Suppression of Type I Interferon Signaling in Myeloid Cells by Autoantibodies in Severe COVID-19 Patients

PURPOSE

Auto-antibodies (auto-abs) to type I interferons (IFNs) have been identified in patients with life-threatening coronavirus disease 2019 (COVID-19), suggesting that the presence of auto-abs may be a risk factor for disease severity. We therefore investigated the mechanism underlying COVID-19 exacerbation induced by auto-abs to type I IFNs.

METHODS

We evaluated plasma from 123 patients with COVID-19 to measure auto-abs to type I IFNs. We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells from the patients with auto-abs and conducted epitope mapping of the auto-abs.

RESULTS

Three of 19 severe and 4 of 42 critical COVID-19 patients had neutralizing auto-abs to type I IFNs. Patients with auto-abs to type I IFNs showed no characteristic clinical features. scRNA-seq from 38 patients with COVID-19 revealed that IFN signaling in conventional dendritic cells and canonical monocytes was attenuated, and SARS-CoV-2-specific BCR repertoires were decreased in patients with auto-abs. Furthermore, auto-abs to IFN-α2 from COVID-19 patients with auto-abs recognized characteristic epitopes of IFN-α2, which binds to the receptor.

CONCLUSION

Auto-abs to type I IFN found in COVID-19 patients inhibited IFN signaling in dendritic cells and monocytes by blocking the binding of type I IFN to its receptor. The failure to properly induce production of an antibody to SARS-CoV-2 may be a causative factor of COVID-19 severity.

Validation of claims-based algorithms for rheumatoid arthritis in Japan: Results from the VALIDATE-J study

AIM

Validity of Algorithms in Large Databases: Infectious Diseases, Rheumatoid Arthritis, and Tumor Evaluation in Japan (VALIDATE-J) study examined algorithms for identifying rheumatoid arthritis (RA) in Japanese claims data.

METHODS

VALIDATE-J was a multicenter, cross-sectional retrospective study. Disease-identifying algorithms were used to detect RA diagnosed between January 2012 and December 2016 using claims data from two Japanese hospitals. An RA diagnosis was confirmed using one of four gold standard definitions. Positive predictive values (PPVs) were calculated for prevalent (regardless of baseline RA-free period) and incident (preceded by a 12-month RA-free period) cases.

RESULTS

Of patients identified using claims-based algorithms, a random sample of 389 prevalent and 134 incident cases of RA were included. Cases identified by an RA diagnosis, no diagnosis of psoriasis, and treatment with any disease-modifying antirheumatic drugs (DMARDs) resulted in the highest PPVs versus other claims-based treatment categories (29.0%-88.3% [prevalent] and 41.0%-78.2% [incident]); cases identified by an RA diagnosis, no diagnosis of psoriasis, and glucocorticoid-only treatment had the lowest PPVs. Across claims-based algorithms, PPVs were highest when a physician diagnosis or decision by adjudicators (confirmed and probable cases) was used as the gold standard and were lowest when American College of Rheumatology/European Alliance of Associations for Rheumatology 2010 criteria were applied. PPVs of claims-based algorithms for RA in patients aged ≥66 years were slightly higher versus a USA Medicare population (maximum PPVs of 95.0% and 88.9%, respectively).

CONCLUSION

VALIDATE-J demonstrated high PPVs for most claims-based algorithms for diagnosis of prevalent and incident RA using Japanese claims data. These findings will help inform appropriate RA definitions for future claims database research in Japan.

Epidemiological trends of traveler's diarrhea in Japan: An analysis of imported infectious disease registry data from 2017-2022

Traveler's diarrhea (TD) is a global problem, and identifying the causative organisms of TD is important for adequate treatment. Therefore, this study retrospectively analyzed TD cases in patients who returned to Japan after traveling abroad to determine the causative organisms by travel region. We included patients with a final diagnosis of TD registered in the Japan Registry for Infectious Diseases from Abroad database from September 25, 2017, to September 1, 2022, from 14 medical institutions. A total of 919 patients were analyzed; the causative TD pathogen was identified in 188 cases (20%), of which 154 were caused by diarrheagenic bacteria, the most common being Campylobacter spp. (64%). A 2.2 mg/dL C-reactive protein concentration cutoff value had some predictive ability for bacterial TD (negative predictive value, 89%). Therefore, the C-reactive protein level may help rule out bacterial diarrhea and prevent unnecessary antimicrobial administration when patients cannot provide a stool specimen.

Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection

Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics.

Effectiveness of cefmetazole versus meropenem for invasive urinary tract infections caused by extended-spectrum β-lactamase-producing Escherichia coli

Cefmetazole is active against extended-spectrum β-lactamase-producing Escherichia coli (ESBLEC) and is a potential candidate for carbapenem-sparing therapy. This multicenter, observational study included patients hospitalized for invasive urinary tract infection due to ESBLEC between March 2020 and November 2021 at 10 facilities in Japan, for whom either cefmetazole or meropenem was initiated as a definitive therapy within 96 h of culture collection and continued for at least 3 d. Outcomes included clinical and microbiological effectiveness, recurrence within 28 d, and all-cause mortality (14 d, 30 d, in-hospital). Outcomes were adjusted for the inverse probability of propensity scores for receiving cefmetazole or meropenem. Eighty-one and forty-six patients were included in the cefmetazole and meropenem groups, respectively. Bacteremia accounted for 43% of the cefmetazole group, and 59% of the meropenem group. The crude clinical effectiveness, 14 d, 30 d, and in-hospital mortality for patients in the cefmetazole and meropenem groups were 96.1% vs 90.9%, 0% vs 2.3%, 0% vs 12.5%, and 2.6% vs 13.3%, respectively. After propensity score adjustment, clinical effectiveness, the risk of in-hospital mortality, and the risk of recurrence were similar between the two groups (P = 0.54, P = 0.10, and P = 0.79, respectively). In all cases with available data (cefmetazole : n = 61, meropenem : n = 22), both drugs were microbiologically effective. In all isolates, bla CTX-M was detected as the extended-spectrum β-lactamase gene. The predominant CTX-M subtype was CTX-M-27 (47.6%). Cefmetazole showed clinical and bacteriological effectiveness comparable to meropenem against invasive urinary tract infection due to ESBLECs.

Validity of claims-based diagnoses for infectious diseases common among immunocompromised patients in Japan

BACKGROUND

To validate Japanese claims-based disease-identifying algorithms for herpes zoster (HZ), Mycobacterium tuberculosis (MTB), nontuberculous mycobacteria infections (NTM), and Pneumocystis jirovecii pneumonia (PJP).

METHODS

VALIDATE-J, a multicenter, cross-sectional, retrospective study, reviewed the administrative claims data and medical records from two Japanese hospitals. Claims-based algorithms were developed by experts to identify HZ, MTB, NTM, and PJP cases among patients treated 2012-2016. Diagnosis was confirmed with three gold standard definitions; positive predictive values (PPVs) were calculated for prevalent (regardless of baseline disease-free period) and incident (preceded by a 12-month disease-free period for the target conditions) cases.

