Young Eun Ha

MERS-CoV outbreak following a single patient exposure in an emergency room in South Korea: an epidemiological outbreak study.

Summary Background In 2015, a large outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) infection occurred following a single patient exposure in an emergency room at the Samsung Medical Center, a tertiary-care hospital in Seoul, South Korea. We aimed to investigate the epidemiology of MERS-CoV outbreak in our hospital. Methods We identified all patients and health-care workers who had been in the emergency room with the index case between May 27 and May 29, 2015. Patients were categorised on the basis of their exposure in the emergency room: in the same zone as the index case (group A), in different zones except for overlap at the registration area or the radiology suite (group B), and in different zones (group C). We documented cases of MERS-CoV infection, confirmed by real-time PCR testing of sputum samples. We analysed attack rates, incubation periods of the virus, and risk factors for transmission. Findings 675 patients and 218 health-care workers were identified as contacts. MERS-CoV infection was confirmed in 82 individuals (33 patients, eight health-care workers, and 41 visitors). The attack rate was highest in group A (20% [23/117] vs 5% [3/58] in group B vs 1% [4/500] in group C; p<0·0001), and was 2% (5/218) in health-care workers. After excluding nine cases (because of inability to determine the date of symptom onset in six cases and lack of data from three visitors), the median incubation period was 7 days (range 2–17, IQR 5–10). The median incubation period was significantly shorter in group A than in group C (5 days [IQR 4–8] vs 11 days [6–12]; p<0·0001). There were no confirmed cases in patients and visitors who visited the emergency room on May 29 and who were exposed only to potentially contaminated environment without direct contact with the index case. The main risk factor for transmission of MERS-CoV was the location of exposure. Interpretation Our results showed increased transmission potential of MERS-CoV from a single patient in an overcrowded emergency room and provide compelling evidence that health-care facilities worldwide need to be prepared for emerging infectious diseases. Funding None.

Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia: clinical impact of antimicrobial resistance on outcome.

Despite the high prevalence of antimicrobial resistance among Pseudomonas aeruginosa bacteremia, the clinical consequence of resistance remains unclear. The purpose of this study was to identify predictors of mortality and evaluate the clinical impact of antimicrobial resistance on outcome in P. aeruginosa bacteremia. A retrospective cohort study including patients with P. aeruginosa bacteremia was performed. The risk factors for antimicrobial resistances were evaluated, and the impact of the respective resistances on mortality was assessed. Of 202 P. aeruginosa bacteremia cases, the resistance rates to ceftazidime, piperacillin, imipenem, fluoroquinolone, and aminoglycoside were 36.6%, 22.3%, 22.8%, 23.8%, and 17.8%, respectively. A prior use of fluoroquinolones and an indwelling urinary catheter were common risk factors for all types of antimicrobial resistance. The overall 30-day mortality rate was 25.2% (51/202), and the risk factors for mortality were corticosteroid use, nosocomial acquisition, polymicrobial infection, an increasing Charlsons weighted co-morbidity index, and intensive care unit care (p < 0.05). As compared with the susceptible group, ceftazidime-, piperacillin-, or imipenem-resistant groups had a higher mortality (p < 0.05). A multivariate analysis showed that resistance to ceftazidime or imipenem remained a significant factor associated with mortality (odds ratio, 2.96; 95% confidential interval, 1.20-7.31; and odds ratio, 2.74; 95% confidential interval, 1.02-7.31, respectively). Antimicrobial resistance, especially to ceftazidime or imipenem, adversely affected outcome in patients with P. aeruginosa bacteremia.

Duration of colonization and risk factors for prolonged carriage of vancomycin-resistant enterococci after discharge from the hospital

BACKGROUND There are no available studies on the duration and risk factors of vancomycin-resistant enterococci (VRE) carriage after hospital discharge. In this study we investigated the duration of colonization with VRE and the risk factors for prolonged carriage in the outpatient clinic after discharge from the hospital. METHODS The study took place from January 2008 to September 2009. Patients were included if they were identified as persistent VRE carriers by follow-up rectal swab or stool cultures in the outpatient setting, after discharge from the hospital without clearance of VRE. The probability of culture positivity and clearance was analyzed from the discharge date. Cox regression was performed to determine the risk factors for prolonged carriage. VRE clearance was defined as VRE-negative rectal (or stool) cultures on at least three consecutive occasions a minimum of 1 week apart. RESULTS One hundred twenty-seven patients were included in this study. Follow-up cultures were conducted for a median of 8.86 weeks (range 1-90 weeks) after hospital discharge. The median duration of culture positivity of VRE was 5.57 weeks (range 0-50.14 weeks). Ninety-six out of 127 patients (75.6%) showed the first negative culture result at a median time of 4.86 weeks (range 0-66 weeks) after discharge. Among these patients, 15 were lost to follow-up after the first negative culture and eight were lost after the second negative culture. Sixty-eight patients (53.5%) were confirmed to have clearance of VRE during follow-up in the outpatient clinic. The median time to clearance after discharge was 8.86 weeks (range 2-90 weeks). In the cleared cases, the median time to the first negative VRE culture result was 4.71 weeks (range 0-66 weeks). Ninety percent of patients showed the first negative culture result at 25 weeks and VRE clearance at 30 weeks after discharge. Surgery or antibiotic use during admission (p = 0.048 and p = 0.001, respectively), dialysis (p = 0.046), and discharge to a nursing home or other health care institution (p = 0.025) were independently associated with prolonged colonization with VRE. CONCLUSIONS The median duration of VRE colonization was 5.57 weeks after hospital discharge. In the cases with clearance during follow-up, the median time to clearance after discharge was 8.86 weeks. Risk factors for prolonged carriage were surgery, antibiotic use during admission, dialysis, and discharge to a nursing home or other health care institution. Therefore, patients with these risk factors should be managed more carefully to prevent transmission of VRE in the outpatient clinic.

