diarrhoea in adults. METHODS: We compared the performance of rectal swabs with stool samples as the reference standard in determining viral, bacterial and protozoal pathogens using real-time multiplex PCR as well as standard stool culture. Paired samples of stool and rectal swab specimens were collected from 304 adult patients with diarrhoea, presented at the Department of Infectious Diseases, University Medical Centre Ljubljana, between June 2016 and August 2017. RESULTS: Overall sensitivity of rectal swab samples in the syndromic molecular approach was 83.2% (95% CI 77.2%-88.1%). Pathogen group-specific analysis of rectal swabs showed sensitivity of 65.6% (95% CI 52.7%-77.1%) for viruses and 57.1% (95% CI 28.9%-82.3%) for parasites. For bacteria, sensitivity was 86.5% (95% CI 79.5%-91.8%) when PCR was performed and 61.4% (95% CI 52.4%-69.9%) when culture for bacteria was performed. Mean threshold cycle (Ct) values for most pathogens were higher in rectal swab specimens than in stool specimens. CONCLUSIONS: Our results indicate that rectal swabs can be used in the diagnosis of diarrhoea in adults when stool specimens are not available or when rapid aetiological determination is needed. However, rectal swabs should be analysed using a molecular approach. The mean Ct value for most pathogens is higher in rectal swab specimens than in stool specimens.

Successful control of the first OXA-48 and/or NDM carbapenemase-producing Klebsiella pneumoniae outbreak in Slovenia 2014-2016.

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) occur only sporadically in Slovenia. AIM: To describe the first Slovenian carbapenemase-producing (CP) Klebsiella pneumoniae and Escherichia coli outbreak which occurred at the tertiary teaching hospital University Medical Centre Ljubljana from October 2014 to April 2015. METHODS: A CPE-positive case was defined as any patient infected or colonized with CPE. A strict definition of a contact patient was adopted. Measures to prevent cross-transmission included cohorting of all CPE carriers with strict contact precautions and assignment of dedicated healthcare workers, cohorting of all contact patients until obtaining the result of screening cultures, systematic rectal screening of contact patients, and tagging of all CPE-positive cases and their contacts. Educational campaigns on CPEs were implemented. Clinical specimens were processed using standard procedures. Pulsed-field gel electrophoresis (PFGE) was used to determine relatedness. Multi-locus sequence typing was performed on CP K. pneumoniae isolates that belonged to different pulsotypes. FINDINGS: Before the outbreak was brought under control, 40 patients were colonized or infected with OXA-48 and/or New Delhi metallo-ß-lactamase (NDM)-producing CPE; in 38 patients OXA-48 and/or NDM-producing K. pneumoniae was detected, in seven OXA-48 and/or NDM-producing E. coli was found together with K. pneumoniae, and in two patients only CP E. coli was isolated. The outbreak was oligoclonal with two major CP K. pneumoniae clusters belonging to ST437 and ST147 in epidemiologically linked patients. CONCLUSION: Initial standard control measures failed to prevent the outbreak. Once the problem had been recognized, strict infection control measures and the education of healthcare workers contributed to the successful control of the outbreak.

One-year outcome following biological or mechanical valve replacement for infective endocarditis.

BACKGROUND: Nearly half of patients require cardiac surgery during the acute phase of infective endocarditis (IE). We describe the characteristics of patients according to the type of valve replacement (mechanical or biological), and examine whether the type of prosthesis was associated with in-hospital and 1-year mortality. METHODS AND RESULTS: Among 5591 patients included in the International Collaboration on Endocarditis Prospective Cohort Study, 1467 patients with definite IE were operated on during the active phase and had a biological (37%) or mechanical (63%) valve replacement. Patients who received bioprostheses were older (62 vs 54years), more often had a history of cancer (9% vs 6%), and had moderate or severe renal disease (9% vs 4%); proportion of health care-associated IE was higher (26% vs 17%); intracardiac abscesses were more frequent (30% vs 23%). In-hospital and 1-year death rates were higher in the bioprosthesis group, 20.5% vs 14.0% (p=0.0009) and 25.3% vs 16.6% (p<.0001), respectively. In multivariable analysis, mechanical prostheses were less commonly implanted in older patients (odds ratio: 0.64 for every 10years), and in patients with a history of cancer (0.72), but were more commonly implanted in mitral position (1.60). Bioprosthesis was independently associated with 1-year mortality (hazard ratio: 1.298). CONCLUSIONS: Patients with IE who receive a biological valve replacement have significant differences in clinical characteristics compared to patients who receive a mechanical prosthesis. Biological valve replacement is independently associated with a higher in-hospital and 1-year mortality, a result which is possibly related to patient characteristics rather than valve dysfunction.

Revisiting the effect of referral bias on the clinical spectrum of infective endocarditis in adults.

Referral bias occurs because of the clustering of patients at tertiary care centers. This may result in the distortion of observed clinical manifestations of rare diseases. This analysis evaluates the effect of referral bias on the epidemiology of infective endocarditis (IE) in the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS). This is a prospective multicenter cohort study comparing transferred and non-transferred patients with IE. Factors independently associated with transfer status were evaluated using multivariable logistic regression. A total of 2,760 patients were included in the analysis, of which 1,164 (42.2%) were transferred from other medical centers. Transferred patients more often underwent surgery for IE (odds ratio [OR] = 2.5; 95% confidence interval [CI] 1.9-3.2). They were also more likely to have complications such as stroke (OR = 1.5; 95% CI 1.3-1.9), heart failure (OR = 1.4; 95% CI 1.1-1.6), and new valvular regurgitation (OR = 1.3; 95% CI 1.1-1.6). The in-hospital mortality rates were similar in both groups. Patients with IE who require surgery and suffer complications are referred to tertiary hospitals more frequently than patients with an uncomplicated course. Hospital transfer has no obvious effect on the in-hospital mortality. Referral bias should be taken into consideration when describing the clinical spectrum of IE.

