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There have been occasional reports on varicella infection among healthcare workers (HCWs) despite varicella-zoster virus (VZV) seropositivity. We compared the levels of humoral and cellular immunity to VZV in seropositive HCWs who had acquired immunity by natural infection or vaccination.Seropositive healthy HCWs with an apparent history of varicella or VZV vaccination once or twice were recruited. Their samples were assessed for anti-VZV IgG levels, the relative avidity index (RAI), and the frequencies of VZV-specific cytokine-producing or polyfunctional CD4A total of 75 seropositive HCWs (29 with a history of varicella, 25 vaccinated once, and 21 vaccinated twice) were assessed for humoral immunity. Cellular responses could be analyzed in 59 (28, 21, and 10 in the respective groups). The anti-VZV IgG level, RAI, and memory CD4Seropositive HCWs without a varicella history, especially those who received the vaccine only once, had significantly lower levels of immune responses to VZV. Such HCWs might need to comply with airborne precautions.

Tuberculosis (TB) is a common opportunistic infection in human immunodeficiency virus (HIV)-infected patients. Patients with multidrug-resistant (MDR)-TB have poor outcomes. This study aimed to determine the prevalence of MDR-TB in HIV/TB co-infected patients in the Korea. We reviewed the medical records of HIV/TB co-infected patients at two university hospitals between January 1998 and December 2020. During the study period, a total of 87 HIV/TB co-infected patients were identified, and drug susceptibility test results were available for 44 of them. The prevalence of MDR-TB in the study population was 15.9% (7/44, 95% confidence interval, 5.1 - 26.7).

Background Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia occur within a few days after the onset of bacteremia, risk factors for early mortality (EM) have not been deeply investigated. We aimed to determine the risk factors for EM and the difference between risk factors associated with EM and late mortality (LM) in CRAB bacteremia. Methods All patients with CRAB bacteremia in 10 hospitals during a 1-year study period were identified. We prospectively collected patients’ clinical data, including microbiological and demographic data, underlying comorbidities, origin of bacteremia, severity of illness, antibiotic therapy, and mortality. Among the cases with mortality within 30 days, EM and LM were defined as death within 3 and more than 5 calendar days from the first positive blood culture, respectively. Results A total of 212 CRAB bacteremia cases were included in the analysis. Of 122 (57.5%) patients with 30-day mortality, EM was observed in 75 (61.5%) patients and LM in 39 (32.0%) patients. The proportion of severe sepsis or septic shock, Pitt score, and Sequential Organ Failure Assessment (SOFA) score were significantly higher in 30-day deaths than 30-day survivors. These factors of clinical severity were also significantly higher in patients with EM than those with LM. While urinary tract infection as the factor of site of infection and the severity of illness were independent predictors of LM, only factors representing the severity of illness were independent risk factors for EM. Appropriate empirical antibiotic therapy was associated with reduced risk of EM. Conclusion The difference between risk factors for EM and LM was identified in this study. Our data suggest that a large proportion of CRAB bacteremia with high severity progress to a rapidly fatal course, regardless of the underlying diseases or source of infection. Further studies might be needed to investigate the microbiological factors associated with CRAB and pathogen-host interaction in patients with EM. Disclosures All Authors: No reported disclosures.

