Usefulness of Stool Multiplex Polymerase Chain Reaction Assays in Patients with Acute Diarrhea / 대한소화기학회지

Background/Aims@#There is a recent increase in the use of stool multiplex PCR assay-based diagnostic tests in patients with acute diarrhea. We used multiplex PCR assays to analyze the distribution of diarrhea-causing bacteria and viruses, as well as the clinical features of patients with acute diarrhea. @*Methods@#We retrospectively reviewed stool specimens of inpatients complaining of acute diarrhea from October 2018 to July 2020.The stool specimens had been tested for bacteria and viruses using multiplex PCR assays. @*Results@#A total of 414 stool specimens from 346 patients were tested, and 152 pathogens were detected in 131 stool samples (131/414, 31.6%). Co-infection was detected in 20 patients (20/346, 5.8%). The common pathogens detected as causes of acute diarrhea, including co-infection, were Clostridium perfringens (34.9%), Clostridioides difficile (19.7%), and Campylobacter spp. (18.4%). The average age of patients with multiplex PCR-positive tests was lower than those with multiplex PCR-negative tests (p=0.001). In patients with suspected C. difficile infection (CDI), the RT-PCR for toxin gene assay was performed in 370 stool samples, 35 of which were positive (9.5%). Furthermore, 16 of the 35 samples were positive on the multiplex PCR assay (45.7%). @*Conclusions@#The multiplex PCR assay revealed that C. perfringens was the most common diarrhea-causing pathogen. In addition, in patients with suspected CDI, the multiplex PCR assay alone was insufficiently sensitive to detect pathogens and a conventional CDI test was additionally required.

Diagnostic Algorithm for the Rapid and CostEffective Detection of Clostridioides difficile Infection: Comparison between C. DIFF QUIK CHEK COMPLETE and VIDAS GDH & Toxin Assay

Background@#We evaluated the analytical performance and cost-effectiveness of lateral flow immunoassays (LFIAs) in detecting Clostridioides difficile glutamate dehydrogenase (GDH) antigen and toxin A/B, followed by a rapid nucleic acid amplification test (NAAT). @*Methods@#A total of 341 unformed stools were tested using a two-step algorithmic approach with C. DIFF QUIK CHEK COMPLETE (QCC) LFIA (TechLab, USA), followed by Xpert C. difficile NAAT (Xpert). The performance of the QCC assay was compared with that of the VIDASC. difficile GDH and toxin A/B assay (bioMérieux, France), an enzyme-linked fluorescence im munoassay. The clinical performance and cost-effectiveness of the diagnostic algorithms using the QCC or VIDAS assays were compared to the results obtained using the Xpert assay alone. @*Results@#For GDH and toxin detection, the QCC and VIDAS assays dem onstrated an almost perfect agreement, with no significant difference in sensitivity (QCC-GDH, 90.5%; VIDAS-GDH, 91.9%; QCC-toxin, 51.4%; VIDAStoxin, 55.4%) and specificity (QCC-GDH, 92.9%; VIDAS-GDH, 89.1%; QCC-toxin, 100%; VIDAS-toxin, 99.6%), compared to the Xpert. The algorithmic approach (GDH and toxin plus Xpert) increased the sensitivity (QCC, 93.2%; VIDAS, 94.6%) and specificity (QCC, 100%; VIDAS, 99.6%). The algorithmic approach reduced the cost compared to the Xpert alone, and the turnaround time of the QCC was shorter than that of the VIDAS assay. @*Conclusions@#Simultaneous detection of GDH and toxin A/B, using QCC or VIDAS assays showed comparable sensitivity and specificity when followed by the Xpert assay. The QCC assay is preferable in turnaround time and cost, which are important considerations for laboratories handling smaller number of samples.