RESULTS

Of patients identified using claims-based algorithms, a random sample of 377 cases was included: HZ (n = 95 [55 incident cases]); MTB (n = 100 [58]); NTM (n = 82 [50]); and PJP (n = 100 [84]). PPVs ranged from 67.4-70.5% (HZ), 67.0-90.0% (MTB), 18.3-63.4% (NTM), and 20.0-45.0% (PJP) for prevalent cases, and 69.1-70.9% (HZ), 58.6-87.9% (MTB), 10.0-56.0% (NTM), and 22.6-51.2% (PJP) for incident cases, across definitions. Adding treatment to the algorithms increased PPVs for HZ, with a small increase observed for prevalent cases of NTM.

CONCLUSIONS

VALIDATE-J demonstrated moderate to high PPVs for disease-identifying algorithms for HZ and MTB using Japanese claims data.

A pitfall of cognitive bias during the pandemic: Two cases of Plasmodium falciparum malaria coinfected or misdiagnosed with COVID-19

We report two the cases of patients with imported Plasmodium falciparum malaria during the COVID-19 pandemic. One was coinfected with COVID-19 and the other was misdiagnosed with COVID-19; either way, the diagnosis of malaria was delayed. These cases suggest that physicians should beware of cognitive biases during pandemics and carefully evaluate febrile patients. Malaria should be considered in any febrile patient returning from a malaria-endemic area.

Evaluation of potential rabies exposure among Japanese international travelers: A retrospective descriptive study

BACKGROUND

Although Japan has been a rabies-free country for >50 years, a few cases have been reported among people traveling abroad. This study aimed to investigate animal exposure among Japanese travelers using the Japanese Registry for Infectious Diseases from Abroad (J-RIDA).

METHOD

In this retrospective analysis, we examined Japanese overseas travelers with animal exposure, as included the J-RIDA database, reported from October 1, 2017, to October 31, 2019, with a focus on pre-exposure prophylaxis (PrEP) administration and the animals to which the patients were exposed.

RESULTS

Among the 322 cases included in the analysis, 19 (5.9%) patients received PrEP and 303 did not. The most common purpose of travel was a non-package tour (n = 175, 54.3%). Most trips (n = 213, 66.1%) were to a single country for <2 weeks. Most patients (n = 286, 87.9%) traveled to countries with a rabies risk. The majority of patients with and without PrEP were injured in rabies-risk countries [n = 270 (89.1%) for non-PrEP and n = 16 (84.2%) for PrEP]. Animals associated with injuries included dogs (55.0%), cats (25.5%), and monkeys (15.5%). Most patients were classified as World Health Organization Category II/III for contact with suspected rabid animals (39.5% and 44.1% for categories II and III, respectively) and had exposure within 5 days of travel. Southeast Asia (n = 180, 55.9%) was the most common region in which travelers were exposed to animals.

CONCLUSIONS

Japanese overseas travelers had contact with animals that could possibly transmit the rabies virus, even on short trips. Promoting pre-travel consultation and increasing awareness of the potential for rabies exposure are important for prevention of rabies among Japanese international travelers.

Enterobiasis in the hospitalized patient

A 33-year-old hospitalized patient felt itching around his anus. Tiny white thread-like worms were observed around his perinatal region. Microscopic examination revealed the presence of elongated, one-sided, flattened eggs inside the worm.

Efficacy of convalescent plasma therapy for COVID-19 in Japan: An open-label, randomized, controlled trial

BACKGROUND

Convalescent plasma is a potential therapeutic option for patients with coronavirus disease 2019 (COVID-19). Despite its use for treating several viral infections, we lack comprehensive data on its efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

METHODS

We conducted a multicenter, open-label, randomized controlled trial of convalescent plasma therapy with high neutralizing activity against SARS-CoV-2 in high-risk patients within five days after the onset of COVID-19 symptoms. The primary endpoint was the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs from days 0-5.

RESULTS

Between February 24, 2021, and November 30, 2021, 25 patients were randomly assigned to either convalescent plasma (n = 14) or standard of care (n = 11) groups. Four patients discontinued their allocated convalescent plasma, and 21 were included in the modified intention-to-treat analysis. The median interval between the symptom onset and plasma administration was 4.5 days (interquartile range, 3-5 days). The primary outcome of the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs did not significantly differ between days 0-5 (1.2 log₁₀ copies/mL in the convalescent plasma vs. 1.2 log₁₀ copies/mL in the standard of care (effect estimate, 0.0 [95% confidence interval, -0.8-0.7]; P = 0.94)). No deaths were observed in either group.

CONCLUSIONS

The early administration of convalescent plasma with high neutralizing activity did not contribute to a decrease in the viral load within five days compared with the standard of care alone.

Evaluation of the seroprevalence of measles, rubella, mumps, and varicella and the requirement for additional vaccination based on the JSIPC guidelines among emergency medical technicians at eight fire stations in Narita, Japan: a project review

Limited data are available regarding the seroprevalence of measles, mumps, rubella, and varicella (MMRV) among emergency medical technicians (EMTs) in Japan. The present study aimed to review a project to evaluate adequate immunity against MMRV for the requirement of additional vaccination among EMTs in accordance with the Japanese Society for Infection Prevention and Control guidelines. A retrospective observational study was conducted as part of a vaccination program for EMTs. Each participant was evaluated for medical history, vaccination history, and serology using the criteria established by the Japanese Society of Infection Prevention and Control. In total, 85 EMTs (median age, 31 years; male, 92.9%) were included. Among the included EMTs, 32 (37.6%), 54 (63.5%), 46 (54.1%), and 84 (98.9%) were seropositive for measles, rubella, mumps, and varicella, respectively, whereas 1 (1.2%), 6 (7.1%), 5 (5.9%), and 0 (0%) were seronegative. Furthermore, 48 (56.5%), 27 (31.8%), 45 (52.9%), and 8 (9.4%) EMTs received an additional dose of vaccines for measles, rubella, mumps, and varicella, respectively. The present study suggests that EMTs are not fully immune to MMRV, which highlights the need for confirming the immune status and additional vaccination requirement to prevent occupational infections.

658. Evaluation of Effectiveness of Cefmetazole vs Meropenem for Invasive Urinary Tract Infections Caused by ESBL-Producing Escherichia coli: A Prospective Multicenter Observational Study

Background

ESBL-producing E. coli (ESBLEC) continues to increase worldwide. For the infection due to ESBLEC, no antimicrobial agent has clearly demonstrated therapeutic effectiveness comparable to that of carbapenem. Overuse of carbapenems may lead to an increase in carbapenem-resistant bacteria. Cefmetazole (CMZ) is active against ESBLEC, however, there are limited multicenter studies on the effectiveness of CMZ, an important carbapenem-sparing therapy for the treatment of ESBLEC.

Methods

This prospective, observational study included patients hospitalized for invasive urinary tract infection (iUTI) due to ESBLEC between March 2020 and November 2021 at 10 centers in Japan, with either CMZ or meropenem (MEM) initiated within 96 hours of culture submission as definitive therapy, and used for at least 4 days. The diagnosis of iUTI was made in patients with a fever of ≥37.5°C, symptom of pyelonephritis such as back pain, pyuria, and ESBLEC detected in urine (≥10^4 CFU/mL). Outcomes included clinical effectiveness (resolution of all clinical symptoms or improvement to pre-infection status) between day 4 to 6 of treatment (early) and between the final day of treatment and 2 days later (late), microbiological effectiveness (reduction to ≤10^3 CFU/ml) between day 4 to 6, and mortality. Outcomes were adjusted for the inverse probability of propensity scores (PS) for receiving CMZ or MEM treatment.

