[Show abstract][Hide abstract] ABSTRACT: During the 2015 Middle East respiratory syndrome coronavirus outbreak in South Korea, we sequenced full viral genomes of strains isolated from 4 patients early and late during infection. Patients represented at least 4 generations of transmission. We found no evidence of changes in the evolutionary rate and no reason to suspect adaptive changes in viral proteins.
Full-text · Article · Feb 2016 · Emerging infectious diseases
[Show abstract][Hide abstract] ABSTRACT: Little is known about differences between immune reconstitution inflammatory syndrome and non-immune reconstitution inflammatory syndrome lymphoma in HIV patients on antiretroviral therapy. The aim of this study was to describe the characteristics of immune reconstitution inflammatory syndrome and non-immune reconstitution inflammatory syndrome lymphoma in Korean HIV patients on antiretroviral therapy compared with lymphoma in those off antiretroviral therapy. Of 1490 Korean HIV patients, 41 (3%) had lymphoma. Of these, 27 cases (66%) were classified as lymphoma off antiretroviral therapy, 8 as immune reconstitution inflammatory syndrome lymphoma, and 6 as non-immune reconstitution inflammatory syndrome lymphoma on antiretroviral therapy. Hodgkin lymphoma was significantly more common among patients with non-immune reconstitution inflammatory syndrome lymphoma on antiretroviral therapy than among those with lymphoma off antiretroviral therapy (P = 0.005), whereas there was no Hodgkin lymphoma among immune reconstitution inflammatory syndrome lymphoma. Stage IV lymphoma was significantly more rare in non-immune reconstitution inflammatory syndrome lymphoma on antiretroviral therapy than in lymphoma off antiretroviral therapy (P = 0.007). Non-immune reconstitution inflammatory syndrome lymphoma on antiretroviral therapy tends to have a better survival rate than lymphoma off antiretroviral therapy (Kaplan–Meier survival analysis, P = 0.167), while immune reconstitution inflammatory syndrome lymphoma exhibited a survival rate similar to lymphoma off ART (P = 0.618). In Korean HIV patients, there were significantly more Hodgkin lymphoma and less advanced stage in non-immune reconstitution inflammatory syndrome lymphoma on antiretroviral therapy than in lymphoma off antiretroviral therapy, in contrast to immune reconstitution inflammatory syndrome lymphoma.
No preview · Article · Jan 2016 · International Journal of STD & AIDS
[Show abstract][Hide abstract] ABSTRACT: We conducted this study to compare the clinical and microbiological characteristics of first and breakthrough neutropenic fever in hematologic malignancy patients after chemotherapy.
Full-text · Article · Jan 2016 · International Journal of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: During the 2015 outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Korea, 186 persons were infected, resulting in 38 fatalities. We isolated MERS-CoV from the oropharyngeal sample obtained from a patient of the outbreak. Cytopathic effects showing detachment and rounding of cells were observed in Vero cell cultures 3 days after inoculation of the sample. Spherical virus particles were observed by transmission electron microscopy. Full-length genome sequence of the virus isolate was obtained and phylogenetic analyses showed that it clustered with clade B of MERS-CoV.
Preview · Article · Jan 2016 · Journal of Korean Medical Science
[Show abstract][Hide abstract] ABSTRACT: We investigated the kinetics of serologic responses to Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using virus neutralization and MERS-CoV S1 IgG ELISA tests. In most patients, robust antibody responses developed by the third week of illness. Delayed antibody responses with the neutralization test were associated with more severe disease.
No preview · Article · Dec 2015 · Emerging infectious diseases
[Show abstract][Hide abstract] ABSTRACT: Rapid identification of the microorganisms in patients with bacteremia may be useful in clinical practice. We evaluated the impact of the multiplex polymerase chain reaction (PCR) on appropriate antibiotic use for patients with gram-positive cocci cluster (GPCC) bacteremia. We divided the GPCC bacteremia cases into a pre-PCR group (2010–2011) and a post-PCR group (2012–2013). A total 664 cases were included in the pre-PCR group; and 570, in the post-PCR group. In methicillin-susceptible Staphylococcus aureus (MSSA) cases, optimal antibiotics were administered earlier in the post-PCR group (77.4 h versus 42.6 h, P = 0.035). Although the proportions of glycopeptide exposure did not differ (54.7% versus 56.7%, P = 0.799), the duration of exposure decreased (69.6 h versus 30.7 h, P = 0.004). In methicillin-resistant S. aureus cases, the time to optimal antibiotics administration did not differ (45.4 h versus 43.7 h, P = 0.275). Multiplex PCR test significantly improved the early initiation of optimal antibiotics in MSSA bacteremia and reduced the unnecessary glycopeptide exposure.