Human alveolar echinococcosis in Slovenia.

Between January 2001 and December 2005, 1263 patients suspected of having echinococcosis were screened serologically by indirect haemagglutination assay (IHA). IHA-positive patient sera were then retested by western blot for confirmation and differentiation between Echinococcus granulosus and Echinococcus multilocularis infection. Of 43 sera confirmed as Echinococcus-positive, nine appeared to be specific for alveolar echinococcosis (AE) caused by E. multilocularis. AE-positive serological results corresponded to the clinical and/or imaging findings concerning the patients' liver cysts. The detected incidence of AE was 0.45/10(5) inhabitants, which suggests that clinicians and health authorities in Slovenia should give greater attention to AE in the future.

Prevalance of and risk factors for hospital-acquired infections in Slovenia-results of the first national survey, 2001.

A one-day survey was conducted in all (19) Slovenian acute-care hospitals in October 2001 to estimate the prevalence of all types of hospital-acquired infections (HAIs) and to identify predominant micro-organisms and risk factors. Among 6695 patients surveyed, the prevalence of patients with at least one HAI was 4.6%. The prevalence of urinary tract infections was highest (1.2%), followed by pneumonia (1.0%), surgical wound infection (0.7%), and bloodstream infection (0.3%). In intensive care units (ICUs) the prevalence of patients with at least one HAI was 26.9% and the ratio of episodes of HAI per number of patients was 33.3%. One or more pathogens were identified in 55.8% of HAIs episodes. Among these, the most frequently single isolated micro-organisms were Staphylococcus aureus (18.2%) and Escherichia coli (10.2%). Risk factors for HAI included central intravascular catheter (adjusted odds ratio (OR) 3.2; 95% confidence intervals (CI) 2.1-4.9), peripheral intravascular catheter (adjusted OR 1.7; 95% CI 1.2-2.4), urinary catheter (adjuster OR 2.4; 95% CI 1.6-3.4), and hospitalization in ICUs (adjusted OR 2.5; 95% CI 1.4-4.3). The results provide the first national estimates for Slovenia.

Epidemiological typing of imipenem-resistant Pseudomonas aeruginosa.

The level of genetic heterogeneity of nine isolates of Pseudomonas aeruginosa resistant or intermediately susceptible to imipenem was determined by epidemiological typing using macrorestriction analysis of chromosomal DNA. The strains were isolated between December 2000 and February 2001 from a variety of specimens from nine patients hospitalized in five different departments of the University Medical Center in Ljubljana and in the nursing home. They belonged to seven genotypes or clones (A-G). Six isolates were heterogeneous, with different B-G genotypes. Three isolates had an identical A genotype but it is more likely that this genotype was more prone to develop imipenem resistance than to spread among the patients.

A case of recurrent Candida parapsilosis prosthetic valve endocarditis: cure by medical treatment alone.

A patient with recurrent fungal endocarditis on prosthetic mitral valve is presented. Candida parapsilosis was the causative agent. The patient was treated medically with conventional amphotericin during the first episode. When the disease recurred conventional amphotericin B was used again, but had to be stopped because of severe side effects. Treatment was continued with amphotericin B colloidal dispersion, followed by fluconazole for 8 months. The patient is healthy 16 months after discontinuation of fluconazole. Medical treatment of fungal endocarditis on prosthetic valves can be successful in selected cases.

Sequential treatment of deep fungal infections with amphotericin B deoxycholate and amphotericin B colloidal dispersion.

Amphotericin B colloidal dispersion (ABCD) is a novel lipid formulation of amphotericin B designed to diminish toxic effects of the drug. In the following report, nine cases of suspected (n = 4) and proven (n = 5) deep Candida infection, treated sequentially with amphotericin B deoxycholate and ABCD, are presented. The treatment was successful in seven cases. During treatment with amphotericin B deoxycholate, a rise in serum creatinine was observed in seven patients, hypokalemia in five, and metabolic acidosis in four. After replacing amphotericin B deoxycholate with ABCD, laboratory parameters improved in four of the seven patients with increased creatinine, in four of the five patients with hypokalemia, and in two of the four patients with metabolic acidosis. Infusion-related rigors were observed in four patients receiving amphotericin B deoxycholate and in one patient treated with ABCD. Reversible elevation of liver enzymes was found in one patient receiving ABCD. In this study ABCD proved less toxic than amphotericin B deoxycholate. The efficacy of ABCD alone cannot be assessed because of previous treatment with amphotericin B deoxycholate, but sequential treatment of deep Candida infections with amphotericin B deoxycholate and ABCD seems to be an effective therapeutic modality, especially in patients requiring prolonged administration of amphotericin B.

Influence of ceftriaxone on emergence of Clostridium difficile.

The influence of long-term ceftriaxone administration on the emergence of Clostridium difficile was studied with 80 patients receiving ceftriaxone for 14 days. In five patients (6.3%) C. difficile was cultured. The appearance of gastrointestinal disturbances during treatment with ceftriaxone was common, but the rate of emergence of C. difficile in immunocompetent patients was not high.