Results

Seventy-seven patients in the CMZ group and 46 in the MEM group were included. In univariate analysis, the CMZ group was older than the MEM group, although the MEM group had higher qSOFA, CRP, more frequent medical device use and concurrent bacteremia at the start of study drugs than the CMZ group (Table). Univariate analysis showed no difference in clinical effectiveness, and 30-day mortality was higher in the MEM group. In all cases with available data (CMZ: n=57, MEM: n=22), both drugs were microbiologically effective. After PS adjustment, clinical effectiveness did not differ between the two groups. The risk of 30-day mortality was lower in CMZ group, whereas the risk of recurrence was similar in both groups.

Conclusion

CMZ is as effective as MEM for the treatment of iUTI, suggesting that it is a promising carbapenem-sparing therapy.

Disclosures

Sho Saito, MD, PhD, DAIICHI SANKYO: Grant/Research Support|EVEC: Grant/Research Support|EVEC: Patents obtained through collaborative research|SHIONOGI: Grant/Research Support|Takeda: Advisor/Consultant.

A review of four cases of COVID-19 medically evacuated by ambulance jet from Asian countries to Japan: Importance of strict infection control measures against multidrug-resistant organisms

International medical evacuation, which is an option to receive better medical care for travelers with emergencies staying in low- and middle-income countries, has been more challenging during the coronavirus disease 2019 (COVID-19) pandemic. We herein discuss our experience with four Japanese patients with COVID-19 who required medical evacuation from Asian countries during the pandemic. Of these, none of the patients had received a COVID-19 vaccine; three patients needed oxygen therapy on admission to our hospital; and one patient died due to respiratory failure on day 50 after hospitalization. It was observed that multidrug-resistant organisms were colonized in two patients after obtaining culture results based on active surveillance. Strict infection control measures against multidrug-resistant organisms should be implemented during the care of patients with COVID-19 who require medical evacuation from high-risk countries. Further, it is important to communicate timely updates regarding the patient's condition with travel assistance agencies as the patient's condition may rapidly change during the course of arranging the evacuation.

Catheter-related bloodstream Mycobacterium wolinskyi infection in an umbilical cord blood transplant recipient: a case report

Background

Catheter-related bloodstream infection (CRBSI), caused by rapidly growing mycobacteria (RGM), is a rare infectious complication in hematopoietic stem cell transplant (HSCT) recipients and can often be misdiagnosed as Gram-positive rod (GPR) bacteremia.

Case presentation

We present a case of CRBSI caused by Mycobacterium wolinskyi, a rare RGM, in a 44-year-old female patient who received an umbilical cord blood transplant.

Conclusions

Rapidly growing mycobacteria can stain as GPRs and may grow in routine blood culture media after 3–4 days of incubation. These features are not widely known to clinicians, and acid-fast staining is therefore recommended when unidentifiable GPRs are detected in blood cultures, especially in immunocompromised patients, such as those with hematologic malignancies or intravascular devices.

Newly developed artificial intelligence algorithm for COVID-19 pneumonia: utility of quantitative CT texture analysis for prediction of favipiravir treatment effect

Purpose

Using CT findings from a prospective, randomized, open-label multicenter trial of favipiravir treatment of COVID-19 patients, the purpose of this study was to compare the utility of machine learning (ML)-based algorithm with that of CT-determined disease severity score and time from disease onset to CT (i.e., time until CT) in this setting.

Materials and methods

From March to May 2020, 32 COVID-19 patients underwent initial chest CT before enrollment were evaluated in this study. Eighteen patients were randomized to start favipiravir on day 1 (early treatment group), and 14 patients on day 6 of study participation (late treatment group). In this study, percentages of ground-glass opacity (GGO), reticulation, consolidation, emphysema, honeycomb, and nodular lesion volumes were calculated as quantitative indexes by means of the software, while CT-determined disease severity was also visually scored. Next, univariate and stepwise regression analyses were performed to determine relationships between quantitative indexes and time until CT. Moreover, patient outcomes determined as viral clearance in the first 6 days and duration of fever were compared for those who started therapy within 4, 5, or 6 days as time until CT and those who started later by means of the Kaplan–Meier method followed by Wilcoxon’s signed-rank test.

Results

% GGO and % consolidation showed significant correlations with time until CT (p < 0.05), and stepwise regression analyses identified both indexes as significant descriptors for time until CT (p < 0.05). When divided all patients between time until CT of 4 days and that of more than 4 days, accuracy of the combined quantitative method (87.5%) was significantly higher than that of the CT disease severity score (62.5%, p = 0.008).

Conclusion

ML-based CT texture analysis is equally or more useful for predicting time until CT for favipiravir treatment on COVID-19 patients than CT disease severity score.

785. Distribution and Associated Mortality in Carbapenem-Resistant Gram-Negative Bacilli in Japan: A Multicenter Study From Multi-Drug Resistant Organisms Clinical Research Network (MDRnet)

Background

Carbapenem-resistant gram-negative bacilli (CRGNB) are increasingly reported around the world as a cause of serious infections. However, the epidemiology and clinical course of patients with CRGNB in Japan is not well understood.

Methods

We prospectively collected CR cases from 4/2019 to 9/2020 in Multi-Drug Resistant organisms clinical research network (MDRnet) consisting of 5 tertiary care facilities in Japan. We looked for all CRGNB, and all unique patients with CR Enterobacterales, CR nonfermenting gram-negative bacilli (NFGNB) and CR Aeromonas sp. isolation were included. Carbapenem resistance was tested by agar dilution method and defined based on the CLSI criteria for each species. Infections were determined by NHSN protocols.

Results

In total, 156 patients (30 Enterobacterales, 119 NFGNB, 7 Aeromonas spp.) were included (11 Enterobacter spp., 11 Klebsiella spp., 86 Pseudomonas aeruginosa, 29 Stenotrophomonas maltophilia, 7 Aeromonas spp.). Acinetobacter sp. was not detected. Isolation sites were sputum (n = 12) and urine (n = 7) in Enterobacterales, sputum (n = 62) and blood (n = 18) in NFGNB, and blood (n = 6) in Aeromonas spp. The median age and male ratio of the patients were 68 years [IQR: 53-74] and 19 (63.3%) in Enterobacterales, 72 years [IQR: 60-79] and 70 (58.8%) in NFGNB and 78 years [IQR: 54-83] and 2 (28.6%) in Aeromonas spp. Ten (33.3%) patients with Enterobacterales, 55 (46.2%) patients with NFGNB, and 6 (85.7%) patients with Aeromonas spp. were infected cases. The others were considered as colonized. There were no patients with ICU stay or intubation in Enterobacterales, while 5 (4.2%) and 4 (3.4%) patients were in ICU and intubated in NFGNB, and 2 patients were in ICU and intubated in Aeromonas spp., respectively. All-cause 30-day mortality rates were 10% in Enterobacterales, 16.8 % in NFGNB and 28.6% in Aeromonas spp. In the infected patients, 3 patients (30%) with Enterobacterales, 12 patients (21.8%) with NFGNB and 1 patient (16.7%) with Aeromonas spp. died within 30 days after isolation.

Flow diagram outlining the characteristics of the patients and species in this study.

Kaplan-Meier survival curves of patients with carbapenem resistant Enterobacterales

Kaplan-Meier survival curves of patients with carbapenem resistant nonfermenting gram-negative bacilli

Conclusion

Mortality rates were high in infected cases of CR Enterobacterales, CR NFGNB and CR Aeromonas spp. Carbapenem-resistant Acinetobacter spp. was not detected, which differed from the CR epidemiology in Europe, the United States, and other Asian countries.