Background Since antimold prophylaxis has been widely used in induction chemotherapy for acute myelogenous leukemia (AML), it should be re-evaluated whether broad spectrum antifungal therapy should be empirically used in prolonged febrile neutropenia. Therefore, we compared clinical outcomes of empirical versus pre-emptive antifungal therapy in patients with AML receiving antimold prophylaxis. Methods From September 2016 to December 2020, all adult AML patients (≥ 18 years) receiving antimold prophylaxis who had febrile neutropenia for ≥ 4 days during induction or re-induction chemotherapy at Seoul National University Hospital were retrospectively reviewed. They were classified into the empirical group (therapeutic broad spectrum antifungal agents had been used without evidence of invasive fungal infection [IFI]) or the pre-emptive group (antimold prophylaxis had been maintained until the emergence of IFI’s evidence). We compared clinical outcomes between the two groups after propensity score matching. Results A total of 229 chemotherapy episodes, 36 in the empirical group and 193 in the pre-emptive group, were analyzed. In the pre-emptive group, broad spectrum antifungal therapy was administered in 45 (23.3%) episodes. After 1:3 matching with age, gender, induction or re-induction chemotherapy, and worst qSOFA score at febrile neutropenia, incidence of proven or probable IFI (0/36 [0%] in the empirical group vs. 5/97 [5.2%] in the pre-emptive group, P=0.323) and all-cause mortality (3/36 [8.3%] in the empirical group vs. 4/97 [4.1%] in the pre-emptive group, P=0.388) were not different between the two groups. Conclusion Clinical outcomes of empirical versus pre-emptive broad spectrum antifungal therapy were comparable in patients with AML receiving antimold prophylaxis. Broad spectrum antifungal therapy could be delayed until the emergence of evidence of IFI, in the current era of antimold prophylaxis. Disclosures All Authors: No reported disclosures.

BACKGROUND/AIMS: Although it is near concluded that renin-angiotensin system inhibitors do not have a harmful effect on coronavirus disease 2019 (COVID-19), there is no report about whether angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEIs) offer any protective role. This study aimed to compare the association of ARBs and ACEIs with COVID-19-related mortality. METHODS: All patients with COVID-19 in Korea between January 19 and April 16, 2020 were enrolled. The association of ARBs and ACEIs with mortality within 60 days were evaluated. A comparison of hazard ratio (HR) was performed between COVID-19 patients and a retrospective cohort of pneumonia patients hospitalized in 2019 in Korea. RESULTS: Among 10,448 COVID-19 patients, ARBs and ACEIs were prescribed in 1,231 (11.7%) and 57 (0.6%) patients, respectively. After adjusting for age, sex, and history of comorbidities, the ARB group showed neutral association (HR, 1.034; 95% CI, 0.765 to 1.399; p = 0.8270) and the ACEI groups showed no significant associations likely owing to the small population size (HR, 0.736; 95% CI, 0.314 to 1.726; p = 0.4810). When comparing HR between COVID-19 patients and a retrospective cohort of patients hospitalized with pneumonia in 2019, the trend of ACEIs showed similar benefits, whereas the protective effect of ARBs observed in the retrospective cohort was absent in COVID-19 patients. Meta-analyses showed significant positive correlation with survival of ACEIs, whereas a neutral association between ARBs and mortality. CONCLUSION: Although ARBs or ACEIs were not associated with fatal outcomes, potential beneficial effects of ARBs observed in pneumonia were attenuated in COVID-19.

The socioeconomic and clinical burden of multidrug-resistant organisms (MDRO), including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), multidrug-resistant Acinetobacter baumannii (MRAB), multidrug-resistant Pseudomonas aeruginosa (MRPA), and carbapenem-resistant Enterobacteriaceae (CRE) have not yet been adequately addressed.We prospectively searched for MDRO bacteremia cases with matched controls from 10 hospitals across Korea during a 6-month period in 2017. Patients were classified into the MDRO, susceptible organism, and no-infection groups. The corresponding susceptible or no-infection controls had been selected according to predefined criteria. We collected clinical information and estimated the total additional medical cost due to MDRO infections using the multistate model.During the 6-month period, a total of 486 MDRO bacteremia cases (260, 87, 18, 20, and 101 cases of MRSA, MRAB, MRPA, CRE, and VRE, respectively) were identified. The 90-d mortality rates were 30.4%, 63.2%, 16.7%, 55.0%, and 47.5%, respectively. The additional costs caused by bacteremia were $15 768, $35 682, $39 908, $72 051, and $33 662 per MDRO type, respectively. Based on these 6-month data, the estimated annual number of bacteremia cases due to these five MDRO in Korea were 7979 (4070, 1396, 218, 461, and 1834 cases, respectively). Overall, this caused an estimated 3280 (1237, 882, 36, 254, and 871, respectively) deaths and cost $294 505 002 ($84 707 359, $74 387 364, $10 344 370, $45 850 215, and $79 215 694, respectively) (range $170,627,020-$416,094,679) in socioeconomic loss.A tremendous clinical and economic burden is caused by MDRO bacteremia compared with antibiotic-susceptible and no-infection groups. Substantial investment and efforts by related government agencies and medical staffs are needed.

