Risk of microbial transmission by reusing gloves after alcohol-based hand hygiene

BACKGROUND

Disinfection of gloves might reduce the the workload of healthcare workers, protect the environment, and bring economic benefits. Thus, the safety of hand hygiene of gloved hands is an important issue.

AIM

We aimed to evaluate the risk of microbial transmission by comparing residual microorganisms after multiple patient contacts, with or without gloves, in clinical practice.

METHODS

Researchers, two with gloved hands (single or double gloves) and one with bare hands, made rounds of patients, followed by alcohol-based hand rub. Hand imprints were obtained before and after the rounds and cultured. The number of colony-forming units (CFUs) of gloved and bare hands was compared, and the colony distribution was evaluated semi-quantitatively by hand region.

FINDINGS AND CONCLUSION

A total of 108 imprints were obtained after 10 rounds. The median CFU counts were significantly higher in the gloved hands (single and double) than in the bare hands (9.00 vs. 3.50, p=0.028). The CFU counts of single- and double-gloved hands were higher after than before contact (p=0.044 and p=0.001, respectively). Carbapenem-resistant Acinetobacter baumannii was identified in a pair of double gloves after a round, which included patients with the same organism with identical antibiotic susceptibility results. The mean percentage of colony-growing compartments from gloved hands was significantly higher than that of bare hands in the finger and wrist regions (p=0.019 and p=0.049, respectively). Compared to bare hands, reuse of gloves increased residual microbial colonies and potential for transmission of multidrug-resistant organisms, even after using alcohol-based hand rub.

Low humoral and cellular immune responses early after breakthrough infection may contribute to severe COVID-19

Background

Little is known about the immune determinants for severe coronavirus disease 2019 (COVID-19) in individuals vaccinated against severe acute respiratory syndrome coronavirus 2. We therefore attempted to identify differences in humoral and cellular immune responses between patients with non-severe and severe breakthrough COVID-19.

Methods

We prospectively enrolled hospitalized patients with breakthrough COVID-19 (severe and non-severe groups) and uninfected individuals who were vaccinated at a similar time (control group). Severe cases were defined as those who required oxygen therapy while hospitalized. Enzyme-linked immunosorbent assays and flow cytometry were used to evaluate humoral and cellular immune responses, respectively.

Results

Anti-S1 IgG titers were significantly lower in the severe group than in the non-severe group within 1 week of symptom onset and higher in the non-severe group than in the control group. Compared with the control group, the cellular immune response tended to be diminished in breakthrough cases, particularly in the severe group. In multivariate analysis, advanced age and low anti-S1 IgG titer were associated with severe breakthrough COVID-19.

Conclusions

Severe breakthrough COVID-19 might be attributed by low humoral and cellular immune responses early after infection. In the vaccinated population, delayed humoral and cellular immune responses may contribute to severe breakthrough COVID-19.

208. Clinical outcomes of empirical versus pre-emptive broad spectrum antifungal therapy in patients with acute myelogenous leukemia receiving antimold prophylaxis

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.

1855. Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteremia

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.

Risk factors for early mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteraemia

OBJECTIVES

Although many deaths due to carbapenem-resistant Acinetobacter baumannii (CRAB) bacteraemia occur within a few days after the onset of bacteraemia, 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 bacteraemia.

METHODS

Clinical information on all patients with CRAB bacteraemia in 10 hospitals during a 1-year period was collected. 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

In total, 212 CRAB bacteraemia 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 was significantly higher in patients with EM than those with LM. Although urinary tract infection as the 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.

CONCLUSION

Our results suggest that a large proportion of CRAB bacteraemia with high severity progresses 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.

The association between greenness exposure and COVID-19 incidence in South Korea: An ecological study

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Different clinical characteristics and impact of carbapenem-resistance on outcomes between Acinetobacter baumannii and Pseudomonas aeruginosa bacteraemia: a prospective observational study

This study aimed to evaluate the differences in clinical characteristics and impact of carbapenem resistance (CR) on outcomes between Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) bacteraemia. We prospectively identified all patients with Ab and Pa bacteraemia in 10 hospitals over 1 year. Treatment failure was defined as all-cause 30-day mortality, persistent bacteraemia, or recurrent bacteraemia within 30 days. We included 304 Ab and 241 Pa bacteraemia cases. CR was detected in 216 patients (71%) with Ab bacteraemia and 55 patients (23%) with Pa bacteraemia. Treatment failure was significantly higher in CR-Ab than in CR-Pa (60.6% vs. 34.5%, P = 0.001). In Ab, severe sepsis or septic shock and high Pitt bacteraemia score were independent risk factors for treatment failure in the inappropriate empirical antibiotics group. In Pa, 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 Ab for treatment failure in both groups, but not in Pa bacteraemia. We demonstrated significant differences in clinical characteristics and impact of CR on clinical outcomes between Ab and Pa bacteraemia, suggesting that different treatment approaches may be needed.

Changes in Anxiety Level and Personal Protective Equipment Use Among Healthcare Workers Exposed to COVID-19

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Booster BNT162b2 COVID-19 Vaccination Increases Neutralizing Antibody Titers Against the SARS-CoV-2 Omicron Variant in Both Young and Elderly Adults

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 (ND₅₀) titers in serum samples. ND₅₀ titers against the omicron variant (median [interquartile range], 5.3 [< 5.0-12.7]) after full primary vaccination were lower than those against the wild-type (144.8 [44.7-294.0]) and delta (24.3 [14.3-81.1]) variants. Furthermore, 19/30 participants (63.3%) displayed lower ND₅₀ titers than the detection threshold (< 10.0) against omicron after full primary vaccination. However, the booster vaccine significantly increased ND₅₀ titers against BetaCoV/Korea/KCDC03/2020, delta, and omicron, although titers against omicron remained lower than those against the other variants (P < 0.001). Our study suggests that booster vaccination with BNT162b2 significantly increases humoral immunity against the omicron variant.

