Detection of Visually Imperceptible Blood Contamination in the Surgical Area Using Luminol Among Different Oral Surgical Procedures: An Observational Study

Introduction Oral surgeons often encounter a significant occupational risk of exposure to potentially harmful infectious diseases during minor oral surgical procedures. These diseases can be transmitted through direct contact with body fluids and aerosolized splatters that may not be visibly detectable. The likelihood of transmission is heightened for clinicians, healthcare workers, and patients alike. The reported prevalence of exposure to blood-borne infections in this field is as high as 90%, with half of these exposures being visually imperceptible. Aim The aim was to detect visually imperceptible blood contamination on personal protective equipment (PPE) and clinical surfaces using the chemiluminescence agent luminol during oral surgical procedures. Materials and methods Thirty minor oral surgical procedures were performed in the Oral and Maxillofacial Surgery Department after obtaining approval from the Institutional Ethics Committee (IEC), Vinayaka Mission's Sankarachariyar Dental College, Vinayaka Mission's Research Foundation, Salem, India. The surgeon, assistant, patient, and clinical surfaces (comprising 15 subsites within the surgical field) wore PPE. The PPE was scrutinized for traces of visually imperceptible blood contamination using luminol. The results of blood splatter on PPE and clinical surfaces in different oral surgical procedures between the non-aerosol and aerosol groups of different durations were analyzed statistically using the chi-square test with p < 0.05 considered significant. Results We observed that visually imperceptible blood contamination in non-aerosol procedures was detected on the assistant PPE kit (46.7%, n = 14), assistant face shield (40%, n = 12), suction apparatus (50%, n = 15), wall (30%, n = 9), and floor (56.7%, n = 17), in both aerosol and non-aerosol procedures. The p-value has been considered statistically significant at p < 0.05 between both the groups (aerosol and non-aerosol). Conclusion Our study results confirmed the presence of undetected blood spillage during aerosol procedures of 30 minutes and non-aerosol surgical procedures of more than 30 minutes over an area of 3.1 feet horizontally and 4.8 feet vertically. So, we strongly emphasize that PPE kits and face shields are mandatory for both surgeon and assistant while performing oral surgical procedures in order to prevent the risk of cross infections, proper infection prevention control protocol for the clinical surfaces also needs to be followed as a standard protocol in all operations.

Stenotrophomonas maltophilia Bacteremia: From Diagnosis to Treatment

Objective

There are many difficulties in diagnosing and treating Stenotrophomonas maltophilia bacteremia. In this study, we aimed to evaluate "true" and "false-positive bacteremia" and assess mortality risk factors and the impact of different treatment regimens.

Materials and Methods

Hospitalized adult patients with S. maltophilia-positive blood cultures were assessed by a two-stage analysis. First, the clinical significance of blood cultures was assessed, and patients were divided into "true" and "false-positive bacteremia" groups. Then, excluding false positives, we analyzed the antimicrobial regimens and the factors associated with 28-day mortality in true bacteremia cases performing univariate and multivariate analyses.

Results

The study included 127 out of 138 patients with S. maltophilia bacteremia. True bacteremia was identified in 51.2% and false-positive bacteremia in 48.8% of patients. In the true bacteremia group, hypotension, nosocomial bacteremia, concomitant infections, a source of bacteremia, two positive blood culture sets, and 28-day mortality were more common. The 28-day mortality was 50.7% among true bacteremia cases. In multivariate analysis, age and solid tumor were the independent predictors of 28-day mortality. Early effective antimicrobial therapy and different antimicrobial regimens, including trimethoprim-sulfamethoxazole (SXT), fluoroquinolones (FQs), and tigecycline (TGC), did not have any significant impact on survival.

Conclusion

Patients with S. maltophilia bacteremia should first be assessed regarding clinical significance. Clinical findings, the presence of multiple positive blood culture sets and the primary sources of bacteremia are useful parameters while discriminating true from false-positive bacteremia. Patients with advanced age and solid tumors should be followed carefully in terms of mortality. Antimicrobial regimens, including SXT, FQs, or TGC, can be preferred in patients with S. maltophilia bacteremia considering antimicrobial resistance and adverse effects or toxicity.

Impact of low- and high-risk operators handling irinotecan on the blood contamination of health care workers in oncology day care units

INTRODUCTION

Health care workers handling antineoplastic drugs (ADs) are at risk of mutagenicity and adverse reproductive effects. Despite protective equipment and AD handling guidelines, AD levels are still detected in caregivers in oncology units. This study attempted to assess blood contamination by irinotecan and its metabolites in all health care workers in oncology day hospital units according to activities specific to each employment category.