Epidemiology and clinical outcomes of bloodstream infections caused by extended-spectrum β-lactamase-producing Escherichia coli in patients with cancer.

Patients with cancer can be vulnerable to infection with antimicrobial-resistant pathogens such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. A cohort study was performed to evaluate the epidemiology and impact of ESBL-producing Escherichia coli (ESBL-EC) bacteraemia on the outcomes of adult patients with cancer. During the 2.5-year study period, a total of 350 cases of E. coli bacteraemia were documented in cancer patients, of which 95 (27.1%) were due to ESBL-EC. Significant factors associated with ESBL-EC bacteraemia were liver disease, immunosuppressant use, recent surgery, and prior use of cephalosporins or fluoroquinolones. The overall 30-day mortality rate was 14.9% (52/350), and the mortality rate was higher in patients with ESBL-EC than in those without ESBL-EC (22.1% vs.12.2%; P=0.02). Multivariate analysis showed that ESBL-EC was an independent risk factor for mortality (odds ratio=3.01, 95% confidence interval 1.45-6.28; P=0.003), along with the presence of septic shock, mechanical ventilation, the severity of underlying diseases, and pneumonia as a source of bacteraemia. Of the 69 isolates in which ESBLs and their molecular relationships were studied, 68 (98.6%) produced CTX-M-type and 51 (73.9%) produced CTX-M-14 and/or CTX-M-15. Twenty-four sequence types (STs) were identified among CTX-M-14- and CTX-M-15-producing E. coli isolates, with ST131 being the most prevalent (12/51; 23.5%). In conclusion, this study confirms that CTX-M-producing E. coli and ST131, which have been shown to be an emerging public health threat, are widely prevalent in cancer patients and can adversely affect the outcome of E. coli bacteraemia in these patients.

Can Levofloxacin Be a Useful Alternative to Trimethoprim-Sulfamethoxazole for Treating Stenotrophomonas maltophilia Bacteremia?

ABSTRACT A retrospective study was conducted to evaluate the efficacy of levofloxacin in the treatment of Stenotrophomonas maltophilia bacteremia. The 30-day mortality rates were similar between the trimerthoprim-sulfamethoxazole (TMP-SMX) and levofloxacin treatment groups. Adverse events related to antibiotics occurred more frequently in patients receiving TMP-SMX, and recurrent bacteremia due to levofloxacin-resistant S. maltophilia strains developed in patients treated with levofloxacin. Our data suggest that levofloxacin can be a useful alternative option for treating S. maltophilia infections.

Community-associated Panton–Valentine leukocidin-negative meticillin-resistant Staphylococcus aureus clone (ST72-MRSA-IV) causing healthcare-associated pneumonia and surgical site infection in Korea

BACKGROUND Community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) has emerged as an important pathogen worldwide in a continent-specific manner. Clinical characteristics of infections caused by CA-MRSA other than USA300, especially in healthcare settings, have not been well established. AIM To conduct a retrospective cohort study to determine the clinical characteristics of infections caused by Panton-Valentine leukocidin (PVL)-negative, multilocus sequence type (ST) 72 staphylococcal cassette chromosome mec (SCCmec) type IV, a major CA-MRSA clone in Korea. METHODS ST72-IV isolates, which were susceptible to fluoroquinolones, gentamicin, rifampicin, and cotrimoxazole, were presumptively identified among 4667 MRSA isolates and then confirmed by SCCmec typing and multilocus sequence typing. A total of 124 cases of ST72-IV infections were analysed. FINDINGS The annual incidence of infections by ST72-IV per 100,000 admissions increased from 45.5 to 66.3 cases during 2007-2009. The most frequently occurring type of infection was skin and soft tissue infection (SSTI) (46.0%), followed by pneumonia (27.4%) and bone and joint infection (9.7%). Surgical site infection accounted for 22.6% and 32.5% of community-onset (CO) healthcare-associated infection and hospital-onset (HO) infection, respectively. Pneumonia was most frequent (45.0%) among HO infection. Multivariate analysis showed that pneumonia increased the odds of all-cause mortality (odds ratio: 18.8; 95% confidence interval: 2.6-133.9) compared with other types of infection. CONCLUSIONS Increasing trends were observed in annual incidence of CO and HO infections by ST72-IV in Korea. Pneumonia was the most frequent among HO infection and was associated with higher mortality. These findings pose important implications for successful antibiotic therapy and infection control in the era of CA-MRSA.