Clinical Characteristics of 40 Patients Infected With the SARS-CoV-2 Omicron Variant in Korea

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.

Treatment for Immune Thrombocytopenia in Coronavirus Disease 2019 (COVID-19) Infection after COVID-19 Vaccination: A Case Report

Thrombocytopenia is one of the rare signs of both the coronavirus disease 2019 (COVID-19) and COVID-19 vaccination. An 85-year-old man was diagnosed with immune thrombocytopenia and COVID-19, 7 days after COVID-19 vaccination. The patient was successfully treated with a short course of intravenous immunoglobulin and oral corticosteroids.

Prevalence of Multidrug-Resistant Tuberculosis in HIV/Tuberculosis Co-Infected Patients

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).

High Prevalence of Human Immunodeficiency Virus Infection among Inmates in Korean Correctional Facilities

BACKGROUND

Epidemiological data are crucial in designing policies for the control of human immunodeficiency virus (HIV) infections. There is a lack of data on the epidemiology of HIV in Korean correctional facilities such as jails and prisons.

METHODS

Clinical characteristics of the study population were collected through a medical record review.

RESULTS

The number of people with HIV infection were 83 and the HIV infection prevalence in correctional facilities of Korea was 0.15%. Among them, 10 (12.0%) were diagnosed with the infection when they were incarcerated. The number of drug users was 38 (45.8%). Syphilis-HIV coinfection was observed in 21 (25.3%) patients. Individuals from the group comprising the drug users were more likely to belong to the lesbian, gay, bisexual, transgender, queer (LGBTQ) community, and had a higher incidence of psychological disorders (31.6% vs. 11.1%, P = 0.029; 50.0% vs. 28.9%, P = 0.049, respectively).

CONCLUSION

Inmates of correctional facilities showed a five times higher prevalence of HIV infection in Korea, nearly half of whom were drug users.

Beneficial Effect of Statins in COVID-19-Related Outcomes-Brief Report: A National Population-Based Cohort Study

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.

Impact of a computerised clinical decision support system on vancomycin loading and the risk of nephrotoxicity

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.

Suboptimal medication adherence in young women living with HIV infection: a Korean nationwide claims study

The epidemiological characteristics of women living with human immunodeficiency virus (HIV) infection have gained little attention as the numbers are small compared with men living with HIV in the Republic of Korea. However, these data are important to achieve effective HIV infection control and to consider the influence of socioeconomic status on HIV transmission. This study utilized the claims database of the Korean National Health Insurance system to analyze women with a newly diagnosed HIV infection during the period 2009-2016. Adherence to antiretroviral agents was calculated using the medication possession ratio. Among 677 women with a newly diagnosed HIV infection, 219 (32.4%) were over 50 years of age; 291 (43.0%) were identified as having acquired immune deficiency syndrome (AIDS). A total of 99 women (14.6%) were National Medical Aid beneficiaries. Optimal medical adherence >95% was found in 62.2% of subjects. Teenage years (odds ratio(OR) 14.9, 95% confidence interval (95CI) 4.9-44.8), AIDS (OR 1.7, 95CI 1.2-2.3), and low economic status requiring National Medical Aid (OR 3.0, 95CI 2.0-4.6) were associated to adherence. Diagnosis prior to 2012 was also associated with poor adherence. In women, particularly young patients with low economic status, extra attention is required to enhance adherence to prescribed medication.

The Importance of Proper History Taking: Asking a Fever Pattern in Patients with Vivax Malaria

Characteristic fever patterns of malarial infection are clues for diagnosis. However, checking fever patterns in febrile patients has been usually missed, and unnecessary tests have been performed. We reviewed electrical medical record to check whether history-taking included questions on fever pattern in febrile patients. Main outcomes were time interval between visit and diagnosis of vivax malaria and proportion of patients who had taken unnecessary tests. Among 134 vivax malarial patients, asking about fever pattern was done in 64 (47.8%). Median time interval between visit and diagnosis was significantly shorter in patients whose fever pattern was asked than those not asked (3.2 hours vs. 18.6 hours; P < 0.001). Unnecessary diagnostic tests were conducted in 27% (17/64) of patients asked about fever pattern and 71% (50/70) in patients not asked (P < 0.001). Proper history-taking can reduce time elapsed for diagnosis and performing unnecessary diagnostic tests in vivax malaria.

Waning Antibody Responses in Asymptomatic and Symptomatic SARS-CoV-2 Infection

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.

Predictive scoring models for persistent gram-negative bacteremia that reduce the need for follow-up blood cultures: a retrospective observational cohort study

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.

Prevalence of cryptococcal antigenemia in hospitalized patients with liver cirrhosis

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.

Prospective evaluation of a rapid antimicrobial susceptibility test (QMAC-dRAST) for selecting optimal targeted antibiotics in positive blood culture

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.

