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Background When to perform echocardiography to rule out infective endocarditis (IE) in patients with viridans group streptococci (VGS) bloodstream infections (BSIs) is unclear. Objectives We aimed to identify independent risk factors for IE in patients with VGS BSI. Methods This retrospective study conducted at Seoul National University Hospital from January 2013 to December 2022 involved patients with VGS and nutritionally variant streptococcal BSI, excluding single positive blood cultures and polymicrobial BSI cases. Independent risk factors were identified by multivariate logistic regression and sensitivity analyses according to echocardiography results, VGS species or the inclusion of possible IE cases. Results Of 845 VGS BSI cases, 349 were analysed and 86 IE cases were identified (24.6%). In the multivariate analysis, heart valve disease [adjusted odds ratio (aOR), 14.14, 95% CI, 6.14–32.58; P  < 0.001], persistent bacteraemia (aOR, 5.12, 95% CI, 2.03–12.94; P  = 0.001), age (per year, aOR, 0.98; 95% CI, 0.96–1.00; P =  0.015), solid cancer (aOR, 0.26; 95% CI, 0.13–0.53; P <  0.001) and haematologic malignancy (aOR, 0.04; 95% CI, 0.01–0.41; P =  0.006) were independently associated with IE. Sensitivity analyses yielded consistent results; also, infection by a member of the mitis group was independent risk factor for IE (aOR, 6.50; 95% CI, 2.87–14.68; P  < 0.001). Conclusions Younger age, heart valve disease, persistent bacteraemia, absence of underlying malignancy and BSI by a member of the mitis group were independent risk factors for IE in patients with VGS BSI. Echocardiographic evaluation could be prudently considered based on these clinicomicrobiological risk factors. [ABSTRACT FROM AUTHOR]

Treatment assessment and patient outcome for sepsis depend predominantly on the timely administration of appropriate antibiotics1–3. However, the clinical protocols used to stratify and select patient-specific optimal therapy are extremely slow4. In particular, the major hurdle in performing rapid antimicrobial susceptibility testing (AST) remains in the lengthy blood culture procedure, which has long been considered unavoidable due to the limited number of pathogens present in the patient’s blood. Here we describe an ultra-rapid AST method that bypasses the need for traditional blood culture, thereby demonstrating potential to reduce the turnaround time of reporting drug susceptibility profiles by more than 40–60 h compared with hospital AST workflows. Introducing a synthetic beta-2-glycoprotein I peptide, a broad range of microbial pathogens are selectively recovered from whole blood, subjected to species identification or instantly proliferated and phenotypically evaluated for various drug conditions using a low-inoculum AST chip. The platform was clinically evaluated by the enrolment of 190 hospitalized patients suspected of having infection, achieving 100% match in species identification. Among the eight positive cases, six clinical isolates were retrospectively tested for AST showing an overall categorical agreement of 94.90% with an average theoretical turnaround time of 13 ± 2.53 h starting from initial blood processing.An ultra-rapid antimicrobial susceptibility testing method is introduced that bypasses the need for traditional blood culture, demonstrating the potential to significantly reduce the turnaround time of reporting drug susceptibility profiles. [ABSTRACT FROM AUTHOR]

The immune escape of Omicron variants significantly subsides by the third dose of an mRNA vaccine. However, it is unclear how Omicron variant-neutralizing antibodies develop under repeated vaccination. We analyze blood samples from 41 BNT162b2 vaccinees following the course of three injections and analyze their B-cell receptor (BCR) repertoires at six time points in total. The concomitant reactivity to both ancestral and Omicron receptor-binding domain (RBD) is achieved by a limited number of BCR clonotypes depending on the accumulation of somatic hypermutation (SHM) after the third dose. Our findings suggest that SHM accumulation in the BCR space to broaden its specificity for unseen antigens is a counterprotective mechanism against virus variant immune escape. Repeat vaccination with COVID-19 mRNA vaccines has been shown to increase breadth of the antibody response. Here the authors demonstrate that B cell clones induced by the ancestral COVID-19 vaccine develop into daughter clones with different reactivity to individual SARS-CoV-2 variants through the accumulation of somatic hypermutations. [ABSTRACT FROM AUTHOR]

Background: The clinical outcomes and immunological features of coronavirus disease 2019 (COVID-19) patients receiving B-cell depletion therapy (BCDT), especially in Omicron variant era, have not been fully elucidated. We aimed to investigate the outcomes and immune responses of COVID-19 patients receiving BCDT during the Omicron period. Methods: We retrospectively compared clinical outcomes between COVID-19 patients treated with BCDT (the BCDT group) and those with the same underlying diseases not treated with BCDT (the non-BCDT group). For immunological analyses, we prospectively enrolled COVID-19 patients receiving BCDT and immunocompetent COVID-19 patients as controls. We measured humoral and cellular immune responses using the enzyme-linked immunosorbent assay and flow cytometry. Results: Severe to critical COVID-19 was more frequent in the BCDT group than in the non-BCDT group (41.9% vs. 28.3%, p =.030). BCDT was an independent risk factor for severe to critical COVID-19 (adjusted odds ratio [aOR] 2.21, 95% confidence interval [CI] 1.21–4.04, p =.010) as well as for COVID-19-related mortality (aOR 4.03, 95% CI 1.17–13.86, p =.027). Immunological analyses revealed that patients receiving BCDT had lower anti-S1 IgG titres and a tendency to higher proportions of activated CD4+ T-cells than the controls. Conclusions: BCDT was associated with worse COVID-19 outcomes in the Omicron period. Humoral immune response impairment and T-cell hyperactivation were the main immunological features of COVID-19 patients treated with BCDT, which may have contributed to the worse outcomes of COVID-19 in this population. [ABSTRACT FROM AUTHOR]

Despite the importance of antigen‐specific T cells in infectious disease, characterizing and tracking clonally amplified T cells during the progression of a patient's symptoms remain unclear. Here, we performed a longitudinal, in‐depth single‐cell multiomics analysis of samples from asymptomatic, mild, usual severe, and delayed severe patients of SARS‐CoV‐2 infection. Our in‐depth analysis revealed that hyperactive or improper T‐cell responses were more aggressive in delayed severe patients. Interestingly, tracking of antigen‐specific T‐cell receptor (TCR) clonotypes along the developmental trajectory indicated an attenuation in functional T cells upon severity. In addition, increased glycolysis and interleukin‐6 signaling in the cytotoxic T cells were markedly distinct in delayed severe patients compared to usual severe patients, particularly in the middle and late stages of infection. Tracking B‐cell receptor clonotypes also revealed distinct transitions and somatic hypermutations within B cells across different levels of disease severity. Our results suggest that single‐cell TCR clonotype tracking can distinguish the severity of patients through immunological hallmarks, leading to a better understanding of the severity differences in and improving the management of infectious diseases by analyzing the dynamics of immune responses over time. [ABSTRACT FROM AUTHOR]

