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Successful empirical therapy of Staphylococcus aureus infections requires the ability to predict methicillin resistance. Our aim was to identify predictors of methicillin resistance in community-onset (CO) invasive S. aureus infections. Sixteen hospitals across Korea participated in this study from May to December 2012. We prospectively included cases of S. aureus infection in which S. aureus was isolated from sterile clinical specimens ≤72 hours after hospitalization. Clinical and epidemiological data were gathered and compared in methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) cases. Community-associated (CA) infections were defined as in previous studies. In total, there were 786 cases of community-onset S. aureus infection, 102 (13.0%) of which were CA-MRSA. In addition to known risk factors, exposure to 3rd generation cephalosporins in the past 6 months [odds ratio (OR), 1.922; 95% confidence interval (CI), 1.176–3.142] and close contact with chronically ill patients in the past month (OR, 2.647; 95% CI, 1.189–5.891) were independent risk factors for MRSA infection. However, no clinical predictors of CA-MRSA were identified. Methicillin resistance, CO infection, and appropriateness of empirical antibiotics were not significantly related to 30-day mortality. MRSA infection should be suspected in patients recently exposed to 3rd generation cephalosporins or chronically-ill patients. There were no reliable predictors of CA-MRSA infection, and mortality was not affected by methicillin resistance. [ABSTRACT FROM AUTHOR]

Investigates the association of complement C4 allotypes with rheumatoid arthritis in Koreans. C4 typing; Frequencies of C4 allotypes; Association of C4AQ0 and C4B5 with HLA.

Background: The increased possibility of bioterrorism has led to reinitiation of smallpox vaccination. In Korea, more than 30 years have passed since the last smallpox vaccinations, and even people who were previously vaccinated are not regarded as adequately protected against smallpox. We evaluated the efficacy and safety of CJ-50300, a newly developed cell culture-derived smallpox vaccine, in healthy adults previously vaccinated against smallpox., Methods: We conducted an open label, single arm, phase III clinical trial to evaluate the efficacy and safety of CJ-50300. Healthy volunteers, previously vaccinated against smallpox, born between 1950 and 1978 were enrolled. CJ-50300 was administered with a bifurcated needle over the deltoid muscle according to the recommended method. The rate of the cutaneous take reaction, humoral immunogenicity, and safety of the vaccine was assessed., Results: Of 145 individuals enrolled for vaccination, 139 completed the study. The overall rates of cutaneous take reactions and humoral immunogenicity were 95.0% (132/139) and 88.5% (123/139), respectively. Although 95.9% (139/145) reported adverse events related to vaccination, no serious adverse reactions were observed., Conclusion: CJ-50300 can be used safely and effectively in healthy adults previously vaccinated against smallpox., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with high mortality rates, but no treatment strategy has yet been established. We performed this study to evaluate the efficacy of linezolid with or without carbapenem in salvage treatment for persistent MRSA bacteremia., Methods: All adult patients with persistent MRSA bacteremia for 7 days from January 2006 through March 2008 who were treated at Seoul National University Hospital were studied. The results of linezolid salvage therapy with or without carbapenem were compared with those of salvage therapy with vancomycin plus aminoglycosides or rifampicin., Results: Thirty-five patients with persistent MRSA bacteremia were studied. The early microbiological response (ie, negative results for follow-up blood culture within 72 hours) was significantly higher in the linezolid-based salvage therapy group than the comparison group (75% vs 17%; P =.006). Adding aminoglycosides or rifampicin to vancomycin was not successful in treating any of the patients, whereas linezolid-based therapy gave an 88% salvage success rate P =.001). The S. aureus-related mortality rate was lower for patients treated with a linezolid salvage regimen than for patients continually treated with a vancomycin-based regimen (13% vs 53%; P =.030)., Conclusions: Linezolid-based salvage therapy effectively eradicated S. aureus from the blood for patients with persistent MRSA bacteremia. The salvage success rate was higher for linezolid therapy than for vancomycin-based combination therapy.

Human leukocyte antigen allele (HLA)-B*5701 is associated with abacavir hypersensitivity. However, the carriage rate of HLA-B*5701 has rarely been studied in Asians. In 534 Korean patients with human immunodeficiency virus infection, HLA-B*5701 status was determined by polymerase chain reaction with HLA-B*5701-specific primers. No patients had the HLA-B*5701 allele (95% confidence interval, 0%-0.7%). This explains the paucity of immunologically confirmed cases of abacavir hypersensitivity in Koreans.