Impact of First-Line Antifungal Agents on the Outcomes and Costs of Candidemia

ABSTRACT Candida species are the leading causes of invasive fungal infection among hospitalized patients and are responsible for major economic burdens. The goals of this study were to estimate the costs directly associated with the treatment of candidemia and factors associated with increased costs, as well as the impact of first-line antifungal agents on the outcomes and costs. A retrospective study was conducted in a sample of 199 patients from four university-affiliated tertiary care hospitals in Korea over 1 year. Only costs attributable to the treatment of candidemia were estimated by reviewing resource utilization during treatment. Risk factors for increased costs, treatment outcome, and hospital length of stay (LOS) were analyzed. Approximately 65% of the patients were treated with fluconazole, and 28% were treated with conventional amphotericin B. The overall treatment success rate was 52.8%, and the 30-day mortality rate was 47.9%. Hematologic malignancy, need for mechanical ventilation, and treatment failure of first-line antifungal agents were independent risk factors for mortality. The mean total cost for the treatment of candidemia was

Osteomyelitis of a long bone due to Fusobacterium nucleatum and Actinomyces meyeri in an immunocompetent adult: A case report and literature review

4,743 per patient. Intensive care unit stay at candidemia onset and antifungal switch to second-line agents were independent risk factors for increased costs. The LOS was also significantly longer in patients who switched antifungal agents to second-line drugs. Antifungal switch to second-line agents for any reasons was the only modifiable risk factor of increased costs and LOS. Choosing an appropriate first-line antifungal agent is crucial for better outcomes and reduced hospital costs of candidemia.

Clinical Presentation and Risk Factors for Cytomegalovirus Colitis in Immunocompetent Adult Patients

BackgroundFusobacterium species are uncommon causes of osteomyelitis. These organisms are normal flora of the oral cavity. Therefore, they mostly cause osteomyelitis of the head and neck. Hematogenous osteomyelitis at distant sites other than the head and neck has rarely been reported in pediatric or immunocompromised patients. Here, we report the first case of osteomyelitis of a long bone combined with a muscle abscess due to Fusobacterium nucleatum in an otherwise healthy adult.Case presentationA 59-year-old Korean man was admitted for pain and swelling of the right lower leg, which had been persistent for two weeks. Magnetic resonance imaging showed osteomyelitis of the right fibula with a surrounding muscle abscess of the right lower leg. Incision and drainage was performed, and repetitive tissue cultures grew F. nucleatum. In this patient, it was presumed that recurrent periodontitis caused hematogenous seeding of F. nucleatum to a distant site leading to osteomyelitis with a muscle abscess. The patient was successfully treated with intravenous ampicillin-sulbactam for three weeks and oral amoxicillin-clavulanate for eight weeks. He also underwent repeated surgical drainage. He has no evidence of recurrence after seven months of follow-up.ConclusionsClinicians should be aware that F. nucleatum could be the etiologic agent of hematogenous osteomyelitis of a long bone in an immunocompetent patient.

Clinical implications of healthcare-associated infection in patients with community-onset acute pyelonephritis

BACKGROUND Cytomegalovirus (CMV) colitis is a common manifestation of CMV end-organ disease, which has typically been described in immunocompromised hosts. Recently, it has been noted that this also occurs in immunocompetent patients. To gather relevant data about clinical presentation, prognosis, and risk factors for development of CMV colitis in immunocompetent hosts, we analyzed all cases that occurred during a 19-year period at our institution. METHODS A case-control study was performed to identify risk factors for CMV colitis in immunocompetent hosts. Electronic medical records of individuals who were admitted and diagnosed with CMV colitis between January 1995 and February 2014 at a tertiary care university hospital were reviewed. Two non-CMV colitis patients who were age- and sex-matched were selected as controls for each case. RESULTS A total of 51 patients with CMV colitis were included in this study along with 102 control patients. Certain conditions including renal disease on hemodialysis, neurologic disease, rheumatologic disease, intensive care unit admission, and exposure to antibiotics, antacids, steroids, or red blood cell (RBC) transfusions within 1 month of diagnosis of colitis were associated with CMV colitis on univariate analysis. Among these, steroid use and RBC transfusion within 1 month were identified as independent risk factors for developing CMV colitis on multivariate analysis. The 30-day mortality rate was 7.8% without any attributable mortality. CONCLUSIONS Steroid use and RBC transfusion within 1 month of the diagnosis of colitis were independent risk factors for development of CMV colitis in immunocompetent hosts.