The fourth vaccination dose confers additional protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection in individuals with no prior coronavirus disease‐19 (COVID‐19). However, its immunological benefit against currently circulating BA.4/5 is unclear in individuals who have received a booster shot and been infected with Omicron variant BA.1/2. We analyzed immune responses in whom had been boosted once and did not have COVID‐19 (n = 16), boosted once and had COVID‐19 when BA.1/2 was dominant in Korea (Hybrid‐6M group, n = 27), and boosted twice and did not have COVID‐19 (Vx4 group, n = 15). Antibody binding activities against RBDo BA.1 and RBDo BA.4/5, antigen‐specific memory CD4+ and CD8+ T‐cell responses against BA.4/5, and B‐cell responses against SARS‐CoV‐2 wild‐type did not differ statistically between the Hybrid‐6M and Vx4 groups. The humoral and cellular immune responses of the Hybrid‐6M group against BA.4/5 were comparable to those of the Vx4 group. Individuals who had been boosted and had an Omicron infection in early 2022 may not have high priority for an additional vaccination. [ABSTRACT FROM AUTHOR]

Background Coronavirus disease 2019 (COVID-19) pandemic affected millions of individuals, and patients with cancer are known to be more susceptible. Vaccines against SARS-CoV-2 have been developed and used for patients with cancer, but scarce data are available on their efficacy in patients under active anti-cancer therapies. Materials and Methods In this study, we semi-quantitatively measured the titers of the immunoglobulin G against the anti-spike protein subunit 1 of SARS-CoV-2 after vaccination of patients with early breast cancer undergoing concurrent chemotherapy, endocrinal or targeted non-cytotoxic treatments, and no treatments. Results Standard doses of COVID-19 vaccines provided sufficient immune responses in patients with early breast cancer, regardless of the type of anticancer therapies. However, the post-vaccination serum anti-spike antibody titers were significantly lower in the patients under cytotoxic chemotherapy. Conclusion Our study emphasizes the importance of the personalized risk stratification and consideration for booster doses in more vulnerable populations. [ABSTRACT FROM AUTHOR]

Background: Humoral immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may wane rapidly in persons recovered from mild coronavirus disease 2019 (COVID-19), but little is known about the longevity.Methods: Serum samples were obtained 8, 12, and 18 months after infection from 20 patients with mild COVID-19. The binding activities of serum antibodies (immunoglobulin [Ig]A, IgG, and IgM) against SARS-CoV-2 antigens of the Wuhan-1 reference strain (wild-type) and the B.1.1.7, P.1, B.1.167.2, and B.1.1.529 variants were measured by enzyme-linked immunosorbent assays. Neutralizing antibody titers were measured using a cytopathic effect-based live virus neutralization assay.Results: Serum IgA and IgG antibodies against spike or receptor-binding domain (RBD) protein of wild-type SARS-CoV-2 were detected for up to 18 months, and neutralizing antibodies persisted for 8 to 18 months after infection. However, any significant antibody responses against RBD proteins of SARS-CoV-2 variants were not observed, and median neutralizing antibody titers against the Delta variant at 8, 12, and 18 months were 8- to 11-fold lower than against wild-type viruses (P<.001).Conclusions: Humoral immunity persisted for up to 18 months after SARS-CoV-2 infection in patients with mild COVID-19. However, humoral immune activity against more recently circulating variants was reduced in this population. [ABSTRACT FROM AUTHOR]

Background: Practical guidance is needed regarding the vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals in resource-limited countries. It includes the number of vaccine doses that should be given to unvaccinated patients who experienced COVID-19 early in the pandemic. Methods: We recruited COVID-19 convalescent individuals who received one or two doses of an mRNA vaccine within 6 or around 18 months after a diagnosis of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Their samples were assessed for IgG-binding or neutralizing activity and cell-mediated immune responses against SARS-CoV-2 wild-type and variants of concern. Results: A total of 43 COVID-19 convalescent individuals were analyzed in the present study. The results showed that humoral and cellular immune responses against SARS-CoV-2 wild-type and variants of concern, including the Omicron variant, were comparable among patients vaccinated within 6 versus around 18 months. A second dose of vaccine did not significantly increase immune responses. Conclusion: One dose of mRNA vaccine should be considered sufficient to elicit a broad immune response even around 18 months after a COVID-19 diagnosis. [ABSTRACT FROM AUTHOR]

Background: Despite the fact of ongoing worldwide vaccination programs for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), understanding longevity, breadth, and type of immune response to coronavirus disease-19 (COVID-19) is still important to optimize the vaccination strategy and estimate the risk of reinfection. Therefore, we performed thorough immunological assessments 1 year post-COVID-19 with different severity. Methods: We analyzed peripheral blood mononuclear cells and plasma samples at 1 year post-COVID-19 in patients who experienced asymptomatic, mild, and severe illness to assess titers of various isotypes of antibodies (Abs) against SARS-CoV-2 antigens, phagocytic capability, and memory B- and T-cell responses. Findings: A total of 24 patients (7, 9, and 8 asymptomatic, mild, and severe patients, respectively) and eight healthy volunteers were included in this study. We firstly showed that disease severity is correlated with parameters of immune responses at 1 year post-COVID-19 that play an important role in protecting against reinfection with SARS-CoV-2, namely, the phagocytic capacity of Abs and memory B-cell responses. Interpretation: Various immune responses at 1 year post-COVID-19, particularly the phagocytic capacity and memory B-cell responses, were dependent on the severity of the prior COVID-19. Our data could provide a clue for a tailored vaccination strategy after natural infection according to the severity of COVID-19. [ABSTRACT FROM AUTHOR]

Remdesivir, an antiviral agent for the treatment of coronavirus disease 2019 (COVID‐19), is metabolized intracellularly, with these metabolites eliminated predominantly in urine. Because of a lack of safety and pharmacokinetic (PK) data, remdesivir is not currently recommended for patients with estimated glomerular filtration rate less than 30 ml/min/1.73 m2 and those on hemodialysis. This study evaluated the PKs of remdesivir and its metabolite, GS‐441524, in patients with COVID‐19 who were and were not receiving renal replacement therapy (RRT). This study enrolled two patients with normal renal function, two with impaired renal function not receiving RRT, two receiving continuous RRT (CRRT), and three undergoing intermittent hemodialysis (IHD). Patients were administered 200 mg remdesivir on the first day, followed by 100 mg/day for 5–10 days. Serial blood samples were collected for PK analysis, and PK parameters were assessed by a noncompartmental method. Systemic exposure to remdesivir was higher in patients with impaired renal function and those receiving CRRT than in patients with normal renal function, but was similar in patients undergoing IHD and those with normal renal function. By contrast, systemic exposure to GS‐441524 was highest in patients undergoing IHD, followed by patients with impaired renal function and those receiving CRRT, and lowest in patients with normal renal function. The PK profiles of remdesivir and GS‐441524 varied according to renal function and RRT. The impact of PK changes of remdesivir and its metabolite on safety and efficacy should be considered when administering remdesivir to patients with COVID‐19 with renal impairment. [ABSTRACT FROM AUTHOR]

The incidence of invasive fungal infection (IFI) in patients with acute myeloid leukemia (AML) has decreased with the introduction of antimold prophylaxis. Although acute lymphoblastic leukemia (ALL) has a lower risk of IFI than does AML, the incidences of IFI in both AML and ALL in the era of antimold prophylaxis should be re-evaluated. We analyzed adults with AML or ALL who had undergone induction, re-induction, or consolidation chemotherapy from January 2017 to December 2019 at Seoul National University Hospital. Their clinical characteristics during each chemotherapy episode were reviewed, and cases with proven or probable diagnoses were regarded as positive for IFI. Of 552 episodes (393 in AML and 159 in ALL), 40 (7.2%) were IFI events. Of the IFI episodes, 8.1% (12/148) and 5.9% (13/220) (P = 0.856) occurred in cases of ALL without antimold prophylaxis and AML with antimold prophylaxis, respectively. After adjusting for clinical factors, a lack of antimold prophylaxis (adjusted odds ratio [aOR], 3.52; 95% confidence interval [CI], 1.35–9.22; P = 0.010) and a longer duration of neutropenia (per one day, aOR, 1.02; 95% CI, 1.01–1.04; P = 0.001) were independently associated with IFI. In conclusion, the incidence of IFI in ALL without antimold prophylaxis was not lower than that in AML. A lack of antimold prophylaxis and prolonged neutropenia were independent risk factors for IFI. Clinicians should be on guard for detecting IFI in patients with ALL, especially those with risk factors. [ABSTRACT FROM AUTHOR]

