Toxic Shock Syndrome (TSS) Caused by Group A Streptococcus: Novel Insights Within the Context of a Familiar Clinical Syndrome

The emergence of invasive infections attributed to group A Streptococcus (GAS) infections, has resurged since the 1980s. The recent surge in reports of toxic shock syndrome due to GAS in Japan in 2024, while sensationalized in the media, does not represent a novel infectious disease per se, as its diagnosis, treatment, and prevention are already well-established.However, due to signs of increasing incidence since 2011, further research is needed. Health authorities in neighboring countries like The Republic of Korea should not only issue travel advisories but also establish meticulous surveillance systems and initiate epidemiological studies on the genotypic variations of this disease while awaiting various epidemiological research findings from Japan.

The Role of Age in Subclinical Atherosclerosis in Asian People Living with Human Immunodeficiency Virus / 감염과화학요법

Background@#People living with human immunodeficiency virus (PLHIV) have an increased risk of atherosclerosis and cardiovascular disease, but specific guidance on when to suspect the onset of these diseases is limited. @*Materials and Methods@#We aimed to identify cardiovascular risk factors in PLHIV using carotid intima-media thickness (IMT) through a cross-sectional, retrospective cohort study that enrolled 217 PLHIV who underwent carotid IMT measurement at a teaching hospital in Korea. We compared clinical characteristics between PLHIV with subclinical atherosclerosis and PLHIV with IMT within the normal range, and used a receiver operating characteristic curve to determine the cut-off age for predicting subclinical atherosclerosis. @*Results@#Among the study population, 115 participants (53.0%) had subclinical atherosclerosis. In logistic regression, age and dyslipidemia were significantly associated with increased carotid IMT even after adjusting for other variables (odds ratio [OR]: 1.11, 95% confidence interval [CI]: 1.06 - 1.15, P <0.001; OR: 3.92, 95% CI: 1.87 - 8.22, P <0.001, respectively). The cut-off age for predicting subclinical atherosclerosis was 39.5 years (area under the curve 0.78, 95% CI: 0.72 - 0.84, P <0.001). @*Conclusion@#Conventional risk factors including age and dyslipidemia were associated with subclinical atherosclerosis in Asian PLHIV. In particular, Asian PLHIV older than 40 years had an increased risk of subclinical atherosclerosis and may benefit from carotid IMT screening.

Previous Long-term Care Facility Admission as a Risk Factor for Scabies in a Medical Facility

The study aimed to elucidate simple and effective risk factors for scabies infection in the medical environment for early detection and prevention of exposure to other patients and medical staff. We conducted a case-control study of patients who were diagnosed with scabies among hospitalized patients between 2008 and 2019 in an acute-care teaching hospital. Each case was matched according to sex and age with two randomly selected controls without scabies during hospitalization. Clinical characteristics of cases at the time of hospital admission were compared to those of the control group. The scabies group included 34 patients and 68 patients who were included in the control group. After adjusting for confounding factors, previous long-term care facility admission was only associated with scabies (adjusted odds ratio, 5.44; 95% confidence interval, 1.46–20.27; P = 0.012). Careful examination, particularly for patients with previous long-term care facility admission, might be useful for the early detection of scabies.

Heterologous Vaccination for Preparing COVID-19 Pandemic / 대한내과학회지

Infectious disease pandemics are characterized by extreme uncertainty. From the more predictable response to seasonal influenza, which occurs each year, we have learned the importance of effective universal vaccines and therapeutic agents to protect high-risk groups. Heterologous vaccination with different types of vaccines to prevent COVID-19 is already recommended for various reasons: shortages of mass vaccine supply; critical adverse events, and potential superior efficacy as a booster dose. However, very few studies have examined the efficacy and safety of heterologous vaccination with mixed types. This review discusses the efficacy of vaccines currently approved in the Republic of Korea, including heterologous vaccination options.

Machine-Learning-Based Approach to Differential Diagnosis in Tuberculous and Viral Meningitis / 감염과화학요법

Background@#Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.Material and Methods: For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machinelearning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information. @*Results@#The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machinelearning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03). @*Conclusion@#The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.

Machine-Learning-Based Approach to Differential Diagnosis in Tuberculous and Viral Meningitis / 감염과화학요법

Background@#Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.Material and Methods: For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machinelearning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information. @*Results@#The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machinelearning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03). @*Conclusion@#The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.