METHODS

The study was performed at two different hospitals: a university hospital and a comprehensive cancer centre. Forty-four participants were categorized according to their daily activity as a high-risk operator (29 nurses/ward aides and 5 cleaning staff) and a low-risk operator (7 doctors and 3 secretaries). The collected blood samples were subjected to UHPLC-MS/MS. The plasma and red blood cell (RBC) levels of irinotecan and its metabolites (SN-38; APC) were determined using a validated analytical method detection test.

RESULTS

Two hundred sixty-four assay results were collected (132 plasma results and 132 RBC results). The comparison between low- and high-risk operator-contaminated workers was not significant (18.33% positive results in low-risk operators vs. 25.98% positive results in high-risk operators; P = 0.22). This homogeneity showed overall contamination within the unit. Positive results were obtained in 21.43% of physicians, 11.11% of secretaries, 25.86% of nurses/ward aides and 26.67% of cleaning staff. These results could be explained by the lack or failure of personal and collective protective equipment. A lack of protection and inadequate decontamination procedures can result in surface contamination.

CONCLUSIONS

This study evaluated blood contamination with irinotecan and its metabolites in health care workers from day hospital care units. Among the 24.24% of contaminations observed in care units, the difference between low- and high-risk operator contamination was not significant (P = 0.22). The impact on blood contamination found is the same between low- and high-risk caregivers. This implies that the protective precautions associated with the handling of anticancer drugs must therefore be followed by all staff, including those believed to be at low risk of exposure.

Push-out bond strength of the calcium silicate-based endodontic cements in the presence of blood: A systematic review and meta-analysis of in vitro studies

OBJECTIVES

The push-out bond strength (POBS) of calcium silicate-based cements (CSCs) to the dentinal wall is considered one of the essential physical properties for clinical success. The presence of blood in the treatment area affects the POBS of these types of cement. This study aimed to evaluate the impact of blood contamination on the bond strength of CSCs and dentinal walls.

MATERIAL AND METHODS

This systematic review was performed by searching electronic databases (MEDLINE-PubMed, Scopus, and EMBASE) to include relevant in vitro studies published between 1992 and April 2020. Two reviewers independently evaluated the selected studies and extracted data on the type of studied CSCs, evaluated area of the teeth, sample size, the dimension of a prepared area, slice thickness, storage duration, the setting of the universal testing machine (UTM), effects of blood contamination on POBS of CSCs and their failure modes. The bond strength of evaluated CSCs in studies was used for network meta-analysis.

RESULTS

Initial searches identified 292 articles, while only 13 articles met the inclusion criteria. Full texts of these articles were evaluated, and data extraction was performed. The effect of blood contamination on bond strength to the dentinal wall was assessed in various CSCs such as PMTA, Biodentine, and AMTA. The network meta-analysis results showed that the bond strength of Biodentine was significantly higher than other types of cement in blood presence (p < .05).

CONCLUSIONS

Based on the current systematic review, despite controversies among the result of the different articles and the lack of data for some CSCs like bioaggregate, it could be concluded that the bond strength of Biodentine to the dentinal wall is better than other evaluated CSCs in the presence of blood.

A comparative study of data-dependent acquisition and data-independent acquisition in proteomics analysis of clinical lung cancer tissues constrained by blood contamination

Proteomics analysis is often troubled by high-abundance proteins in samples such as plasma. However, many surgical tissue samples inevitably have got contaminated with blood before cryopreservation. Selection of an appropriate method to minimize the effect of high-abundance proteins is important for proteomics analysis of blood contaminated tissues. Here, we investigated and compared the abilities of data-independent acquisition (DIA) and data-dependent acquisition (DDA) strategies for the proteomics analysis of blood contaminated clinical tissue samples. Twelve pairs of carcinoma and para-carcinoma tissue samples from lung cancer patients were used for proteomics assays separately by DIA and DDA, and the blood contamination level in samples was evaluated by contamination index (CI). Compared with the DDA strategy, DIA in whole exhibited much better analytical capabilities in proteomics analysis of these samples with more identified protein groups and a higher discovery of differential proteins. With CI value increasing, whether DIA or DDA showed decreasing analysis ability. However, for samples with high CI values, the DIA strategy still shows acceptable analytical capability and indicates better blood pollution resistance than the DDA strategy. Our results implied that for clinical tissue samples, particularly for those contaminated with blood, DIA strategy should be a preferred method in proteomics studies.