We aimed to estimate the socioeconomic burden of pneumonia due to multidrug-resistant Acinetobacter baumannii (MRAB) and Pseudomonas aeruginosa (MRPA).We prospectively searched for MRAB and MRPA pneumonia cases and matched them with controls with susceptible-organism pneumonia and non-infected cases from ten hospitals over a 6-month period. The matching criteria were: same principal diagnosis, same surgery or intervention during hospitalization, age (years ± 10), sex, and admission date within 60 days. The total additional direct medical cost was estimated by the multistate model. A total of 108 cases of MRAB pneumonia [MRAB-P] and 28 cases of MRPA pneumonia [MRPA-P] were identified. The 90-day mortality rate was 37.0% and 39.3% for MRAB-P and MRPA-P, respectively. The additional medical costs were $42,203 and $35,556 for MRAB-P and MRPA-P, respectively. The estimated number of MRAB-P and MRPA-P cases were 1,309–2,483 and 339–644, respectively with estimated deaths being 485–920 and 133–253 in a year, respectively. The annual socioeconomic burden was $12,053,593–$22,898,271 and $15,241,883–$28,994,008, respectively. We estimated that MRAB-P and MRPA-P occurred in 1,648–3,172 patients, with 618–1,173 deaths, and caused $27,295,476–$51,892,279 in socioeconomic burden nationwide. It is time to investigate and invest in prevention of multidrug-resistant bacterial pneumonia.

We aimed to estimate the socioeconomic burden of pneumonia due to multidrug-resistant Acinetobacter baumannii (MRAB) and Pseudomonas aeruginosa (MRPA). We prospectively searched for MRAB and MRPA pneumonia cases and matched them with susceptible-organism pneumonia and non-infected patients from 10 hospitals. The matching criteria were: same principal diagnosis, same surgery or intervention during hospitalisation, age, sex, and admission date within 60 days. We calculated the economic burden by using the difference in hospital costs, the difference in caregiver costs, and the sum of productivity loss from an unexpected death. We identified 108 MRAB pneumonia [MRAB-P] and 28 MRPA pneumonia [MRPA-P] cases. The estimated number of annual MRAB-P and MRPA-P cases in South Korea were 1309-2483 and 339-644, with 485-920 and 133-253 deaths, respectively. The annual socioeconomic burden of MRAB-P and MRPA-P in South Korea was $64,549,723-122,533,585 and $15,241,883-28,994,008, respectively. The results revealed that MRAB-P and MRPA-P occurred in 1648-3127 patients, resulted in 618-1173 deaths, and caused a nationwide socioeconomic burden of $79,791,606-151,527,593. Multidrug-resistant organisms (MDRO) impose a great clinical and economic burden at a national level. Therefore, controlling the spread of MDRO will be an effective measure to reduce this burden.

Concerns about the effectiveness of current vaccines against the rapidly spreading severe acute respiratory syndrome-coronavirus-2 omicron (B.1.1.529) variant are increasing. This study aimed to assess neutralizing antibody activity against the wild-type (BetaCoV/Korea/KCDC03/2020), delta, and omicron variants after full primary and booster vaccinations with BNT162b2. A plaque reduction neutralization test was employed to determine 50% neutralizing dilution (ND

