This study aimed to evaluate the diagnostic usefulness of real-time (RT) polymerase chain reaction (PCR) on blood samples for diagnosis of invasive aspergillosis and mucormycosis in patients with suspected invasive mould infection.Adult patients with suspected invasive mould infection were prospectively enrolled at a tertiary referral hospital in Seoul, South Korea between 2017 and 2020. Standard tests for diagnosis of invasive mould infection and RT-PCR for Aspergillus, Mucor and Rhizopus using blood samples were performed. We evaluated the diagnostic performance of RT-PCR tests in patients diagnosed with proven and probable invasive aspergillosis or mucormycosis infection, according to the modified definitions of the EORTC/MSG 2019.A total of 102 patients with suspected invasive mould infection were enrolled. Of these patients, 46 (45%) were classified as having proven (n = 13) or probable (n = 33) invasive aspergillosis, 21 (21%) as proven (n = 17) or probable (n = 4) invasive mucormycosis and 18 (18%) as possible invasive mould infection. The remaining 13 (13%) were classified as not having invasive mould infection. Patients with possible invasive mould infection (n = 18) and coinfection of aspergillosis and mucormycosis (n = 4) were excluded from the final analysis. The sensitivity and specificity of the Aspergillus PCR were 54.3% ([25/46], 95% confidence interval [CI]: 40.2-67.9%) and 94.1% ([32/34], 95% CI: 80.9-98.4%), respectively. The sensitivity and specificity of the Mucor or Rhizopus PCR were 57.1% ([12/21], 95% CI: 36.6-75.5%) and 76.3% ([45/59], 95% CI: 64.0-85.3), respectively.Our study suggests that blood PCR can be a useful adjunct test for diagnosing patients with suspected invasive mould infection.
Although there have been several studies regarding the immunogenicity of one or two booster doses of the measles−mumps−rubella (MMR) vaccine in measles-seronegative young adults, limited data are available about how long the immune response is sustained compared with natural infection. This study included seronegative healthcare workers (HCWs) (aged 21−38 years) who received one or two doses of the measles−mumps−rubella (MMR) vaccine and HCWs with laboratory-confirmed measles infection during an outbreak in 2019. We compared neutralizing antibody titers measured using the plaque reduction neutralization (PRN) test and measles-specific immunoglobulin G (IgG) using chemiluminescent immunoassays 2 years after vaccination or infection. Among 107 HCWs with seronegative measles IgGs, the overall seroconversion rate of measles IgGs remained 82.2% (88/107), and 45.8% (49/107) of the participants had a medium (121−900) or high (>900) PRN titer after 2 years from one or two booster doses. The measles-neutralizing antibody titers of both PRN titer (ND50) and geometric mean concentration 2 years after natural infection were significantly higher than those of one or two booster doses of the MMR vaccine (p < 0.001 and p < 0.001, respectively). Our results suggest that serologic screening followed by appropriate postexposure prophylaxis can be beneficial for young HCWs without a history of natural infection especially in a measles outbreak setting, because of possible susceptibility to measles despite booster MMR vaccination 2 years ago. Long-term data about sustainable humoral immunity after one or two booster vaccination are needed based on the exact vaccination history.