Seventy-three liver abscess isolates of serotype K1 Klebsiella pneumoniae from a nationwide collection in Korea were genotypically characterized using pulsed-field gel electrophoresis and multilocus sequence typing. We found that serotype K1 K. pneumoniae strains that caused liver abscesses in Korea were genotypically related and that most were sequence type 23.

Objective: To control an outbreak of Shewanella algae and S. putrefaciens infections by identifying the risk factors for infection and transmission., Design: Matched case-control study., Setting: A university-affiliated tertiary acute care hospital in Seoul, Republic of Korea, with approximately 1,600 beds., Patients: From June 20, 2003, to January 16, 2004, a total of 31 case patients with Shewanella colonization or infection and 62 control patients were enrolled in the study., Interventions: Requirement to use single-use measuring cups and standard precautions (including hand washing before and after patient care and use of gloves)., Results: S. algae or S. putrefaciens was isolated from blood, for 9 (29.0%) of 31 patients who acquired one of the organisms; from bile, for 8 (25.8%), and from ascitic fluid, for 8 (25.8%). The attack rate of this outbreak was 5.8% (31 patients infected or colonized, of 534 potentially exposed on ward A) and the pathogenicity of the two species together was 77.4% (24 patients infected, of 31 who acquired the pathogens). The estimated incubation period for Shewanella acquisition was 3-49 days. Using logistic analysis, we identified the following risk factors: presence of external drainage catheters in the hepatobiliary system (odds ratio [OR], 20; P < .001), presence of hepatobiliary disease (OR, 6.4; P < .001), admission to the emergency department of the hospital (OR, 2.9; P = .039), wound classification of "contaminated" or "dirty or infected" (OR, 16.5; P = .012), an American Society of Anesthesiologists score of 3 or higher (OR, 8.0; P = .006), duration of stay in ward A (OR, 1.1; P < .001), and, for women, an age of 60-69 years (OR, 13.3; P = .028). A Shewanella isolate was recovered from the surface of a shared measuring cup, and 12 isolates of S. algae showed the same pulsed-field gel electrophoresis pattern., Conclusions: This Shewanella outbreak had a single-source origin and spread by contact transmission via a contaminated measuring cup. Shewanella species are emerging as potentially serious human pathogens in hospitals and could be included in hospital infection surveillance systems.

Objectives: This study was performed to determine the incidence of herpes zoster and seroprevalence of varicella-zoster virus (VZV) in young adults of South Korea, where VZV seroprevalence remains relatively high., Methods: In South Korea, military service is compulsory for all healthy young men and hence those in military service might provide a reflection of the general population. The computerized database of the Armed Forces Medical Command was examined to identify the number of reported herpes zoster cases. In order to evaluate VZV seroprevalence, serum samples were obtained from randomly selected subjects among those who had been admitted to the Armed Forces Capital Hospital., Results: A total of 705 cases of herpes zoster were reported between June 2004 and May 2005. The annual incidence rate of herpes zoster was 141 (95% CI 131.0-151.8) per 100000 population. A total of 192 subjects were enrolled for the analysis of VZV seroprevalence. All subjects were male and their median age was 21 (range 19-24) years. The overall anti-VZV IgG seropositivity prevalence was 92.7% (178/192, 95% CI 88.0-95.7%)., Conclusion: We have described a population-based study of the epidemiology of VZV infections in the military personnel of South Korea.

Objectives: To evaluate the incidence of early syphilis based on time from initiation of highly active antiretroviral therapy (HAART) in human immunodeficiency virus (HIV)-infected patients., Study Design: Five hundred thirty-nine HIV-positive patients undergoing HAART were followed up to 4 years to identify early (primary or secondary) syphilis. Incidence rate trends according to time from HAART initiation were evaluated by Poisson regression after adjustment for calendar year., Results: With median follow-up of 2.9 years, 56 (10.4%) patients experienced early syphilis, 17 (3.2%) with primary syphilis, and 39 (7.2%) with secondary syphilis. The overall incidence rate of early syphilis for 4 years after the start of HAART was 4.57 per 100 person-years (95% confidence interval, 3.45-5.93). The incidence rate of early syphilis significantly increased in proportion to the years after the start of HAART (3.4-6.1 per 100 person-year, P for trend <0.001)., Conclusions: Early syphilis incidence in HIV-infected patients increased in proportion to HAART duration. The finding suggests that screening for syphilis in HIV-infected patients who initiate HAART should be encouraged with attention to the time passed since HAART initiation.