The relationship between changes in anxiety levels and personal protective equipment (PPE) use is yet to be evaluated. The present study assessed this relationship among healthcare workers (HCWs) involved in the care of patients with coronavirus disease 2019 (COVID-19).An online survey was conducted in a municipal hospital with 195 nationally designated negative pressure isolation units in Korea. Anxiety level was measured using the self-rating anxiety scale (SAS), and changes in anxiety levels were assessed based on the time when COVID-19 vaccine was introduced in March 2021 in Korea. Monthly PPE usage between June 2020 and May 2021 was investigated.The mean SAS score (33.25 ± 5.97) was within normal range and was lower than those reported in previous studies conducted before COVID-19 vaccination became available. Among the 93 HCWs who participated, 64 (68.8%) answered that their fear of contracting COVID-19 decreased after vaccination. The number of coveralls used per patient decreased from 33.6 to 0. However, a demand for more PPE than necessary was observed in situations where HCWs were exposed to body fluids and secretions (n = 38, 40.9%). Excessive demand for PPE was not related to age, working experience, or SAS score.Anxiety in HCWs exposed to COVID-19 was lower than it was during the early period of the pandemic, and the period before vaccination was introduced. The number of coveralls used per patient also decreased although an excessive demand for PPE was observed.

Since severe acute respiratory syndrome-coronavirus-2 variant B.1.1.529 (omicron) was first reported to the World Health Organization on November 24, 2021, the cases of the omicron variant have been detected in more than 90 countries over the last month. We investigated the clinical and epidemiological characteristics of the first 40 patients with the omicron variant who had been isolated at the National Medical Center in South Korea during December 4–17, 2021. The median age of the patients was 39.5 years. Twenty-two patients (55%) were women. Seventeen patients (42.5%) were fully vaccinated, and none were reinfected with the omicron. Eighteen (45%) had recent international travel history. Half of the patients (19, 47.5%) were asymptomatic, while the others had mild symptoms. Six patients (15%) showed lung infiltrations on chest image; however, none required supplemental oxygen. These mild clinical features are consistent with recent case reports on the omicron variant from other countries., Graphical Abstract

BackgroundMultidrug-resistant organisms (MDROs), including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), multidrug resistant Acinetobacter baumannii (MRAB), multidrug resistant Pseudomonas aeruginosa (MRPA), and carbapenem-resistant Enterobacteriaceae (CRE) are particularly important public health threats, but their detailed clinical outcomes and socioeconomic burden are adequately addressed.MethodsWe prospectively searched for these MDROs bacteraemia cases with matched controls from 10 hospitals across Korea, in a 6-month period, in 2017. Patients were classified into the MDRO, susceptible organism, and no-infection groups. The corresponding susceptible or no-infection controls had similar principal diagnosis at admission time, major surgery or intervention during hospitalization, age (± 10 years), sex, and within ± 60 days of admission date. We collected detailed clinical information and estimated the total additional direct medical cost of each MDRO bacteraemia case using the multistate model. ResultsOf 486 MDRO bacteraemia cases identified for MRSA, MRAB, MRPA, CRE, and VRE, at 260, 87, 18, 20, and 101, respectively, their 90-day mortality rates (overall, 40.3%) were 30.4%, 63.2%, 16.7%, 55.0%, and 47.5%, respectively. Their additional medical costs (overall, $27,700) were $15,768, $35,682, $39,908, $72,051, and $33,662 (compared to the no-infection group), respectively. Overall, these five MDRO bacteraemia cases occurred in 7,979 patients, caused 3,280 deaths, and cost $294,505,002 (range, $170,627,020 to $416,094,679) socioeconomic loss. ConclusionsTremendous clinical and economic burden occurred with MDRO bacteraemia compared with those of antibiotic-susceptible and no-infection groups. Substantial investment and efforts by related government agencies and medical staffs are needed to urgently prevent the increase, spread and expansion of antibiotic-resistant bacteria.