Recovery of Tenofovir-induced Nephrotoxicity following Switch from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in Human Immunodeficiency Virus-Positive Patients

Background

Tenofovir disoproxil fumarate (TDF)-induced nephrotoxicity is related to high plasma tenofovir concentrations. Tenofovir alafenamide (TAF) is a tenofovir prodrug with 90% lower plasma tenofovir concentrations. The aim of this study was to evaluate changes in tenofovir-induced nephrotoxicity in Human Immunodeficiency Virus (HIV)-positive patients who switched from TDF to TAF.

Materials and Methods

We identified all HIV-positive patients who switched from elvitegravir/cobicistat/emtricitabine/TDF to elvitegravir/cobicistat/emtricitabine/TAF at a tertiary hospital. We assessed tubulopathy and renal dysfunction before TDF administration, at the time TAF was used following at least 3 months of TDF use, and 3 months after TAF administration. Tubulopathy was defined by the presence of at least three abnormalities in fractional excretion of phosphate, fractional excretion of uric acid, urinary β2-microglobulin, urinary N-acetyl-β-D-glucosaminidase, glucosuria or proteinuria. Renal dysfunction was defined as decreased by more than 25% in the estimated glomerular filtration rate (eGFR) relative to baseline.

Results

In 80 patients, the mean eGFR was 96.8 mL/min/1.73 m² before administration of TDF, 81.2 (P <0.001) at the time of change to TAF, 90.9 (P <0.001) after TAF administration. Renal dysfunction occurred in 19 patients (23.8%) after TDF use for a median 15 months, 11 (57.9%) of these patients recovered from renal dysfunction after TAF administration. Six patients (7.5%) had tubulopathy before TDF administration, 36 (45.0%) after TDF administration (P <0.001), 12 (15.0%) after TAF administration (P = 0.002).

Conclusion

Tenofovir-induced nephrotoxicity in HIV-positive patients receiving TDF was mostly reversible after changing to TAF. Thus, TAF-containing regimens can be administered safely to HIV-positive patients with tenofovir-induced nephrotoxicity.

Three-year outcome of rapid HIV testing at public health centers in Seoul, Republic of Korea: a short report

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.

Clinical Course and Outcomes of Patients with Severe Acute Respiratory Syndrome Coronavirus 2 Infection: a Preliminary Report of the First 28 Patients from the Korean Cohort Study on COVID-19

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.

Clinical Score System to Differentiate Severe Fever with Thrombocytopenia Syndrome Patients from Patients with Scrub Typhus or Hemorrhagic Fever with Renal Syndrome in Korea

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality in East Asia. This study aimed to develop, for primary care providers, a prediction score using initial symptoms and basic laboratory blood tests to differentiate between SFTS and other endemic zoonoses in Korea.

METHODS

Patients aged ≥ 18 years diagnosed with endemic zoonoses during a 3-year period (between January 2015 and December 2017) were retrospectively enrolled from 4 tertiary university hospitals. A prediction score was built based on multivariate logistic regression analyses.

RESULTS

Of 84 patients, 35 with SFTS and 49 with other endemic zoonoses were enrolled. In multivariate logistic regression analysis, independent predictors of SFTS included neurologic symptoms (odds ratio [OR], 12.915; 95% confidence interval [CI], 2.173-76.747), diarrhea (OR, 10.306; 95% CI, 1.588-66.895), leukopenia (< 4,000/mm³) (OR, 19.400; 95% CI, 3.290-114.408), and normal C-reactive protein (< 0.5 mg/dL) (OR, 24.739; 95% CI, 1.812-337.742). We set up a prediction score by assigning one point to each of these four predictors. A score of ≥ 2 had 82.9% sensitivity (95% CI, 71.7%-87.5%) and 95.9% specificity (95% CI, 88.0%-99.2%). The area under the curve of the clinical prediction score was 0.950 (95% CI, 0.903-0.997).

CONCLUSION

This study finding suggests a simple and useful scoring system to predict SFTS in patients with endemic zoonoses. We expect this strategic approach to facilitate early differentiation of SFTS from other endemic zoonoses, especially by primary care providers, and to improve the clinical outcomes.

Application of the severe fever with thrombocytopenia syndrome prediction score: Differentiation of febrile diseases using basic laboratory parameters

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.

Estimation of the Number of HIV Infections and Time to Diagnosis in the Korea

BACKGROUND

Statistical data of undiagnosed people living with human immunodeficiency virus (PLHIV) are of great importance to human immunodeficiency virus (HIV) infection control. This study estimated the total number of PLHIV using nationwide claims data.

METHODS

This study used data of the incident HIV cases identified by the National Health Insurance System between 2009 and 2015. The number of patients with acquired immune deficiency syndrome (AIDS) was identified by diagnoses or prescription records. The estimated number of PLHIV and the time to diagnosis were calculated from the incident numbers of HIV and AIDS cases using the HIV Modeling Tool of the European Center for Disease Prevention and Control.

RESULTS

Between 2009 and 2015, a total of 7,033 PLHIV and 2,899 AIDS patients were diagnosed. In 2009, the number of incident HIV cases was 873 (460 AIDS patients), increasing to 995 (337 AIDS patients) in 2015. Besides, the estimated number of prevalent cases was 10,753 in 2009, compared to 14,880 in 2015. Patients visiting health facilities accounted for 42.9% (4,616/10,753) in 2009 and 64.1% (9,544/14,880) in 2015. In 2009, there were 8,363 (77.8%) undiagnosed HIV cases, experiencing a decline to 6,215 (41.8%) in 2015. It took a mean of 6.96 years to diagnose after HIV infection.

