Carbapenem-resistant Acinetobacter baumannii Outbreak in a COVID-19 Isolation Ward and Successful Outbreak Control with Infection Control Measures.

BACKGROUND: Even amid the coronavirus disease-19 (COVID-19) pandemic, the spread of multidrug-resistant bacteria and infection control are still important tasks. After recognizing the carbapenem-resistant Acinetobacter baumannii (CRAB) outbreak that occurred in the isolation room for COVID-19, we would like to introduce what infection control measures were implemented to eradicate it. MATERIALS AND METHODS: All COVID-19 patients with CRAB in any specimen admitted to the COVID-19 isolation ward of the tertiary hospital in Korea from October to November 2021 were analyzed. RESULTS: During the outbreak, 23 patients with COVID-19 and CRAB infections were identified. The index case was an 85-year-old female referred from a long-term care facility. CRAB was identified in sputum culture in most patients (91.3%). The CRAB outbreak occurred mainly in the rooms around the index case. Environmental cultures on the floor, air inlet, air outlet, and window frame of the rooms were performed. The antimicrobial resistance patterns of CRAB from patients and the environment were identical; whole-genome sequencing analyses revealed isolated clonality. Infection control measures with enhanced environmental cleaning using 1,000 ppm sodium hypochlorite and phenolic compounds, enhanced hand hygiene, additional education, and mandatory additional gowning and gloving of COVID-19 personal protective equipment (PPE) were applied on 29 October. No CRAB infection cases occurred from 2 November for two weeks. CONCLUSION: In addition to applying PPE and COVID-19 precautions in COVID-19 isolation wards, adhering to strict contact precautions along with environmental control can help prevent the spread of multidrug-resistant bacteria.

2023 Korean Association of Urogenital Tract Infection and Inflammation guidelines for gonococcal infection.

The incidence of gonorrhea has increased significantly in recent years in the United States, especially among sexually active twenty-year-olds. Although the incidence of gonorrhea has decreased in Korea since the early 2000s, it is still common among people in their twenties. Nucleic acid amplification test (NAAT) is the most sensitive diagnostic test for detecting gonococcal infection. Gram-staining is a simple and useful laboratory test for diagnosing symptomatic male gonococcal urethritis. Although bacterial culture can be used to detect antimicrobial susceptibility, its sensitivity is lower than that of NAAT. Treatment for uncomplicated gonorrhea infection is a single intramuscular injection of ceftriaxone 500 mg. Doxycycline (100 mg twice daily for 7 days) is added if there is a possibility of co-infection with chlamydia. If ceftriaxone is difficult to use, spectinomycin 2 g can be injected intramuscularly in Korea. Patients with gonorrhea should have repeated examinations within three months at the exposure site because of a high risk of re-infection. A person diagnosed with gonorrhea should discuss the nature of the infection, the importance of informing partners, when sexual activity can resume, and how to reduce the risk of sexually transmitted infections.

Risk Factors of Severe Clostridioides difficile Infection; Sequential Organ Failure Assessment Score, Antibiotics, and Ribotypes.

We aimed to determine whether the Sequential Organ Failure Assessment (SOFA) score predicts the prognosis of patients with Clostridioides difficile infection (CDI). In addition, the association between the type of antibiotic used and PCR ribotypes was analyzed. We conducted a propensity score (PS)-matched study and machine learning analysis using clinical data from all adult patients with confirmed CDI in three South Korean hospitals. A total of 5,337 adult patients with CDI were included in this study, and 828 (15.5%) were classified as having severe CDI. The top variables selected by the machine learning models were maximum body temperature, platelet count, eosinophil count, oxygen saturation, Glasgow Coma Scale, serum albumin, and respiratory rate. After propensity score-matching, the SOFA score, white blood cell (WBC) count, serum albumin level, and ventilator use were significantly associated with severe CDI (P < 0.001 for all). The log-rank test of SOFA score ≥ 4 significantly differentiated severe CDI patients from the non-severe group. The use of fluoroquinolone was more related to CDI patients with ribotype 018 strains than to ribotype 014/020 (P < 0.001). Even after controlling for other variables using propensity score matching analysis, we found that the SOFA score was a clinical predictor of severe CDI. We also demonstrated that the use of fluoroquinolones in hospital settings could be associated with the PCR ribotype in patients with CDI.