No preview · Article · Dec 2015 · Diagnostic microbiology and infectious disease
[Show abstract][Hide abstract] ABSTRACT: Since the first imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection was reported on May 20, 2015 in Korea, there have been 186 laboratoryconfirmed cases of MERS-CoV infection with 36 fatalities. Ninety-seven percent (181/186) of the cases had exposure to the health care facilities. We are reporting a superspreading event that transmitted MERS-CoV to 81 persons at a hospital emergency room (ER) during the Korean outbreak in 2015. The index case was a 35-yr-old man who had vigorous coughing while staying at the ER for 58 hr. As in severe acute respiratory syndrome outbreaks, superspreading events can cause a large outbreak of MERS in healthcare facilities with severe consequences. All healthcare facilities should establish and implement infection prevention and control measure as well as triage policies and procedures for early detection and isolation of suspected MERS-CoV cases.
Preview · Article · Oct 2015 · Journal of Korean Medical Science
[Show abstract][Hide abstract] ABSTRACT: Background:
The incidence of herpes zoster is substantial during bortezomib treatment in patients with multiple myeloma (MM).
This study aimed to elucidate the effect of chemotherapy with or without bortezomib in MM patients on their herpes zoster incidence and varicella zoster virus (VZV)-specific cell-mediated immunity (CMI).
Peripheral blood mononuclear cells were collected at baseline and after 1 month of bortezomib-based or thalidomide-based chemotherapy and then analyzed using VZV-specific interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay. The clinical data from these patients were analyzed in relation to the ELISPOT results.
Of 58 patients analyzed, 39 patients received bortezomib and the other 19 patients, thalidomide. Among them, 5 patients developed herpes zoster during chemotherapy; all 5 were being treated with the bortezomib-based regimen and were not receiving prophylactic anti-viral agents. The median onset of herpes zoster was 32 days (range, 15-95 days) from the initiation of chemotherapy. Among patients who received bortezomib therapy, acyclovir prophylaxis significantly reduced the risk for herpes zoster (100-day cumulative incidence, 0% vs. 49.5%; p<0.001). Spot-forming cell (SFC) counts in the IFN-γ ELISPOT assay decreased from baseline after bortezomib (p=0.011) or thalidomide (p=0.096) treatment. Patients with baseline SFCs greater than 20/10(6) mononuclear cells exhibited significantly higher incidence of herpes zoster (100-day cumulative incidence, 34.8% vs. 0%; p=0.040).
Bortezomib treatment significantly reduced VZV-specific CMI, and high baseline SFC counts in patients receiving this treatment without acyclovir prophylaxis were associated with a significantly increased risk for herpes zoster.
No preview · Article · Oct 2015 · Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology
[Show abstract][Hide abstract] ABSTRACT: Background:
Asymptomatic bacteriuria (ABU) is common and often leads to unnecessary antimicrobial use. Reducing antibiotic overuse for ABU is therefore an important issue for antimicrobial stewardship. We performed this study to investigate the appropriateness of ABU management and to evaluate physicians' knowledge and practice regarding ABU.
We reviewed all urine cultures of ≥10(5) cfu/mL of bacteria among inpatients in a 900-bed hospital in 2011. Each episode of bacteriuria was classified into ABU or urinary tract infection (UTI). ABU was defined as a positive urine culture (≥10(5) cfu/mL) without symptoms or signs suggesting UTI. In October 2012 a cross-sectional survey of resident physicians was undertaken using an anonymous, self-administered questionnaire.
We identified 219 ABU cases among 1167 positive urine cultures, of which 70 (32.0 %) were inappropriately treated. Female gender, old age, pyuria, hematuria, and positive nitrite on urinalysis were associated with inappropriate ABU treatment in a multivariate analysis (P < 0.05). The response rate to the survey was 74.2 % (95/128). The mean knowledge score was 37.3 %, and 33.7 % of respondents were able to distinguish ABU from UTI, but less than half knew the indications for treating ABU. Even after ABU was correctly diagnosed, concerns about postoperative infections (38.6 %), UTI (9.1 %), and abnormal urinalysis (29.5 %) prevented proper management. About half of the respondents reported to prescribing antibiotics for ABU despite knowing they were not indicated.
About one third of ABUs were inappropriately managed. Lack of knowledge and discrepancies between knowledge and practice, contributed to antimicrobial overuse for ABU. Our findings highlight the importance of developing interventions, including education, audit and feedback, to tackle the problem of inappropriate treatment of ABU.