Disclosures

Sho Saito, n/a, Shionogi (Grant/Research Support) David van Duin, MD, PhD, Entasis (Advisor or Review Panel member)genentech (Advisor or Review Panel member)Karius (Advisor or Review Panel member)Merck (Grant/Research Support, Advisor or Review Panel member)Pfizer (Consultant, Advisor or Review Panel member)Qpex (Advisor or Review Panel member)Shionogi (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)Utility (Advisor or Review Panel member) Yohei Doi, MD, PhD, AstraZeneca (Speaker's Bureau)bioMerieux (Consultant)FujiFilm (Advisor or Review Panel member, Speaker's Bureau)Gilead (Consultant)GSK (Consultant)Meiji (Consultant)MSD (Consultant)Shionogi (Consultant) Yohei Doi, MD, PhD, Astellas (Individual(s) Involved: Self): Grant/Research Support; AstraZeneca (Individual(s) Involved: Self): Speakers' bureau; bioMerieux (Individual(s) Involved: Self): Consultant, Speakers' bureau; Chugai (Individual(s) Involved: Self): Consultant; Entasis (Individual(s) Involved: Self): Consultant; FujiFilm (Individual(s) Involved: Self): Advisor or Review Panel member; Gilead (Individual(s) Involved: Self): Consultant; GSK (Individual(s) Involved: Self): Consultant; Kanto Chemical (Individual(s) Involved: Self): Grant/Research Support; MSD (Individual(s) Involved: Self): Speaking Fee; Pfizer (Individual(s) Involved: Self): Grant/Research Support; Shionogi (Individual(s) Involved: Self): Grant/Research Support, Speakers' bureau; Teijin Healthcare (Individual(s) Involved: Self): Speakers' bureau; VenatoRx (Individual(s) Involved: Self): Consultant

Potential for false-positive results with quantitative antigen tests for SARS-CoV-2: A case of a child with acute respiratory infection

The quantitative antigen test based on the chemiluminescent enzyme immunoassay for SARS-CoV-2 has been used in international airports for quarantine in Japan. While cases of false-positive rapid antigen tests for SARS-CoV-2 were reported, false-positive cases of the quantitative antigen test with clinical information are rare. Here, we report a case of acute respiratory infection whose quantitative antigen test for SARS-CoV-2 was suspected to be false positive. A 9-month-old boy who presented with fever and rhinorrhea was admitted to our hospital under the Quarantine Act. He was diagnosed with COVID-19 based on the quantitative antigen test for SARS-CoV-2 performed at the quarantine station. None of the accompanying family members were positive for COVID-19. Nucleic acid amplification tests (NAAT) for SARS-CoV-2 were all negative, and multiplex polymerase chain reaction detected human rhinovirus or enterovirus infection. This case suggests that the results of the quantitative antigen test should be interpreted together with clinical information, and NAAT should be performed when false-positive results are suspected to avoid unnecessary isolation.

The profile of patients hospitalized with COVID-19 under the Quarantine Act in a designated hospital near an international airport in Japan

The Japanese Government has implemented quarantine measures in response to the COVID-19 pandemic. Individuals testing positive at the airport's quarantine office were lodged either in a designated hotel or hospital under the Quarantine Act. The aim of this study is to describe the management of patients with COVID-19 admitted under the Quarantine Act and to evaluate its impact on medical resources. Data were retrospectively collected, including demographics, comorbidities, status at admission, clinical condition, treatment, outcomes, status at discharge, duration of hospitalization, and the cost of hospitalization for all patients hospitalized with COVID-19 at this facility under the Quarantine Act between January 2020 and April 2021. A total of 48 patients (39 males, 9 females; median age: 38.5 years) with COVID-19, half (52.1%) of which were Japanese, were hospitalized under the Quarantine Act. The majority (87.5%) of the patients lived or planned to stay outside of Chiba Prefecture. The most frequent time of admission was 9 PM-1 AM. Hypoxia on admission was observed in 10 (20.8%) patients and oxygen therapy was provided to 8 (16.7%). One patient died due to respiratory failure. The median duration of hospitalization was 11 days. The total cost of hospitalization was 82,705,289 yen (approximately $760,000), which was covered by public funds. Patients hospitalized with COVID-19 under the Quarantine Act were younger and less severely ill than inpatients with COVID-19 from among the general population in Japan (according to a COVID-19 registry), but consumed a significant amount of medical resources at this hospital. An efficient system to manage patients with COVID-19 in designated hotels should be created and indications for hospitalization should be determined.

Validity of claims-based algorithms for selected cancers in Japan: Results from the VALIDATE-J study

Purpose

Real‐world data from large administrative claims databases in Japan have recently become available, but limited evidence exists to support their validity. VALIDATE‐J validated claims‐based algorithms for selected cancers in Japan.

Methods

VALIDATE‐J was a multicenter, cross‐sectional, retrospective study. Disease‐identifying algorithms were used to identify cancers diagnosed between January or March 2012 and December 2016 using claims data from two hospitals in Japan. Positive predictive values (PPVs), specificity, and sensitivity were calculated for prevalent (regardless of baseline cancer‐free period) and incident (12‐month cancer‐free period; with claims and registry periods in the same month) cases, using hospital cancer registry data as gold standard.

Results

22 108 cancers were identified in the hospital claims databases. PPVs (number of registry cases) for prevalent/incident cases were: any malignancy 79.0% (25 934)/73.1% (18 119); colorectal 84.4% (3519)/65.6% (2340); gastric 87.4% (3534)/76.8% (2279); lung 88.1% (2066)/79.9% (1636); breast 86.4% (4959)/59.9% (3185); pancreatic 87.1% (582)/80.4% (508); melanoma 48.7% (46)/42.9% (36); and lymphoma 83.6% (1457)/77.8% (1035). Specificity ranged from 98.3% to 100% (prevalent)/99.5% to 100% (incident); sensitivity ranged from 39.1% to 67.6% (prevalent)/12.5% to 31.4% (incident). PPVs of claims‐based algorithms for several cancers in patients ≥66 years of age were slightly higher than those in a US Medicare population.

Conclusions

VALIDATE‐J demonstrated high specificity and modest‐to‐moderate sensitivity for claims‐based algorithms of most malignancies using Japanese claims data. Use of claims‐based algorithms will enable identification of patient populations from claims databases, while avoiding direct patient identification. Further research is needed to confirm the generalizability of our results and applicability to specific subgroups of patient populations.

Measles in a measles-eliminated country: A case report of a measles-infected postpartum mother and infant in Japan

Japan has maintained measles elimination status since 2015. However, sporadic outbreaks of measles have been continuously reported. Here, we report a case of a measles-infected postpartum mother and infant in Japan. A 28-year-old Japanese woman, who had previously received a dose of the measles vaccination, experienced fever 5 days postpartum. Subsequently, a maculopapular rash appeared, and she was diagnosed with measles. Moreover, her baby developed a fever and maculopapular rash on the 13th day of life, 2 days after postexposure prophylaxis with intravenous immunoglobulin, and was also diagnosed with measles. Both showed full recovery. This case suggests that measles can still be a threat in a measles-eliminated country, and the administration of two doses of measles vaccination to women prior to childbearing age is crucial to protect newborns from measles.