CONCLUSION

This study estimates the total burden of HIV infection in Korea for the first time using an internationally recognized HIV modeling tool. Claims data can be used to estimate the number of undiagnosed cases by identifying the total number of PLHIV and AIDS patients visiting health facilities.

Delays in Isolating Patients Admitted to Hospital with Pulmonary Tuberculosis in Korea

BACKGROUND

Delays in isolating patients admitted to hospital with active pulmonary tuberculosis (PTB) can contribute to nosocomial transmission; however, in Korea, patients with clinically diagnosed PTB are not routinely isolated while awaiting microbiological confirmation of the diagnosis. We aimed to assess the extent of delays in isolating patients admitted with PTB and to identify the factors associated with delayed isolation.

METHODS

We retrospectively reviewed the electronic medical records of patients aged ≥ 18 years with active PTB, between January 2008 and December 2017, from two Korean hospitals.

RESULTS

Among 1,062 patients, 612 (57.6%) were not isolated on admission day. The median time from admission to isolation was 1 day (interquartile range: 0-2 days). The independent risk factor most strongly associated with delayed isolation was admission to departments other than pulmonology or infectious diseases departments (adjusted odds ratio [aOR], 5.302; 95% confidence interval [CI], 3.177-8.847; P < 0.001). Factors associated with isolation on admission day were a past history of tuberculosis (TB) (aOR, 0.669; 95% CI, 0.494-0.906; P = 0.009), night sweats (aOR, 0.530; 95% CI, 0.330-0.851; P = 0.009), and apical infiltrates on chest radiographs (aOR, 0.452; 95% CI, 0.276-0.740; P = 0.002).

CONCLUSION

Concerning patients subsequently diagnosed with active PTB, > 50% were not isolated on admission day. We suggest that the patients with clinically suspected PTB including the elderly who have a past history of TB, night sweats, or apical infiltration on chest radiographs, be presumptively isolated on admission, without waiting for microbiological confirmation of the diagnosis.

Association of HIV-syphilis coinfection with optimal antiretroviral adherence: a nation-wide claims study

Condomless sex is not totally discouraged after achieving undetectable human immunodeficiency virus (HIV) load, but the prevalence of sexually transmitted diseases (STDs) in the group is unknown. This study was retrospective in nature, using the claims database of the National Health Insurance system from 2008 to 2016. The clinical characteristics of people living with HIV with or without syphilis coinfection were analyzed. People with HIV and syphilis coinfection were divided into two groups according to antiretroviral therapy adherence, as optimal and suboptimal adherence groups by a medication possession ratio of 95%. Of the 9393 people living with HIV, 4536 (48.3%) were diagnosed with syphilis coinfection. Optimal adherence was associated with syphilis coinfection (odds ratio [OR] 1.18; 95% confidence interval [95CI] 1.08-1.30; p = .001). This suggests that unsafe sex occurs regardless of medication adherence. Being male, bacterial/protozoa STDs, and genital herpes virus infection were also risk factors for HIV-syphilis coinfection. Although HIV is unlikely to be transmittable when viral load is controlled, consistent use of condoms is necessary to prevent infection with syphilis.

238. Direct identification of Bacterial Species with MinION Nanopore Sequencer In Clinical Specimens Suspected of Polybacterial Infection

Background

Conventional culture tests usually identify only a few bacterial species, which can grow well in the culture system, in the cases of polybacterial infection. 16S rRNA gene nanopore sequencing enables semi-quantitative identification of bacterial genetic materials. We aimed to evaluate usefulness of 16s rRNA gene nanopore sequencing in the cases suspected of polybacterial infection.

Methods

The research was conducted in a single university hospital for one year. Conventional bacterial culture identification and nanopore sequencing of 16s rRNA gene were carried out simultaneously for cases where polybacterial infection is strongly suspected. Blood agar plate was used for conventional culture, and Microscan (Beckman Coulter, United States) and Vitek 2 (Biomerieux, FR) automated systems were used for identification. For nanopore sequencing, 16S rRNA gene PCR was performed from the clinical specimens, and sequencing libraries were generated from the PCR products using the rapid barcoding sequencing kit (Oxford nanopore technologies, UK). MinION sequencing was performed for 1–3 hours and the generated reads were analyzed using the EPI2ME 16S BLAST workflow.

Results

Specimens were obtained from 15 patients; 6 liver abscess, 2 psoas abscess, 2 thigh abcess, 1 paraspinal abscess, 1 mycotic aneurysm, 1 necrotizing fasciitis, 1 fingertip gangrene and 1 abscess in coccyx area. 16s rRNA gene nanopore sequencing showed monobacterial organism in 8 (53.3%) specimens and polybacterial organisms in 7 (46.6%) specimens. In three (37.5%) cases of 8 cases with monobacterial infections identified by 16s rRNA gene sequencing, no organism was grown in conventional culture, possibly due to previous antibiotic administration. Notably, among 8 cases with polybacterial infection by 16s rRNA gene nanopore sequencing test, traditional culture test showed polybacterial infection in only two (25%) cases and single bacterial organism was identified in the other 6 (75%) cases.

Conclusion

Nanopore sequencing of 16s rRNA gene using the MinION sequencer may be useful for identification of causing microorganism and differentiation between monobacterial and polybacterial infection when polybacterial infection is suspected.

Disclosures

All authors: No reported disclosures.