Rapid and accurate diagnosis of Clostridium difficile infection by real-time polymerase chain reaction

BACKGROUND/AIMS: The incidence and severity of Clostridium difficile infection (CDI) have increased worldwide, resulting in a need for rapid and accurate diagnostic methods. METHODS: A retrospective study was conducted to compare CDI diagnosis methods between January 2014 and December 2014. The stool samples, which were obtained in presumptive CDI patients, were compared for their diagnostic accuracy and rapidity, including real-time polymerase chain reaction (PCR) of toxin genes, C. difficile toxin assay, and culture for C. difficile. RESULTS: A total of 207 cases from 116 patients were enrolled in this study and 117 cases (56.5%) were diagnosed as having CDI. Among the 117 cases, the sensitivities of real-time PCR, C. difficile toxin assay, and culture for C. difficile were 87.2% (102 cases; 95% CI, 80.7%–92.8%), 48.7% (57 cases; 95% CI, 41.0%–59.8%), and 65.0% (76 cases; 95% CI, 60.2%–78.5%), respectively (P < 0.005). Notably, 34 cases (29.0%) were diagnosed with CDI by real-time PCR only. The time required to obtain results was 2.27 hours (136.62±82.51 minutes) for real-time PCR, 83.67 hours (5,020.66±3,816.38 minutes) for toxin assay, and 105.79 hours (6,347.68±3,331.46 minutes) for culture (P < 0.005), respectively. CONCLUSIONS: We confirmed that real-time PCR of toxin genes is the most effective diagnostic method for accurate and early diagnosis of CDI. It also helps to diagnose hypervirulent CDI, such as ribotype 027 infection.

Usefulness of neutrophil gelatinase-associated lipocalin(NGAL) to confirm subclinical acute kidney injury and renal prognosis in patients following surgery / 고신대학교의과대학학술지

OBJECTIVES: The neutrophil gelatinase-associated lipocalin (NGAL) level following non cardiac surgery is useful for predicting acute kidney damage. However, there is insufficient conclusive evidence as to whether NGAL can be used to predict subclinical AKI following non-cardiac surgery. METHODS: We measured serum NGAL and creatinine levels in 41 patients following non-cardiac surgery, and the increase of these variables was used to predict acute decreases in kidney function. RESULTS: The study included a total of 41 patients. The mean age was 64.65 ± 17.09 years. The serum creatinine concentration was increased 12 hours after surgery. The mean SD serum NGAL decreased after 4hours after surgery and continued to decrease after 12 hours after surgery. The incidence of subclinical AKI determined by the 4 hour serum NGAL level was 10(24.4%), and the incidence of serum creatinine elevation was 0(0.0%). The incidence of subclinical AKI determined by the 12 hour serum NGAL level was 4(9.8%), and the incidence of subclinical AKI determined by serum creatinine was 4(9.8%). The elevation of NGAL was more rapid than the serum creatinine 4 hours after surgery. CONCLUSIONS: We verified the usefulness of the serum NGAL level as a predictive factor for subclinical AKI after non-cardiac surgery.

Evaluation of the VIDAS Anti-HCV Assay for Detection of Hepatitis C Virus Infection

BACKGROUND: Anti-hepatitis C virus antibody (anti-HCV) assays are recommended for screening HCV-infected persons. The VIDAS Anti-HCV Assay (bioMérieux, France), based on the enzyme-linked fluorescence test principle, was recently introduced in Korea. We evaluated the clinical performance of the VIDAS assay. METHODS: One hundred HCV-positive and 1,002 HCV-negative blood samples confirmed by Architect anti-HCV (Abbott Laboratories, USA) and COBAS TaqMan HCV real-time PCR (Roche Diagnostics, USA) or the Procleix Ultrio Plus Assay (Gen-Probe Incorporated, USA) were obtained from the Human Serum Bank (HSB) and tested by VIDAS. In case of discrepant results, we conducted a recombinant immunoblot assay (RIBA). RESULTS: The agreement rates for known HCV-positive and HCV-negative samples between the VIDAS assay and the HSB testing were 100% (95% confidence interval [CI]: 96.4-100%) and 99.5% (95% CI: 98.8-99.8%), respectively. One of the five discrepant samples was positive for Core 2+ and NS3-2 2+ reactivity, two samples were negative, and the other two were indeterminate regarding NS4 2+ reactivity in RIBA. We observed a significant but weak positive correlation between the titers of VIDAS and Architect assays (r=0.315, P<0.001). CONCLUSIONS: The VIDAS anti-HCV assay, developed on the VIDAS automated immunoassay platform based on the ready-to-use, single-sample test concept may be useful in small-to-medium-sized laboratories. It showed good agreement with Architect anti-HCV and COBAS PCR assays and is therefore useful for detection of HCV infection. Weakly test-positive (ambiguous) samples require additional testing by another anti-HCV, RIBA, or HCV RNA assay.