Epidemiological trends of imported infectious diseases in Japan: Analysis of imported 2-year infectious disease registry data

INTRODUCTION

The epidemiology of infectious diseases in Japan remains undefined despite the increasing tourism. GeoSentinel, an epidemiological surveillance system for reporting imported infectious diseases, has only two participating facilities in Japan. Although the number of infectious diseases is reported by the National Institute of Infectious Diseases, there is no detailed clinical information about these cases. Therefore, we established J-RIDA (Japan Registry for Infectious Diseases from Abroad) to clarify the status of imported infectious diseases in Japan and provide detailed information.

METHODS

J-RIDA was started as a registry of imported infectious diseases. Case registration began in October 2017. Between October 2017 and September 2019, 15 medical institutions participated in this clinical study. The registry collected information about the patient's age, sex, nationality, chief complaint, consultation date, date of onset, whether visit was made to a travel clinic before travel, blood test results (if samples were collected), travel history, and final diagnosis.

RESULTS

Of the 3046 cases included in this study, 46.7% to Southeast Asia, 13.0% to Africa, 13.7% to East Asia, 11.5% to South Asia, 7.5% to Europe, 3.8% to Central and South America, 4.6% to North America, 3.9% to Oceania, and 2.8% to Central and west Asia. More than 85% of chief complaints were fever and general symptoms, gastrointestinal symptoms, respiratory symptoms, or dermatologic problems. The most common diseases were travelers' diarrhea, animal bite, upper respiratory infection, influenza, and dengue fever.

CONCLUSIONS

We summarized two-year cases registered in Japan's imported infectious disease registry. These results will significantly contribute to the epidemiology in Japan.

A Favipiravir-induced Fever in a Patient with COVID-19

We herein report the first case of a fever induced by favipiravir, a potential coronavirus disease 2019 therapeutic drug. An 82-year-old man diagnosed with bilateral pneumonia was transferred to our hospital following a positive severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test. He was treated with compassionate use of favipiravir. Both his oxygen demand and fever gradually improved after admission; however, his fever relapsed, and the C-reactive protein (CRP) levels increased on day 7. We diagnosed his fever as being favipiravir-induced. The fever resolved a few days after favipiravir discontinuation, demonstrating the accuracy of the diagnosis. This case revealed that favipiravir can induce a fever.

Acute Gouty Arthritis During Favipiravir Treatment for Coronavirus Disease 2019

A 42-year-old man exhibiting hypoxia was diagnosed with coronavirus disease 2019. He had medical histories of type 2 diabetes, hyperlipidemia, hyperuricemia, and gout attack. He received favipiravir for compassionate use for 14 days. Subsequently, he showed increased uric acid levels and developed acute gouty arthritis. Favipiravir may induce not only hyperuricemia but also acute gouty arthritis. It should therefore be used with caution in patients with a history of gout and those with hyperuricemia, especially when used at a higher dose and for a longer duration than is typical.

A case of imported COVID-19 diagnosed by PCR-positive lower respiratory specimen but with PCR-negative throat swabs

A 35-year-old woman presented with fever and mild diarrhoea without any respiratory symptoms 9 days after travelling to Japan from Wuhan, China. Her computed tomography scan revealed pneumonia. The first polymerase chain reaction (PCR) test on throat swab for the novel corona virus upon admission was negative. Therefore, she was treated for community-acquired pneumonia, but fever persisted. On hospital day 5, PCR test on induced sputum was positive, but a second polymerase chain reaction test on throat swab remained negative. She was discharged, fully recovered, on hospital day 12. A lower respiratory tract specimen should be obtained for better diagnosis of corona virus disease 2019, even in the absence of respiratory symptoms for patients with significant travel or exposure history.

Review of the first comprehensive outpatient parenteral antimicrobial therapy program in a tertiary care hospital in Japan

OBJECTIVES

The infectious diseases team at Kameda Medical Center, Japan, implemented a new outpatient parenteral antimicrobial therapy (OPAT) program in July 2012 and expanded the program with the support of home care services. This study reviews the OPAT program after 5.5 years of operation.

METHODS

We prospectively collected data about the age, sex, diagnoses, causative organisms, types of OPAT, modes of administration, selected antibiotics, treatment durations, bed days saved, outcomes, readmissions, and estimated cost reductions of all patients who were treated in the OPAT program from July 2012 to December 2017.

RESULTS

Of the 66 patients treated under the OPAT program, 45 (68.2%) were treated using clinic OPAT, and 21 (31.8%) were treated using homecare OPAT. The most commonly targeted organism was methicillin-susceptible Staphylococcus aureus. Continuous infusion with elastomeric pumps was employed in 55 patients (83.3%). Cefazolin was the most frequently used antibiotic (39.4%), followed by penicillin G (24.2%). The median OPAT duration was 13 days (range, 3-51), and the total bed days saved was 923. The estimated medical cost reduction was approximately 87,000 US dollars.

CONCLUSIONS

Our experience shows that OPAT is a safe and feasible practice not only for efficient bed utilization and medical cost savings but also for better antimicrobial stewardship.

A case of maternal varicella: Expected role of primary care physicians in confirming immune status for varicella in women at childbearing age

At 19-week gestation, a 32-year-old Japanese woman presented with a 3-day history of fever and vesicular rashes on the skin and was diagnosed with varicella, which resolved after antiviral therapy. In the primary clinic, her immunity to rubella and measles, but not to varicella, was confirmed at preconception counseling. Maternal varicella infection can cause congenital varicella syndrome characterized by congenital malformations and neurological deficits. This case recommends that all women of childbearing age should be assessed for immunity to varicella before pregnancy and that primary care physicians should take initiatives for preventing maternal varicella.

Comparison between IMP carbapenemase-producing Enterobacteriaceae and non-carbapenemase-producing Enterobacteriaceae: a multicentre prospective study of the clinical and molecular epidemiology of carbapenem-resistant Enterobacteriaceae

BACKGROUND

Carbapenem-resistant Enterobacteriaceae (CRE) are classified as carbapenemase-producing Enterobacteriaceae (CPE) and non-CPE; the majority of CPE in Japan produce IMP carbapenemase.

OBJECTIVES

We evaluated the clinico-epidemiological and microbiological information and effects of IMP-type carbapenemase production in CRE.

METHODS

Patients with isolations of CRE (MICs of meropenem ≥2 mg/L, imipenem ≥2 mg/L or cefmetazole ≥64 mg/L) from August 2016 to March 2018 were included. Microbiological analyses and WGS were conducted and clinical parameters were compared between groups. Independent predictors for the isolation of CPE from patients were identified by logistic regression. For comparing clinical outcomes, a stabilized inverse probability weighting method was used to conduct propensity score-adjusted analysis.

RESULTS

Ninety isolates (27 CPE and 63 non-CPE) were collected from 88 patients (25 CPE and 63 non-CPE). All CPE tested positive for IMP carbapenemase. Antibiotic resistance (and the presence of resistance genes) was more frequent in the CPE group than in the non-CPE group. Independent predictors for CPE isolation were residence in a nursing home or long-term care facility, longer prior length of hospital stay (LOS), use of a urinary catheter and/or nasogastric tube, dependent functional status and exposure to carbapenem. Although in-hospital and 30 day mortality rates were similar between the two groups, LOS after CRE isolation was longer in the CPE group.