Although adherence to clinic visits is important for successful clinical outcome in HIV treatment, little is known about the reasons patients with HIV miss appointments. We prospectively monitored the self-reported reasons for missed clinic appointments among HIV patients at a university hospital in South Korea from June through December 2006. Of the 1562 scheduled clinic visits, 131 (8%) of appointments were missed. Work schedule, forgetfulness and lack of motivation were the primary reasons given for missed appointments. Considering these factors when scheduling appointments may improve adherence to clinic attendance among HIV-infected patients.

Limited data on the clinical outcome of vancomycin treatment compared with that of beta-lactam treatment in patients with methicillin-susceptible Staphylococcus aureus bacteremia (MSSA-B) are available. We used different and complementary approaches: (i) a retrospective cohort study using a propensity score to adjust for confounding by treatment assignment and (ii) a matched case-control study. Of all patients with S. aureus bacteremia (SAB) in two university-affiliated hospitals over a 7-year period, 294 patients with MSSA-B were enrolled in the cohort study. The cases for the case-control study were defined as patients who received vancomycin treatment for MSSA-B; the controls, who were patients that received beta-lactam treatment for MSSA-B, were selected at a 1:2 (case:control) ratio according to the objective matching scoring system and the propensity score system. In the cohort study, SAB-related mortality in patients with vancomycin treatment (37%, 10/27) was significantly higher than that in those with beta-lactam treatment (18%, 47/267) (P = 0.02). In addition, multivariate analysis revealed that vancomycin treatment was associated with SAB-related mortality when independent predictors for SAB-related mortality and propensity score were considered (adjusted odds ratio of 3.3, 95% confidence interval of 1.2 to 9.5). In the case-control study using the objective matching scoring system and the propensity score system, SAB-related mortality in case patients was 37% (10/27) and in control patients 11% (6/54) (P < 0.01). Our data suggest that vancomycin is inferior to beta-lactam in the treatment of MSSA-B.

Primary drug resistance is an emerging problem in HIV infections. We have investigated the current prevalence of primary resistance in Korea and compared it with previous data. Drug-naive HIV patients attending the outpatient clinic of Seoul National University Hospital between April and August 2006 were enrolled. A medical interview and a genotypic resistance test were performed for each patient. The International AIDS Society-USA Panel consensus statement issued in 2006 was used to define resistance mutations. Eighty-one drug-naive HIV patients were enrolled. Two (2.5%) were infected with primary drug-resistant virus: M41L and K103N, respectively. In our previous study, conducted between 1998 and 2002, three (6%) of 50 subjects harbored resistant viruses. Thus the frequency of primary resistance was lower in the present sample than in the earlier one, though the difference is not statistically significant (p = 0.37). In view of our findings, routine antiretroviral resistance tests for drug-naive HIV patients are not obligatory in Korea.

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA), originally restricted to hospitals, has emerged as a significant pathogen in the community. Although MRSA accounts for over 60% of S. aureus in tertiary hospitals in Korea, little is known about the epidemiology of community-associated MRSA (CA-MRSA)., Methods: From January to July 2005, a hospital laboratory-based survey was conducted in seven community-based or tertiary hospitals. The medical records and Health Insurance Review Agency databases were reviewed and MRSA isolated from patients without apparent risk factors was defined as CA-MRSA. Susceptibilities to 12 antibiotics were tested by the disc diffusion method. SCCmec typing, Panton-Valentine leucocidin (PVL) gene detection and multilocus sequence typing (MLST) were performed according to published protocols., Results: Of 3,251 S. aureus, 1,900 (58.4%) were MRSA. CA-MRSA accounted for 112 (5.9%) of the MRSA. Of the 112 CA-MRSA isolates, 27 and 33 were found to be pathogens and colonizers, respectively. Fifty-two isolates from the patients with chronic otitis media were classified as 'undetermined'. Most of the 27 CA-MRSA patients had skin and soft tissue infections or acute ear infections. None of the patients died during the study period. Among 72 isolates tested, 64% were multidrug-resistant. SCCmec type IVa was the most common type among the colonizers and pathogens. On MLST analysis, ST72 was predominant, but ST5 and ST239 were prevalent in the 'undetermined' group. None possessed the PVL gene., Conclusions: Despite MRSA-endemic hospital settings, CA-MRSA infections are not common in Korea. A new clone of CA-MRSA, ST72-SCCmec type IVa without the PVL gene, is the most common form.

