Early diagnosis and early treatment of human immunodeficiency virus (HIV) infection are essential for clinical and public health benefits. Diagnostic algorithms for early diagnosis are being emphasized, and rapid tests at the point of care have been expanded to improve voluntary testing rates. Despite advances in laboratory diagnostic tests, early HIV infection can still be missed due to window periods, and it is crucial to recognize the limitations of testing methods and the potential for false negative and false positive results.

Early diagnosis and early treatment of human immunodeficiency virus (HIV) infection are essential for clinical and public health benefits. Diagnostic algorithms for early diagnosis are being emphasized, and rapid tests at the point of care have been expanded to improve voluntary testing rates. Despite advances in laboratory diagnostic tests, early HIV infection can still be missed due to window periods, and it is crucial to recognize the limitations of testing methods and the potential for false negative and false positive results.

Early diagnosis and early treatment of human immunodeficiency virus (HIV) infection are essential for clinical and public health benefits. Diagnostic algorithms for early diagnosis are being emphasized, and rapid tests at the point of care have been expanded to improve voluntary testing rates. Despite advances in laboratory diagnostic tests, early HIV infection can still be missed due to window periods, and it is crucial to recognize the limitations of testing methods and the potential for false negative and false positive results.

Early diagnosis and early treatment of human immunodeficiency virus (HIV) infection are essential for clinical and public health benefits. Diagnostic algorithms for early diagnosis are being emphasized, and rapid tests at the point of care have been expanded to improve voluntary testing rates. Despite advances in laboratory diagnostic tests, early HIV infection can still be missed due to window periods, and it is crucial to recognize the limitations of testing methods and the potential for false negative and false positive results.

Human Q fever, a zoonosis caused by Coxiella burnetii, presents with diverse clinical manifestations ranging from mild self-limited febrile illnesses to life-threatening complications such as endocarditis or vascular infection. Although acute Q fever is a benign illness with a low mortality rate, a large-scale outbreak of Q fever in the Netherlands led to concerns about the possibility of blood transfusion-related transmission or obstetric complications in pregnant women. Furthermore, a small minority (< 5%) of patients with asymptomatic or symptomatic infection progress to chronic Q fever. Chronic Q fever is fatal in 5–50% of patients if left untreated. In South Korea, Q fever in humans was designated as a notifiable infectious disease in 2006, and the number of Q fever cases has increased sharply since 2015. Nonetheless, it is still considered a neglected and under-recognized infectious disease. In this review, recent trends of human and animal Q fever in South Korea, and public health concerns regarding Q fever outbreaks are reviewed, and we consider how a One Health approach could be applied as a preventive measure to prepare for zoonotic Q fever outbreaks.

Background/Aims: To identify changes in symptoms and pulmonary sequelae in patients with coronavirus disease 2019 (COVID-19). Methods: Patients with COVID-19 hospitalized at seven university hospitals in Korea between February 2020 and February 2021 were enrolled, provided they had ≥ 1 outpatient follow-up visit. Between January 11 and March 9, 2021 (study period), residual symptom investigations, chest computed tomography (CT) scans, pulmonary function tests (PFT), and neutralizing antibody tests (NAb) were performed at the outpatient visit (cross-sectional design). Additionally, data from patients who already had follow-up outpatient visits before the study period were collected retrospectively. Results: Investigation of residual symptoms, chest CT scans, PFT, and NAb were performed in 84, 35, 31, and 27 patients, respectively. After 6 months, chest discomfort and dyspnea persisted in 26.7% (4/15) and 33.3% (5/15) patients, respectively, and 40.0% (6/15) and 26.7% (4/15) patients experienced financial loss and emotional distress, respectively. When the ratio of later CT score to previous ones was calculated for each patient between three different time intervals (1–14, 15–60, and 61–365 days), the median values were 0.65 (the second interval to the first), 0.39 (the third to the second), and 0.20 (the third to the first), indicating that CT score decreases with time. In the high-severity group, the ratio was lower than in the low-severity group. Conclusions In COVID-19 survivors, chest CT score recovers over time, but recovery is slower in severely ill patients. Subjects complained of various ongoing symptoms and socioeconomic problems for several months after recovery.

Erythema nodosum (EN) is the most common form of panniculitis and may be triggered by a variety of stimuli, including infections, drugs, pregnancy, sarcoidosis, inflammatory bowel disease, and malignancies. Rare cases of vaccination-related EN have been reported, but none due to the coronavirus disease 2019 (COVID-19) vaccine of Pfizer have been documented. We report a case of EN associated with the Pfizer vaccine. A 43-year-old woman presented with acute-onset painful nodular lesions that appeared bilaterally on the extensor surface of the lower legs. These lesions appeared 5 days after the first dose of Pfizer vaccination. The patient reported no recent infectious history other than fever for 3 days after vaccination. Skin biopsy revealed inflammation extending into the subcutaneous fat with a septal distribution. It is important for physicians to be aware of the side effects of the COVID-19 vaccine because more people are bound to be vaccinated.