CONCLUSIONS

IMP-CPE were associated with prolonged hospital stays and had different clinical and microbiological characteristics compared with non-CPE. Tailored approaches are necessary for the investigational and public health reporting, and clinical and infection prevention perspectives for IMP-CPE and non-CPE.

Consideration concerning similarities and differences between ANCA-associated vasculitis and IgG-4-related diseases: case series and review of literature

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and immunoglobulin G4-related diseases (IgG4-RD) are regarded as entirely different disease types with different etiological mechanisms. However, we experienced two cases that had clinical features of both AAV and IgG4-RD. The first case is an 81-year-old woman who showed periaortitis and retroperitoneal fibrosis and periarteritis with elevation of myeloperoxidase-anti-neutrophil cytoplasmic antibody and IgG4 levels. The second case is a 63-year-old woman who had dura mater, ear, nose, lung, and kidney involvement with serum negative for ANCA and elevated IgG4. Renal biopsy revealed tubulointerstitial nephritis involving IgG4⁺ plasma cells (IgG4⁺/IgG⁺ cell ratio of ≥ 40%). On the other hand, lung biopsy showed features of granulomatosis with polyangiitis (GPA). These two cases suggested that AAV and IgG4-RD might overlap. To investigate the similarities and differences between AAV and IgG4-RD, we retrospectively analyzed 13 cases of typical GPA, a subtype of AAV, and 13 cases of typical IgG4-RD at our hospital for comparison of clinical features and found some differences that can be useful in the differential diagnosis between the two diseases. Although AAV and IgG4-RD are distinguishable based on characteristic findings in many cases, the diagnosis can be unclear in rare cases, in which clinicians should consider possible coexistence of AAV and IgG4-RD when performing further workup. Here, we discuss the similarities and differences between AAV and IgG4-RD on the basis of our results and past literature.

503. Comparison of IMP Carbapenemase-Producing Enterobacteriaceae (CPE) and Non-Carbapenemase-Producing Enterobacteriaceae: A Multicenter Prospective Study of Clinical and Molecular Epidemiology in Japan

Background

IMP CPE are the dominant CPE type in Japan. We aimed to compare its epidemiology to that of non-CPE (NCPE).

Methods

Patients with isolation of carbapenem-resistant Enterobacteriaceae (CRE) with meropenem MIC ≥2 mg/L or imipenem MIC ≥2 mg/L and cefmetazole MIC ≥64 mg/L were included from August 2016 to March 2018. Adjusted outcome analyses were conducted using a generalized estimating equation model with weighting based on the inverse probability of propensity scores (PS).

Results

Ninety isolates (27 CPE and 63 NCPE) were collected from 88 patients (53 male) in 7 hospitals. CPE included 10 E. cloacae (ENC), 6 K. pneumoniae (KP), 4 E. coli (EC), 3 C. freundii (CF), 2 K. oxytoca, and 1 each of E. aerogenes (EA) and S. marcescens (SM). NCPE included 34 EA, 15 ENC, 4 each of KP, SM, and 2 CF. All CPE were positive for IMP carbapenemase (11 IMP-11, 6 IMP-42, 4 IMP-6, and 3 each of IMP-10 and IMP-1). Most of CPE/NCPE were isolated from sputum (39%), intra-abdomen (21%), and urine (20%). Levofloxacin, gentamicin, and amikacin resistance were found in 6 (22%), 4 (15%), and 1 (4%) CPE, respectively, and 6 (10%), 6 (10%), and 0 NCPE, respectively. Eighteen (67%) blaIMP were transferable by conjugation. Cases of CPE involved older patients with more frequent use of devices and carbapenem exposure than those in cases of NCPE (table). The mortality was similar in the 2 groups. Length of hospital stay (LOS) after CPE/NCPE isolation was significantly higher in the CPE group after PS adjustment (P = 0.02).

Conclusion

CPE had distinct epidemiological characteristics, and CPE isolation was associated with a prolonged hospital stay. Defining the underlying resistance mechanism of CRE is important for appropriate management.

Disclosures

All authors: No reported disclosures.

Catheter-related bloodstream infection by Microbacterium paraoxydans in a pediatric patient with B-cell precursor acute lymphocytic leukemia: A case report and review of literature on Microbacterium bacteremia

Microbacterium species are coryneform gram-positive rods that are widely distributed in the environment and have been recently recognized as rare pathogens in humans. However, information about the epidemiologic and clinical characteristics of Microbacterium species is scarce. We herein reported an 11-year-old girl with acute leukemia who was found to have catheter-related bloodstream infection in her neutropenic phase. Gram-positive bacilli repeatedly grew on the blood cultures and were later confirmed by 16S rRNA analysis as Microbacterium paraoxydans. A literature review found available clinical courses in 21 cases (7 pediatric cases) of Microbacterium spp. bacteremia. Our case and those in literature suggested that Microbacterium spp. bacteremia often occurs in patients with indwelling central venous catheters; the literature review further suggested that removal of central venous catheters is required in most cases and that 16S rRNA sequence was useful in identifying in detail the species of Microbacterium.

Disseminated toxoplasmosis with atypical symptoms which developed with exacerbation of systemic lupus erythematosus

Toxoplasma is a common parasite worldwide that mainly affects the brain, lungs and eyes. Although toxoplasmic encephalitis is a lethal disease without treatment, past case reports show most patients with systemic lupus erythematosus who developed toxoplasmic encephalitis were misdiagnosed and treated as neuropsychiatric systemic lupus erythematosus, which led to unfavorable outcomes. We herein describe a case of disseminated toxoplasmosis affecting all the above organs with atypical symptoms, which developed with exacerbation of systemic lupus erythematosus. She had initially manifested with retinochoroiditis without vitritis, mild cognitive impairment and an isolated lung mass. These are completely different from the classic symptoms of toxoplasmosis that have been reported in patients with HIV infection and/or those after hematopoietic transplantation. Our case, together with previously reported cases, suggests the manifestation of toxoplasmosis that develops in systemic lupus erythematosus patients can be different from that seen in conventional cases and varies between individual patients. Our case highlights both the difficulty in and the importance of diagnosing toxoplasmosis in patients with systemic lupus erythematosus and provides helpful information to identify this rare, devastating, yet treatable disease.

1178. A Multicenter Prospective Study of Clinical and Molecular Epidemiological Analysis of Carbapenem-Resistant Enterobacteriaceae (CRE) and Carbapenemase-Producing Enterobacteriaceae (CPE) in Japan

Background

Data of a multicenter study on CRE from Japan are limited. Comparative analyses of carbapenemase-producing Enterobacteriaceae (CPE) and non-carbapenemase-producing CRE (NCP-CRE) have not yet been conducted.

Methods

Cases with CPE or CRE (defined as (1) meropenem [MPM] MIC, ≥2 mg/L or (2) imipenem [IPM] MIC, ≥2 mg/L and cefmetazole MIC, ≥64 mg/L [CLSI criteria]) were included from August 2016 to May 2017. PCR was used to detect carbapenemase.