Acquired somatic mutations in hematopoietic stem and progenitor cells (clonal hematopoiesis or CH) are associated with advanced age, increased risk of cardiovascular and malignant diseases, and decreased overall survival. These adverse sequelae may be mediated by altered inflammatory profiles observed in patients with CH. A pro-inflammatory immunologic profile is also associated with worse outcomes of certain infections, including SARS-CoV-2 and its associated disease Covid-19. Whether CH predisposes to severe Covid-19 or other infections is unknown. Among 525 individuals with Covid-19 from Memorial Sloan Kettering (MSK) and the Korean Clonal Hematopoiesis (KoCH) consortia, we show that CH is associated with severe Covid-19 outcomes (OR = 1.85, 95%=1.15–2.99, p = 0.01), in particular CH characterized by non-cancer driver mutations (OR = 2.01, 95% CI = 1.15–3.50, p = 0.01). We further explore the relationship between CH and risk of other infections in 14,211 solid tumor patients at MSK. CH is significantly associated with risk of Clostridium Difficile (HR = 2.01, 95% CI: 1.22–3.30, p = 6×10−3) and Streptococcus/Enterococcus infections (HR = 1.56, 95% CI = 1.15–2.13, p = 5×10−3). These findings suggest a relationship between CH and risk of severe infections that warrants further investigation. Clonal haematopoiesis (CH) has been associated with altered inflammatory profiles and increased risk of cardiovascular and malignant diseases. Here, the authors analyze patient data from two different cohorts and show that CH is associated with severe infections and severe Covid19. [ABSTRACT FROM AUTHOR]

Background: Understanding the memory T-cell response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for assessing the longevity of protective immunity after SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19) vaccination. However, the longitudinal memory T-cell response up to 8 months post-symptom onset (PSO) according to the severity of illness is unknown.Methods: We analyzed peripheral blood mononuclear cells (PBMCs) from healthy volunteers or patients with COVID-19 who experienced asymptomatic, mild, or severe illness at 2, 5, and 8 months PSO. SARS-CoV-2 spike, nucleocapsid, and membrane protein-stimulated PBMCs were subjected to flow cytometry analysis.Results: A total of 24 patients (7 asymptomatic, 9 with mild disease, and 8 with severe disease) and 6 healthy volunteers were analyzed. SARS-CoV-2-specific OX40+CD137+CD4+ T cells and CD69+CD137+CD8+ T cells persisted at 8 months PSO. Also, antigen-specific cytokine-producing or polyfunctional CD4+ T cells were maintained for up to 8 months PSO. Memory CD4+ T-cell responses tended to be greater in patients who had severe illness than in those with mild or asymptomatic disease.Conclusions: Memory response to SARS-CoV-2, based on the frequency and functionality, persists for 8 months PSO. Further investigations involving its longevity and protective effect from reinfection are warranted. [ABSTRACT FROM AUTHOR]

Before 2014, the only test used for anonymous voluntary human immunodeficiency virus (HIV) screening at public health centers (PHCs) in the Republic of Korea was an enzyme-linked immunosorbent assay (ELISA), which takes around 3 days to obtain results. In 2014, to encourage voluntary anonymous HIV screening tests, the Seoul Metropolitan Government adopted a rapid HIV screening test at PHCs. The rapid HIV screening test was introduced at four PHCs in 2014 and all 25 PHCs after 2015. We compared the numbers of HIV screening tests and confirmed positive individuals before and after introduction of the rapid HIV screening test. In 2012–2013, before the introduction of rapid HIV screening test, an average of 330 HIV screening tests were performed monthly (355 in 2012 and 305 in 2013) and 69 individuals were confirmed to have HIV in 2012 and 93 in 2013. After the introduction of the rapid HIV screening test, anonymous voluntary HIV screening increased to a monthly average of 447 tests in 2014, 2099 in 2015, and 2409 in 2016. These identified 38 new cases in 2014, 116 in 2015, and 143 in 2016. Adoption of the rapid HIV screening test has increased the number of HIV screening tests and confirmed cases. [ABSTRACT FROM AUTHOR]

Waning humoral immunity in coronavirus disease patients has raised concern over usefulness of serologic testing. We investigated antibody responses of 58 persons 8 months after asymptomatic or mildly symptomatic infection with severe acute respiratory syndrome coronavirus 2. For 3 of 4 immunoassays used, seropositivity rates were high (69.0%-91.4%). [ABSTRACT FROM AUTHOR]

Neutralizing antibodies on hand: Stereotypic antibodies (Abs) are produced in healthy individuals by preexisting naïve B cells that have not undergone somatic hypermutation or class switching. Kim et al. have identified stereotypic neutralizing Abs (nAbs) against SARS-CoV-2 spike protein receptor binding domain (RBD) in healthy individuals and patients with COVID-19. They detected RBD-specific stereotypic variable heavy chain (VH) Ab clonotypes composed of Ig heavy variable 3-53 (IGHV3-53) or IGHV3-66 and Ig heavy joining 6 (IGHJ6) genes in 13 of 17 patients with COVID-19. One stereotypic nAb could inhibit in vitro replication of a clinical isolate of SARS-CoV-2. These VH clonotypes were also found in 6 of 10 healthy individuals with no evidence of exposure to SARS-CoV-2, and together, these findings provide evidence of the presence of preexisting nAbs to SARS-CoV-2. Stereotypic antibody clonotypes exist in healthy individuals and may provide protective immunity against viral infections by neutralization. We observed that 13 of 17 patients with COVID-19 had stereotypic variable heavy chain (VH) antibody clonotypes directed against the receptor binding domain (RBD) of SARS-CoV-2 spike protein. These antibody clonotypes were composed of immunoglobulin heavy variable 3-53 (IGHV3-53) or IGHV3-66 and immunoglobulin heavy joining 6 (IGHJ6) genes. These clonotypes included IgM, IgG3, IgG1, IgA1, IgG2, and IgA2 subtypes and had minimal somatic mutations, which suggested swift class switching after SARS-CoV-2 infection. The different IGHV chains were paired with diverse light chains resulting in binding to the RBD of SARS-CoV-2 spike protein. Human antibodies specific for the RBD can neutralize SARS-CoV-2 by inhibiting entry into host cells. We observed that one of these stereotypic neutralizing antibodies could inhibit viral replication in vitro using a clinical isolate of SARS-CoV-2. We also found that these VH clonotypes existed in 6 of 10 healthy individuals, with IgM isotypes predominating. These findings suggest that stereotypic clonotypes can develop de novo from naïve B cells and not from memory B cells established from prior exposure to similar viruses. The expeditious and stereotypic expansion of these clonotypes may have occurred in patients infected with SARS-CoV-2 because they were already present. [ABSTRACT FROM AUTHOR]