Lessons Learned from an Experience with Vancomycin-Intermediate Staphylococcus aureus Outbreak in a Newly Built Secondary Hospital in Korea.

A vancomycin-intermediate Staphylococcus aureus (VISA) outbreak occurred in an intensive care unit (ICU) in South Korea. We aimed to investigate the condition that led to the VISA outbreak and seek measures to prevent further spread of the multidrug-resistant organism. A total of three VISA isolates were obtained from two patients and a health care worker (HCW) in a newly built 450-bed secondary hospital. Extensive screening of close contacts for VISA in terms of space sharing and physical contact, irrespective of contact time, was performed. Furthermore, multilocus sequence type, staphylococcal cassette chromosome mec type, and spa type profiles were determined for all VISA isolates. The relationship between vancomycin use and the minimum inhibitory concentration (MIC) of S. aureus was also investigated. Molecular typing showed that the strains of the three VISA isolates were identical, indicating horizontal hospital transmission. We assumed that VISA colonised in the HCW could have transmitted to the two patients, which resulted in one infection and one colonisation. The affected HCW was excused from work and was decolonised with mupirocin. Five weeks after the interventions, no additional VISA isolates were identified. No relationship between vancomycin use and MIC of S. aureus was identified. Extensive screening of contacts in addition to decolonisation is crucial in preventing the further spread of VISA.

Surveillance of COVID-19-Associated Multisystem Inflammatory Syndrome in Children, South Korea.

A concerning development during the coronavirus disease pandemic has been multisystem inflammatory syndrome in children. Reports of this condition in East Asia have been limited. In South Korea, 3 cases were reported to the national surveillance system for multisystem inflammatory syndrome in children. All case-patients were hospitalized and survived with no major disease sequelae.

Longitudinal study of meningococcal carriage rates in university entrants living in a dormitory in South Korea.

University students, especially those living in dormitories, are known to have a high risk of invasive meningococcal disease. We performed a longitudinal study to investigate the change in Neisseria meningitidis carriage rates and identify the risk factors for carriage acquisition in university students in South Korea. We recruited university entrants who were admitted to a student dormitory. Pharyngeal swabs were taken from participants at baseline, 1 month, and 3 months, and the subjects completed a questionnaire. Culture and real-time polymerase chain reaction (PCR) for species-specific ctrA and sodC genes were performed. The cultured isolates or PCR-positive samples were further evaluated for epidemiologic characterization using serogrouping, PorA typing, FetA typing, and multilocus sequence typing (MLST). At the first visit, we enrolled 332 participants who were predominantly male (64.2%) with a median age of 19 years. Meningococcal carriage rates increased from 2.7% (95% confidence interval [CI] 0.9-4.4%) at baseline to 6.3% (95% CI 3.4-9.0%) at 1 month and 11.8% (95% CI 7.8-15.6%) at 3 months. Nongroupable isolates accounted for 50.0% of all isolates, with serogroup B being the next most prevalent (24.1%). In the study population, male sex (OR 2.613, 95% CI 1.145-5.961, p = 0.022) and frequent pub or club visits (OR 3.701, 95% CI 1.536-8.919, p = 0.004) were significantly associated with meningococcal carriage. Based on serotype and MLST analyses, six carriers transmitted meningococci to other study participants. N. meningitidis carriage rates among new university entrants who lived in a dormitory significantly increased within the first 3 months of dormitory stay, probably owing to the transmission of identical genotype among students. Based on the risk of meningococcal disease, meningococcal vaccination should be considered for students before dormitory admission.

[Evaluation of usefulness of the panel test composed of malaria non-specific tests as a surrogate marker].