Results

From five tertiary hospitals, 24 isolates (14 CPE and 10 NCP-CRE) were collected from 22 patients. Of the 10 NCP-CRE, seven were Enterobacter aerogenes and three were Enterobacter cloacae; of the 14 CPE, five were Klebsiella pneumoniae; 3, E. cloacae; 3, E. coli; 2, Citrobacter freundii; and 1, E. aerogenes. CPE were frequently isolated from the urine (5 [42%]) and sputum (3 [25%]) and NCP-CRE from sputum (4 [40%]), bile (3 [30%]), and urine (2 [20%]). Cases with CPE were older with more frequent use of urinary catheter and/or NG tube than NCP-CRE (table). The 30-day mortality or length of hospital stay (LOS) did not differ between the two groups. Majority (n = 12) of CPE were identified to carry bla_IMP (MPM MIC, ≥2 mg/L), and two CPE were positive for bla_OXA-181 and bla_OXA-232 (MPM MIC, ≤1 mg/L). All NCP-CRE had IPM MIC of ≥2 mg/L; 7 (70%) had MPM of ≤1 mg/L. Resistance to amikacin (AMK) and levofloxacin (LFX) was noted in one and five CPE, respectively, whereas all NCP-CRE were sensitive, and nine bla_IMP and 1 bla_oxa-232 were transferable by conjugation.

Conclusion

CPE and NCP-CRE had different clinical characteristics. Non-β-lactam treatment options were more available for NCP-CRE than CPE. CPE and NCP-CRE might require different control strategies.

Disclosures

All authors: No reported disclosures.

1045. A Multicenter Propensity Score-Adjusted Retrospective Study for Comparison of the Outcome of Treatment With Third-Generation Cephalosporin vs. Broad-Spectrum Antibiotics for Enterobacter Bacteremia

Background

Enterobacter spp. can develop resistance during prolonged therapy with third-generation cephalosporins (3GC: ceftriaxone, cefotaxime, or ceftazidime) because of derepression of AmpC β-lactamase. However, the clinical significance of this phenomena remains undetermined. This study aims to assess the outcome of patients with 3GC-susceptible Enterobacter bacteremia (EB) who received definite therapy with 3GC or broad-spectrum antibiotics (BSA) using propensity score analysis.

Methods

In this retrospective, cohort study conducted at two tertiary care hospitals in Japan, we determined consecutive patients with EB identified from the laboratory databases between January 2010 and December 2017. We enrolled patients with 3GC-susceptible EB treated with 3GC or BSA (defined as fourth-generation cephalosporins, carbapenems, and piperacillin/tazobactam) as definitive therapy. The primary outcome was 28-day mortality. The secondary outcome was the emergence of antimicrobial-resistant strain during antimicrobial therapy. We compared outcomes using the propensity scores and inverse-probability-weighting (IPW) adjustment to decrease the confounding by indication.

Results

We identified 320 patients with EB; of these, 191 cases were eligible (86 treated with 3GC and 105 treated with BSA). All the measured covariates were well balanced after the IPW adjustment. We observed no significant differences in the unadjusted mortality [5.8% in the 3GC group vs. 13.3% in the BSA group; risk difference, −7.5%; 95% confidence interval (CI): −15.7–0.6; P = 0.09], and the IPW-adjusted mortality (5.1% vs. 9.4%; risk difference −4.3%; 95% CI: −12.2–3.5; P = 0.3) between the groups. The results of the propensity score-matched analysis and sensitivity analysis were similar. Furthermore, we did not observe the emergence of antimicrobial resistance during antimicrobial therapy in both groups.

Conclusion

Definitive therapy with 3GC for susceptible EB was not associated with an increased risk of the 28-day mortality after adjustment for potential confounders with the propensity score analysis or with the emergence of antimicrobial-resistant strain.

Disclosures

All authors: No reported disclosures.

Lactococcus lactis cholangitis and bacteremia identified by MALDI-TOF mass spectrometry: A case report and review of the literature on Lactococcus lactis infection

Lactococcus lactis is a rare causative organism in humans. Cases of L. lactis infection have only rarely been reported. However, because it is often difficult to identify by conventional commercially available methods, its incidence may be underestimated. We herein report the case of a 70-year-old man with cholangiocarcinoma who developed L. lactis cholangitis and review previously reported cases of L. lactis infection. Our case was confirmed by matrix-assisted desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This case shows L. lactis is a potential causative pathogen of cholangitis and that MALDI-TOF MS can be useful for the rapid and accurate identification of L. lactis infection. We searched the literature for published case reports on cholangitis and any other infections caused by L. lactis, and thereby identified 36 cases, including our case. At least 66.7% (n = 24) of the cases had significant underlying conditions; 15 of the cases involved patients with an immunocompromised status. At least 41.7% (n = 15) had a significant food consumption history, such as the consumption of unpasteurized dairy products. The clinical sources of L. lactis were diverse and endocarditis was the most common diagnosis (n = 8), followed by hepatobiliary infection (n = 6), central nervous system infection (n = 5), and peritonitis (n = 4). The prognosis was favorable in most cases.

Vertebral Osteomyelitis Caused by Helicobacter cinaedi Identified Using Broad-range Polymerase Chain Reaction with Sequencing of the Biopsied Specimen

A 65-year-old man presented with gradually exacerbating low back pain. Magnetic resonance imaging revealed vertebral osteomyelitis in the Th11-L2 vertebral bodies and discs. The patient showed negative findings on conventional cultures. Direct broad-range polymerase chain reaction (PCR) with sequencing of the biopsied specimen had the highest similarity to the 16S rRNA gene of Helicobacter cinaedi. This case suggests that direct broad-range PCR with sequencing should be considered when conventional cultures cannot identify the causative organism of vertebral osteomyelitis, and that this method may be particularly useful when the pathogen is a fastidious organism, such as H. cinaedi.

A successful salvage therapy with daptomycin and linezolid for right-sided infective endocarditis and septic pulmonary embolism caused by methicillin-resistant Staphylococcus aureus

Although vancomycin administration is recommended for the treatment of infective endocarditis (IE) caused by methicillin-resistant Staphylococcus aureus (MRSA), it is unclear whether an alternative agent, daptomycin, can be used to treat IE with pulmonary complications. A 26-year-old female who had undergone surgical repair of a ventricular septal defect as an early teenager presented with fever, headache, and vomiting. She was admitted to our hospital and diagnosed with right-sided IE with septic pulmonary embolism caused by MRSA. Vancomycin, rifampicin, and gentamicin were administered; however, exacerbation of drug eruption due to the antimicrobial agents on the 11th day led us to switch from vancomycin and rifampicin to daptomycin. Furthermore, we included linezolid to treat lung abscesses that accompanied the septic pulmonary embolism. We confirmed negative blood cultures on the 18th day. On the same day, a patch closure for the ventricular septal defect and tricuspid valve replacement were performed. She was discharged on the 65th day with an uneventful postoperative course. This experience suggests that daptomycin and linezolid are effective salvage therapies for right-sided IE caused by MRSA and accompanied by pulmonary complications.

Legionella pneumonia appeared during hospitalization in a patient with hematological malignancy confirmed by sputum culture after negative urine antigen test

Legionella pneumophila is recognized as a common causative organism for community-acquired pneumonia, but it is rarely a causative organism for hospital-acquired pneumonia, except in cases of hospital outbreak. Recently, most of the Legionella cases have been diagnosed using the urine antigen test. However, this test can reliably detect only L. pneumophila serogroup 1. Here we report a 63-year-old male patient who was recently diagnosed with acute leukemia and treated with chemotherapy and who developed pneumonia on hospital day 8 during the nadir phase. He was later diagnosed with Legionella pneumonia by culture despite a negative urine antigen test. This case suggests that Legionella pneumonia is an important differential diagnosis for pneumonia in inpatients in the early phase of hospitalization and that when Legionella infection is clinically suspected, culture using selective media or molecular tests should be performed even if the urine antigen test is negative.