Background: Herpes zoster (HZ) infection of hematopoietic stem cell transplant (HSCT) patients is of clinical concern. Vaccination could help restore immunity to varicella zoster virus (VZV); however, temporal changes in immunogenicity and safety of live HZ vaccines after HSCT is still unclear. The aim of this study was to elucidate the temporal immunogenicity and safety of the HZ vaccine according to time since HSCT and to determine optimal timing of vaccination.Methods: Live HZ vaccine was administered to patients 2-5 years or > 5 years post-HSCT. Control groups comprised patients with a hematologic malignancy who received cytotoxic chemotherapy and healthy volunteers. Humoral and cellular immunogenicity were measured using a glycoprotein enzyme-linked immunosorbent assay (gpELISA) and an interferon-γ (IFN-γ) enzyme-linked immunospot (ELISPOT) assay. Vaccine-related adverse events were also monitored.Results: Fifty-six patients with hematologic malignancy (41 in the HSCT group and 15 in the chemotherapy group) along with 30 healthy volunteers were enrolled. The geometric mean fold rises (GMFRs) in humoral immune responses of the 2-5 year and > 5 year HSCT groups, and the healthy volunteer group, were comparable and significantly higher than that of the chemotherapy group (3.15, 95% CI [1.96-5.07] vs 5.05, 95% CI [2.50-10.20] vs 2.97, 95% CI [2.30-3.83] vs 1.42, 95% CI [1.08-1.86]). The GMFR of cellular immune responses was highest in the HSCT 2-5 year group and lowest in the chemotherapy group. No subject suffered clinically significant adverse events or reactivation of VZV within the follow-up period.Conclusion: Our findings demonstrate that a live HZ vaccine is immunogenic and safe when administered 2 years post-HSCT. [ABSTRACT FROM AUTHOR]

Background: We assessed cell-mediated immune (CMI) responses of influenza vaccination in patients with cancer receiving immune checkpoint inhibitors (ICIs), which remain elusive.Methods: Vaccine-elicited CMI responses in patients receiving ICIs or cytotoxic agents were investigated by flow cytometry. Polyfunctional cells were defined as T cells that express 2 or more of interleukin 2 (IL-2), interleukin 4 (IL-4), interferon gamma (IFN-γ), and CD107a. An adequate CMI response was defined as an increase of polyfunctional T cells against both H1N1 and H3N2 strains.Results: When comparing ICI (n = 11) and cytotoxic chemotherapy (n = 29) groups, H1N1-specific IL-4 or IFN-γ-expressing CD4+ T cells, IL-2, IL-4, IFN-γ, or CD107a-expressing CD8+ T cells, H3N2-specific IFN-γ-expressing CD4+ T cells, and CD107a-expressing CD8+ T cells were more frequent in the ICI group. Fold changes in polyfunctional H3N2-specific CD4+ (median, 156.0 vs 95.7; P = .005) and CD8+ (155.0 vs 103.4; P = .044) T cells were greater in the ICI group. ICI administration was strongly associated with an adequate CMI response for both CD4+ and CD8+ T cells (P = .003).Conclusions: CMI responses following influenza vaccination were stronger in the ICI group than in the cytotoxic chemotherapy group. Influenza vaccination should be strongly recommended in patients with cancer receiving ICIs. [ABSTRACT FROM AUTHOR]

During the 2015 Korea Middle East Respiratory Syndrome coronavirus (MERS-CoV) outbreak, a lymphoma patient developed MERS pneumonia. His pneumonia improved by 45 days after illness onset, but the polymerase chain reaction tests remained (+) for 6 months. However, replication-competent virus was detected by 60 days after illness onset. [ABSTRACT FROM AUTHOR]

Background: Carbapenem is frequently used when gram negative bacilli (GNB) bacteremia is detected especially in neutropenic patients. Consequently, appropriate treatment could be delayed in GNB bacteremia cases involving organisms which are not susceptible to carbapenem (carba-NS), resulting in a poor clinical outcomes. Here, we explored risk factors for carba-NS GNB bacteremia and its clinical outcomes in patients with acute myelogenous leukemia (AML) that underwent chemotherapy.Methods: We reviewed all GNB bacteremia cases that occurred during induction or consolidation chemotherapy, over a 15-year period, in a tertiary-care hospital.Results: Among 489 GNB bacteremia cases from 324 patients, 45 (9.2%) were carba-NS and 444 (90.8%) were carbapenem susceptible GNB. Independent risk factors for carba-NS GNB bacteremia were: carbapenem use at bacteremia onset (adjusted odds ratio [aOR]: 91.2; 95% confidence interval [95%CI]: 29.3-284.1; P < 0.001); isolation of carbapenem-resistant Acinetobacter baumannii (aOR: 19.4, 95%CI: 3.4-112.5; P = 0.001) in the prior year; and days from chemotherapy to GNB bacteremia (aOR: 1.1 per day, 95%CI: 1.1-1.2; P < 0.001). Carba-NS bacteremia was independently associated with in-hospital mortality (aOR: 6.6, 95%CI: 3.0-14.8; P < 0.001).Conslusion: Carba-NS organisms should be considered for antibiotic selection in AML patients having these risk factors. [ABSTRACT FROM AUTHOR]

Background It is difficult to select an appropriate empirical antibiotic treatment regimen for patients with culture-negative pyogenic vertebral osteomyelitis (PVO). Having knowledge of the distribution of microorganisms according to patient characteristics can help clinicians make informed choices regarding empirical antibiotics. The aim of this study was to determine the microbial distribution among individuals with PVO according to their demographic and clinical characteristics. Methods We reviewed the medical records of patients admitted to our hospital with culture-confirmed PVO between January 2005 and December 2017 and collected data on demographics, underlying diseases, and radiographic and microbiological results. Statistical analysis was performed to identify associations between specific bacteria and specific patient characteristics. Results A total of 586 patients were included in the study. The prevalence of Staphylococcus aureus infections was higher in young patients than in old patients, while gram-negative bacterial infections and Enterococcus were more prevalent in older patients. Gram-negative bacterial infections were more common in women than in men (32.1% vs 16.4%; P  < .05), in patients with cirrhosis than in those without (32.7% vs 21.1%; P  < .05), and in patients with a solid tumor than in those without (31.0% vs 20.7%; P  < .05). Methicillin-resistant S. aureus infections were more prevalent in patients with chronic renal disease than in those without (34.4% vs 14.7%; P  < .05). Conclusions The microbial etiology of PVO varies according to patient characteristics. Patient characteristics should thus be considered when choosing empirical antibiotics in patients with culture-negative PVO. [ABSTRACT FROM AUTHOR]

Background: Surgical site infection (SSI) is the most common healthcare-associated infection. We report an outbreak of neurosurgical site infections caused by Serratia marcescens after craniotomy in a tertiary care hospital. Methods: Between August 6 and 21, 2018, five cases of early-onset SSI caused by S. marcescens after craniotomy were recorded in a 1786-bed tertiary care hospital. Cultures were collected from potential environmental sources and healthcare workers. Whole-genome sequencing (WGS) was used to investigate the genetic relationships among S. marcescens isolates. Results: The outbreak involved five patients; S. marcescens was isolated from the cerebrospinal fluid, pus, tissue, and blood samples from these patients. S. marcescens was also isolated from shaving razors and brushes. All S. marcescens isolates from the infected patients and razors showed the same resistance patterns on antibiotic-susceptibility tests. WGS revealed close clustering among four of five isolates from the patients and among three of four isolates from the razors. No additional patient developed S. marcescens infection after we stopped using the razors for scalp shaving. Conclusions: We report an outbreak of neurosurgical site infections after craniotomy, which was associated with shaving razors contaminated by S. marcescens. Shaving scalps with razors should be avoided to prevent SSI. [ABSTRACT FROM AUTHOR]