[Show abstract][Hide abstract] ABSTRACT: Staphylococcus aureus colonizes the nose, throat, skin, and gastrointestinal (GI) tract of
humans. GI carriage of S. aureus is difficult to eradicate and has been shown to facilitate the
transmission of the bacterium among individuals. Although staphylococcal colonization of
the GI tract is asymptomatic, it increases the likelihood of infection, particularly skin and soft
tissue infections caused by USA300 isolates. We established a mouse model of persistent
S. aureus GI colonization and characterized the impact of selected surface antigens on colonization.
In competition experiments, an acapsular mutant colonized better than the parental
strain Newman, whereas mutants defective in sortase A and clumping factor A showed
impaired ability to colonize the GI tract. Mutants lacking protein A, clumping factor B, poly-
N-acetyl glucosamine, or SdrCDE showed no defect in colonization. An S. aureus wall teichoic
acid (WTA) mutant (ΔtagO) failed to colonize the mouse nose or GI tract, and the
tagO and clfA mutants showed reduced adherence in vitro to intestinal epithelial cells. The
tagO mutant was recovered in lower numbers than the wild type strain in the murine stomach
and duodenum 1 h after inoculation. This reduced fitness correlated with the in vitro
susceptibility of the tagO mutant to bile salts, proteases, and a gut-associated defensin.
Newman ΔtagO showed enhanced susceptibility to autolysis, and an autolysin (atl) tagO
double mutant abrogated this phenotype. However, the atl tagO mutant did not survive better
in the mouse GI tract than the tagO mutant. Our results indicate that the failure of the
tagO mutant to colonize the GI tract correlates with its poor adherence and susceptibility to
bactericidal factors within the mouse gut, but not to enhanced activity of its major autolysin.
[Show abstract][Hide abstract] ABSTRACT: There are limited data describing the clinical characteristics of pyogenic spondylitis caused by Gram-negative bacteria (GNB). The aim of this study was to investigate the predisposing factors and clinical characteristics of pyogenic spondylitis caused by GNB compared to Gram-positive cocci (GPC).
We performed a retrospective review of medical records from patients with culture-confirmed pyogenic spondylitis at four tertiary teaching hospitals over an 8-year period.
A total of 344 patients with culture-confirmed pyogenic spondylitis were evaluated. There were 62 patients (18.0%) with pyogenic spondylitis caused by GNB and the most common organism was Escherichia coli (n = 35, 10.2%), followed by Pseudomonas aeruginosa (n = 10, 2.9%). Pyogenic spondylitis caused by GNB was more frequently associated with the female gender (64.5 vs. 35.5%, P <0.01), preexisting or synchronous genitourinary tract infection (32.3 vs. 2.1%, P< 0.01), and intra-abdominal infection (12.9 vs. 0.4%, P< 0.01) compared to patients with GPC. Although pyogenic spondylitis caused by GNB presented with severe sepsis more frequently (24.2 vs. 11.3%, P = 0.01), the mortality rate (6.0 vs. 5.2%) and the proportion of patients with residual disability (6.0 vs. 9.0%), defined as grade 3 or 4 (P = 0.78) 3 months after completion of treatment, were not significantly different compared to GPC patients.
GNB should be considered as the etiologic organism when infectious spondylitis develops in a patient with preexisting or synchronous genitourinary tract and intra-abdominal infection. In addition, the mortality rate and clinical outcomes are not significantly different between pyogenic spondylitis caused by GNB and GPC.
[Show abstract][Hide abstract] ABSTRACT: Clinical reasoning ability is an important factor in a physician's competence and thus should be taught and tested in medical schools. Medical schools generally use objective structured clinical examinations (OSCE) to measure the clinical competency of medical students. However, it is unknown whether OSCE can also evaluate clinical reasoning ability. In this study, we investigated whether OSCE scores reflected students' clinical reasoning abilities.
Sixty-five fourth-year medical students participated in this study. Medical students completed the OSCE with 4 cases using standardized patients. For assessment of clinical reasoning, students were asked to list differential diagnoses and the findings that were compatible or not compatible with each diagnosis. The OSCE score (score of patient encounter), diagnostic accuracy score, clinical reasoning score, clinical knowledge score and grade point average (GPA) were obtained for each student, and correlation analysis was performed.
Clinical reasoning score was significantly correlated with diagnostic accuracy and GPA (correlation coefficient = 0.258 and 0.380; P = 0.038 and 0.002, respectively) but not with OSCE score or clinical knowledge score (correlation coefficient = 0.137 and 0.242; P = 0.276 and 0.052, respectively). Total OSCE score was not significantly correlated with clinical knowledge test score, clinical reasoning score, diagnostic accuracy score or GPA.
OSCE score from patient encounters did not reflect the clinical reasoning abilities of the medical students in this study. The evaluation of medical students' clinical reasoning abilities through OSCE should be strengthened.This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially.
Preview · Article · Feb 2015 · The American Journal of the Medical Sciences
[Show abstract][Hide abstract] ABSTRACT: Tumor necrosis factor-α (TNF-α) inhibitors are increasingly used in treatment of inflammatory disorders because of their immunomodulatory efficacy. Increased risk of infection is an adverse effect of anti-TNF-α therapy. The incidence rate and severity of herpes zoster is significantly higher in patients on anti-TNF-α therapy than in the general population. The clinical presentation of varicella zoster virus infection is also often atypical in these patients. We experienced a patient who presented with a disseminated varicelliform rash while on etanercept therapy for ankylosing spondylitis.