116. Risk Factors and Clinical Outcomes of Carbapenem Non-Susceptible Gram-Negative Bacteremia in Patients with Acute Myelogenous Leukemia

Background

Early administration of susceptible antibiotics is crucial in Gram-negative bacteremia (GNB), especially in immunocompromised patients. We aimed to explore risk factors and clinical outcomes of carbapenem non-susceptible (Carba-NS) GNB in patients with acute myelogenous leukemia (AML).

Methods

Cases of all GNB during induction or consolidation chemotherapy for AML in a 15-year period in a tertiary hospital were retrospectively reviewed. Independent risk factors for Carba-NS GNB were sought and its clinical outcomes were compared with those of carbapenem susceptible (Carba-S) GNB.

Results

Among 485 GNB cases from 930 patients, 440 (91%) were Carba-S and 45 (9%) were Carba-NS GNB. Frequent Carba-NS isolates were Stenotrophomonas maltophilia (n = 23), Pseudomonas aeruginosa (n = 11), and Acinetobacter baumannii (n = 10). Independent risk factors for Carba-NS GNB were carbapenem use at the onset of GNB (aOR [95% CI], 78.6 [24.4–252.8]; P < 0.001), the isolation of imipenem-resistant A. baumannii in the prior 1 year (aOR [95% CI], 14.6 [2.7–79.9]; P = 0.002), time interval from chemotherapy to GNB ≥20 days (aOR [95% CI], 4.7 [1.7–13.1]; P = 0.003), and length of hospital stay ≥30 days (aOR [95% CI], 3.4 [1.3–9.1]; P = 0.013). Except breakthrough GNBs which occurred during carbapenem treatment, the frequency of Carba-NS GNB was 48% (19/40) in cases having ≥2 risk factors other than carbapenem use. 30-day overall mortality (Carba-NS, 36% vs. Carba-S, 6%; P < 0.001) and in-hospital mortality (Carba-NS, 47% vs. Carba-S, 9%; P < 0.001) were significantly higher in Carba-NS GNB.

Conclusion

Carba-NS GNB in AML patients was independently associated with the use of carbapenem, the past isolation of resistant organism, and late onset of GNB, and its clinical outcomes were poorer than those of Carba-S GNB. Carba-NS organisms should be considered for antibiotic selection in AML patients having these risk factors.

Disclosures

All authors: No reported disclosures.

273. Low Positive Predictive Value of β-d-Glucan in Hematology Patients Receiving Antimold Prophylaxis

Background

Detection of β-D-glucan (BDG) in serum is recognized as the mycological evidence in the diagnosis of invasive fungal infection (IFI). However, its diagnostic value in low prevalence of IFI has not been elucidated. We aimed to examine the performance of BDG in hematology patients receiving antimold prophylaxis.

Methods

We retrospectively reviewed all BDG results performed for the purpose of diagnosis or surveillance for IFI in hematology patients receiving posaconazole or micafungin prophylaxis from January 2017 to February 2019 in a tertiary hospital. At least two consecutive positive results of BDG were regarded as positive BDG. All the episodes were classified into true-positive (TP, positive BDG with probable/proven IFI), true-negative (TN, negative BDG without probable/proven IFI), false-positive (FP, positive BDG without probable/proven IFI), false-negative (FN, negative BDG with probable/proven IFI), and nonevaluable (could not be determined for the occurrence of breakthrough IFI). When BDG test was performed in the setting of persistent fever ≥72 hours in spite of broad-spectrum antibiotics or with a suspicion of IFI, it was defined as a diagnostic BDG episode, while others were defined as a surveillance BDG episode.

Results

Of a total of 140 episodes, 24 episodes were non-evaluable. Among 116 evaluable episodes, 75 received induction chemotherapy for acute leukemia or myelodysplastic syndrome, 35 underwent stem cell transplantation, and 10 had intensive treatment for graft-vs.-host disease. There were three episodes of probable/proven IFI (2.6%). Ninety-one (78.4%) were performed with diagnostic purpose, while 25 (21.6%) were performed for surveillance. TP, TN, FP, and FN were 2 (1.7%), 91, 22, and 1, respectively. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 66.7%, 80.5%, 8.3% and 98.9%, respectively. PPV was 13.3% and 0% in diagnostic and surveillance BDG episodes, respectively.

Conclusion

The PPV of BDG was low in hematology patients receiving antimold prophylaxis, even in the diagnostic-driven episodes. The routine screening of BDG is not helpful, and the BDG test may be used for exclusion of IFI rather than for diagnosis in these patients.

Disclosures

All authors: No reported disclosures.

Suicide Risk in Persons with HIV/AIDS in South Korea: a Partial Test of the Interpersonal Theory of Suicide

PURPOSE

The high disease burden associated with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) is linked to the elevated suicide risk in this population. Informed by the interpersonal theory of suicide, this study examined how and under which conditions depression is related to suicide risk in people living with HIV/AIDS.

METHODS

A total of 202 outpatients with HIV/AIDS participated in a cross-sectional and multi-center survey involving four university hospitals in South Korea. This self-reported survey included the Hospital Anxiety and Depression Scale, Interpersonal Needs Questionnaire, and Mini-International Neuropsychiatric Interview suicidality module.