We developed and validated 2 species-independent protein-based assays to detect Middle East respiratory syndrome coronavirus functional antibodies that can block virus receptor-binding or sialic acid-attachment. Antibody levels measured in both assays correlated strongly with virus-neutralizing antibody titers, proving their use for serologic confirmatory diagnosis of Middle East respiratory syndrome. [ABSTRACT FROM AUTHOR]

Background: The prolonged manifestation of concurrent leukopenia, thrombocytopenia and normal C-reactive protein (CRP) (named as SFTS prediction score) in febrile diseases is not usual and may be used to make an initial differential diagnosis, which is a characteristic finding of severe fever with thrombocytopenia syndrome (SFTS). Methods: The dynamics of SFTS prediction scores was investigated in SFTS patients. The study subjects for the comparison were febrile patients aged ≥ 16 years with SFTS scores of 2 (S2) or 3 (S3) who visited an emergency room for a 4-year study period. The dynamic distribution of S2 and S3 at presentation with regards to onset of illness, the characteristics of responsible diseases and the predictability of SFTS in both groups were described. Results: In 104 patients with SFTS, the daily proportion of S2 or S3 ranged from 58.3 to 100% from day (D) 1 to D12 after the onset of illness. The S2 subtype of 'leukopenia plus thrombocytopenia' and S3 represented 72.7–100% of all scores. In contrast, for the 130 patients in the febrile cohort, 73.8% of evaluations were distributed between D1 and D4 after the onset of illness, and 68.8% of patients had the S2 subtype of 'leukopenia plus normal CRP'. Upper respiratory infection was the most frequent (50.0%) cause of diseases. Pneumonia (13.8%) and urosepsis (6.2%) initially presented with either S2 with normal CRP or S3 but had poor prognosis. The presence of S2 or S3 predicted SFTS with sensitivity and specificity of 0.85 (0.42–0.99; 95% CI) and 0.98 (0.98–0.98; 95% CI), respectively. Conclusion: The temporal distribution and composition of S2 or S3 were unique in several febrile diseases including SFTS, and the SFTS prediction score may be useful for differentiating febrile diseases in primary care settings of SFTS endemic areas. [ABSTRACT FROM AUTHOR]

The benefits of screening for cryptococcal antigenemia and of preemptive antifungal treatment in HIV-infected patients have been proven. Liver cirrhosis is an important risk factor for cryptococcal infections. Cryptococcal infections are rapidly fatal in patients with liver cirrhosis, especially when diagnosis is delayed. However, screening for cryptococcal antigenemia has not been investigated in these patients. The aim of this study was to investigate the prevalence of cryptococcal antigenemia in hospitalized patients with liver cirrhosis. This prospective study was conducted at Seoul National University Hospital from July 2017 to January 2018. We included patients with liver cirrhosis who were admitted regardless of symptoms or signs suggesting cryptococcal infections. The severity of cirrhosis was evaluated from Child-Pugh and model for end-stage liver disease (MELD) scores. Serum cryptococcal antigenemia was determined using a latex agglutination test. A total of 294 patients were included in the analysis, comprising 104 (35.4%), 100 (34.0%), and 90 (30.6%) patients in Child-Pugh classes A, B, and C, respectively. There were 21 cases of spontaneous bacterial peritonitis, and 14 of hepatic encephalopathy, but none of cryptococcal peritonitis or meningitis. In addition, none of the patient specimens tested positive in the serum cryptococcal latex agglutination test (one-sided 97.5% confidence interval, 0% ∼ 1.2%). Liver cirrhosis is a major risk factor for cryptococcal infections, but the prevalence of serum cryptococcal antigen positivity in patients with liver cirrhosis is very low. Therefore, screening for cryptococcal antigenemia and preemptive antifungal treatment in cirrhotic patients might not be beneficial. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of the intervention targeting the redundant combination of antianaerobic antimicrobials on its incidence and associated antimicrobial consumption. To reveal the characteristics of the combination and the change in the related workload over time was an additional aim of the study. The combinations of metronidazole or clindamycin with antianaerobic antimicrobials were classified into redundant or acceptable, according to the target indications. A pharmacist-based prospective audit and feedback targeting the redundant antianaerobic combination was conducted. Segmented regression analysis was performed to evaluate the impact of the intervention. As a quantitative index of the interventional activity, the change in the number of signed consultation notes was evaluated. After the initiation of the intervention, the median monthly cumulative incidence of the redundant combination decreased from 5.29 (Interquartile range [IQR] 4.94–5.70) to 3.33 (IQR 2.87–3.71) (p < 0.001) per 1000 admissions per month. The consumption of concurrently administered metronidazole and clindamycin decreased from 3.34 (IQR 2.97–4.10) to 1.74 (IQR 1.19–1.93) (p < 0.001) per 1000 patient-days per month. Segmented regression analysis revealed that the monthly cumulative incidence decreased by 28.5% after the initiation of the intervention (change in level − 1.640, p = 0.019) and the monthly consumption decreased by 33.9% (change in level − 1.409, p = 0.009). The number of consultation notes per 1000 admissions per month decreased over time (regression coefficient − 0.004, p < 0.001). The pharmacist-based intervention significantly reduced the incidence and associated antimicrobial consumption of the redundant antianaerobic combination. The overall related workload reduced steadily over time. [ABSTRACT FROM AUTHOR]

In "Longitudinal Analysis of Human Memory T-Cell Response According to the Severity of Illness up to 8 Months After Severe Acute Respiratory Syndrome Coronavirus 2 Infection" by Kang et al [J Infect Dis. 2021 Jul 1;224(1):39-48], X-axis labels were accidentally omitted from the graphs in Figures 1A and 2A. The X-axis on both figures' graphs should be labeled "CD137.". [Extracted from the article]

Middle East respiratory syndrome coronavirus (MERS-CoV) infections in humans can cause asymptomatic to fatal lower respiratory lung disease. Despite posing a probable risk for virus transmission, asymptomatic to mild infections can go unnoticed; a lack of seroconversion among some PCR-confirmed cases has been reported. We found that a MERS-CoV spike S1 protein-based ELISA, routinely used in surveillance studies, showed low sensitivity in detecting infections among PCR-confirmed patients with mild clinical symptoms and cross-reactivity of human coronavirus OC43-positive serum samples. Using in-house S1 ELISA and protein microarray, we demonstrate that most PCR-confirmed MERS-CoV case-patients with mild infections seroconverted; nonetheless, some of these samples did not have detectable levels of virus-neutralizing antibodies. The use of a sensitive and specific serologic S1-based assay can be instrumental in the accurate estimation of MERS-CoV prevalence. [ABSTRACT FROM AUTHOR]