Infectious Diseases Physician Workforce in Korea

This study aimed to evaluate the infectious disease (ID) physician workforce in Korea. We investigated the acquisition of ID physicians from 1992 to 2019 with their current working place in the Health Care System. We defined ID physicians working at general or tertiarycare hospitals as active ID physicians. A total 275 physicians acquired ID as a sub-specialty.Among the 275, 242 were active ID physicians. The density of active ID physicians was 0.47 per 100,000 population. Of all the 17 administrative districts, 11 (64.7%) fell short of 0.47, and 131 medical institutions employed the service of ID physicians. The median number of beds per adult ID physician was 372 (interquartile range, 280–507). It is essential to secure human resources to respond to emerging infectious diseases and perform the inherent work of ID physicians.

Infectious Diseases Physician Workforce in Korea

This study aimed to evaluate the infectious disease (ID) physician workforce in Korea. We investigated the acquisition of ID physicians from 1992 to 2019 with their current working place in the Health Care System. We defined ID physicians working at general or tertiarycare hospitals as active ID physicians. A total 275 physicians acquired ID as a sub-specialty.Among the 275, 242 were active ID physicians. The density of active ID physicians was 0.47 per 100,000 population. Of all the 17 administrative districts, 11 (64.7%) fell short of 0.47, and 131 medical institutions employed the service of ID physicians. The median number of beds per adult ID physician was 372 (interquartile range, 280–507). It is essential to secure human resources to respond to emerging infectious diseases and perform the inherent work of ID physicians.

Persistent severe acute respiratory syndrome coronavirus 2 detection after resolution of coronavirus disease 2019-associated symptoms/signs

There are limited data on the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in respiratory specimens after resolution of coronavirus disease 2019 (COVID-19)-associated symptoms/signs. We determined duration of SARS-CoV-2 virus shedding in symptomatic patients after remission of symptoms. We investigated the duration of SARS-CoV-2 RNA detection using real-time reverse transcriptase polymerase chain reaction for SARS-CoV-2 in nasopharyngeal/oropharyngeal swabs or sputum or saliva. Six patients were included in the final analysis. The median (range) duration of SARS-CoV-2 viral detection after hospitalization was 34 days (22 to 67). After resolution of symptoms/signs, SARS-CoV-2 RNA was detected for median (range) of 26 days (9 to 48). Among the six patients, one had persistent detection of SARS-CoV-2 RNA until day 67 of hospitalization, which was 30 days after symptom resolution. This case represents the longest duration of SARS-CoV-2 detection, and highlights the need for long-term follow up of COVID-19 patients despite resolution of symptoms to confirm SARS-CoV-2 clearance.

Early Intravenous Colistin Therapy as a Favorable Prognostic Factor for 28-day Mortality in Patients with CRAB Bacteremia: a Multicenter Propensity Score-Matching Analysis

BACKGROUND: Carbapenem-resistant Acinetobacter baumannii (CRAB) infection is associated with high mortality. One of the strategies to reduce the mortality in patients with CRAB infections is to use intravenous colistin early but the effect of this strategy has not been proven. Therefore, we investigated the association of early colistin therapy with 28-day mortality in patients with CRAB bacteremia. METHODS: This retrospective multicenter propensity score-matching analysis was conducted in the Korea by reviewing the medical records of adult patients with CRAB bacteremia between January 2012 and March 2015. Early colistin therapy was defined as intravenous colistin administration for > 48 hours within five days after the blood culture collection. To identify the risk factors associated with the 28-day mortality in CRAB bacteremia, the clinical variables of the surviving patients were compared to those of the deceased patients. RESULTS: Of 303 enrolled patients, seventy-six (25.1%) patients received early colistin therapy. The 28-day mortality was 61.4% (186/303). Fatal or rapidly-fatal McCabe classifications, intensive care unit admission, Sequential Organ Failure Assessment scores ≥ 8, vasopressor use, and acute kidney injury were statistically independent poor prognostic factors. Catheter-related infection and early colistin therapy (adjusted odds ratio [aOR], 0.45; 95% confidence interval [CI], 0.21–0.94) were independent favorable prognostic factors associated with 28-day mortality in patients with CRAB bacteremia. Early colistin therapy was still significantly associated with lower 28-day mortality in the propensity score-matching analysis (aOR, 0.31; 95% CI, 0.11–0.88). CONCLUSION: This study suggests that early colistin therapy might help reduce the mortality of patients with CRAB bacteremia.