Abstract Patients with Legionnaires disease occasionally experience initial clinical improvement but radiological progression. However, data on this issue are so far limited. The aim of this study was to investigate changes in chest radiograph findings in patients with Legionnaires disease who showed initial clinical improvement and to identify risk factors and outcomes in these patients. All patients diagnosed with Legionnaires disease at a tertiary hospital in South Korea between March 2011 and May 2020 were retrospectively enrolled. Legionnaires disease was defined as abnormal chest radiographs accompanied by a positive finding on at least one of the following tests: urinary antigen test, sputum Legionella polymerase chain reaction, and sputum Legionella culture. Clinical improvement was defined as defervescence and decreased C-reactive protein level. Clinical and radiological records were reviewed on treatment days 7 and 14 and at discharge. We describe the characteristics of patients with clinical improvement but radiological deterioration on treatment for Legionnaires disease and compared them with patients with initial clinical improvement and stable or resolving chest radiograph findings. Of 140 patients with Legionnaires disease, 33 (24%) showed initial clinical deterioration, while the remaining 107 (76%) showed initial clinical improvement on day 7. The latter 107 patients were analyzed in this study; 22 (21%) showed radiological progression despite the clinical improvement. Risk factors for these patients were a high pneumonia severity index score and the use of mechanical ventilation. Mortality did not significantly differ between those with initial clinical improvement but radiological deterioration and those with both initial clinical and radiological improvement (28% vs 12%, P = .49). About one-fifth of patients with Legionnaires disease, especially those who had a high pneumonia severity index score and underwent mechanical ventilation, showed radiological deterioration despite of clinical improvement 1 week after appropriate treatment, while outcomes were not significantly worse in these patients. Therefore, our findings support that close monitoring without modification of antibiotics use is warranted in those who have clinical improvement regardless of radiologic findings.
Abstract Background Carbapenem-resistant Enterobacteriaceae (CRE) infection is an emerging clinical issue. One of the mechanisms of carbapenem-resistance is carbapenemase production. This study aimed to identify whether clinical outcomes differ by CRE resistance mechanism and to evaluate risk factors for mortality in patients with CRE bacteremia. Methods We conducted a retrospective cohort study comparing 14-day mortality between patients with carbapenemase-producing (CP)-CRE and non-CP-CRE bacteremia during January 2011 to October 2018. Only monomicrobial Escherichia coli or Klebsiella pneumoniae bacteremia were included in the study. A modified carbapenem inactivation method was used for phenotypic detection of carbapenemase production. The presence of a variety of carbapenemase genes was evaluated by PCR with specific primers. Results Of 134 patients with monomicrobial CRE bacteremia, 48 (35.8%) were infected with CP-CRE, and 86 (64.1%) were infected with non-CP-CRE. The most common carbapenemase in CP-CRE isolates was KPC (66.7%), followed by NDM-1 (18.8%), OXA-48-like (10.4%), and VIM (4.1%). Baseline characteristics were similar between the two groups (Table 1). However, the CP-CRE group was significantly more likely to undergo removal of eradicable foci and to have meropenem MIC >8 µg/mL. A total of 33 (24.6%) patients died within 14 days, including 9 (18.8%) in the CP-CRE group and 24 (27.9%) in the non-CP-CRE group. Deceased patients were more likely to have a higher Pitt bacteremia score, nosocomial acquisition, ineradicable or not-eradicated foci, immunosuppressant use, inappropriate definitive treatment (Table 2). Combination therapy for definitive treatment was associated with decreased mortality. In a multivariate analysis including carbapenemase production, a higher Pitt bacteremia score (aOR, 5.15), ineradicable or not-eradicated foci (aOR, 4.05) and combination therapy for definitive treatment (aOR, 0.35) were independent risk factors for mortality. Conclusion Our study suggests that carbapenemase production is not a mortality risk factor in CRE bacteremia and provides additional evidence for early source control and combination therapy. Disclosures All authors: No reported disclosures.
This study aimed to evaluate whether fluvoxamine reduces clinical deterioration in adult patients with mild to moderate coronavirus disease 2019 (COVID-19), and to identify risk factors for clinical deterioration in patients admitted to a community treatment center (CTC).A randomized, placebo-controlled trial was conducted in a CTC, in Seoul, Korea from January 15, 2021, to February 19, 2021. Symptomatic adult patients with positive results of severe acute respiratory syndrome coronavirus 2 real time-polymerase chain reaction within 3 days of randomization were assigned at random to receive 100 mg of fluvoxamine or placebo twice daily for 10 days. The primary outcome was clinical deterioration defined by any of the following criteria: oxygen requirement to keep oxygen saturation over 94.0%, aggravation of pneumonia with dyspnea, or World Health Organization clinical progression scale 4 or greater.Of 52 randomized participants [median (interquartile range) age, 53.5 (43.3 - 60.0) years; 31 (60.0%) men], 44 (85.0%) completed the trial. Clinical deterioration occurred in 2 of 26 patients in each group (P >0.99). There were no serious adverse events in either group. Clinical deterioration occurred in 15 (6.0%) of 271 patients admitted to the CTC, and all of them were transferred to a hospital. In multivariate analysis, age between 55 and 64, fever and pneumonia at admission were independent risk factors for clinical deterioration.In this study of adult patients with symptomatic COVID-19 who were admitted to the CTC, there was no significant differences in clinical deterioration between patients treated with fluvoxamine and placebo (ClinicalTrials.gov Identifier: NCT04711863).