Objectives: MALDI-TOF MS has been successfully used for empirical antibiotic selection. However, limited data are available regarding the usefulness of MALDI-TOF MS in common resistant organisms compared with rapid antimicrobial susceptibility testing (AST). We prospectively evaluated the usefulness of rapid AST, compared with MALDI-TOF MS, for optimal antibiotic selection by infectious disease (ID) physicians in patients with bacteraemia including polymicrobial infection.Methods: Three hundred and fifty-nine patients with positive blood culture were included for analysis. ID physicians prospectively decided on antibiotic regimens with consensus at each timepoint of receiving results of Gram stain, MALDI-TOF MS and rapid AST, the last of which was performed using QMAC-dRAST.Results: ID physicians with MALDI-TOF MS results chose optimal targeted antibiotics in 255 (71.0%) cases, with appropriate antibiotic selection in 303 (84.4%) cases. The proportion of optimal targeted antibiotic selection and appropriate antibiotic selection was significantly lower for resistant strains than for susceptible strains [62.5% versus 79.2% (P < 0.001) and 68.2% versus 100% (P < 0.001), respectively]. QMAC-dRAST results led to optimal antibiotic treatment in 95 (91.3%) of the 104 cases receiving non-optimal targeted antibiotics. Optimal targeted treatments based on QMAC-dRAST results were possible in 322 (98.2%) of the 328 cases with monobacterial infection and in 345 (96.1%) of the 359 cases with monobacterial and polymicrobial infection.Conclusions: MALDI-TOF MS has a high chance of failure in guiding ID physicians to optimal antibiotics, especially against resistant organisms. With increasingly common resistant organisms, rapid AST is needed to identify optimal targeted antibiotics early in bacteraemia. [ABSTRACT FROM AUTHOR]

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease localized to China, Japan, and Korea that is characterized by severe hemorrhage and a high fatality rate. Currently, no specific vaccine or treatment has been approved for this disease. To develop a therapeutic agent for SFTS, we isolated antibodies from a phage-displayed antibody library that was constructed from a patient who recovered from SFTS virus (SFTSV) infection. One antibody, designated as Ab10, was reactive to the Gn envelope glycoprotein of SFTSV and protected host cells and A129 mice from infection in both in vitro and in vivo experiments. Notably, Ab10 protected 80% of mice, even when injected 5 days after inoculation with a lethal dose of SFTSV. Using cross-linker assisted mass spectrometry and alanine scanning, we located the non-linear epitope of Ab10 on the Gn glycoprotein domain II and an unstructured stem region, suggesting that Ab10 may inhibit a conformational alteration that is critical for cell membrane fusion between the virus and host cell. Ab10 reacted to recombinant Gn glycoprotein in Gangwon/Korea/2012, HB28, and SD4 strains. Additionally, based on its epitope, we predict that Ab10 binds the Gn glycoprotein in 247 of 272 SFTSV isolates previously reported. Together, these data suggest that Ab10 has potential to be developed into a therapeutic agent that could protect against more than 90% of reported SFTSV isolates. [ABSTRACT FROM AUTHOR]

This study examined factors associated with the intention to take an HIV test among men who have sex with men (MSM) in South Korea. An internet website-based survey was conducted among users of the only and largest online MSM website between 20 July 2016, and 20 August 2016. A total of 2915 participants completed the survey and answered questions related to sociodemographic information, health behaviors, sexual behaviors, and HIV testing history. Of these, 2587 (88.7%) participants responded as having an intention to take an HIV test. A multivariable logistic regression analysis revealed the following as having reduced the intention to undergo HIV testing: very good subjective health status and no sexual interactions during the last 6 months (Adjusted odds ratios [AOR] 0.45 and 0.54, respectively). In contrast, increased intention to take an HIV test was associated with being 20–29 years old, 30–39 years old, not paying or receiving money for sex, having a history of HIV testing, and taking an HIV test once per 12 months (AOR 2.64, 2.13, 1.54, 1.81, and 2.17, respectively). In conclusion, HIV testing among MSM in this study was associated with age, subjective health status, sex(es) of one’s sexual partner(s) during the last 6 months, sexual risk behaviors, HIV testing history, and undergoing regular HIV testing. [ABSTRACT FROM AUTHOR]

Infection is one of the main causes of early-treatment mortality in multiple myeloma (MM) patients during autologous stem cell transplantation (autoSCT). In the present study, we sought to determine the incidence of, and risk factors for, infection during hospital stays after autoSCT. We retrospectively evaluated 324 autoSCT events that occurred in 285 MM patients between 2006 and 2015, and reviewed the clinical characteristics of patients and history of infections. Sixty-eight infection events occurred, including bacteremia (24), other bacterial infections (7), as well as infections caused by Cytomegalovirus (17), Herpes simplex virus (12), Varicella zoster virus (3), Aspergillus (3) and Pneumocystis jiroveci (2). There was no significant difference in number of infections in the 2006-2010 and 2011-2015 periods (P = 0.194). Risk factors for bacteremia included higher beta-2 microglobulin levels at diagnosis [≥3.5 mg/L; adjusted odds ratio (aOR) 3.544 (95% CI 1.070-11.736), P = 0.038] and previous bortezomib treatment [aOR 4.270 (95% CI 1.389-13.125), P = 0.011]. In-hospital mortality occurred in 1.2% of all cases and all were infection-related. In conclusion, infection was the main cause of in-hospital mortality in patients who underwent autoSCT. Bacteremia was the most common type of microbiologically confirmed infection, and was associated with higher beta-2 microglobulin levels and previous bortezomib treatment. [ABSTRACT FROM AUTHOR]

The incidence of disseminated Mycobacterium avium complex (MAC) infection in HIV patients has fallen markedly since the introduction of effective antiretroviral therapy (ART). However, current guidelines still recommend primary prophylaxis. We conducted a retrospective cohort study in a university-affiliated hospital from January 1998 to January 2014. During that period, HIV patients who had at least one CD4 cell count below 50 cells/mm3 and had been treated with ART were enrolled. We compared incidence of disseminated MAC infection in the 12 months after the first CD4 cell count below 50 cells/mm3 between prophylaxis and nonprophylaxis groups. A total of 157 patients were enrolled and the total observation period was 144 patient-years (PY). Thirty-three patients (21%) received primary MAC prophylaxis. The initial CD4 cell count of the prophylaxis group was lower than that of the nonprophylaxis group ( P = 0.024), but the proportion of patients who reached a CD4 cell count >100 cells/mm3 ( P = 0.234) and were virologically suppressed ( P = 0.513) 12 months after ART commencement was not different in the prophylaxis and nonprophylaxis groups. The incidence of MAC did not differ significantly between the groups (3.4/100 PY versus 0.8/100 PY, P = 0.368). Routine MAC prophylaxis may be not required in the era of effective ART. [ABSTRACT FROM AUTHOR]

Background: Cytopenia occurs frequently during cytotoxic chemotherapy. Little is known about the optimal timing of influenza vaccination for patients receiving chemotherapy. This study compared the immunogenicity of an influenza vaccine administered concurrently with chemotherapy (day 1) and within the cytopenic period (day 11) during 3-week cytotoxic chemotherapy cycles.Methods: Adult patients with solid cancer undergoing scheduled 3-week cytotoxic chemotherapy were randomly assigned to receive the 2014-2015 seasonal influenza vaccine on day 1 or 11 during the chemotherapy cycle. Patients were stratified by their age (<60 and ≥60 years) and previous influenza vaccination status. Antibody responses to influenza vaccine strains H1N1, H3N2, and B were measured before and 21 to 28 days after vaccination with a hemagglutination inhibition antibody assay.Results: Ninety-seven patients were randomized into a day 1 group (n = 43) or a day 11 group (n = 54). Eighty-three patients were included in the final analysis. The mean age was 54 (± 11) years. Cancer types included breast (61%) and lung cancer (30%). Baseline characteristics were not significantly different between the groups. Seroprotection rates after vaccination were also not significantly different for the day 1 and 11 groups (strain H1N1, 67% vs 75% [P = .403]; strain H3N2, 77% vs 80% [P = .772]; strain B, 21% vs 27% [P = .472]). Seroconversion rates and postvaccination geometric mean titers were also similar for the groups. Vaccine-related adverse events were more common in the day 11 group (13% vs. 32%; P = .040).Conclusions: The antibody responses to influenza vaccination on days 1 and 11 during a 3-week cytotoxic chemotherapy cycle were comparable. Influenza vaccination can be performed concurrently with cytotoxic chemotherapy or during the cytopenic period. Cancer 2017;123:841-48. © 2016 American Cancer Society. [ABSTRACT FROM AUTHOR]