Spectrophotometric Analysis of Coronal Discolouration Induced by ProRoot MTA, Biodentine and MTA Repair HP Used for Pulpotomy Procedures

OBJECTIVE

To assess and quantify coronal tooth discolouration by ProRoot MTA, Biodentine and MTA repair HP as pulpotomy agents and to identify colour stability of these materials in presence of blood contamination.

METHODS

120 human premolar teeth were used in the study. The teeth were sectioned horizontally 1 mm apical to the cementoenamel junction. A retrograde cavity extending within 2 mm of the incisal edge was prepared. The specimens were randomly distributed as; Control: Group 1, ProRoot MTA: Group 2, Biodentine: Group 3 and MTA repair HP: Group 4. The groups werefurther subdivided on basis of exposure to saline (subgroup A) or blood (subgroup B). The access was sealed with light cured Glass ionomer cemet and the specimens were stored in artificial saliva at 37°C. The Colour change was evaluated with a spectrophotometer at: day 0 (T0), day 1 (T1), day 7 (T7), 1 month (T30), 2 months (T60), and 6 months (T180). The colour measurements were recorded using the Commission Internationale de l'Eclairage L*a*b* value.

RESULTS

For all groups, there was a sharp increase in L* parameter at T1. At 6 months, Group 1B (Control + blood) showed maximum decrease in luminosity followed by Group 2A (ProRoot + saline) > Group 4B (MTA repair HP + blood) > Group 2B (ProRoot + blood). Group 3A (Biodentine + saline) showed the least amount of decrease in luminosity followed by Group 4A (MTA repair HP + saline) and Group 3B (Biodentine + blood). No significant difference was found in ∆E change between any of the groups from baseline to 180 days (P>0.05).

CONCLUSION

Relative to L* parameter, it was possible to observe a statistically significant decrease in luminosity in the Group1B (Control + blood) followed by ProRoot MTA (Group 2A and 2B) and MTA repair HP (Group 4A and 4B). Biodentine (Group 3A and 3B) showed least tooth discolouration in terms of L* parameter.

Cerebrospinal fluid hemoglobin levels as markers of blood contamination: relevance for α-synuclein measurement

OBJECTIVES

Cerebrospinal fluid α-synuclein (CSF α-syn) represents a possible biomarker in Parkinson's disease (PD) diagnosis. CSF blood contamination can introduce a bias in α-syn measurement. To date, CSF samples with a red blood cells (RBC) count >50 RBC × 10⁶/L or haemoglobin (Hb) concentration >200 μg/L are excluded from biomarker studies. However, investigations for defining reliable cut-off values are missing.

METHODS

We evaluated the effect of blood contamination on CSF α-syn measurement by a systematic approach in a cohort of 42 patients with different neurological conditions who underwent lumbar puncture (LP) for diagnostic reasons. CSF samples were spiked with whole blood and serially diluted to 800, 400, 200, 100, 75, 50, 25, 5, 0 RBC × 10⁶/L. CSF α-syn and Hb levels were measured by ELISA.

RESULTS

In neat CSF, the average concentration of α-syn was 1,936 ± 636 ng/L. This value increased gradually in spiked CSF samples, up to 4,817 ± 1,456 ng/L (+149% α-syn variation) in samples with 800 RBC × 10⁶/L. We established different cut-offs for discriminating samples with α-syn level above 5, 10, and 20% variation, corresponding to a Hb (RBC) concentration of 1,569 μg/L (37 RBC × 10⁶/L), 2,082 μg/L (62 RBC × 10⁶/L), and 3,118 μg/L (87 RBC × 10⁶/L), respectively.

CONCLUSIONS

Our data show the high impact of CSF blood contamination on CSF α-syn levels, highlighting the measurement of Hb concentration as mandatory when assessing CSF α-syn. The thresholds we calculated are useful to classify CSF samples for blood contamination, considering as reliable only those showing a Hb concentration <1,569 μg/L.

Blood contamination of the pharmaceutical staff by irinotecan and its two major metabolites inside and outside a compounding unit

BACKGROUND

Caregivers in healthcare settings are exposed to a risk of antineoplastic drug contamination which can lead to adverse health effects. Biological monitoring is necessary to estimate the actual level of exposure of these workers. This study was conducted with the aim of assessing blood contamination levels by irinotecan and its metabolites of pharmaceutical staff operating inside and outside a compounding unit.

METHODS

The study took place within the pharmaceutical unit of a French comprehensive cancer centre. Blood samples were collected from the pharmacy workers operating inside and outside the compounding unit, and analysed by UHPLC-MS/MS. Plasma and red blood cell irinotecan and its metabolites (SN-38; APC) were determined with a validated analytical method detection test.