Concern about resistance to chlorhexidine has increased due to the wide use of the latter. The impact of the qacA/B and smr chlorhexidine tolerance genes on the outcome of methicillin-resistant Staphylococcus aureus (MRSA) infections is unclear. We evaluated the prevalence and clinical impact of, and microbiological risk factors for, qacA/B tolerance in MRSA bacteremia. MRSA bacteremia that occurred more than two days after intensive care unit admission between January 2009 and December 2018 was identified from a prospective cohort of S. aureus bacteremia in a tertiary-care hospital from South Korea. A total of 183 MRSA blood isolates was identified, and the major genotype found was ST5-MRSA-II (87.4%). The prevalences of qacA/B and smr were 67.2% and 3.8%, respectively. qacA/B-positive isolates were predominantly ST5-MRSA-II (96.7% [119/123]), the dominant hospital clone. In a homogenous ST5-MRSA-II background, qacA/B positivity was independently associated with septic shock (aOR, 4.85), gentamicin resistance (aOR, 74.43), and non-t002 spa type (aOR, 74.12). qacA/B positivity was found to have decreased significantly in ST5-MRSA-II in association with a decline in qacA/B-positive t2460, despite the increasing use of chlorhexidine since 2010 (P < 0.001 for trend). Continuous surveillance of the qac genes, and molecular characterization of their plasmids, are needed to understand their role in MRSA epidemiology.
Abstract Background Staphylococcus aureus can cause various types of infection, but involvement of biliary tract is rare. There were only few case reports and no clinical studies. We assessed the clinical characteristics and outcomes of S. aureus bacteremia from a biliary source (biliary SAB) in a large cohort of SAB patients and compared the cases with those of catheter-related SAB. Methods We performed a matched case–control study within a prospective observational cohort of patients with SAB at a 2,700-bed tertiary hospital. All adult patients with SAB were observed for 12 weeks from July 2008 to July 2018. Biliary SAB was defined as the case of S.aureus isolated from blood culture with appropriate clinical biliary infection symptoms (fever, abdominal pain, or jaundice) and signs (abdominal tenderness or liver enzyme elevation with obstructive pattern). Biliary SAB cases were matched 1:3 to control patients with catheter-related SAB based on age, gender, ward, and case year. Results A total of 1,818 patients with SAB were enrolled in the entire cohort, and 42 (2%) were biliary SAB. Among patients with biliary SAB, 32 (76%) had solid tumor involving pancreaticobiliary tract or liver, 30 (71%) had biliary drainage stent, 14 (33%) were biliary procedure-related infection, and 24 (57%) had recent broad-spectrum antibiotics exposure (Table 1). When biliary SAB patients were compared with 126 patients with catheter-related SAB, they were significantly more likely to have community-onset SAB, solid tumor, and lower APACHE II score; and less likely to have metastatic infection (P = 0.03) (Table 2). Biliary SAB, solid tumor, and a high Charlson comorbidity index were associated with 12-week mortality. In multivariate analysis, biliary SAB (aOR, 5.5; 95% CI, 2.47–12.25) and a high Charlson comorbidity index (aOR, 1.32; 95% CI, 1.12–1.54) were independent risk factors for 12-week mortality. Conclusion Biliary SAB was relatively rare and developed mainly in pancreaticobiliary cancer patients and in recent broad-spectrum antibiotic users. High mortality was probably attributable to underlying cancers. When biliary tract infection caused by S. aureus is clinically suspected, early aggressive treatment for SAB should be considered. Disclosures All authors: No reported disclosures.