Background: Carbapenem-resistance (CR) causes poor clinical outcomes and has limited treatment options. We aim to evaluate the differences in clinical characteristics and impact of carbapenem-resistance on outcomes between Acinetobacter baumannii (ABA) and Pseudomonas aeruginosa (PAE) bacteraemia. Methods: We prospectively identified all patients with ABA and PAE bacteraemia in 10 hospitals over a 1-year period and collected their detailed clinical information. Treatment failure was defined as all-cause 30-day mortality, persistent bacteraemia, or recurrence within 30 days.Results: We included 304 ABA and 241 PAE bacteraemia cases. CR was detected in 216 ABA (71%) and 55 PAE (23%). Treatment failure was significantly higher in CR-ABA than in CR-PAE (60.6% vs. 34.5%, P = 0.001). Multivariate analyses were stratified by patient data according to CR and the appropriateness of empirical therapy. For ABA patients, severe sepsis or septic shock and high Pitt bacteraemia score were independent risk factors for treatment failure in the inappropriate empirical antibiotics group. Pneumonia was a significant risk factor in the appropriate group. For PAE patients, hospital-acquired infection and high Pitt bacteraemia score were independent risk factors for treatment failure in both groups. CR was an independent risk factor in ABA for treatment failure in both the inappropriate (adjusted odds ratio [aOR]: 6.17, 95% confidence interval [CI]: 1.13-33.75, P = 0.036) and appropriate empirical treatment groups (aOR: 4.15, 95% CI: 1.16-14.84, P = 0.029), but not for patients with PAE bacteraemia. Conclusions: We demonstrated significant differences in the clinical characteristics and impact of CR on the clinical outcomes between ABA and PAE bacteraemia. Our findings suggest that different approaches may be needed to treat ABA and PAE bacteraemia.

We investigated the kinetics of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in 7 asymptomatic persons and 11 patients with pneumonia. The geometric mean titer of neutralizing antibodies declined from 219.4 at 2 months to 143.7 at 5 months after infection, indicating a waning antibody response.

The rapid spread of COVID-19 has caused an emergency situation worldwide. Investigating the association between environmental characteristics and COVID-19 incidence can be of the occurrence and transmission. The objective of this study was to evaluate the association between greenness exposure and COVID-19 cases at the district levels in South Korea. We also explored this association by considering several environmental indicators.District-level data from across South Korea were used to model the cumulative count of COVID-19 cases per 100,000 persons between January 20, 2020, and February 25, 2021. Greenness exposure data were derived from the Environmental Geographic Information Service of the Korean Ministry of Environment. A negative binomial mixed model evaluated the association between greenness exposure and COVID-19 incidence rate at the district level. Furthermore, we assessed this association between demographic, socioeconomic, environmental statuses, and COVID-19 incidence.Data from 239 of 250 districts (95.6%) were included in the analyses, resulting in 127.89 COVID-19 cases per 100,000 persons between January 20, 2020 and February 25, 2021. Several demographic and socioeconomic variables, districts with a higher rate of natural greenness exposure, were significantly associated with lower COVID-19 incidence rates (incidence rate ratio (IRR), 0.70; 95% confidence interval (CI), 0.54-0.90; P-value = 0.008) after adjusting covariates, but no evidence for the association between built greenness and COVID-19 incidence rates was found.In this ecological study of South Korea, we found that higher rates of exposure to natural greenness were associated with lower rates of COVID-19 cases.

Panton-Valentine leukocidin (PVL) is a virulent cytotoxin and an indicator of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection. In this study, we evaluated the prevalence and clinical and molecular characteristics of PVL-positive invasive S. aureus (ISA) infections in Korea.A collection of 1,962 nonduplicate clinical isolates were screened for multilocus sequence typing, staphylococcal cassette chromosome mec (SCCmec), accessory gene regulator typing, major toxins, and antimicrobial susceptibility. Twenty-eight (1.4%) PVL-positive S. aureus samples were found; of them 19 (67.9%) were MRSA (8 CA and 11 healthcare-associated infections). Seventeen patients (60.7%) were men (median age: 63 years; range: 13-93 years) and 12 patients (42.9%) had no underlying comorbidities. The most common infections were skin and skin structure infection (SSSI) and pneumonia. The 30-day mortality rate was 37.0%. The most common PVL-positive MRSA clones were ST8-SCCmec IVa and ST30-SCCmec IVc along with their single-locus variants. Antimicrobial susceptibility and toxin-gene profile differed according to the clone.ISA infections caused by PVL-positive strains are rare in Korea, with the two most common infections being SSSI and pneumonia. Our findings indicated that several PVL-positive MRSA clones, predominantly ST8-SCCmecIVa and ST30-SCCmecIVc, were circulating and causing sporadic cases of ISA infections in the community and hospital settings.