RESULTS

Participants' mean age was 48.6 (SD = 13.4) and the majority was male (89.1%). The proportions of those at high, medium, and low suicide risk were 18.5%, 20%, and 15.4%, respectively. Depression was associated with suicide risk directly and indirectly by increasing perceived burdensomeness (PB) and the indirect effect of depression on suicide risk mediated by PB was contingent on the level of thwarted belongingness (TB). PB was associated with suicide risk even after controlling for depression, suggesting its independent effect on suicide risk.

CONCLUSIONS

PB and TB are potential mechanisms through which depression is associated with suicide risk, supporting the applicability of the interpersonal theory of suicide to understanding a complex interplay of risk factors in people with HIV/AIDS. Moreover, given the independent association of PB with suicide risk, as well as a protective effect of TB in suicide risk, monitoring and management of these factors should be included in the care of people with HIV/AIDS.

Clinical Prediction Score for Community-Onset Bloodstream Infections Caused by Extended-Spectrum Beta-Lactamase-Producing Escherichia coli and Klebsiella Species

BACKGROUND

This study aimed to identify the predictors and build a prediction score for community-onset bloodstream infections (CO-BSIs) caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella species.

METHODS

All CO-BSIs caused by E. coli and Klebsiella species from 2012 to 2015 were grouped into derivation (BSIs from 2012 to 2014) and validation (BSIs in 2015) cohorts. A prediction score was built using the coefficients of the multivariate logistic regression model from the derivation cohort.

RESULTS

The study included 886 CO-BSIs (594 and 292 in the derivation and validation cohorts, respectively). The independent predictors of CO-BSIs caused by ESBL-producing E. coli and Klebsiella species included: 1) identification of ESBL-producing microorganisms from any clinical culture within one year of admission, 2) beta-lactam or fluoroquinolone treatment within 30 days (with 2 or more courses within 90 days; with 1 course within 90 days), 3) hospitalization within one year, 4) the presence of an indwelling urinary catheter at the time of admission. The area under the curve (AUC) of the clinical prediction score was 0.72 (95% confidence interval [CI], 0.68-0.77). In the validation cohort, the AUC was 0.70 (95% CI, 0.63-0.77).

CONCLUSIONS

The results of this study suggest a simple and easy-to-use scoring system to predict CO-BSIs caused by ESBL-producing E. coli and Klebsiella species.

Effects of One-dose Varicella Vaccination on Disease Severity in Children during Outbreaks in Seoul, Korea

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.

Optimal Timing of Zoster Vaccination After Shingles: A Prospective Study of the Immunogenicity and Safety of Live Zoster Vaccine

Background

Zoster vaccination is recommended for people with a history of herpes zoster (HZ), but the most effective timing of vaccine administration after zoster illness is unresolved. This prospective observational study compared the immunogenicity and safety of administering HZ vaccine at 6-12 months and 1-5 years after zoster illness.

Materials and Methods

Blood samples were collected before the administration of live zoster vaccine and 6 weeks after vaccination. Varicella-zoster virus (VZV) IgG concentrations and T-cell responses were assessed by glycoprotein enzyme-linked immunosorbent assay and interferon-γ enzyme-linked immunospot assay (ELISPOT), respectively.

Results

The baseline geometric mean value (GMV) of VZV IgG was higher in the 6-12 months group than in the 1-5 years group (245.5 IU/mL vs. 125.9 IU/mL; P = 0.021). However, the GMV increased significantly in both groups (P = 0.002 in the 6-12 months group; P <0.001 in the 1-5 years group). The results of the ELISPOT assay were not significant for differences of the GMV between baseline and 6-week post-vaccination groups, while the GMV increased significantly in both groups (P = 0.001 in the 6-12 months group; P <0.001 in the 1-5 years group).

Conclusion

The immunogenicity of zoster vaccine may be similar whether administered 6-12 months, or >1 year after zoster illness.

Trial Registration

ClinicalTrials.gov Identifier: NCT02704572

Campylobacter jejuni Foodborne Infection Associated with Cross-contamination: Outbreak in Seoul in 2017

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.

Increasing varicella incidence rates among children in the Republic of Korea: an age-period-cohort analysis

In the Republic of Korea, despite the introduction of one-dose universal varicella vaccination in 2005 and achieving a high coverage rate of 98.9% in 2012, the incidence rate has been increased sevenfold. This study aimed to investigate time trends of varicella incidence rate, assessing the age, period and birth cohort effects. We used national data on the annual number of reported cases from 2006 to 2017. A log-linear Poisson regression model was used to estimate age-period-cohort effects on varicella incidence rate. From 2006 to 2017, the incidence of varicella increased from 22.5 cases to more than 154.8 cases per 100 000. Peak incidence has shifted from 4 to 6 years old. The estimated period and cohort effects showed significant upward patterns, with a linear increasing trend by net drift. There has been an increase in the incidence among the Korean population regarding period and cohort despite the universal vaccination of varicella vaccine. Our data suggest the need for additional studies to address the current gap in herd immunity.

Hypertension Risk with Abacavir Use among HIV-Infected Individuals: A Nationwide Cohort Study

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 <50% [HR, 1.9 (95% CI, 1.5-2.4), p<0.0001] or requiring prophylactic antibiotics [HR, 1.2 (95% CI, 1.0-1.3), p=0.023], were at risk of hypertension induced by abacavir, as were men, individuals aged ≥40 years, and patients visiting tertiary hospitals in urban areas.

CONCLUSION

When present, poor ART adherence, requiring prophylactic antibiotics, male sex, and older age may warrant additional concern for hypertension in patients treated with abacavir.