RESULTS

A total of 17/78 (21.8%) plasma and red blood cell-based assays were found to be contaminated among staff. Overall, the total number of positive assays was significantly higher for staff members working outside the compounding unit than for workers working inside it (P = 0.022), with respectively 5/42 (11.9%) and 12/36 (33.3%) positive assays. For plasma dosages, the "outside" group had a significantly higher number of positive assays (P = 0.014). For red blood cell-based assays, no significant difference was found (P = 0.309).

CONCLUSIONS

This study reveals that pharmaceutical staff serving in health care settings are exposed to a risk of antineoplastic drug contamination, not only inside the compounding room but also in adjacent rooms. The results would help to raise awareness and potentially establish protective measures for caregivers working in areas close to the compounding room as well.

Effectiveness of double-gloving method on prevention of surgical glove perforations and blood contamination: A systematic review and meta-analysis

AIMS

To determine the effectiveness of the double-gloving method on preventing surgical glove perforation and blood contamination compared with single gloving.

DESIGN

Systematic review.

DATA SOURCES

Seven electronic databases were searched including: Embase, CINAHL, OVID, Medline, Pubmed, Web of Science, and Foreign Medical Literature Retrieval Service in March 2020.

REVIEW METHOD

Our systematic review and meta-analysis was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline. Risk of bias of Cochrane Handbook (Version 5.1.0) was applied to evaluate the study quality. Revman 5.3 was used to calculate the effect size of odds ratio (OR) with 95% confidence interval (CI). Meta-analysis with forest plot and funnel plot was performed to compare the rate of surgical glove perforation and to determine the published bias, respectively. This review has been registered with ID: CRD42020189694 on the web site of PROSPERO.

RESULTS

Seven randomized controlled trials regarding the efficacy of double gloving on reducing surgical glove perforation were identified and a total of 7090 gloves were tested. After analyzing the pooled data, we identified that the rate of surgical glove perforation in the double-gloving group was lower than that of single gloving with statistical significance (OR = 0.75, 95% CI: 0.64-0.89, p < .05). It was statistically significant that surgical glove perforation was lower in the double-inner gloves as well as matched outer-inner perforated gloves compared with that of single glove (OR = 0.05, 95% CI: 0.03-0.07, p < .05).

CONCLUSION

Findings of this systematic review demonstrate that double gloving could reduce the rate of surgical-glove perforation. Meanwhile, the risk of being contaminated by a blood-borne pathogen during surgery could be reduced by wearing double gloves. We strongly suggest that surgical team members when operating should wear double gloves to protect themselves and reduce the risk of occupational blood exposure.

IMPACT

The necessity of double gloving for preventing blood contamination was demonstrated. The rate of surgical glove perforation is statistically significant in double-gloving group compared to single gloving. Double gloving could reduce the risk of being contaminated during surgery by blood-borne pathogen. Evidence is provided for surgical team and decision makers that double gloving could reduce occupational exposure.

Is the blood of a surgeon performing HIPEC contaminated by irinotecan, its major metabolites and platinum compounds?

Objectives

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a beneficial surgical technique for patients, but the surgeons are being exposed to cytotoxic drugs. Few biomonitoring studies were led on blood samples in the context of HIPEC. This study aimed to evaluate the surgeon’s plasmatic and red blood cell (RBC) contamination by irinotecan, two of its major metabolites and platinum compounds.

Methods

HIPEC procedures performed using the coliseum techniques were observed between September 2015 and April 2018 in a French comprehensive cancer center. Irinotecan and its metabolites SN-38 and APC were dosed by UHPLC with a limit of quantification determined at 50 pg/mL. Platinum compounds were dosed by inductively coupled plasma mass spectrometry with a limit of quantification determined at 16 pg/mL.

Results

Despite collective and personal protective equipment, 80% of plasma samples were contaminated by irinotecan and 33% by platinum compounds out of 21. The results showed that the surgeon was contaminated after HIPEC and even after a period of HIPEC inactivity. Nineteen percent of plasmatic samples and 45% of RBC samples were contaminated by SN-38, the active metabolite of irinotecan. APC was only found in some RBC samples (33%).

Conclusions

Even if this study shows blood contamination by irinotecan, two of its major metabolites (including active SN-38) and platinum compounds both in the plasma and RBC of a surgeon performing the HIPEC procedures, further studies should be performed to confirm these results. Additional studies should be carried out to further investigate the contamination in the context of HIPEC and more broadly in the hospital.