Background In July 2017, there was an outbreak of Campylobacter jejuni infection in three auxiliary police squads in Seoul, Korea. An epidemiological investigation was conducted to identify the cause and source of the illness. Materials and methods A retrospective cohort study of all members of the three auxiliary police squads was conducted. Self-administered questionnaires were distributed to all members of the three squads and the food handlers. Rectal swabs were collected from symptomatic police and food handlers. Results The overall attack rate was 20.4%, and the epidemic curve indicated a point source type outbreak. Of the 257 auxiliary policemen who consumed the incriminated lunch, 55 met the case definition. Of 36 rectal swabs, 10 were positive for C. jejuni and had the same pulsed-field gel electrophoresis pattern. The major symptoms were loose stool (100%) and abdominal pain (59.3%); the median incubation period was 69 hours. In the univariate epidemiological analysis, watermelon (relative risk [RR], 5.75; 95% confidence interval [CI], 2.14-15.43), half-cut chicken soup (RR, 3.96; 95% CI, 1.49-10.54), steamed rice with millet (RR, 2.73; 95% CI, 1.29-5.77), and radish kimchi (RR, 2.57; 95% CI, 1.45-4.55) were positively associated with the illness. Inspection of the food service facility found that the drainpipe under the meat cleaning sink did not work. Conclusion This outbreak could have been caused by cross-contamination with C. jejuni from raw chicken via environmental sources.

PURPOSE A high risk of cardiovascular disease (CVD) is reported for HIV-infected individuals. While a link between abacavir and CVD risk is suggested, an association between abacavir and hypertension remains unclear. This study evaluated hypertension risk with abacavir use in comparison to non-abacavir antiretroviral treatment (ART). MATERIALS AND METHODS From a nationwide cohort of HIV-infected individuals on their initial ART, 6493 who were free of hypertension at baseline were analyzed. The use of ART was treated as a time-varying covariate measured as a daily unit. Incidence rate of hypertension was calculated, and Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) with 95% confidence interval (CI) of incident hypertension overall and among subgroups. RESULTS From the 6493 participants, 24072 person-years (PY) of follow-up were contributed during 2008-2016. The incidence rates of hypertension were 4.6 and 3.6 per 100 PY for abacavir and non-abacavir ART users, respectively. The population attributable fraction of abacavir use on hypertension was 12%. Abacavir exposure did not elevate the risk of hypertension among overall study population [HR, 1.2 (95% CI, 1.0-1.4), p=0.061]. However, those with poor ART adherence, defined as a medication possession ratio

Supplemental Digital Content is available in the text., Objective: Although statins are widely prescribed lipid-lowering drugs, there are concerns about the safety of their use in the context of coronavirus disease 2019 (COVID-19), since statins increase the expression of ACE2 (angiotensin-converting enzyme 2). This study aimed to disclose the association between statins and 60-day COVID-19 mortality. Approach and Results: All patients hospitalized with laboratory-confirmed COVID-19 were enrolled in this study from January 19 to April 16, 2020, in Korea. We evaluated the association between the use of statins and COVID-19–related mortality in the overall and the nested 1:2 propensity score–matched study. Furthermore, a comparison of the hazard ratio for death was performed between COVID-19 patients and a retrospective cohort of patients hospitalized with pneumonia between January and June 2019 in Korea. The median age of the 10 448 COVID-19 patients was 45 years. Statins were prescribed in 533 (5.1%) patients. After adjusting for age, sex, and comorbidities, Cox regression showed a significant decrease in hazard ratio associated with the use of statins (hazard ratio, 0.637 [95% CI, 0.425–0.953]; P=0.0283). Moreover, on comparing the hazard ratio between COVID-19 patients and the retrospective cohort of hospitalized pneumonia patients, the use of statins showed similar benefits. Conclusions: The use of statins correlates significantly with lower mortality in patients with COVID-19, consistent with the findings in patients with pneumonia.

