Concordance between IDEXX Legiolert® (liquid culture assay) and plate culture (ISO 11731:2017) for the detection and quantification of Legionella pneumophila in water samples.

BACKGROUND: Legionella pneumophila is a water-borne bacterium that can cause Legionnaires' disease. Legiolert® (IDEXX, USA) is a low-labour liquid culture assay for the detection and enumeration of L. pneumophila (SG1-15) from water. AIM: To analyse concordance between Legiolert and ISO 11731:2017 plate culture method (membrane filtration and culture on selective agars) using hospital water samples (N = 100). METHODS: Incubation was at 39 °C and 36 °C, respectively, for seven days, followed by most-probable enumeration for Legiolert and subculturing and serogrouping of suspected Legionella colonies, with plate culture. FINDINGS: L. pneumophila (SG1-15) was isolated from 25 out of 100 samples when using Legiolert or plate culture. Fourteen additional Legiolert samples tested positive for L. pneumophila; analysis of the same samples by plate culture was negative (12 out of 14) or yielded only Legionella rubrilucens (two out of 14; confirmed via matrix-assisted ionization/desorption time-of-flight mass spectrometry). L. pneumophila was not captured from Quanti-Tray/Legiolert pouch wells of these positive samples after subculture of puncture aliquots on buffered charcoal yeast-extract agar. Both methods in concordance did not detect L. pneumophila in 61 out of 100 samples. CONCLUSION: Legiolert and plate culture are both satisfactory methods to detect L. pneumophila from water samples, and both to detect isolated L. pneumophila in 25% of the sample population. Legiolert provides a faster time to result, and is less resource-demanding and labour-intensive; however, there may be a low risk of cross-reactivity with other organisms. Both methods are suitable for the analysis of water in healthcare settings, where the monitoring of L. pneumophila is imperative in preventing cases of Legionnaires' disease.

Failure of a hollow-fibre shower filter device to prevent exposure of patients to Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa in hospital water is a risk for invasive infection. Point-of-use (POU) filters are used to reduce patient exposure to the organism, and hollow-fibre filters are becoming more popular. However, retrograde colonization of the filter mechanism may contaminate the effluent. AIMS: To assess the efficacy of POU filter head (polysulfone; hollow-fibre matrix) shower filters in preventing the exposure of high-risk patient groups to P. aeruginosa. METHODS: Pre-flush (opening the outlet and collecting the first 100 mL of water) samples were analysed to measure P. aeruginosa contamination from 25 shower outlets (∼21% of all showers on the six wards), with and without a hollow-fibre filter. P. aeruginosa was measured in a subset of outlets harbouring P. aeruginosa (sampling period 19th August 2019 to 10th January 2020). FINDINGS: Water from all 25 showers was heavily colonized [>300 colony-forming units (cfu)/mL] with P. aeruginosa at the showerhead. P. aeruginosa was found in 32% (8/25) of post-filter shower water effluent samples with a geometric mean of 4x106 cfu/mL (N=4) (6.8x104-2x108). Filters were sampled at 15-150 days of use (median 15 days), with 26% (6/23) of filter units becoming colonized before the expiry date. CONCLUSION: POU filter showerhead units may not be effective in preventing exposure of vulnerable patients to P. aeruginosa in hospital water due to retrograde contamination (external contamination of the showerhead passed back to the filter cartridge itself) or failure of the hollow-fibre filter matrix. Reliance should not be placed on the use of hollow-fibre filters to protect patients from exposure to P. aeruginosa without repeated microbiological monitoring.

Thermal disinfection at suboptimal temperature of Pseudomonas aeruginosa biofilm on copper pipe and shower hose materials.