Thirty years of translational research in Mobility Medicine: Collection of abstracts of the 2020 Padua Muscle Days

More than half a century of skeletal muscle research is continuing at Padua University (Italy) under the auspices of the Interdepartmental Research Centre of Myology (CIR-Myo), the European Journal of Translational Myology (EJTM) and recently also with the support of the A&CM-C Foundation for Translational Myology, Padova, Italy. The Volume 30(1), 2020 of the EJTM opens with the collection of abstracts for the conference "2020 Padua Muscle Days: Mobility Medicine 30 years of Translational Research". This is an international conference that will be held between March 18-21, 2020 in Euganei Hills and Padova in Italy. The abstracts are excellent examples of translational research and of the multidimensional approaches that are needed to classify and manage (in both the acute and chronic phases) diseases of Mobility that span from neurologic, metabolic and traumatic syndromes to the biological process of aging. One of the typical aim of Physical Medicine and Rehabilitation is indeed to reduce pain and increase mobility enough to enable impaired persons to walk freely, garden, and drive again. The excellent contents of this Collection of Abstracts reflect the high scientific caliber of researchers and clinicians who are eager to present their results at the PaduaMuscleDays. A series of EJTM Communications will also add to this preliminary evidence.

Blood Contamination in CSF and Its Impact on Quantitative Analysis of Alpha-Synuclein

Analysis of cerebrospinal fluid (CSF) is important for diagnosis of neurological diseases. Especially for neurodegenerative diseases, abnormal protein abundance in CSF is an important biomarker. However, the quality of CSF is a key factor for the analytic outcome. Any external contamination has tremendous impact on the analysis and the reliability of the results. In this study, we evaluated the effect of blood contamination in CSF with respect to protein biomarker identification. We compared three distinct measures: Combur10-Test^® strips, a specific hemoglobin ELISA, and bottom-up mass spectrometry (MS)-based proteomics for the determination of the general blood contamination level. In parallel, we studied the impact of blood contamination on the detectability of alpha-synuclein (aSyn), a highly abundant protein in blood/erythrocytes and a potential biomarker for Parkinson’s disease. Comparable results were achieved, with all three approaches enabling detection of blood levels in CSF down to 0.001%. We found higher aSyn levels with increasing blood contamination, highlighting the difficulty of authentic quantification of this protein in CSF. Based on our results, we identified other markers for blood contamination beyond hemoglobin and defined a grading system for blood levels in CSF samples, including a lower limit of tolerable blood contamination for MS-based biomarker studies.

Blood contamination, a problem or a lucky chance to analyze non-invasively Myokines in mouth fluids?

Use of saliva in clinical studies are increasing to identify methods less invasive than blood sampling in search for systemic changes of biomarkers related to physical activity, aging, late aging and rehabilitation. The consensus is that the diagnostic value of whole saliva is compromised by the presence of blood, but we are looking at the contamination as a major opportunity for non-invasive analyses of serological biomarkers. The aim of this preliminary study was to evaluate the presence of serum in mouth fluids of healthy seniors and the eventual changes after a modest trauma, i.e., tooth brushing. Seven heathy persons, aged more than 65 years, drooling saliva in a test tube provided the fluids for the analyses. After low speed centrifugation, small aliquots of supernatants were frozen in liquid nitrogen and stored at -80° until use. Aliquots were thawed and used for quantification by the Lowry method of total proteins and by colorimetric ELISA of serum albumin, fibrinogen and lysozyme. Hemoglobin content was quantified by Spectrophotometry. Adjustment of saliva dilution, after a preliminary test, increased the homogeneity of the analytes’ content determined by colorimetric ELISA. The control reference to judge the quantity of serum in saliva was a pool of sera from age-matched healthy persons. Saliva collected from the seven healthy elderly person before and after tooth-and-gum, brushing presented measurable amount of the analytes, including fibrinogen, a minor component of the pooled sera. Tooth brushing did not induced statistically significant difference in analytes’ contents, suggesting that a measurable blood contamination is a frequent event in elderly persons. In conclusion, fibrinogen analysis in saliva is a promising approach to quantify serological biomarkers by a non-invasive procedure that will increase acceptability and frequency of analyses during follow-up in aging and rehabilitation.

Risk factors for blood-contaminated cerebrospinal fluid collection in dogs

OBJECTIVE

To determine the risk factors for blood contamination during cerebrospinal fluid (CSF) collection in dogs.

STUDY DESIGN AND METHODS

This is a prospective study of 170 CSF samples. Data collected included signalment of the patient, body condition score, site of CSF collection (cerebellomedullary cistern (CMC) or lumbar cistern (LC)), number of attempts, clinician expertise, final diagnosis, time of day, skull conformation and day of the week. Analysis of the CSF samples was then performed, and the presence of blood contamination (red blood cells >500/µl) was recorded. Logistic regression was used to quantify the association of potential risk factors of the procedure. Multivariate analysis was performed on the variables that were statistically significant.