Background A vancomycin loading dose is recommended for the treatment of serious methicillin-resistant Staphylococcus aureus (MRSA) infections. However, clinicians often do not adhere to these recommendations, mainly due to nephrotoxicity risk, unfamiliarity with the guideline, or complexity of calculating an individual dose. Therefore, we introduced a computerised clinical decision support system (CDSS) for vancomycin loading (hereafter Vancomycin CDSS) to promote the use of vancomycin loading dose. Methods We describe a quasi-experimental study spanning 6 months before and 18 months after the deployment of a Vancomycin CDSS. The Vancomycin CDSS was integrated into the hospital’s electronic medical record system in the form of a vancomycin order set. Our primary endpoint was the incidence of nephrotoxicity; the secondary endpoint was mean initial vancomycin trough levels. We also conducted a survey to evaluate the reasons why clinicians opted not to utilise a vancomycin loading dose. Results After implementation of Vancomycin CDSS, 363 out of 746 patients (49 %) who were first administered vancomycin received a loading dose. We did not find significant differences in nephrotoxicity between the pre- and post-intervention groups, nor between the loading- and non-loading groups. In the pre-intervention group, the mean initial vancomycin trough level was 7.10 mg/L, which was significantly lower than that in the post-intervention group of 11.11 mg/L. In the vancomycin loading group, the mean initial trough level was 11.95 mg/L, compared to 7.55 mg/L in the non-loading group. The main reason stated for not prescribing a vancomycin loading dose was concern about nephrotoxicity. Conclusion Introduction of the Vancomycin CDSS did not increase nephrotoxicity and increased the mean initial dose and trough level of vancomycin.

Background Although the risk factors for positive follow-up blood cultures (FUBCs) in gram-negative bacteremia (GNB) have not been investigated extensively, FUBC has been routinely carried out in many acute care hospitals. We attempted to identify the risk factors and develop a predictive scoring model for positive FUBC in GNB cases. Methods All adults with GNB in a tertiary care hospital were retrospectively identified during a 2-year period, and GNB cases were assigned to eradicable and non-eradicable groups based on whether removal of the source of infection was possible. We performed multivariate logistic analyses to identify risk factors for positive FUBC and built predictive scoring models accordingly. Results Out of 1473 GNB cases, FUBCs were carried out in 1268 cases, and the results were positive in 122 cases. In case of eradicable source of infection, we assigned points according to the coefficients from the multivariate logistic regression analysis: Extended spectrum beta-lactamase-producing microorganism (+ 1 point), catheter-related bloodstream infection (+ 1), unfavorable treatment response (+ 1), quick sequential organ failure assessment score of 2 points or more (+ 1), administration of effective antibiotics (− 1), and adequate source control (− 2). In case of non-eradicable source of infection, the assigned points were end-stage renal disease on hemodialysis (+ 1), unfavorable treatment response (+ 1), and the administration of effective antibiotics (− 2). The areas under the curves were 0.861 (95% confidence interval [95CI] 0.806–0.916) and 0.792 (95CI, 0.724–0.861), respectively. When we applied a cut-off of 0, the specificities and negative predictive values (NPVs) in the eradicable and non-eradicable sources of infection groups were 95.6/92.6% and 95.5/95.0%, respectively. Conclusions FUBC is commonly carried out in GNB cases, but the rate of positive results is less than 10%. In our simple predictive scoring model, zero scores—which were easily achieved following the administration of effective antibiotics and/or adequate source control in both groups—had high NPVs. We expect that the model reported herein will reduce the necessity for FUBCs in GNB cases.