Although the importance of the initial regimen in highly active antiretroviral therapy (HAART) has been emphasized, the effect on clinical outcome of early modification of the initial HAART regimen has not been well-defined. The analysis included antiretroviral-naive HIV patients who started HAART between 1999 and 2005 at a university hospital. Early modification was defined as any drug change within 2 months of starting HAART. The effect of early regimen modification on the occurrence of new AIDS-defining illness or death was assessed using Kaplan-Meier survival estimates, and hazard ratios were estimated using Cox's proportional hazards regression model. Of 398 patients beginning HAART, 21% experienced early modification of their regimen, the most common reason being gastrointestinal toxicity (49%). After adjusting for risk factors for occurrence of a new AIDS event or death, identified by univariate analysis, the hazards ratio contrasting early modification with maintenance of initial HAART regimen was 3.06 (95% confidence interval, 1.36-6.90; p = 0.007). There were significant differences between the AIDS event-free survival curves of patients in clinical categories B or C with or without early modification of initial HAART regimen (p = 0.0002), but no significant difference in patients in clinical category A (p = 0.706). A considerable proportion of patients who started HAART changed treatment regimen mainly due to intolerance early after start of HAART. Early modification of an initial HAART regimen was associated with poor clinical outcome in HIV patients in the advanced clinical categories.

This study was performed to determine the incidence and seroprevalence of hepatitis A virus (HAV) infections in young soldiers in the Republic of Korea Army. From January 2000 through December 2004, a total of 147 hepatitis A cases were reported to the Armed Forces Medical Command. The annual incidence rates were 7.4 per 100,000 persons in 2000, 1.6 in 2001, 4.4 in 2002, 9.8 in 2003, and 6.2 in 2004, based on the reported cases among approximately 500,000 soldiers. All patients were males with a median age of 21 yr (range, 19-27). The most common symptom was nausea (86.5%), and all patients had recovered without complications. In addition, in order to evaluate the seroprevalence of HAV infection in young adults, serum samples were obtained from randomly selected young subjects among those who had been admitted to the Armed Forces Capital Hospital from September 2005 to February 2006. A total of 200 subjects were enrolled in the study to analyze the anti-HAV immune status. The overall anti-HAV IgG seropositive rate was 2% (4/200, 95% CI, 0.60-5.21%). Given the changing epidemiology of the disease and the associated increase in morbidity, it was suggested that routine HAV vaccination for Korean military personnel might be necessary.

The prevalence of parasitic infections was investigated in human immunodeficiency virus (HIV)-infected patients (n = 105) who visited Seoul National University Hospital, Seoul, Korea, during the period from 1995 to 2003. Fecal samples were collected from 67 patients for intestinal parasite examinations, and sputum or bronchoalveolar lavage samples from 60 patients for examination of Pneumocystis carinii. Both samples were obtained from 22 patients. Thirty-three (31.4%) of the 105 were found to have parasitic infections; Cryptosporidium parvum (10.5%; 7/67), Isospora belli (7.5%; 5/67), Clonorchis sinensis (3.0%; 2/67), Giardia lamblia (1.5%; 1/67), Gymnophalloides seoi (1.5%; 1/67), and Pneumocystis carinii (28.3%; 17/60). The hospital records of the 11 intestinal parasite-infected patients showed that all suffered from diarrhea. This study shows that parasitic infections are important clinical complications in HIV-infected patients in the Republic of Korea.

Objectives: To evaluate the clinical features of ciprofloxacin-resistant Enterobacter bacteremia and to examine the risk factors for ciprofloxacin resistance in Enterobacter species isolates causing bacteremia., Design: A case-control study., Setting: A 1,500-bed, tertiary-care university hospital and referral center., Patients: All patients older than 16 years with Enterobacter species isolated from blood were enrolled. The medical records of 183 patients with clinically significant Enterobacter bacteremia from January 1998 to December 2002 were identified. We compared patients with bacteremia caused by ciprofloxacin-susceptible isolates with patients with bacteremia caused by ciprofloxacin-resistant isolates., Results: Twenty-three (12.6%) of the patients had bacteremia caused by isolates resistant to ciprofloxacin. There were no significant differences in age, gender, underlying diseases, primary site of infection, or Acute Physiology and Chronic Health Evaluation II score between the ciprofloxacin-resistant and the ciprofloxacin-susceptible groups. Broad-spectrum cephalosporin resistance, defined as resistance to cefotaxime or ceftazidime in vitro, was detected in 21 (91.3%) of 23 ciprofloxacin-resistant isolates compared with 65 (40.6%) of 160 ciprofloxacin-susceptible isolates (P < .001). Multivariate analysis revealed that independent risk factors for ciprofloxacin resistance were the prior receipt of fluoroquinolones (P < .001) and broad-spectrum cephalosporin resistance (P < .001)., Conclusions: In Enterobacter species isolates causing bacteremia, ciprofloxacin resistance was closely associated with the prior receipt of fluoroquinolones and broad-spectrum cephalosporin resistance. The close relationship between ciprofloxacin resistance and broad-spectrum cephalosporin resistance is particularly troublesome because it severely restricts the therapeutic options for Enterobacter species infection.