1056. Predicting Central Nervous System Complications in Staphylococcus aureus Bacteremia Using Clinical Scoring System

Background

Central nervous system (CNS) complications occurring in patients with Staphylococcus aureus bacteremia (SAB) are the most severe complications. In this study, we compared clinical data of SAB patients between cases with and without CNS complication and analyzed the risk factor of CNS complications.

Methods

Data from cases with SAB occurred during 5 years at four hospitals were collected. The presence of CNS complications was confirmed by brain MRI, CT, or lumbar puncture. We excluded the cases who already had CNS lesions such as trauma, brain tumor, or cerebrovascular accident. We also excluded the cases who were died or transfer out &lt;7 days of bacteremia onset. Cases were divided into complication group or noncomplication group according to the presence of CNS complication. We compared the clinical profiles between the groups, and analyzed the risk factor of CNS complications by multivariate logistic regression analysis.

Results

A total of 1,085 cases of SAB patients were included. Among these, 43 (4%) cases were complication group (embolic infarct [n = 23], brain hemorrhage [n = 8], infarct with hemorrhage [n = 8], and brain abscess or meningitis [n = 4]), while 810 (74%) cases were noncomplication group. Two hundred and forty-one cases were excluded. The results of multivariate analysis were shown in table. When selecting by having less than three factors among SOFA &gt; 5, methicillin-susceptible, endovascular infection (weight 2), presence of metastatic infection and community onset, it helps to exclude CNS complications (AUC of ROC curve = 0.77, P &lt; 0.01, sensitivity; 67.5%, specificity: 75.5%, positive predictive value: 12.9%, negative predictive value 97.7%).

Conclusion

CNS complication could be excluded by using clinical variables

Disclosures

All authors: No reported disclosures.

2445. Efficacy and Tolerability of Linezolid for Treatment of Infectious Spondylitis

Background

Infectious spondylitis requires long-term antibiotic treatment for 6 weeks or more, and the use of intravenous antibiotics during this period causes social loss and costs due to hospitalization. Linezolid has high oral bioavailability and is not affected by changes in renal or hepatic function. We investigated the clinical and microbiological effects of linezolid in infectious spondylitis caused by β-lactam resistant Gram-positive bacteria.

Methods

Clinical data about patients who were diagnosed infectious spondylitis and treated with linezolid for more than 4 weeks were collected by electronic medical record retrospectively at 3 tertiary hospitals from 2006 to 2016. Clinical and microbiological success after treatment were determined using medical record or bacterial culture results identified in blood or tissue.

Results

Twenty Korean cases were treated with linezolid more than 4 weeks during the study period. Median duration of linezolid treatment was 40.5 days. Major causative organism was methicillin-resistant Staphylococcus aureus (n = 15), followed by methicillin-resistant coagulase-negative Staphylococcus (n = 3). In 10 of 20 patients treated with linezolid, antibiotics were changed for side effects or de-escalation of antibiotics. The most common reason for discontinuation of linezolid was thrombocytopenia (n = 6). Fourteen patients were cured, 4 failed and 2 cases of mortality occurred due to other causes than infectious spondylitis. Nine of 13 patients who were assessed as vancomycin treatment failure were cured. Cytopenia was most common drug adverse reaction, and severe cytopenia (grade II or more of NCI criteria) was 11.11% in neutropenia, 12.96% in anemia and 20.37% in thrombocytopenia.

Conclusion

Linezolid can be used as an effective antibiotic agent in patients with infectious spondylitis, especially when treatment failure of the first-line treatment is expected. Linezolid can be administered orally in outpatient clinic, reducing healthcare cost. Since cytopenia (especially thrombocytopenia) are common, a regular follow-up of complete blood cell count is needed.

Disclosures

All authors: No reported disclosures.

2074. Performance and Impact Evaluation of Direct Rapid Antibiotic Susceptibility Testing on Antibiotic Treatment Accuracy in Clinical Setting

Background

Timely and effective antibiotics treatment is crucial in early period of bacteremia. Antibiotic susceptibility testing (AST) is essential for choosing an optimal antibiotics treatment, but conventional AST requires 2 days from confirmation of blood culture positivity. Direct rapid antibiotic susceptibility testing (dRAST) based on microfluidic agarose cannel chip technology determines antibiotic susceptibility by time lapse imaging in 6 hours. We evaluated the performance of dRAST to improve selection of adequate antibiotic in clinical practice settings.

Methods

Two hundred eighty-three patients with positive blood culture (BC) bottles were included for analysis. BC bottles from these patients were processed by current microbiology analyzer: Microscan for Gram positive strains and VITEK2 for Gram-negative strains. At the same time, AST was performed using dRAST. The susceptibility results were reported to infectious diseases specialists who determine optimal antibiotics based on AST results. We compared the time differences and accuracy of dRAST with those of conventional method.

Results

Of 283 patients, 117 (41.5%) patients were infected with Gram positive bacteria, 163 (57.4%) patients were infected with Gram negative bacteria and 3 (1.1%) patients were infected with Gram-positive and -negative bacteria. The total turnaround time for conventional method and dRAST from blood culture collection was 78.3 ± 27.0 and 55.9 ± 18.9 hours, respectively. Seventy-seven of 95 (81.1%) patients who received ineffective or suboptimal antibiotic treatment after confirming the results of Gram stain and 81 of 86 (94.2%) patients who received unnecessary broad-spectrum antibiotic treatment could have received adjusted optimal treatment based on dRAST.