Background: Pyomyositis (PM) is a serious soft tissue infection and despite its clinical importance, previous studies have not been able to fully determine the clinical characteristics and microbial epidemiology of PM in Korea, which we therefore aimed to investigate. Materials and Methods: We retrospectively identified 140 adult patients diagnosed with PM from 13 general hospitals between January 2012 and December 2015. We analyzed the clinical and microbial characteristics of community-onset PM and compared them with communityacquired (CA) and healthcare-associated (HCA) PM. Results: One hundred eleven organisms were isolated from 96 (68.6%) patients with PM.Staphylococcus aureus (38 patients) was the most common pathogen, followed by streptococci (24 patients), and enteric Gram-negative organisms (27 patients). Methicillin-resistant S.aureus (MRSA) was identified in four (2.9%) patients and in-hospital mortality reached 8.6% (12/140). Enterococci isolates were identified in the HCA PM subgroup only The proportion of MRSA isolates was not comparable between CA and HCA PM subgroups. In the 83 patients with PM infected by monomicrobial pathogens, isolates of Gram-negative organisms were more commonly found in HCA PM subgroup than in CA PM subgroup (47.6% [10/21] of patients with HCA PM vs. 20.7% [12/58] of patients with CA PM; P = 0.01). Conclusion Gram-positive cocci such as S. aureus and streptococci were dominant etiologies in community-onset PM, whereas MRSA appears to an uncommon causative organism of PM in Korea. Enteric Gram-negative organisms should also be considered as major etiologies, especially in HCA PM patient population in Korea.

As the number of people vaccinated increases, people who complain of adverse reactions continue to occur. We experienced a case characterized by low blood pressure, persistent fever, edema due to increased systemic vascular permeability, and systemic inflammation confirmed by image and laboratory examinations after ChAdOx1 coronavirus disease 2019 (COVID-19) vaccination. The diagnostic criteria for multisystem inflammatory syndrome (MIS) in adults are known as fever of 3 days or more in adults, 2 or more mucocutaneous/ gastrointestinaleurologic symptoms, elevation of inflammatory markers, and clinical/ imaging diagnosis of heart failure. A 67-year-old man who was medicated for hypertension and diabetes was admitted complaining of fever, maculopapular rash, diarrhea, headache, chills, and dizziness 6 days after the first vaccination of ChAdOx1 nCoV-19 in Korea.The COVID-19 test was negative but with low blood pressure, leukocytosis, skin rash, pulmonary edema, and increased inflammation markers. His lab findings and clinical course were consistent with those of MIS after COVID-19 vaccination. He was medicated with methylprednisolone 1 mg/kg and diuretics and recovered rapidly. He was discharged after 2 weeks and confirmed cure at outpatient clinic. We report an MIS case after COVID-19 vaccination in Korea.

Background: Pyomyositis (PM) is a serious soft tissue infection and despite its clinical importance, previous studies have not been able to fully determine the clinical characteristics and microbial epidemiology of PM in Korea, which we therefore aimed to investigate. Materials and Methods: We retrospectively identified 140 adult patients diagnosed with PM from 13 general hospitals between January 2012 and December 2015. We analyzed the clinical and microbial characteristics of community-onset PM and compared them with communityacquired (CA) and healthcare-associated (HCA) PM. Results: One hundred eleven organisms were isolated from 96 (68.6%) patients with PM.Staphylococcus aureus (38 patients) was the most common pathogen, followed by streptococci (24 patients), and enteric Gram-negative organisms (27 patients). Methicillin-resistant S.aureus (MRSA) was identified in four (2.9%) patients and in-hospital mortality reached 8.6% (12/140). Enterococci isolates were identified in the HCA PM subgroup only The proportion of MRSA isolates was not comparable between CA and HCA PM subgroups. In the 83 patients with PM infected by monomicrobial pathogens, isolates of Gram-negative organisms were more commonly found in HCA PM subgroup than in CA PM subgroup (47.6% [10/21] of patients with HCA PM vs. 20.7% [12/58] of patients with CA PM; P = 0.01). Conclusion Gram-positive cocci such as S. aureus and streptococci were dominant etiologies in community-onset PM, whereas MRSA appears to an uncommon causative organism of PM in Korea. Enteric Gram-negative organisms should also be considered as major etiologies, especially in HCA PM patient population in Korea.