BACKGROUND: Hospital-acquired infections caused by Pseudomonas aeruginosa have been linked to contaminated shower systems in health care. Thermal disinfection, whereby colonized outlets are flushed with existing hot water supplies, is a commonly used method to disinfect contaminated systems. Temperatures of 60°C are recommended for inactivation of P. aeruginosa; however, this is often not achievable at outlets. AIM: To investigate whether thermal disinfection at a suboptimal temperature (58°C) can effectively eradicate planktonic P. aeruginosa and biofilm adherent on copper piping and shower hoses. Exposure times of up to 60 min and efficacy of repeated cycles were evaluated. METHODS: A type culture and an environmental strain of P. aeruginosa isolated from a hospital shower were tested. Planktonic bacteria and biofilm adhered to sections of copper pipe and shower hoses were exposed to water at 58°C for up to 60 min. Biofilms were tested with static water, flushing water and repeated cycles of disinfection. Remaining viable bacteria after disinfection were enumerated. FINDINGS: Planktonic P. aeruginosa remained viable after up to 60 min of thermal disinfection. With static water, biofilm was removed from copper piping after 15 min, but remained viable in shower hoses for up to 60 min. With thermal flushing, biofilm was fully eradicated from copper piping after 2 min, but remained viable on shower hoses. Repeated cycles did not shorten thermal disinfection exposure times. CONCLUSION: Thermal disinfection at 58°C was effective at eliminating biofilm on copper; however, biofilm on shower hoses remained viable after 60 min of exposure.

Evaluation of droplet production by a new design of clinical handwash basin for the healthcare environment.

Splashing from handwash basins may be a source of bacteria in the healthcare environment. A novel splash-reducing basin was assessed for its ability to reduce droplet formation during simulated handwashing. The basin was compared to two conventional basins commonly used in healthcare. Basins were mounted in a test system and tap flushed for 30-s with and without handwashing. Droplets were visualized with fluorescent dye. With conventional basins, >1000 droplets were formed during 30-s flushes and found to spread further than 2-m. The novel basin significantly reduced the number of droplets formed during handwashing and reduced the distance spread.

A 24-month cost and outcome analysis comparing traditional fronto-orbital advancment and remodeling with endoscopic strip craniectomy and molding helmet in the management of unicoronal craniosynostosis: A retrospective bi-institutional review.

INTRODUCTION: Endoscopic strip craniectomy with helmeting (ESCH) has been shown to be a safe and efficacious alternative to fronto-orbital remodeling (FOR) for selected children with craniosynostosis. In addition to clinical factors, there may be economic benefits from the use of ESCH instead of FOR. METHODS: A retrospective review of 23 patients with nonsyndromic unicoronal craniosynostosis (UCS) treated with FOR was carried out at Great Ormond Street Hospital (GOSH) for Children in London, UK. Secondary data were used for the ESCH cohort from a paper published by Jimenez and Barone (2013). Data were collected on surgical time, transfusion rates, length of hospital stay, adverse event rates, reintervention rates, and overall costs. Costs were categorized and then assigned to the appropriate data sets. RESULTS: The mean age of patients undergoing FOR (vs. ESCH) was 17.4 mo (vs. 3.1 mo) with a mean surgical time of 234 min (vs. 55 min), mean transfusion volume of 221.6 mL (vs. 80.0 mL), mean transfusion rate of 14/23 (vs. 2/115), and a total immediate overnight stay of 3.13 days (vs. 97% next-day discharge). The FOR group had a higher adverse event rate (5/23 vs. 4/115, p=<0.005) and a higher number requiring extraocular muscle surgery (4/23 vs. 7/109, p=0.16). There was a substantial difference in overall costs between the two groups. Total variance cost for the FOR group was £7436.5 vs. £4951.35, representing a cost difference of £2485.15 over the 24-month study period. CONCLUSION: ESCH, in comparison to FOR, appears as a more economical method in the management of USC patients, as well as having clinical benefits including reduced adverse event rate and improved ophthalmic outcomes.

Hepatocellular carcinoma in association with membranous obstruction of inferior vena cava.

We report a patient with hepatocellular carcinoma (HCC) with membranous obstruction of the inferior vena cava (IVC). He underwent balloon dilatation of the IVC with good results. The HCC was managed by chemoembolization followed by resection. At follow up of eleven months the patient is asymptomatic.

Tuberculous cold abscess simulating pancreatic pseudocyst.