BACKGROUND: Although malaria-specific antibody or antigen test is useful for the diagnosis of malaria infection, its cost-effectiveness has to be concerned in the area where malaria prevalence is very low. We created a panel test composed of malaria non-specific parameters, namely hematology autoanalyzer-derived results with or without addition of HDL-cholesterol data, and evaluated its usefulness in comparison with malaria-specific antibody test. METHODS: For 395 patients tested for malaria smear, the hematology parameters such as platelet count, NRBC (%) and VCS (volume, conductivity, scattering) parameters of WBC, and HDL-cholesterol data were analyzed. Statistical significance of each parameter and that of panel test with or without addition of HDL-cholesterol were evaluated. RESULTS: Malaria antibody test showed sensitivity of 97.1% and specificity of 99.1%. Each parameter of platelet count, NRBC (%), D parameter and HDL-cholesterol showed sensitivity of 86.8%, 41.2%, 81.8%, and 70.6%, and specificity of 85.9%, 96.3%, 72.3%, and 81.7%, respectively. Panel test without including HDL-cholesterol showed sensitivity of 91.2% and specificity of 81.6%, and that including HDL-cholesterol showed sensitivity of 91.2% and specificity of 86.2%. CONCLUSIONS: The malaria non-specific panel test composed of hematology autoanalyzer-derived parameters showed relatively good, but slightly lower sensitivity than that of malaria-specific antibody test. It might be used as a screening test for the diagnosis of malaria infection, and addition of HDL cholesterol improved little the usefulness of the panel test.

Novel acquired metallo-beta-lactamase gene, bla(SIM-1), in a class 1 integron from Acinetobacter baumannii clinical isolates from Korea.

Carbapenem resistance mediated by acquired carbapenemase genes has been increasingly reported, particularly for clinical isolates of Pseudomonas aeruginosa and Acinetobacter spp. Of 1,234 non-duplicate isolates of carbapenem-resistant Pseudomonas spp. and Acinetobacter spp. isolated at a tertiary-care hospital in Seoul, Korea, 211 (17%) were positive for metallo-beta-lactamase (MBL). Of these, 204 (96%) had either the bla(IMP-1) or bla(VIM-2) allele. In addition, seven Acinetobacter baumannii isolates were found to have a novel MBL gene, which was designated bla(SIM-1). The SIM-1 protein has a pI of 7.2, is a new member of subclass B1, and exhibits 64 to 69% identity with the IMP-type MBLs, which are its closest relatives. All SIM-1-producing isolates exhibited relatively low imipenem and meropenem MICs (8 to 16 microg/ml) and had a multidrug resistance phenotype. Expression of the cloned bla(SIM-1) gene in Escherichia coli revealed that the encoded enzyme is capable of hydrolyzing a broad array of beta-lactams, including penicillins, narrow- to expanded-spectrum cephalosporins, and carbapenems. The bla(SIM-1) gene was carried on a gene cassette inserted into a class 1 integron, which included three additional cassettes (arr-3, catB3, and aadA1). The strains were isolated from sputum and urine specimens from patients with pneumonia and urinary tract infections, respectively. All patients had various underlying diseases. Pulsed-field gel electrophoresis of SmaI-digested genomic DNAs showed that the strains belonged to two different clonal lineages, indicating that horizontal transfer of this gene had occurred and suggesting the possibility of further spread of resistance in the future.

The clinical utility of polymerase chain reaction for the diagnosis of pleural tuberculosis.

BACKGROUND: There is no exact consensus about the usefulness of the Mycobacterium tuberculosis polymerase chain reaction (PCR) testing for the diagnosis of tuberculous pleural effusion because of the diverse PCR methods and the different diagnostic criteria that are described in other studies. METHODS: We analyzed pleural effusion specimens obtained from 111 patients for whom the exclusion of the possibility of tuberculous pleural effusion was necessary. We performed M. tuberculosis PCR testing using the Cobas Amplicor MTB test (Roche Diagnostic Systems), which is fully automated and commercially available. RESULTS: Results of the M. tuberculosis PCR test of pleural effusion specimens were positive for 7 (17.1%) of the 41 patients with confirmed pleural tuberculosis and for 3 (18.8%) of the 16 patients with probable pleural tuberculosis. The overall sensitivity and specificity of M. tuberculosis PCR testing of pleural effusion were 17.5% and 98.1%, respectively. The sensitivity of M. tuberculosis PCR testing for each group of patients with tuberculous pleural effusion detected by smear-positive results, smear-negative and culture-positive results, and culture-negative and pleural biopsy-positive results, was 100.0%, 33.3%, and 3.7%, respectively. Of the 57 patients with pleural tuberculosis, only 3 (5.3%) had positive results of M. tuberculosis PCR testing along with negative results of smearing, negative results of pleural pathological analysis, and a low level of adenosine deaminase. CONCLUSION: For specimens such as pleural effusion, in which the bacillary load is very low, the clinical utility of PCR testing seems highly limited.