Evaluation of Centaur Syphilis, Immulite Syphilis, and Mediace TPLA for Detecting Treponemal Antibodies

BACKGROUND: We evaluated the efficacy of two chemiluminescence immunoassays that detect treponemal antibodies, Centaur Syphilis and Immulite Syphilis, in comparison with Mediace Treponema pallidum latex agglutination (TPLA). METHODS: The study was conducted in two phases. In the first phase, we tested 1,147 serum samples that were sequentially submitted for routine syphilis serology. In the second phase, we tested a panel of 119 frozen serum samples that had previously tested positive by Mediace RPR. The kappa value, total agreement percentage, and sensitivity and specificity were analyzed. RESULTS: Of the 1,147 random samples, 24 (2.09%) tested positive with Centaur Syphilis, 16 (1.39%) with Immulite Syphilis, and 19 (1.66%) with Mediace TPLA. Of the 119 Mediace RPR-positive samples, 103 (86.6%) tested positive with Centaur Syphilis, 101 (84.9%%) with Immulite Syphilis, and 105 (88.2%) with Mediace TPLA. The percent agreements (kappa values) were 98.8% (0.934) between Centaur Syphilis and Mediace TPLA, 99.0% (0.94) between Immulite Syphilis and Mediace TPLA, and 99.2% (0.955) between Centaur Syphilis and Immulite Syphilis. To measure the sensitivity and specificity of each treponemal test, samples showing agreement in three or four of the tests (three treponemal tests and Mediace-RPR) were regarded as true positive (n=117) or true negative (n=1,142). The respective values for sensitivity and specificity were 100% and 99.6% for Centaur Syphilis, 98.3% and 100% for Immulite Syphilis, and 99.2% and 99.7% for Mediace TPLA. CONCLUSIONS: Results from the three treponemal assays were in good agreement. Greater sensitivity of Centaur Syphilis and greater specificity of Immulite Syphilis were suggested.

Evaluation of Centaur Syphilis, Immulite Syphilis, and Mediace TPLA for Detecting Treponemal Antibodies

BACKGROUND: We evaluated the efficacy of two chemiluminescence immunoassays that detect treponemal antibodies, Centaur Syphilis and Immulite Syphilis, in comparison with Mediace Treponema pallidum latex agglutination (TPLA). METHODS: The study was conducted in two phases. In the first phase, we tested 1,147 serum samples that were sequentially submitted for routine syphilis serology. In the second phase, we tested a panel of 119 frozen serum samples that had previously tested positive by Mediace RPR. The kappa value, total agreement percentage, and sensitivity and specificity were analyzed. RESULTS: Of the 1,147 random samples, 24 (2.09%) tested positive with Centaur Syphilis, 16 (1.39%) with Immulite Syphilis, and 19 (1.66%) with Mediace TPLA. Of the 119 Mediace RPR-positive samples, 103 (86.6%) tested positive with Centaur Syphilis, 101 (84.9%%) with Immulite Syphilis, and 105 (88.2%) with Mediace TPLA. The percent agreements (kappa values) were 98.8% (0.934) between Centaur Syphilis and Mediace TPLA, 99.0% (0.94) between Immulite Syphilis and Mediace TPLA, and 99.2% (0.955) between Centaur Syphilis and Immulite Syphilis. To measure the sensitivity and specificity of each treponemal test, samples showing agreement in three or four of the tests (three treponemal tests and Mediace-RPR) were regarded as true positive (n=117) or true negative (n=1,142). The respective values for sensitivity and specificity were 100% and 99.6% for Centaur Syphilis, 98.3% and 100% for Immulite Syphilis, and 99.2% and 99.7% for Mediace TPLA. CONCLUSIONS: Results from the three treponemal assays were in good agreement. Greater sensitivity of Centaur Syphilis and greater specificity of Immulite Syphilis were suggested.