Background In Korea, the incidence of varicella has increased despite the introduction of a universal one-dose vaccination for children aged 12–15 months in 2005. A previous study demonstrated that the vaccine effectiveness was insufficient to prevent against varicella. We assessed the effect of the varicella vaccination on disease severity. Methods Epidemiologic investigation of varicella cases in Seoul metropolitan area from 2015 to 2017 were used. Varicella-related symptoms such as rash were determined by the clinical practitioners. Disease severity of patients was assessed by the number of skin lesions and divided into mild (≤ 50) and moderate (51–249) to severe (≥ 250). Unconditional logistic regression analysis was performed and age was controlled. Results Among a total of 1,008 varicella cases reported, 869 cases were breakthrough cases and 139 were unvaccinated cases. The risk for occurrence of moderate-to-severe disease in the breakthrough group was 0.57 times less than that of the unvaccinated group. Conclusion These data suggest that national varicella vaccination may have a significant effect on attenuation of disease severity in children., Graphical Abstract

To investigate associations of the duration of voriconazole treatment and radiological response with relapse of invasive pulmonary aspergillosis (IPA) in immunocompromised patients, we explored the risk factors for IPA relapse after successful initial treatment. All patients with proven or probable IPA who had finished voriconazole treatment between 2005 and 2019 in a tertiary-care hospital were reviewed. IPA relapse was defined as re-diagnosis of proven or probable IPA at the same site within 1 year after treatment termination. Short course of voriconazole treatment was defined as a treatment less than 9 weeks, which is a median of the recommended minimum duration of therapy from the Infectious Disease Society of America. The radiological response was defined as a reduction in IPA burden by more than 50% on chest computed tomography. Of 87 patients who had completed voriconazole treatment, 14 (16.1%) experienced IPA relapse. Multivariable Cox regression identified that short voriconazole treatment duration (adjusted hazard ratio [aHR], 3.7; 95% confidence interval [CI], 1.1–12.3; P = 0.033) and radiological non-response (aHR, 4.6; 95% CI, 1.2–17.5; P = 0.026) were independently associated with relapse of IPA after adjusting for several clinical risk factors. Longer duration of therapy should be considered for those at higher risk of relapse.

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.

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected pneumonia emerged in Wuhan, China in December 2019. In this retrospective multicenter study, we investigated the clinical course and outcomes of novel coronavirus disease 2019 (COVID-19) from early cases in Republic of Korea. Methods All of the cases confirmed by real time polymerase chain reaction were enrolled from the 1st to the 28th patient nationwide. Clinical data were collected and analyzed for changes in clinical severity including laboratory, radiological, and virologic dynamics during the progression of illness. Results The median age was 40 years (range, 20–73 years) and 15 (53.6%) patients were male. The most common symptoms were cough (28.6%) and sore throat (28.6%), followed by fever (25.0%). Diarrhea was not common (10.7%). Two patients had no symptoms. Initial chest X-ray (CXR) showed infiltration in 46.4% of the patients, but computed tomography scan confirmed pneumonia in 88.9% (16/18) of the patients. Six patients (21.4%) required supplemental oxygen therapy, but no one needed mechanical ventilation. Lymphopenia was more common in severe cases. Higher level of C-reactive protein and worsening of chest radiographic score was observed during the 5–7 day period after symptom onset. Viral shedding was high from day 1 of illness, especially from the upper respiratory tract (URT). Conclusion The prodromal symptoms of COVID-19 were mild and most patients did not have limitations of daily activity. Viral shedding from URT was high from the prodromal phase. Radiological pneumonia was common from the early days of illness, but it was frequently not evident in simple CXR. These findings could be plausible explanations for the easy and rapid spread of SARS-CoV-2 in the community., Graphical Abstract