Background: This study was conducted to evaluate the risk factors for infection and clinical outcomes of bacteremic spontaneous bacterial peritonitis (SBP) due to ESBL-producing E. coli and K. pneumoniae, in patients with advanced liver cirrhosis., Methods: The ESBL production was determined by NCCLS guidelines and/or double-disk synergy tests, on stored E. coil and K. pneumoniae blood isolates collected between 1998 and 2002. Of the patients with advanced liver cirrhosis, 15 case patients, with SBP due to ESBL-producers, were compared with 30 matched controls, with SBP due to non-ESBL-producers., Results: There were no significant differences in age, sex, Child-Pugh scores, or APACHE II scores between the two groups. Significant factors associated with infection by ESBL-producing organisms, according to univariate analysis, were: ICU care, indwelling urinary catheter, central venous catheterization, an invasive procedure within the previous 72 hours, and prior use of antibiotics within the previous 30 days. When assessing the clinical response at 72 hours after the initial antimicrobial therapy, the treatment failure rate was significantly higher in the ESBL group (73.3% vs. 16.7%, p<0.001). Also, overall 30-day mortality rates were 60% (9/15) in the ESBL groups and 23.3% (7/30) in the control group (p=0.015)., Conclusion: Among patients with advanced liver cirrhosis, bacteremic SBP due to ESBL-producing E. coil and K. pneumoniae was associated with adverse outcomes, and significantly higher mortality.

Genes conferring resistance to one of the macrolide-lincosamide-streptogramin (MLS) antibiotics may confer cross-resistance to others, because they have similar effects on bacterial protein synthesis. In Korea, over 70% of Staphylococcus aureus isolates are methicillin-resistant and erythromycin-resistant methicillin-resistant S. aureus (MRSA) is also prevalent. We investigated the frequency of MLS resistance in erythromycin-resistant S. aureus isolates. A total of 682 isolates of S. aureus were collected in a nationwide antibiotic resistance survey. Susceptibility to erythromycin, clindamycin, and quinupristin/dalfopristin was tested by disk diffusion. In all, 37% of the methicillin-susceptible S. aureus (MSSA) and 97% of the MRSA isolates were resistant to at least one of the MLS antibiotics, whereas all were susceptible to quinupristin/dalfopristin. Out of 518 strains that were resistant to erythromycin, 60 clindamycin-susceptible (30 MSSA, 30 MRSA) and 44 clindamycin-resistant isolates (14 MSSA, 30 MRSA) were selected at random from these strains. Thirteen genes related to MLS resistance were detected in these isolates by PCR. Of the 104 MSSA and MRSA strains tested, 98 harbored one or more erm gene. The most common was erm(A), with erm(C) next. But, msr(A), lnu(A), and mef(A) were rare and no resistance to streptogramin A was encountered., (Copyright Mary Ann Liebert, Inc.)