Antimicrobial Susceptibility of Stenotrophomonas maltophilia Isolates from Korea, and the Activity of Antimicrobial Combinations against the Isolates

The aim of this study was to determine antimicrobial susceptibility of recent clinical Stenotrophomonas maltophilia isolates from Korea, and to compare the activity levels of several combinations of antimicrobials. A total of 206 non-duplicate clinical isolates of S. maltophilia was collected in 2010 from 11 university hospitals. Antimicrobial susceptibility testing was performed using the Clinical Laboratory Standards Institute agar dilution method. In vitro activity of antimicrobial combinations was tested using the checkerboard method. The susceptibility rates to trimethoprim-sulfamethoxazole and minocycline were 96% and 99%, respectively. The susceptibility rate to levofloxacin was 64%. All of four antimicrobial combinations showed synergy against many S. maltophilia isolates. A combination of trimethoprim-sulfamethoxazole plus ticarcillin-clavulanate was most synergistic among the combinations. None of the combinations showed antagonistic activity. Therefore, some of the combinations may be more useful than individual drugs in the treatment of S. maltophilia infection. Further clinical studies are warranted to validate our in vitro test results.

Higher Prevalence of Klebsiella pneumoniae Extended-Spectrum beta-Lactamase in Patients on Renal Replacement Therapy

The prevalence of antibiotic resistance is higher in patients undergoing renal replacement therapy (RRT) than in patients who did not undergo RRT. We investigated the presence of KP (Klebsiella pneumoniae) in patients who underwent RRT. All data were collected retrospectively by accessing patient medical records from 2004 to 2011 for the culture results of all patients who were positive for KP. We grouped the patients by the presence of extended-spectrum beta-lactamase (ESBL) into a KP ESBL(-) group (KP[-]) and a KP ESBL(+) group (KP[+]). In total, 292 patients (23.1%) were in the KP(+) group, and 974 patients (76.9%) were in the KP(-) group. A greater percentage of KP(+) was found in patients who underwent RRT (7.5%) than in patients who did not undergo RRT (3.2%) (OR, 2.479; 95% CI,1.412-4.352). A Cox's hazard proportional model analysis was performed, and for patients with pneumonia, the risk of KP(+) was 0.663 times higher in patients who had lower albumin levels, 2.796 times higher in patients who had an inserted Levin tube, and 4.551 times higher in patients who underwent RRT. In conclusion, RRT can be a risk factor for KP(+) in patients with pneumonia.

Analysis of Comparability Test between Reagent Lots in Immunoassay

Lot-to-lot reproducibility is an important issue in immunoassays and reagent lot-to-lot comparability test comparing the results of new reagent lot with those of used lot using patients' samples or controls is usually performed to detect the difference between lots. However, there are no universally used acceptability criteria regarding reagent lot-to-lot comparability test. We performed reagent comparability test between different lots of alpha-fetoprotein (AFP) reagents and tried to determine its comparability by several criteria. Both the commercialized controls and in-house controls for AFP made from pooled patients' sera were measured 10 times using the old and new lots of reagents, whenever a reagent lot was changed. The differences in the mean control values, the percent difference (% difference), and the difference to between-run standard deviation ratio (D:SD ratio) between successive lots were calculated. We compared the results of reagent comparability test to arbitrarily determined acceptability criteria suggested by CLSI C54-A. Although comparability between reagent lots was determined according to how strictly we set the criteria, some lot-to-lot differences between certain pairs of lots exceeded the criteria. We hope that the results of this study might be helpful to perform reagent lot-to-lot comparability test and set the criteria for reagent comparability test between lots in other laboratories.

Gender Difference in the Level of HDL Cholesterol in Korean Adults / 가정의학회지

BACKGROUND: High density lipoprotein (HDL) cholesterol level varies with ethnicity and gender. In Korea there has not been an agreement on standards for HDL cholesterol level. Therefore, in order to establish a foundation for research on HDL cholesterol, we investigated the gender difference in HDL cholesterol level after adjusting associated factors. METHODS: The study population included 4,465 individuals (1,833 men, 2,632 women) representing 33,502,918 Koreans 20 years of age or older, who participated in the 2005 Korean National Health and Nutrition Survey. After stratifying by gender, we analyzed the HDL cholesterol level according to the general characteristics of the study population. Then we identified independent factors associated with HDL cholesterol level. After adjusting for covariates, we estimated the gender difference in HDL cholesterol level. RESULTS: We demonstrated that age, current smoking, body mass index, alcohol intake, triglyceride and low density lipoprotein cholesterol level have significant impact on HDL cholesterol level. In addition, educational status was also an important factor for men, while fat intake was a significant factor for women. After adjusting associated factors, the means (standard errors) of HDL cholesterol level were 43.8 (0.2) mg/dL in men and 46.3 (0.2) mg/dL in women, respectively. CONCLUSION: The mean gender difference in HDL level (2.5 mg/dL) in Korean adults was, therefore, less than those observed in previous western studies.