A patient with a peripancreatic lymph node tuberculosis mimicking pancreatic pseudocyst is reported, which was diagnosed on exploration to be a tuberculous cold abscess. The patient responded to antituberculous drugs after drainage of the cold abscess.

Mastoid obliteration with hydroxyapatite--the value of high resolution CT scanning in detecting recurrent cholesteatoma.

Mastoid obliteration carries a risk of enclosing cholesteatoma within the mastoid cavity. Using temporal bones obliterated with either muscle or hydroxyapatite granules, the value of high resolution CT scanning in the early detection of 'epithelial pearls' was studied. The results showed that scanning was effective in detecting small epithelial pearls within the cavity obliterated with hydroxyapatite, but not so effective when muscle was used. This is explained by the difference in the CT density between epidermoid cysts and hydroxyapatite allowing the cysts (dark shadows) to be identified easily within a white background. The authors also studied scans performed on 31 ears following mastoid obliteration with hydroxyapatite. There was no residual cholesteatoma in the obliterated area but there was an area of abnormality identified within the obliterated area in one patient due to a cholesterol granuloma.

The diagnostic and therapeutic impact of MRI: an observational multi-centre study.

AIM: To provide information about the diagnostic and therapeutic impact of magnetic resonance imaging (MRI) and to compare the findings across diagnostic groups. MATERIALS AND METHODS: A prospective, observational study of 2017 consecutive referrals for MRI of the head, spine or knee at four imaging centres. Clinicians completed questionnaires before MRI stating initial diagnoses, diagnostic confidence and treatment plans. After imaging, a second questionnaire evaluated clinicians' revised diagnosis and treatment plans in the light of imaging findings. Patients were grouped into nine diagnostic categories for analysis. Comparison between pre- and post-imaging was used to assess the diagnostic and therapeutic impact of MRI. RESULTS: In seven of nine diagnostic groups MRI findings were associated with a diagnostic impact. Diagnoses were revised or discarded following normal MR findings and diagnostic confidence was increased by confirmative MR findings. There was no statistically significant diagnostic impact for suspected pituitary or cerebello-pontine angle lesions. In five of nine diagnostic groups (knee meniscus, knee ligament, multiple sclerosis, lumbar and cervical spine) MRI findings had a clear impact on treatment plans. CONCLUSION: This study demonstrates that in most diagnostic categories, MRI influences diagnosis and treatment. However, experimental studies are needed to prove that these diagnostic and therapeutic impacts lead to improved health.Hollingworth (2000). Clinical Radiology55, 825-831.

Self reported health status and magnetic resonance imaging findings in patients with low back pain.

The authors present a prospective study of quality of life (SF-36) and MRI findings in patients with low back pain (LBP). Disc herniation and nerve root compression contribute to LBP and poor quality of life. However, significant proportions of asymptomatic subjects have disc herniation and neural compromise. Little is known about the influence of disc abnormalities and neural compression on quality of life in symptomatic patients. The purpose of this study was to assess the relationship between the extent of disc abnormality, neural impingement and quality of life. A total of 317 consecutive patients with LBP referred for MRI completed an SF-36 health status questionnaire immediately before imaging and again 6 months later. Patients were grouped according to the most extensive disc abnormality and any neural compromise reported at MRI. The relationship between symptoms, radiological signs and SF-36 scores was assessed. Eighty percent (255/317) and 65% (205/317) of patients completed the initial and 6-month SF-36, respectively. Thirty-six percent of patients (115/317) had one or more herniated discs and 44% (140/317) had neural impingement. There was little relationship between the extent of disc abnormality and quality of life. Patients with radiological evidence of neural impingement reported better general health (P < 0.01). SF-36 scores improved at 6 months in four dimensions, but general health deteriorated (P < 0.01). Patients with neural impingement had improved pain scores at 6 months (P < 0.05). The study results showed that the pain and dysfunction caused by disc herniation and neural compromise are not sufficiently distinct from other causes of back pain to be distinguished by the SF-36. Whilst neural compromise may be the best radiological feature distinguishing patients who may benefit from intervention, it cannot predict quality of life deficits in the diffuse group of patients with LBP.