Objective:Ascitic fluid infections (AFI) in cirrhotic patients can be classified into two groups: spontaneous bacterial peritonitis (SBP) and culture-negative neutrocytic ascites (CNNA). The aim of this study was to compare the clinical characteristics and outcomes of the two groups of patients with AFI. Methods:We retrospectively reviewed the medical records of cirrhotic patients with AFI. We evaluated demographic data, clinical presentations of AFI, laboratory findings, liver function, and mortality rates. Results:Between January 2005 and December 2014, 533 patients with AFI were evaluated; 259 (48.6%) had SBP and 274 (51.4%) CNNA. Ascites neutrophil count (4410/mm3versus 1046/mm3,p < .001) and the blood culture positive rate (38.1% versus 20.1%,p < .001) were higher in the SBP group, which also had a higher MELD score (24.29 versus 22.05,p = .004). Seven-day mortality was higher in the SBP group (9.4% versus 4.5%,p = .027) but there was no significant difference in 30-day (22.1% versus 17.5%) or 90-day mortality rate (36.1% versus 36.4%). Conclusions:Patients in the SBP group had a higher MELD score, ascites neutrophil count, and positive blood culture rate. Although seven-day mortality rate was higher in the SBP group, the 30-day and 90-day mortality rates were similar in the two groups. [ABSTRACT FROM PUBLISHER]

(B, D, F) Frequencies of IgM+, IgA+, and IgG+ antigen-specific memory B cells according to the severity of illness and different antigens. SARS-CoV-2, antibody, phagocytosis, memory B cells, memory T cells Keywords: SARS-CoV-2; antibody; phagocytosis; memory B cells; memory T cells EN SARS-CoV-2 antibody phagocytosis memory B cells memory T cells 1 2 2 05/26/22 20220524 NES 220524 In the original article, there was a mistake in Figure 3 as published. [Extracted from the article]

To identify the factors associated with perceived unmet medical needs in human immunodeficiency virus (HIV)-infected adults, we analyzed the results from a series of city-wide cross-sectional surveys of HIV-infected adults living in Seoul, Korea. Multivariate logistic regression analysis was used to identify factors related to unmet medical needs. Among the 775 subjects included in the study, 15.4% had perceived unmet medical needs. Significant factors included age group (35-49 years; adjusted odds ratio [aOR], 1.80; 95% confidence interval [CI], 1.06-3.06), lower monthly income (aOR, 3.75 for the <$900/mo group and 2.44 for the $900-$1800/mo group; 95% CI, 1.68-8.35 and 1.18-5.04, respectively), beneficiaries of the National Medical Aid Program (aOR, 1.78; 95% CI, 1.01-3.17), recent CD4 cell counts <500/μL (aOR, 1.53; 95% CI, 1.01-2.33). Taken together, these data reveal strong associations of middle age and low socioeconomic status with perceived unmet medical needs among HIV-infected adults. [ABSTRACT FROM AUTHOR]

Background: To promote appropriate antimicrobial use in bloodstream infections (BSIs), we initiated an intervention program consisting of electronic alerts and automated infectious diseases consultations in which the identification and antimicrobial susceptibility test (ID/AST) results were reported. Methods: We compared the appropriateness of antimicrobial prescriptions and clinical outcomes in BSIs before and after initiation of the program. Appropriateness was assessed in terms of effective therapy, optimal therapy, de-escalation therapy, and intravenous to oral switch therapy. Results: There were 648 BSI episodes in the pre-program period and 678 in the program period. The proportion of effective, optimal, and de-escalation therapies assessed 24 hours after the reporting of the ID/AST results increased from 87.8% (95% confidence interval [CI] 85.5–90.5), 64.4% (95% CI 60.8–68.1), and 10.0% (95% CI 7.5–12.6) in the pre-program period, respectively, to 94.4% (95% CI 92.7–96.1), 81.4% (95% CI 78.4–84.3), and 18.6% (95% CI 15.3–21.9) in the program period, respectively. Kaplan-Meier analyses and log-rank tests revealed that the time to effective (p<0.001), optimal (p<0.001), and de-escalation (p = 0.017) therapies were significantly different in the two periods. Segmented linear regression analysis showed the increase in the proportion of effective (p = 0.015), optimal (p<0.001), and de-escalation (p = 0.010) therapies at 24 hours after reporting, immediately after program initiation. No significant baseline trends or changes in trends were identified. There were no significant differences in time to intravenous to oral switch therapy, length of stay, and 30-day mortality rate. Conclusion: This novel form of stewardship program based on intervention by infectious disease specialists and information technology improved antimicrobial prescriptions in BSIs. [ABSTRACT FROM AUTHOR]

BackgroundSeveral case series have reported on clinical and radiographic characteristics of patients with vertebral osteomyelitis (VO) caused by non-tuberculous mycobacteria (NTM). However, only a few patients were included, and systematic reviews are still lacking. The aim of this study was to update and summarise the pre-disposing conditions, clinical and radiographic characteristics of such cases due to NTM.MethodsIn this study, a systematic review was conducted of the English-language literature from 1961–2014 to investigate the pre-disposing conditions and characteristics of cases of VO due to NTM. Also, six additional cases diagnosed in the study hospitals were described; these cases are included in an analysis of a total of 69 cases of NTM VO.ResultsThe most common species, regardless of the presence of HIV co-infection, wasM. aviumComplex followed byM. xenopi. Ten cases with HIV infection had a median CD4 lymphocyte count of 320/mm3(range = 41–465/mm3) at the time of diagnosis of NTM VO. The VO in the cases with HIV infections occurred at an earlier age and more often involved the thoracic spine than in the cases without HIV infection. Pre-disposing trauma or surgery was reported in 14.5% (10/69) of the cases. A variety of immunosuppressive diseases were observed in 49.3% of the patients, including the 10 with HIV infections and corticosteroids were used in 27.5% of the cases. Surgery was performed in 67.6% and improvement was reported in 80.6%.ConclusionNTM should be considered in immunocompromised patients with indolent VO without confirmation of tuberculosis. [ABSTRACT FROM PUBLISHER]