Postchemotherapy Changes in Cytokine Levels and Their Correlation with Hematological Parameters in Patients with Vivax Malaria / 임상검사와정도관리

BACKGROUND: Inflammatory cytokines play an important role in human immune responses to malaria, although the role of these mediators in pathogenesis is unclear. In this study, we evaluated changes in cytokine levels following chemotherapy, and determined whether cytokine levels in serum correlated with the hematological parameters in the Korean vivax malarial patients. METHODS: The study population was composed of 31 patients in Inje University Ilsan Paik Hospital who were diagnosed with Plasmodium vivax infection. Cytokine profiles, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-10 levels, were assessed in serum samples obtained from the malaria patients three times, at the time of diagnosis (stage I) and after treatment with hydroxychloroquine (stage II) and primaquine (stage III). The level of each cytokine was measured using commercially available serum-based ELISA kits. Hematological parameters were simultaneously measured using a hematology autoanalyzer. RESULTS: At thetime of diagnosis, the TNF-alpha (mean, 62.9 pg/mL), IL-6 (mean, 45.5 pg/mL), and IL-10 (mean, 237.7 pg/mL) levels in the malaria patients were higher than the reference values. After treatment with hydroxychloroquine, these levels (TNF-alpha, P<0.01; IL-6, P<0.05; IL-10, P<0.01) significantly decreased to near-normal levels. Significant positive correlations were observed among the cytokine levels, but not between the cytokine levels and other hematological parameters. CONCLUSIONS: In this study, TNF-alpha, IL-6, and IL-10 levels increased at the time of diagnosis and rapidly decreased to normal levels after treatment the levels of these cytokines did not correlate with other hematological parameters.

The Effect of Contact Precautions and Active Surveillance Culture on the Methicillin-Resistant Staphylococcus aureus Reduction in an Intensive Care Unit / 병원감염관리

BACKGROUND: This study investigated the effectiveness of reinforced contact precautions and active surveillance cultures (ASCs) in reducing the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and other healthcare-associated infections (HAIs). METHODS: A before- and after-experimental study was performed at the intensive care unit (ICU) in a university-affiliated hospital. Reinforced contact precautions were applied to all patients, and ASCs for MRSA were performed for newly admitted patients at the time of admission and once a week thereafter. The HAIs were investigated in accordance with the National Nosocomial Infections Surveillance (NNIS) definitions and compared before and after the interventions. The data were analyzed using descriptive statistics. RESULTS: The number of HAIs caused by MRSA decreased from 2.2 to 0.5 per 100 patients discharged (P=0.02) and from 3.6 to 1.0 per 1,000 patient-days (P=0.032). The number of overall HAIs decreased from 7.6 to 4.0 per 100 patients discharged (P=0.011) and from 12.7 to 7.3 per 1,000 patient-days (P=0.034). The invasive device-associated infections caused by MRSA and other pathogens decreased, but the decrease was not statistically significant. CONCLUSION: Reinforced contact precautions and ASCs were effective in decreasing both MRSA infections and overall HAIs in the ICU. Further, it was assumed that the incidence of device-associated infections would have decreased if the intervention period was extended.

The Incidence and Clinical Features of Clostridium difficile Infection; Single Center Study / 대한소화기학회지

BACKGROUND/AIMS: Clostridium difficile is the predominant cause of nosocomial diarrhea. Recently, the incidence of Clostridium difficile infection (CDI) increases in Europe and North America. A retrospective study was performed to evaluate the change of incidence and clinical features of CDI in Korea. METHODS: From January 2003 to December 2008, inpatients diagnosed with CDI in Seoul Paik hospital were enrolled. The diagnosis of CDI was made when patients complained diarrhea with any positive results in C. difficile toxin assay, stool culture, or endoscopy. The incidence, recurrence rate, and clinical features were compared between early period (2003-2005) and late period (2006-2008). RESULTS: The incidence of CDI was 21.73 cases per 10,000 admitted patients in early period group, and significantly increased to 71.71 cases per 10,000 admitted patients in late period group (p<0.01). The hospital stay duration at the time of CDI diagnosis was shorter in late period group. Cephalosporin had the highest ratio as the causative antibiotics of CDI. However, there was no difference in recurrence rate between early and late period groups. Recurrence associated clinical factor was serum albumin level. CONCLUSIONS: The incidence of CDI showed increasing tendency during recent 6 years. The awareness of increasing disease burden is the first step in control of CDI.