Conclusion

The use of dRAST system would accelerate earlier effective antibiotic administration and reduce the antibiotic selective pressure in patients with bacteremia.

Disclosures

J. Choi, QuantaMatrix Inc.: Employee, equity interest. S. Han, QuantaMatrix Inc.: Employee, equity interest. D. Y. Kim, QuantaMatrix Inc.: Board Member, equity interest. S. Kwon, QuantaMatrix Inc.: Board Member, equity interest.

Cost-Effectiveness of Voluntary HIV Testing Strategies in a Very Low-Prevalence Country, the Republic of Korea

BACKGROUND

The Republic of Korea has a very low prevalence of human immunodeficiency virus (HIV) infection, but the number of new HIV diagnoses has steadily risen, strongly indicating a large number of undetected HIV infections. Thus, it is important for Korean public health authorities to adopt and encourage cost-effective HIV detection tools, such as rapid HIV screening tests. In this study, we aimed to evaluate the cost-effectiveness of enzyme-linked immunosorbent assays (ELISA) and rapid tests in a public health center (PHC) setting.

METHODS

We developed a decision analytic model to assess the per-examinee cost and the cost-effectiveness of identifying HIV patients in a PHC setting using two HIV testing strategies: conventional HIV screening by ELISA versus rapid HIV testing. Analysis was performed in two scenarios: HIV testing in an average-risk population and in a high-risk population.

RESULTS

Compared to the ELISA, the rapid test was cost-saving and cost-effective. The per-examinee cost was USD 1.61 with rapid testing versus USD 3.38 with ELISA in an average-risk population, and USD 4.77 with rapid testing versus USD 7.62 with ELISA in a high-risk population. The cost of identifying a previously undiagnosed HIV case was USD 26,974 with rapid testing versus USD 42,237 with ELISA in an average-risk population, and USD 153 with rapid testing versus USD 183 with ELISA in a high-risk population.

CONCLUSION

Rapid testing would be more cost-effective than using conventional ELISA testing for identifying previously undiagnosed HIV-infected cases in Korea, a country with extremely low HIV prevalence.

Clinical and Molecular Characterization of Panton-Valentine Leukocidin-Positive Invasive Staphylococcus aureus Infections in Korea

AIM

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.

RESULTS

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.

CONCLUSIONS

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.

Factors Contributing to Missed Visits for Medical Care among Human Immunodeficiency Virus-Infected Adults in Seoul, Korea

BACKGROUND

It is important that patients with human immunodeficiency virus (HIV) remain under medical care to improve their health and to reduce the potential for HIV transmission. We explored factors associated with missed visits for HIV medical care according to age group.

METHODS

Data were derived from a city-wide, cross-sectional survey of 812 HIV-infected adults in Seoul. Multiple logistic analyses were used to explore predictors of missed visits.

RESULTS

Of the 775 subjects, 99.3% were treated with antiretroviral therapy (ART) and 12.5% had missed a scheduled appointment for HIV medical care during the past 12 months. Compared with the group aged ≥ 50 years, the 20-34-years and 35-49-years groups were strongly associated with missed visits (adjusted odds ratio [aOR], 5.0 and 2.2, respectively). When divided by age group, lower education level (aOR, 3.0) in subjects aged 20-34 years, low income (aOR, 3.5), National Medical Aid beneficiary (aOR, 0.3), and treatment interruption due to side effects of ART (aOR, 3.4) in subjects aged 35-49 years, and National Medical Aid beneficiary (aOR, 7.1) in subjects aged ≥ 50 years were associated with missed visits.

CONCLUSION

In conclusion, younger age was a strong predictor of missed visits for HIV medical care. However, the risk factors differed according to age group, and the strongest predictor in each age group was related to socioeconomic status.

Delayed diagnosis of extrapulmonary tuberculosis presenting as fever of unknown origin in an intermediate-burden country

Background

Tuberculosis (TB), especially extrapulmonary tuberculosis (EPTB), is an important cause of fever of unknown origin (FUO) in TB-burdened areas. Little information is known about patients with EPTB with clinical features presenting as FUO and about the factor of delaying the diagnosis.

Methods

We retrospectively analyzed EPTB patients who were referred with FUO at 3 university-affiliated hospitals over 8 years (2010–2017). The subjects were assigned to groups of early diagnosis and delayed diagnosis within 3 days of an initial comprehensive evaluation from the referral. Clinical and laboratory variables were compared between the groups.

Results

A total of 95 patients with febrile EPTB were included. Localizing symptoms and/or signs suggestive of anatomy were identified in 62.1% of the patients. Concurrent lung involvement by TB was presented by 49.5% (47/95) of the patients, and only 23.4% of them showed typical findings of pulmonary TB on simple chest X-ray. Most of the patients showed abnormal lesions on cross-sectional CT (98.9%) and MRI (100%). The clinical variables and blood test results of patients were not significantly different between the two groups. The less typical imaging finding of EPTB on CT (38.5% vs. 79.0%) and MRI (37.5% vs. 79.0%) in the delayed diagnosis group was a risk factor for delayed diagnosis.

Conclusion

Febrile EPTB referred as FUO showed nonspecific clinical manifestations. The active application of cross-sectional imaging tests according to clinical clues or randomly in the absence of local manifestations, combined with invasive diagnostic approaches even for atypical presentations may lead to an earlier diagnosis of febrile EPTB.