Diagnostic delay for imported malaria: A case of Plasmodium falciparum malaria misdiagnosed as common cold

A 37‐year‐old Japanese man experienced fever and headache 8 days after returning to Japan following a 6‐month stay in Nigeria. He visited two clinics but was sent home from each with a diagnosis of common cold. He was eventually brought to the emergency department with an altered mental status. Severe P. falciparum malaria was confirmed; his initial parasitemia index was 5.4%. He recovered fully with antimalarial treatment. This case suggests that primary care physicians should obtain recent travel history and consider malaria for any febrile patient who has returned from a malaria‐endemic area.

Outpatient parenteral antibiotic therapy (OPAT) in Asia: missing an opportunity

Objectives

Healthcare facilities internationally have grown outpatient parenteral antibiotic administration services for the last few decades. The literature contains publications from dozens of countries describing systematized processes with specialist oversight and their levels of service provision and outcomes. Such descriptions are absent in the majority of Asian countries. We sought to elucidate the extent and nature of outpatient parenteral antibiotic therapy (OPAT) in Asia and to consider the ramifications and opportunities for improvement.

Methods

Utilizing colleagues and their personal networks, we surveyed healthcare facilities across 17 countries in Asia to ascertain the current means (if any) of providing OPAT. In that survey we also sought to explore the capacity and interest of these facilities in developing systematized OPAT services.

Results

Responses were received from 171 different healthcare facilities from 17 countries. Most (97/171, 57%) stated that they administer outpatient parenteral antibiotics, but only 5 of 162 facilities (3%) outside of Singapore described comprehensive services with specialist oversight.

Conclusions

There is very likely a large unrecognized problem of unchecked outpatient parenteral antibiotic administration in Asia. Developing comprehensive and systematized OPAT in Asia is needed as a priority in an environment in which the infectious diseases community is demanding broad stewardship approaches. There are nonetheless challenges in establishing and sustaining OPAT programmes. Local champions and leverage off identified local incentives and needs are key to regional advancement.

A 10-year profile of enterococcal bloodstream infections at a tertiary-care hospital in Japan

OBJECTIVES

The first aim of this study is to characterize the epidemiology of enterococcal bloodstream infections (BSIs) at a Japanese tertiary-care hospital. The second aim is to identify predictive factors for 30-day mortality.

METHODS

We conducted a single center retrospective observational study. All patients with enterococcal BSI between 2005 and 2014 were enrolled. Univariate and multivariate analysis were performed to evaluate predictive factors for 30-day mortality.

RESULTS

A total of 410 patients with enterococcal BSI were enrolled. Enterococcus faecalis was identified in 200 patients (48.8%) and Enterococcus faecium in 124 patients (30.2%). Isolates were susceptible to ampicillin and vancomycin (67.3% and 97.8%, respectively). Isolates that were not susceptible to vancomycin were either Enterococcus casseliflavus or Enterococcus gallinarum. All strains of E. faecalis and 10.8% of E. faecium strains were susceptible to ampicillin. Thirty-day mortality was 24.8%. Predictive factors for 30-day mortality were Charlson Comorbidity Index (CCI) 1-2 (adjusted odds ratio [OR] 6.07, 95% confidence interval [CI]: 1.22-30.2), CCI 3-4 (adjusted OR 8.79, 95% CI: 1.70-45.4), CCI ≥5 (adjusted OR 17.6, 95% CI: 3.52-88.2), E. faecium bacteremia (adjusted OR 2.19, 95% CI: 1.27-3.76), Pitt Bacteremia Score (PBS) ≥5 (adjusted OR 15.1, 95% CI: 6.41-35.6), and source control (adjusted OR 0.39, 95% CI: 0.22-0.72).

CONCLUSION

Vancomycin-resistant strains of E. faecalis and E. faecium were not seen in this cohort. In addition, all strains of E. faecalis and 10.8% of E. faecium strains were susceptible to ampicillin. Predictive factors for 30-day mortality were CCI score, E. faecium bacteremia, PBS score, and source control.

Unique characteristics of community-onset healthcare- associated bloodstream infections: a multi-centre prospective surveillance study of bloodstream infections in Japan

BACKGROUND

Analysis of bloodstream infections (BSIs) is valuable for their diagnosis, treatment and prevention. However, limited data are available in Japan.

AIM

To investigate the characteristics of patients with bacteraemia in Japan.

METHODS

This study was conducted in five hospitals from October 2012 to September 2013. Clinical, demographic, microbiological and outcome data for all blood-culture-positive cases were analysed.

FINDINGS

In total, 3206 cases of BSI were analysed: 551 community-onset healthcare-associated (CHA)-BSIs, 1891 hospital-acquired (HA)-BSIs and 764 community-acquired (CA)-BSIs. The seven- and 30-day mortality rates were higher in patients with CHA- and HA-BSIs than in patients with CA-BSIs. The odds ratios (ORs) for seven-day mortality were 2.56 [95% confidence interval (CI) 1.48-4.41] and 2.63 (95% CI 1.64-4.19) for CHA- and HA-BSIs, respectively. The ORs for 30-day mortality were 2.41 (95% CI 1.63-3.57) and 3.31 (95% CI 2.39-4.59) for CHA- and HA-BSIs, respectively. There were 499 cases (15.2%) of central-line-associated BSI and 163 cases (5.0%) of peripheral-line-associated BSI. Major pathogens included coagulase-negative staphylococci (N = 736, 23.0%), Escherichia coli (N = 581, 18.1%), Staphylococcus aureus (N = 294, 9.2%) and Klebsiella pneumoniae (N = 263, 8.2%). E. coli exhibited a higher 30-day mortality rate among patients with HA-BSIs (22.3%) compared with patients with CHA-BSIs (12.3%) and CA-BSIs (3.4%). K. pneumoniae exhibited higher 30-day mortality rates in patients with HA-BSIs (22.0%) and CHA-BSIs (22.7%) compared with patients with CA-BSIs (7.8%).

CONCLUSION

CHA- and HA-BSIs had higher mortality rates than CA-BSIs. The prognoses of E. coli- and K. pneumonia-related BSIs differed according to the category of bacteraemia.

Multicenter Study of the Clinical Presentation of Staphylococcus lugdunensis Bacteremia in Japan

Staphylococcus lugdunensis (SL) is a bacterium with a highly pathogenicity than most other coagulase-negative Staphylococcus spp. (CoNS). In Japan, data on this pathogen are sparse, and the current prevalence of SL bacteremia is unknown. Therefore, we investigated the prevalence of SL in blood culture specimens in a prospective multicenter study across 5 facilities. A total of 3,284 patients had positive blood cultures, and 2,478 patients had bacteremia. Among the patients with bacteremia, 7 patients (0.28%) had SL bacteremia. A total of 281 patients had CoNS bacteremia, with SL accounting for 2.49% of these cases. Of the 7 patients with SL bacteremia, 1 patient (14.3%) had infective endocarditis, and 1 patient (14.3%) died within 30 days. In this study, SL resulted in the development of bacteremia in select patients. Clinicians in Japan should be aware of the prevalence of SL and the complications of SL bacteremia.