Lot-to-lot Reagent Variation in Immunoassay: Retrospective Analysis of Daily Quality Control Results / 임상검사와정도관리

BACKGROUND: Lot-to-lot reagent reproducibility is an important issue in immunoassays. However, there have been no universal criteria for acceptable lot-to-lot reproducibility. We sought to evaluate the inter-lot reagent difference by analyzing the results of various quality control materials during a certain period of time. METHODS: The results of control materials using different reagent lots and same control lots for immunoassays of HBsAg, anti-HBs, alpha-fetoprotein (AFP), ferritin, and CA 19-9 were analyzed. The average value, standard deviation, and coefficient of variation obtained from each reagent lot were calculated and differences in mean control values between two different reagent lots were assessed. We also analyzed the difference between the last control result using one reagent and the first control result using a new reagent. RESULTS: There was no significant difference in control values among reagent lots during this study period in all immunoassays of HBsAg, anti-HBs, AFP, ferritin, and CA 19-9. Some of the reagents showed statistical differences in QC values, but the difference was not considered clinically different. Also, at the time of reagent lot change, there was no significant difference in reagent parallel tests. CONCLUSIONS: Lot-to-lot reagent variation was not significant in immunoassays evaluated in this study. However, this study has been performed during relatively short period by one to three reagent lot changes, parallel testing should be continuously checked at reagent lot changes in each laboratory for continuous quality assurance. These results can be used as basic data for setting the criteria of acceptance on inter-lot difference in reagent parallel tests.

The Usefulness of the Alanine Aminotransferase Test for Blood Donors / 대한수혈학회지

BACKGROUND: The usefulness of the alanine aminotransferase (ALT) test has been questioned after the introduction of anti-Hepatitis C virus (HCV) screening and the HCV nucleic acid test (NAT). A major proportion of the blood discarded according to a positive screening test is composed of ALT-high blood. This study was performed to investigate the usefulness of the ALT test. METHODS: The number of donors with a high ALT level was analyzed using the 2007 database of 2,028,684 donors. The HBsAg and anti-HCV positive donors were grouped into the ALT or =90 IU/L group. Anti-HBc, anti-HBs and HBV DNA tests were performed for 402 high-ALT samples. RESULTS: A total of 30,077 (1.5%) donors had an ALT> or =65 IU/L, and 18,594 (61.8%) of them had an ALT of 65~89 IU/L. The mean ages of the groups with ALT or =90 IU/L were 24, 26 and 25 years, respectively and HBsAg was positive in 0.13, 0.36 and 0.88%, respectively, and anti-HCV was positive in 0.30, 0.39 and 0.52%, respectively. HBV DNA was not detected in the 402 samples with an ALT> or =65 IU/L and a negative HBsAg test. CONCLUSION: Based on an analysis of a donor databases, the HBV infection rates were higher in blood donors with high ALT. Although HBV DNA was not detected in the high-ALT samples with negative HBsAg, because of the high HBsAg positivity in the high-ALT samples, it would be desirable to retain the ALT screening test when considering the possibility of false negative reactions of the current hepatitis B screening test.

Differences in the Perception of Blood Transfusion Risk between Laypeople and Transfusion Experts in Korea / 대한수혈학회지

BACKGROUND: Generally, laypeople perceive blood transfusion risk differently from experts like physicians. Acknowledging such differences may improve risk communication. This study characterized how blood transfusion experts in Korea perceive the blood transfusion risks compared to laypeople in a past study. METHODS: A one-month e-mail survey targeting blood transfusion experts was conducted in October 2007. The questionnaire was designed to assess the demographics of the respondents, their response to the term 'blood transfusion', and the perceived risks of a transfusion. In all, 103 interviews were completed. RESULTS: The words evoked by the term 'blood transfusion' included blood, blood donation, life, surgery, and risk. About 24.2~31.1% of the respondents gave a moderate or high rating for the perceived risk of blood transfusion. About 72.8% of experts agreed that the blood supplied in Korea is safe, while 55.6% of laypeople agreed to the same question. If they needed a transfusion, about 85.4% of the respondents replied that they would accept the blood transfusion, and experts were more willing to receive a blood transfusion than laypeople. The relative perceived blood transfusion risk was 4.4+/-2.8 (out of 10), which was similar to the result with laypeople. CONCLUSION: Experts, as compared to laypeople, think that the blood supplied in Korea is safer and had higher acceptance rates of transfusion. Awareness of such differences may be helpful when sharing medical decisions between medical staff and their patients at blood transfusion scenes.

