Influence of easing COVID-19 strategies following downgrading of the national infectious disease category on COVID-19 occurrence among hospitalized patients in Japan.

PURPOSE: We aimed to evaluate the influence of easing COVID-19 preventive measures following its downgrading to a common infectious disease on COVID-19 occurrence among hospitalized patients. METHODS: Nosocomial occurrence of COVID-19 was compared between periods with national infectious disease category 5 versus the preceding category 2 equivalent. Changes in the revised manual included a shorter duration of work restrictions for infected health care practitioners (HCPs); no work restriction for HCPs exposed to SARS-CoV-2 with a negative test on days 1, 3 and 5; discontinuation of universal pre-admission screening; and pre-emptive isolation of patients without screening. Wearing an N95 mask and face shield was required in procedure/care with moderate-to high-risk contact. RESULTS: Although the mean monthly number of infected HCPs increased from 8.1 to 12.7 in the category 5 period (p = 0.034) and that of pre-admission screening decreased to one-fourth, the COVID-19 incidence in hospitalized patients remained similar between the two study periods (1.60 ± 5.59/month versus 1.40 ± 2.63/month, p = 0.358). Clusters, defined as ≥3 COVID-19 patients on the ward, were experienced twice in the preceding period and only once in the category 5 period. The index cases causing nosocomial SARS-CoV-2 transmission mostly involved rehabilitation therapists in the preceding period; five of six index cases were patients in the category 5 period. Following the expanded indication for N95 masks, neither SARS-CoV-2 transmission to patients nor transmission from infected patients was observed in HCPs for 1 year. CONCLUSION: With sustained, enhanced standard precautions, easing prevention strategies could limit nosocomial SARS-CoV-2 infections.

Timing of Assessment of Humoral and Cell-Mediated Immunity after Influenza Vaccination.

Assessment of the immune response to influenza vaccines should include an assessment of both humoral and cell-mediated immunity. However, there is a lack of consensus regarding the timing of immunological assessment of humoral and cell-mediated immunity after vaccination. Therefore, we investigated the timing of immunological assessments after vaccination using markers of humoral and cell-mediated immunity. In the 2018/2019 influenza season, blood was collected from 29 healthy adults before and after vaccination with a quadrivalent inactivated influenza vaccine, and we performed serial measurements of humoral immunity (hemagglutination inhibition [HAI] and neutralizing antibody [NT]) and cell-mediated immunity (interferon-gamma [IFN-γ]). The HAI and NT titers before and after vaccination were strongly correlated, but no correlation was observed between the markers of cell-mediated and humoral immunity. The geometric mean titer and geometric mean concentration of humoral and cellular immune markers increased within 2 weeks after vaccination and had already declined by 8 weeks. This study suggests that the optimal time to assess the immune response is 2 weeks after vaccination. Appropriately timed immunological assessments can help ensure that vaccination is effective.

Clinical characteristics and analysis of prognostic factors in methicillin-resistant Staphylococcus aureus endocarditis: A retrospective multicenter study in Japan.

BACKGROUND: Infective endocarditis (IE) caused by MRSA (methicillin-resistant Staphylococcus aureus) is associated with a high mortality rate. This study aimed to elucidate the characteristics of patients with MRSA-IE in Japan and identify the factors associated with prognosis. METHODS: This retrospective study included patients with a confirmed diagnosis of IE caused by MRSA, between January 2015 and April 2019. RESULTS: A total of 65 patients from 19 centers were included, with a mean age of 67 years and 26 % were female. Fifty percent of the patients with IE were had nosocomial infections and 25 % had prosthetic valve involvement. The most common comorbidities were hemodialysis (20 %) and diabetes (20 %). Congestive heart failure was present in 86 % of patients (NYHA class I, II: 48 %; III, IV: 38 %). The 30-day and in-hospital mortality rates were 29 % and 46 %, respectively. Multi-organ failure was the primary cause of death, accounting for 43 % of all causes of death. Prognostic factors for in-hospital mortality were age, disseminated intravascular coagulation, daptomycin and/or linezolid as initial antibiotic therapy, and surgery. Surgical treatment was associated with a lower mortality rate (odds ratio [OR], 0.026; 95 % confidence interval [CI], 0.002-0.382; p = 0.008 for 30-day mortality and OR, 0.130; 95 % CI; 0.029-0.584; p = 0.008 for in-hospital mortality). CONCLUSION: Mortality due to MRSA-IE remains high. Surgical treatment is a significant prognostic predictor of MRSA-IE.