RESULTS

Of the 170 CSF samples, 53 per cent were collected from the CMC (n=90) and 47 per cent from the LC (n=80). Blood contamination was seen in 20 per cent (n=34) of the samples, 8.9 per cent (n=8) in CMC and 32.5 per cent (n=26) in LC samples. Increased odds of obtaining a contaminated CSF sample were associated with lower level of clinician expertise (odds ratio: 2.5; 95 per cent confidence interval: 0.9-6.7; P=0.046) and with LC versus CMC collection site (odds ratio: 8.1; 95 per cent confidence interval: 2.1-12.9; P=0.001).

CLINICAL SIGNIFICANCE

There is increased likelihood of blood contamination when collecting CSF from the LC compared with the CMC site. Increased clinician experience reduced the risk of CSF blood contamination, but none of the other variables examined significantly influenced this.

The Influence of Blood Contamination on Cerebrospinal Fluid Diagnostics

Background: Blood contamination due to traumatic lumbar puncture presents a diagnostic pitfall in cerebrospinal fluid (CSF) analysis. It is controversially discussed if phagocytosis of erythrocytes which can be found in the CSF after subarachnoid hemorrhage can also develop in vitro in the presence of artificial blood contamination. Furthermore, there is no consensus about the acceptable amount of artificial blood contamination on CSF protein results.

Methods: Two measurement series were performed in order to investigate the role of artificial blood contamination on the possible development of erythrophages and siderophages in the CSF: (1) blood contamination was simulated in vitro by adding blood into the CSF. (2) CSF was investigated when blood contamination occurred during a traumatic lumbar puncture. In both types of experiments, CSF including blood was incubated for 24 h and for 72 h at room temperature or at 4°C. In the third measurement series, the effects of artificial blood contamination on CSF protein results were investigated. Blood contamination was simulated in vitro by adding different amounts of blood ending up with five different samples containing erythrocyte counts of 2,500, 5,000, 7,500, 10,000, and 20,000 per μl CSF.

Results: Cytological examination revealed no evidence of erythrophages or siderophages in vitro. In contrast, already a low blood contamination (2,500 erythrocytes/μl CSF) led to false pathological results of total protein and albumin. Along with increasing amounts of blood, the frequency of false pathological protein results increased. A blood contamination of 5,000 erythrocytes/μl CSF resulted in a false positive intrathecal IgM production in nearly every fifth patient. In contrast, blood contamination with 5,000 erythrocytes/μl CSF was the acceptable amount of blood which did not lead to a false positive intrathecal synthesis of IgG and IgA.

Conclusion: Erythrophages and siderophages do not develop in vitro. An extensive diagnostic work up for the source of blood in the CSF should be performed when erythrophages or siderophages are found in the CSF. The contamination of CSF with increasing volume of blood resulted in falsely elevated CSF protein concentrations. Hence, the amount of blood contamination has to be taken into consideration when interpreting CSF protein measurement results.

Bordetella holmesii Contamination of Platelet Concentrates: Revisiting the Definition of a Positive Culture

Bacterial contamination remains the most important infectious risk of platelet transfusion. After an initially positive result, a second test is performed on the blood products and the initial culture bottle to confirm the contamination. Based on the blood center's decision algorithm used, results can be either confirmed negative, positive, or indeterminate, or be unconfirmed or discordant. Here, we report the first cases of platelet concentrates contaminated with Bordetella holmesii The in vitro growth characteristics of this unusual contaminant in platelet concentrate were investigated. Two B. holmesii strains isolated from platelet concentrates, as well as a control strain (Serratia marcescens), were spiked into platelet concentrates (PCs) at 1 and 10 CFU/ml. PCs were stored at 20 to 24°C under agitation. Samples were collected on days 2, 3, 4, and 7 for colony count and for bacterial screening using the BacT/Alert 3D system. Two PCs were detected as being positive for B. holmesii However, recultures were negative. In vitro, B. holmesii did not grow but remained detectable in PCs. Its viability diminished rapidly in contact with human plasma. Upon screening using the BacT/Alert 3D system, the majority of products spiked with B. holmesii were negative. This is the first description of PCs contaminated with B. holmesii This bacterium survives in blood products and remains dormant at low concentrations in blood products stored at room temperature, thus making difficult its detection with the BacT/Alert 3D system. The present definition of a true-positive culture of PCs may be overly restrictive for certain bacterial strains.