Trichuris trichiura Infection Diagnosed by Colonoscopy: Case Reports and Review of Literature

Trichuris trichiura, commonly referred to as a whipworm, has a worldwide distribution, particularly among countries with warm, humid climates. In Korea, trichuriasis was a highly prevalent soil-transmitted helminthiasis until the 1970s. However, the nationwide prevalence decreased to 0.02% in 2004 as a result of national control activities and improvement in the socioeconomic status of Koreans. Most infected individuals have no distinct symptoms, if lightly infected. The diagnosis is typically confirmed by detection of T. trichiura eggs on examination of a stool sample; few reports have described detection of the parasite during colonoscopy. Recently, we managed 4 patients with trichuriasis who were diagnosed by detection of the parasite on colonoscopy, and we reviewed the literature on the colonoscopic diagnosis of T. trichiura in Korea. We suggest that colonoscopy might be a useful diagnostic tool, especially when infected by only a few male worms with no eggs in the stool.

Effectiveness of Sodium Fluoride as a Glycolysis Inhibitor on Blood Glucose Measurement: Comparison of Blood Glucose using Specimens from the Korea National Health and Nutrition Examination Survey / 대한진단검사의학회지

BACKGROUND: Accurate measurement of blood glucose concentrations is essential for defining diabetes, and the minimization of ex vivo glycolysis has been recommended. Recent guidelines advocate two kinds of methods for sample collection and processing: either the sodium fluoride (NaF) method or immediate refrigeration using a serum separation tube (SST). We investigated the difference between the two methods in measuring subsequent glucose concentrations using blood specimens from participants recruited for the fourth Korean National Health and Nutrition Examination Survey. METHODS: Paired venous blood samples were collected in an SST and a NaF tube from 1,103 men and women. SST serum was separated within 30 min, including standing for 15 min, and then refrigerated. The NaF samples were refrigerated, but not separated until immediately before analysis. We compared the blood glucose concentrations between the SST (SST glucose) and NaF (NaF glucose) methods. RESULTS: The mean SST glucose was significantly higher than NaF glucose (99.0 mg/dL vs 96.5 mg/dL, P<0.05). NaF glucose showed a negative mean bias of 2.6 mg/dL vs SST glucose but showed high correlation (R=0.9899). There was no significant correlation between the bias of blood glucose concentrations by two methods and the storage time of NaF glucose. CONCLUSIONS: The negative bias associated with the use of NaF tubes may significantly affect the prevalence of diabetes. Serum separation and refrigeration within 30 min after venous sampling is recommended over NaF method, not only to minimize the preanalytical impact on detecting diabetes but also to reduce sample volume and number of tubes.

Perception of the Risks of Blood Transfusion in Koreans / 대한진단검사의학회지

BACKGROUND: The perceived risks of blood transfusions are important to be considered in creating a blood service policy. We surveyed the perception of blood transfusion risks among Korean laypeople. METHODS: A one-month nationwide telephone survey was conducted in September, 2007. The questionnaire was designed to assess the demographics of respondents, their responses to the term 'blood transfusion', and the perceived risks of a transfusion. A total of 500 interviews were completed. RESULTS: The words evoked by the term 'blood transfusion' included blood, donation, AIDS, help, and patients. About one third (33.6-35.8%) of the respondents gave a moderate to high rating for the perceived risks of blood transfusions. More than half (55.6%) of the respondents agreed that the blood supply in Korea is safe, and 81.6% of the respondents agreed to be transfused when transfusion is needed. The perceived risk of a blood transfusion was greater in women than in men and in people who never had a transfusion than those who had. More men than women agreed that the blood supply in Korea is safe, and the proportion of respondents who agreed to be transfused when needed was higher in men and in less educated people. The relative perceived transfusion risk (scale of 10) was 4.5+/-2.3. CONCLUSIONS: The Koreans in the survey had a tendency of positive thinking about blood transfusions, and previous transfusion experiences appear to decrease the fear about transfusions. These results will be useful in understanding how Koreans think about the risks associated with transfusions.