Many studies have investigated risk factors for suicidal ideation and suicide attempt; however, most have failed to show differences in risk factors between suicidal ideation and suicide attempt among the human immunodeficiency virus (HIV)-infected population. This study was designed to identify differences in risk factors between suicidal ideation and suicide attempts among HIV-infected adults in Seoul. A face-to-face survey of 457 HIV-infected adults was conducted by the Seoul Metropolitan Government in 2013. Multivariate logistic regression analysis was used to identify factors associated with suicidal ideation and suicide attempt. Among 422 participants, 44% had suicidal ideation, and 11% had suicide attempts. The independent risk factors for suicidal ideation were young and middle age, living with someone, history of AIDS-defining opportunistic disease, history of treatment for depression, lower social support, and psychological status. Beneficiaries of National Medical Aid, economic barriers to treatment, history of treatment for depression, and lower psychological status were independently associated with suicide attempts. Patients with HIV in Korea were treated without cost in some centers. Thus, experiencing an economic barrier to treatment might be due in part to ignorance of HIV care policies. Our findings indicate that suicide attempts are associated with socioeconomic factors and information inequality regarding medical care. In conclusion, suicidal ideation closely associated with the psychosocial factors, whereas suicide attempt demonstrates a stronger association with socioeconomic factors. Suicide prevention measures should be implemented to provide information to help HIV-infected patients. [ABSTRACT FROM AUTHOR]

We investigated the kinetics of serologic responses to Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using virus neutralization and MERS-CoV S1 IgG ELISA tests. In most patients, robust antibody responses developed by the third week of illness. Delayed antibody responses with the neutralization test were associated with more severe disease. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus is an endemic disease in Asia. It has been a rural disease, but indigenous urban cases have been observed in Seoul, South Korea. Urban scrub typhus may have a significant impact because of the large population. Methods: Indigenous urban scrub typhus was epidemiologically identified in Seoul, the largest metropolitan city in South Korea, using national notifiable disease data from 2010 to 2013. For detailed analysis of clinical features, patients from one hospital that reported the majority of cases were selected and compared to a historic control group. Chigger mites were prospectively collected in the city using a direct chigger mite-collecting trap, and identified using both phenotypic and 18S rDNA sequencing analyses. Their infection with Orientia tsutsugamushi was confirmed by sequencing the 56-kDa antigen gene. Results: Eighty-eight cases of urban scrub typhus were determined in Seoul. The possible sites of infection were mountainous areas (56.8%), city parks (20.5%), the vicinity of one's own residence (17.0%), and riversides (5.7%). Eighty-seven chigger mites were collected in Gwanak mountain, one of the suspected infection sites in southern Seoul, and seventy-six (87.4%) of them were identified as Helenicula miyagawai and eight (9.2%) as Leptotrombidium scutellare. Pooled DNA extracted from H. miyagawai mites yielded O. tsutsugamushi Boryong strain. Twenty-six patients from one hospital showed low APACHE II score (3.4 ± 2.7), low complication rate (3.8%), and no hypokalemia. Conclusions: We identified the presence of indigenous urban scrub typhus in Seoul, and a subgroup of them had mild clinical features. The chigger mite H. miyagawai infected with O. tsutsugamushi within the city was found. In endemic area, urban scrub typhus needs to be considered as one of the differential febrile diseases and a target for prevention. Author Summary: Scrub typhus is one of the high burdened infectious diseases in endemic rural areas. Our study showed that the disease could be endemic in urban areas. Indigenous urban scrub typhus may also have significant impact in terms of a disease burden and differential diagnosis. A low rate of characteristic eschar and skin rash may make the clinical suspicion more troublesome. Scrub typhus is the 3rd most frequent notifiable infectious disease in South Korea. Seoul is a densely populated capital city located in northwestern South Korea. We epidemiologically identified indigenous urban cases. A subgroup of them showed mild clinical characteristics. Direct mite collection from a suspected infection site, Mt. Gwanak in Seoul, showed that Helenicula miyagawai (87.4%) and Leptotrombidium scutellare (9.2%) were the dominant species. In addition, O. tsutsugamushi-specific gene, tsa56, was identified in a fraction of the collected H. miyagawai. The 18S rDNA sequencing of the chigger mites was complementarily helpful for the differentiation of species. Our data are from one region, but urban scrub typhus is likely a scenario in endemic areas. Urban areas should be included as possible locations for scrub typhus. [ABSTRACT FROM AUTHOR]

Background: There are limited data describing the clinical characteristics of pyogenic spondylitis caused by Gram-negative bacteria (GNB). The aim of this study was to investigate the predisposing factors and clinical characteristics of pyogenic spondylitis caused by GNB compared to Gram-positive cocci (GPC). Methods: We performed a retrospective review of medical records from patients with culture-confirmed pyogenic spondylitis at four tertiary teaching hospitals over an 8-year period. Results: A total of 344 patients with culture-confirmed pyogenic spondylitis were evaluated. There were 62 patients (18.0%) with pyogenic spondylitis caused by GNB and the most common organism was Escherichia coli (n = 35, 10.2%), followed by Pseudomonas aeruginosa (n = 10, 2.9%). Pyogenic spondylitis caused by GNB was more frequently associated with the female gender (64.5 vs. 35.5%, P <0.01), preexisting or synchronous genitourinary tract infection (32.3 vs. 2.1%, P< 0.01), and intra-abdominal infection (12.9 vs. 0.4%, P< 0.01) compared to patients with GPC. Although pyogenic spondylitis caused by GNB presented with severe sepsis more frequently (24.2 vs. 11.3%, P = 0.01), the mortality rate (6.0 vs. 5.2%) and the proportion of patients with residual disability (6.0 vs. 9.0%), defined as grade 3 or 4 (P = 0.78) 3 months after completion of treatment, were not significantly different compared to GPC patients. Conclusion: GNB should be considered as the etiologic organism when infectious spondylitis develops in a patient with preexisting or synchronous genitourinary tract and intra-abdominal infection. In addition, the mortality rate and clinical outcomes are not significantly different between pyogenic spondylitis caused by GNB and GPC. [ABSTRACT FROM AUTHOR]

Background: Scrub typhus is an endemic disease in Asia. It has been a rural disease, but indigenous urban cases have been observed in Seoul, South Korea. Urban scrub typhus may have a significant impact because of the large population. Methods: Indigenous urban scrub typhus was epidemiologically identified in Seoul, the largest metropolitan city in South Korea, using national notifiable disease data from 2010 to 2013. For detailed analysis of clinical features, patients from one hospital that reported the majority of cases were selected and compared to a historic control group. Chigger mites were prospectively collected in the city using a direct chigger mite-collecting trap, and identified using both phenotypic and 18S rDNA sequencing analyses. Their infection with Orientia tsutsugamushi was confirmed by sequencing the 56-kDa antigen gene. Results: Eighty-eight cases of urban scrub typhus were determined in Seoul. The possible sites of infection were mountainous areas (56.8%), city parks (20.5%), the vicinity of one’s own residence (17.0%), and riversides (5.7%). Eighty-seven chigger mites were collected in Gwanak mountain, one of the suspected infection sites in southern Seoul, and seventy-six (87.4%) of them were identified as Helenicula miyagawai and eight (9.2%) as Leptotrombidium scutellare. Pooled DNA extracted from H. miyagawai mites yielded O. tsutsugamushi Boryong strain. Twenty-six patients from one hospital showed low APACHE II score (3.4 ± 2.7), low complication rate (3.8%), and no hypokalemia. Conclusions: We identified the presence of indigenous urban scrub typhus in Seoul, and a subgroup of them had mild clinical features. The chigger mite H. miyagawai infected with O. tsutsugamushi within the city was found. In endemic area, urban scrub typhus needs to be considered as one of the differential febrile diseases and a target for prevention. [ABSTRACT FROM AUTHOR]

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]