Objective: To determine the impact of delayed treatment of methicillin-resistant Staphylococcus aureus bacteraemia (MRSA bacteraemia) on mortality., Patients and Methods: We used two different and complementary approaches: a retrospective cohort study and a matched case-control study. Of the total of all patients with S. aureus bacteraemia in a tertiary hospital over a 4 year period, 127 patients with MRSA bacteraemia were enrolled in the cohort study. The cases for the case-control study were defined as patients who received appropriate empirical treatment for MRSA bacteraemia; the controls, who were patients who received inappropriate empirical treatment for MRSA bacteraemia, were selected according to the matching variables of age, sex, severity of underlying illness, classification of main underlying disease and prior hospital stay. On the 14-point matching scale that was used to select the best controls, the average score (+/-S.D.) of the 30 controls was 11.2 (+/-2.0)., Results: In the cohort study, the difference in S. aureus bacteraemia-related mortality between appropriate (30%, 9/30) and inappropriate (39%, 38/97) empirical treatment was not significant (P=0.36). In addition, multivariate analysis did not indicate that inappropriate empirical treatment was associated with mortality when independent predictors for mortality were considered (adjusted OR 1.1, 95% CI 0.4-3.1). In the case-control study, S. aureus bacteraemia-related mortality in case patients was 30% (9/30) and in control patients 33% (10/30) (P>0.99, McNemar's test). In four of the nine discordant pairs, the case patients died whereas the control patients lived., Conclusions: Our data suggest that an initial delay of 2 days in the use of appropriate antibiotics, especially of vancomycin or other glycopeptides, before the preliminary microbiological report may not adversely affect the outcome in patients with MRSA bacteraemia.

Staphylococcus aureus, one of the most frequently isolated pathogens in both hospitals and the community, has been particularly efficient at developing resistance to antimicrobial agents. As methicillin-resistant S. aureus (MRSA) has prevailed and, furthermore, as S. aureus with reduced susceptibility to vancomycin has emerged, the therapeutic options for the treatment of S. aureus infections have become limited. To update the current status of antibiotic resistance, clinical S. aureus isolates were collected from eight university-affiliated hospitals from June 1999 to January 2001. Susceptibility tests with 28 antibiotics were performed by the disk diffusion method. Among a total of 682 isolates, the methicillin resistance rate was 64% (439 of 682), and most of the MRSA isolates were resistant to multiple classes of antibiotics. Although a constitutive macrolide-lincosamide-streptogramin B resistance phenotype was common, no isolates were resistant to quinupristin-dalfopristin or linezolid. Rifampin, fusidic acid, trimethoprim-sulfamethoxazole, and arbekacin showed superior in vitro activity compared with the other antibiotics against the MRSA isolates. No isolates showed reduced susceptibility to vancomycin.

A vancomycin-resistant Enterococcus (VRE) outbreak occurred at a hematology/oncology (HO) service in a tertiary acute care hospital, 1 January to 30 April 2002. This study was undertaken to identify risk factors, and to establish relations between seasonal factors and this VRE outbreak. Every patient (n = 82) and health care worker (HCW) (n = 31) at the HO unit was screened by rectal swab and stool culture during the VRE outbreak. Environmental surface culture (n = 35) and pulsed-field gel electrophoresis (PFGE) of VRE isolates were preformed. Among a total of 82 patients, 17 had VRE. All VRE isolates were E. faecium, the 6 studied further were Van A with identical PFGE patterns. Cultures of surfaces and HCWs were negative for VRE. Prolonged hospital stay (p = 0.02), male gender (p = 0.02), and care in a 6-bed room (p < 0.01) were risk factors for acquisition of VRE. An association with the VRE outbreak period was found again for long hospital stay, but also for the antibiotic usage pattern, frequent surgery and a high proportion of new inexperienced staff (52% vs 4% before the outbreak (p < 0.01, Fisher's exact test). Sudden personnel turnover in high-risk units should be avoided.

Objective: To evaluate the outcome of attempted Hickman catheter salvage in neutropenic cancer patients with Staphylococcus aureus bacteremia who were not using antibiotic lock therapy., Design: Retrospective cohort study., Setting: A university-affiliated, tertiary-care hospital with 1,500 beds for adult patients., Patients: All neutropenic cancer patients who had a Hickman catheter and S. aureus bacteremia (32 episodes in 29 patients) between January 1998 and March 2002., Methods: Salvage attempts were defined as cases where the Hickman catheter was not removed until we obtained the results of follow-up blood cultures performed 48 to 72 hours after starting treatment with antistaphylococcal antibiotics. Salvage was considered to be successful if the Hickman catheter was still in place 3 months later without recurrent bacteremia or death., Results: Catheter salvage was attempted in 24 (75%) of the 32 episodes. Of the salvage attempts, the success rate was 50% (12 of 24). Salvage attempts were successful in 14% (1 of 7) of the episodes with positive follow-up blood cultures, and in 65% (11 of 17) of those with negative follow-up blood cultures (P = .07). If the analysis is confined to cases with no external signs of catheter infection, salvage attempts were successful in 14% (1 of 7) of the episodes with positive follow-up blood cultures and in 80% (8 of 10) of those with negative follow-up blood cultures (P = .02)., Conclusion: In neutropenic cancer patients with S. aureus bacteremia, attempted catheter salvage without antibiotic lock therapy was successful in 50% of the cases.