Evaluation of emergency department ultrasound machines for the presence of occult blood

OBJECTIVES

Bedside ultrasound in the emergency department is a common diagnostic tool, especially when evaluating trauma patients. Many trauma patients have blood on their chest and abdomen that may contact the probe during examination. The primary aim of this study was to investigate whether occult blood contamination was present on the emergency department ultrasound machine, both after daily use and after use in trauma.

METHODS

For a period of 31 days, the ultrasound machine at the trauma centre emergency department in Saskatoon, Saskatchewan, was tested once daily and following all Level 1 traumas. The ultrasound machine probes and keyboard were swabbed, and contamination was detected using a commercially available phenolphthalein blood testing kit. Any visible blood contamination was also noted. The machine was then cleaned following each positive test and re-tested to ensure the absence of contamination.

RESULTS

Over the study period, the ultrasound machine tested positive for occult blood contamination on 10% of daily tests and on 43% of assessments after its use in trauma. The curvilinear probe was most frequently contaminated (daily, 6%; trauma, 26%), followed by the keyboard (daily, 3%; trauma, 26%), but both lacked visible contamination.

CONCLUSIONS

In this single centre study, there was evidence of occult blood on the emergency department ultrasound machine after both routine use and major trauma cases, highlighting the need for a standardized cleaning and disinfection protocol.

Detection of Visually Imperceptible Blood Contamination in the Oral Surgical Clinic using Forensic Luminol Blood Detection Agent

Aim and Objectives:

Oral surgical procedures can cause spread of infections in the clinics through visually imperceptible, splattered, and aerosolized blood. The aim of this study was to evaluate visually imperceptible blood contamination of clinical surfaces and personal protective equipment (PPE) in an oral surgery clinic using luminol.

Materials and Methods:

Following ethical approval, oral surgical procedures were performed under local anesthesia in a disinfected clinic, and PPE was used by the oral surgeon, dental assistant, and patients. After the procedure, clinical surfaces and PPE were evaluated for traces of visually imperceptible blood contamination using luminol. Data regarding blood contamination and the duration of the procedure were collected. Nonparametric tests, with 95% significance level (Epi Info, Stat Calc 7, CDC, Atlanta, USA), were used to identify statistical interactions between the duration of the procedure and the frequency of blood contamination.

Results:

Blood contamination was detected in flooring below surgical field (86.67%), instrument tray, operating light, dental chair, and suction unit (100%). Except head caps and shoe covers, blood contamination was detected in all the PPE used by the clinical personnel, and the eyewear and chest drapes used by patients. An increase in the surgical time beyond 40 min significantly increased the risk of blood contamination in the handcuffs of the clinical personnel (P < 0.01).

Discussion and Conclusion:

Visually imperceptible blood contamination of the clinical surfaces and PPE is associated with minor oral surgical procedures. This mandates the cleaning and disinfection of all clinical surfaces before and after minor oral surgical procedures and PPE for clinicians and patients during every procedure.

Effect of blood contamination on the compressive strength of three calcium silicate-based cements

The aim of this study was to investigate the effect of human blood exposure on the compressive strength of various calcium silicate-based cements. Two hundred and eighty-eight customised cylindrical moulds were randomly divided into three groups according to material used: ProRoot MTA, Biodentine or CEM cement (n = 96). Each group was divided into two subgroups according to exposure conditions: PBS or blood. Then, the compressive strength of the specimens was measured after 6 h, 24 h, 72 h and 7 days. The compressive strength of CEM cement could not be measured after 6 and 24‏ h regardless of the exposure conditions nor could the compressive strength of 6 h blood-exposed ProRoot MTA. The compressive strength of blood-exposed ProRoot MTA was only significantly lower after 6 h, but no difference was seen at other time intervals. Blood exposed did adversely affected the compressive strength of Biodentine. The compressive strength of all groups significantly increased over time (P < 0.005).

Hepatitis B Reverse Seroconversion and Transmission in a Hemodialysis Center: A Public Health Investigation and Case Report

In March 2013, public health authorities were notified of a new hepatitis B virus (HBV) infection in a patient receiving hemodialysis. We investigated to identify the source and prevent additional infections. We reviewed medical records, interviewed the index patient regarding hepatitis B risk factors, performed HBV molecular analysis, and observed infection control practices at the outpatient hemodialysis facility where she received care. The index patient's only identified hepatitis B risk factor was hemodialysis treatment. The facility had no other patients with known active HBV infection. One patient had evidence of a resolved HBV infection. Investigation of this individual, who was identified as the source patient, indicated that HBV reverse seroconversion and reactivation had occurred in the setting of HIV (human immunodeficiency virus) infection and a failed kidney transplant. HBV whole genome sequences analysis from the index and source patients indicated 99.9% genetic homology. Facility observations revealed multiple infection control breaches. Inadequate dilution of the source patient's sample during HBV testing might have led to a false-negative result, delaying initiation of hemodialysis in isolation. In conclusion, HBV transmission occurred after an HIV-positive hemodialysis patient with transplant-related immunosuppression experienced HBV reverse seroconversion and reactivation. Providers should be aware of this possibility, especially among severely immunosuppressed patients, and maintain stringent infection control.

Infection Transmission Associated with Point of Care Testing and the Laboratory's Role in Risk Reduction

Lack of knowledge and confusion exists regarding safe and appropriate use of blood glucose monitoring equipment. Increasing numbers of diabetics, and exponential growth in blood glucose monitoring presents increased opportunities for infection transmission between patients. Diabetics have increased exposure to blood and blood borne pathogens from frequent blood glucose monitoring. Risk factors have been identified in infectious outbreaks and by analysis of testing practice. Point of care blood glucose meters are frequently contaminated by blood. Bacterial and viral organisms survive on surfaces and in dried blood. Instrumentation is shared between patients, and is heavily utilized in institutional settings, so that serial testing is performed on multiple patients within a short timeframe. Hand hygiene, glove changes and meter disinfection between testing events has been found to be inconsistent. Time pressure for meter usage competes with proper cleaning and disinfection procedures. Meter storage areas are frequently contaminated by blood. Multi-use lancets, improperly used for serial patient blood sampling, are a source for infection transmission. Test strips in vials, frequently contaminated by bacterial organisms, present potential hazard. The responsibility of the clinical laboratory is to insure successful implementation of practices that insure patient safety. Risk reduction strategies include single-use auto-disabling skin puncture devices for blood sampling; hand hygiene and glove change for every testing event; effective meter cleaning and disinfection for every testing event; meter use restriction to a single patient; safe practices for glucose meter storage; infection control practices to reduce contamination of blood glucose test strips or changes in test strip packaging and test strip dispensing.

Prevalence of Bacterial Contamination when using a Diversion Pouch during Blood Collection: A Single Center Study in Malaysia

BACKGROUND

The implementation of diversion pouches is to minimise the risk of bacterial contamination as the initial blood flow is prevented from entering primary bag collections as it is diverted into a pouch. This study was carried out to determine the prevalence of bacterial contamination in the diversion pouches used during blood collections in the Transfusion Department of Hospital Seberang Jaya, Penang, Malaysia.

METHODS

BD Bactec™ Fx instrument detection system was performed on 702 samples of 20 mL of diverting blood in diversion pouch. The inocullum volume was 10 mL for both aerobic and anaerobic bottles cultures and incubated for 5 days in the BD Bactec™ Fx instrument. Positive sample was flagged by BD Bactec™ Fx instrument and subculture to identify the species of organism.

RESULTS

The results showed that of 702 samples, 12 (1.7%) were contaminated. The bacterial species identified were coagulase negative Staphylococcus, Staphylococcus aureus and Gram positive Bacilli.

CONCLUSION

The results strongly suggest that the usage of diversion pouch is of significant importance in reducing bacterial contamination during blood collection.

The detection of blood contamination in human follicular fluid

PURPOSE

The aim of this study was to compare the reliability of the methods conventionally used to identify low levels of blood contamination in human follicular fluid (hFF) as applicable in the clinical environment.

METHODS

Follicular fluid (n = 339) and plasma samples (n = 20) were collected from patients (n = 138) attending the Centre for Fertility Studies, HF Verwoerd Hospital, University of Pretoria, South Africa. hFF blood contamination was assessed by means of (a) visual inspection, (b) hematocrit (Hct), (c) spectrophotometric analysis, (d) spectrophotometric hemoglobin kit, and (e) Combur-9-test urine sticks.

RESULTS

(1) Neither hematocrit nor spectrophotometry provided reliable detection at low levels of blood contamination. (2) Visual inspection presented with a better discriminatory ability than either Hct or spectrophotometry. (3) Combur-9-test sticks identified up to 50% of blood-contaminated fluids. (4) Spectrophotometrically determined hemoglobin levels presented with weak discriminatory abilities for detecting blood-contaminated fluids.

CONCLUSIONS

Visual inspection as performed in this study provides a fast and relatively reliable method for the determination of blood-contaminated hFFs. In a laboratory environment, however, it would be recommended that a combination of visual inspection, Hct, and spectrophotometric evaluation be employed for the selection of blood-free fluids.