The prevalence of transmitted resistance to antiretroviral drugs varies geographically, with little known about this effect in Asia. In Korea, zidovudine has been widely administered, without charge, through the National AIDS program since the early 1990s; with other potent antiretroviral agents also being introduced in the late 1990s. An analysis of the drug susceptibility to antiretroviral drugs was performed by genotyping of the drug-resistant mutations in HIV on plasma samples from 50 HIV-infected patients who had received no treatment, between February 1998 and November 2002, which was interpreted according to the consensus guidelines of the International AIDS Society-USA panel. The median CD4 cell count was 100 cells/mm3; the mean plasma RNA level was (5.19 +/- 0.56) log copies per milliliter. Of the 50 subjects tested 4 (8.0%) had one or more major drug-resistance mutation. The prevalence of resistance to multiple classes of drugs was 2.0%. No mutations, associated with resistance to non nucleoside reverse transcriptase inhibitors, were identified. Resistant mutations of the reverse-transcriptase gene were found at codons 67, 70, 118, 215, and 219, and a resistant mutation of the protease gene was found only at codon 46 (2.6%, 1 of 39). There was an 8.0% prevalence of primary drug resistance to antiretroviral drugs in Korean patients infected with HIV-1.

Toxoplasma gondii tachyzoites were isolated from the blood of an ocular patient, and have been successfully passaged in the laboratory, for over a year, by peritoneal inoculation in mice. The isolated parasite was designated the Korean Isolate-1 (KI-1) and its characteristics were compared with those of the RH strain, a wellknown virulent strain originating from a child who suffered from encephalitis. The morphology, pathogenicity, infectivity and cell culture characteristics of the KI-1 were similar to those of the RH strain. Both RH and KI-1 antigens were detected by an anti-T. gondii monoclonal antibody (mAb), Tg563, against the major surface protein SAG1 (30 kDa), whereas no reaction was observed against an anti-Neospora caninum mAb, 12B4. The KI-1 was confirmed as an isolate of T. gondii. A long-term laboratory maintenance and characterization of a local T. gondii isolate is reported for the first time in the Republic of Korea.

In summer 2002, a nationwide outbreak of acute hemorrhagic conjunctivitis occurred in South Korea. The etiologic agent was confirmed as coxsackievirus A24 variant (CA24v) by virus isolation and sequencing of a part of the VP1 gene. Phylogentic analysis, based on the protease 3C sequences, showed that the Korean isolates were clustered into a lineage distinct from the CA24v isolates reported in previous outbreaks in Asia.

Vivax malaria reemerged in the Republic of Korea in 1993. Most of the cases occurred among soldiers in the region adjacent to the Demilitarized Zone (DMZ) until 1995. To determine the rate of dispersion of vivax malaria, we evaluated its epidemiologic characteristics. Of 13,903 cases of vivax malaria reported in 2000, 40.1% (5,577) were reported among Republic of Korea military personnel, 26.2% (3,641) among veterans discharged less than two years from the military, and 33.7% (4,685) among civilians. Cases of vivax malaria have rapidly increased annually among counties bordering the DMZ, and have spread to approximately 40 km south of the DMZ. Chemoprophylaxis administered to military personnel may have been responsible for the decreasing number of cases among the Republic of Korea military population. The first mosquito-transmitted cases appeared in early June. Therefore, chemoprophylaxis should be instituted in early April to reduce the number of infected mosquitoes. Extensive intervention is warranted to reduce the spread of vivax malaria in the Republic of Korea.

Methicillin-resistant Staphylococcus aureus (MRSA) accounts for more than 70% of S. aureus isolates from tertiary hospitals in Korea. Clinical isolates of S. aureus were collected from eight provincial, university-affiliated hospitals during the period from June 1999 to January 2001 for nationwide surveillance. All isolates were screened for reduced susceptibility to vancomycin by using brain heart infusion agar containing 4 micro g of vancomycin per milliliter. Population analysis and the determination of the MIC of vancomycin were done for the isolates which grew on the screening agar plates. Of 682 total isolates, MRSA accounted for 64% (439 of 682). Of 27 (4%) isolates that grew on the screening agar plates, none showed the heteroresistance phenotype. No strains with reduced susceptibility to vancomycin were identified.

A wide variety of neurologic complications associated with human immunodeficiency virus-type 1 (HIV-1) infection result from HIV-1 itself or secondarily related to immunosuppression. In Korea, the number of HIV-1 seropositive populations is increasing, but little has been known about the neurologic complications of HIV-1 infection. To investigate the neurologic complications in HIV-1 infected Korean patients, we performed a cross-sectional study in consecutive admissions to the Seoul National University Hospital between March 1998 and June 1999. Thirty-four HIV-1 seropositive patients were included. As a result, a total of 26 HIV-1 related neurologic complications were identified from 17 patients. Among them, 10 patients showed cognitive/motor abnormalities: 3 HIV-1-associated dementia and 7 possible HIV-1-associated minor cognitive/motor disorder. Neuromuscular complications were found in 10 patients: 9 distal symmetric polyneuropathy, and 1 possible chronic inflammatory demyelinating polyradiculoneuropathy. In 3 patients with focal brain lesions, 2 were presumptively diagnosed as having primary CNS lymphoma, and 1 as having progressive multifocal leukoencephalopathy in the posterior fossa, based on history, clinical findings, serology, radiological appearances, and response to empirical therapy. Other complications included cryptococcal meningitis and only soft neurologic signs without any neurologic disease. Most of these complications (88%) occurred in the advanced stage of infection.

To determine HIV-1 subtypes in Korean patients, we analyzed the nucleotide sequences of the HIV-1 env gene isolated from 19 Korean patients. DNA was extracted from cultured lymphocytes and the proviral V3 env gene was amplified by nested polymerase chain reaction. DNA sequences were determined using a cycle sequencer with fluorescence-labeled dye terminators, and aligned using a set of reference sequences. The phylogenetic tree was constructed by the neighbor-joining method. Most of the enrolled patients were in the advanced stage of AIDS with CD4+ lymphocyte counts ranging from 10 to 560 (median 50) per mm3. Eighteen of the nineteen patients' sequences fall into subtype B (95%) and one was subtype A (5%). The tetrameric motifs at the tip of the V3 loop were comprised of GPGR (10 cases, 53%), GPGS (5 cases, 26%), and GPGQ, GPGG, GQGR, and APGS (one case each, 5%). Subtype B was found to be the most predominant clade of HIV-1 in our AIDS patients.

Plasmodium vivax malaria re-emerged in South Korea in 1993, and epidemics continue since then. We examined genetic variation in the region encompassing the apical membrane antigen-1 (PvAMA-1) of the parasites by DNA sequencing of the 22 re-emerging P. vivax isolates. The genotype of the PvAMA-1, which was based on sequence data previously reported for the polymorphic regions, showed that two haplotypes were present at one polymorphic site. Compared with reported data, the two types, SKOR type I and type II, were similar to Chinese CH-10A and CH-05A isolates, respectively. Thus, the present study showed that two genotypes of AMA-1 genes coexist in the re-emerging Korean P. vivax.

The incidence of tuberculosis in renal transplant patients has been reported to be fairly low and disseminated tuberculosis presenting with cutaneous manifestations has not been reported previously in these patients. We report the case of a 62-y-old kidney transplant recipient with a long-term history of chronic immunosuppressive therapy who presented with high fever, rapidly progressing respiratory failure and disseminated erythematous pustular cutaneous lesions.

The human polyomavirus JC virus (JCV) is the etiologic agent of the fatal demyelinating central nervous system disease progressive multifocal leukoencephalopathy (PML), which occurs in 4-7% of AIDS patients. Two Korean AIDS patients with PML were assayed for JCV, and the virus was genotyped by polymerase chain reaction, DNA sequencing and phylogenetic analysis. Using immunohistochemical analysis, we also examined the distribution of JCV antigen in the brains of the patients. The JCV genome was detected in peripheral lymphocytes, brain and cerebrospinal fluid from these Korean PML patients. Although type 2 is the most common genotype in Asia, the genotype of the JCV in these two AIDS patients was characterized as type 1, which is of European origin. We found that JCV antigen was selectively detected in oligodendrocytes and astrocytes of the brains from these patients. Compared to the prototype type 1 (Mad-1), two different nucleotides (G-->C) in the KOR-1 strain identified here were found at positions 2488 and 2490 of the major capsid protein VP1 gene. In summary, this is the first report of PML in Korean AIDS patients; it is also the first isolation of JCV type 1 in PML in East Asians., (Copyright 2002 S. Karger AG, Basel)