Difference in the impact of coinfections and secondary infections on antibiotic use in patients hospitalized with COVID-19 between the Omicron-dominant period and the pre-Omicron period.

INTRODUCTION: This study evaluated the effect of coinfections and/or secondary infections on antibiotic use in patients hospitalized with coronavirus disease 2019 (COVID-19). METHOD: Days of therapy per 100 bed days (DOT) in a COVID-19 ward were compared between 2022 (Omicron period) and 2021 (pre-Omicron period). Antibiotics were categorized as antibiotics predominantly used for community-acquired infections (CAIs) and antibiotics predominantly used for health care-associated infections (HAIs). Bacterial and/or fungal infections which were proved or assumed on admission were defined as coinfections. Secondary infections were defined as infections that occurred following COVID-19. RESULTS: Patients with COVID-19 during the Omicron period were older and had more comorbidities. Coinfections were more common in the Omicron period than in the pre-Omicron period (44.4% [100/225] versus 0.8% [2/257], respectively, p < 0.001), and the mean DOT of antibiotics for CAIs was significantly increased in the Omicron period (from 3.60 to 17.84, p < 0.001). Secondary infection rate tended to be higher in the Omicron period (p = 0.097). Mean DOT of antibiotics for HAIs were appeared to be lower in the COVID-19 ward than in the general ward (pre-Omicron, 3.33 versus 6.37, respectively; Omicron, 3.84 versus 5.22, respectively). No multidrug-resistant gram-negative organisms were isolated in the COVID-19 ward. CONCLUSION: Antibiotic use for CAIs was limited in the pre-Omicron period but increased in the Omicron period because of a high coinfection rate on admission. With the antimicrobial stewardship, excessive use of antibiotics for HAIs was avoided in the COVID-19 ward during both periods.

Antimicrobial therapy and outcome of methicillin-resistant Staphylococcus aureus endocarditis: A retrospective multicenter study in Japan.

BACKGROUND: MRSA (methicillin-resistant Staphylococcus aureus)-infective endocarditis (IE) is associated with high morbidity and mortality. This study aimed to assess data from patients with MRSA-IE across multiple facilities in Japan, with a specific focus on antimicrobial therapy and prognosis. METHODS: This retrospective study enrolled patients with a confirmed diagnosis of IE attributed to MRSA, spanning the period from January 2015 to April 2019. RESULTS: Sixty-four patients from 19 centers were included, with a median age of 67 years. The overall mortality rate was 28.1% at 30 days, with an in-hospital mortality of 45.3%. The most frequently chosen initial anti-MRSA agents were glycopeptide in 67.2% of cases. Daptomycin and linezolid were selected as initial therapy in 23.4% and 17.2% of cases, respectively. Approximately 40% of all patients underwent medication changes due to difficulty in controlling infection or drug-related side effects. Significant prognostic factors by multivariable analysis were DIC for 30-day mortality and surgical treatment for 30-day and in-hospital mortality. For vancomycin as initial monotherapy, there was a trend toward a worse prognosis for 30-day and in-hospital mortality (OR, 6.29; 95%CI, 1.00-39.65; p = 0.050, OR, 3.61; 95%CI, 0.93-14.00; p = 0.064). Regarding the choice of initial antibiotic therapy, statistical analysis did not show significant differences in prognosis. CONCLUSION: Glycopeptide and daptomycin were the preferred antibiotics for the initial therapy of MRSA-IE. Antimicrobial regimens were changed for various reasons. Prognosis was not significantly affected by choice of antibiotic therapy (glycopeptide, daptomycin, linezolid), but further studies are needed to determine which antimicrobials are optimal as first-line agents.

Clinical features of pasteurellosis without an animal bite or scratch in comparison with bite/scratch pasteurellosis.

Pasteurellosis is a common zoonotic infection that occurs after an animal bite or scratch (B/S). We compared the clinical features of six patients with non-B/S pasteurellosis with those of 14 patients with B/S infections. Pasteurella multocida was identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in all six non-B/S infections, whereas 13 of the 14 B/S infections were identified with diagnostic kits. The non-B/S infections were pneumonia (n = 3), skin and soft tissue infections (n = 2), and bacteremia (n = 1). Pneumonia occurred in two patients with underlying pulmonary disease, whereas ventilator-associated pneumonia developed in one patient with cerebral infarction. Pasteurella multocida was isolated from a blood specimen and nasal swab from a patient with liver cirrhosis (Child-Pugh class C) and diabetes. Cellulitis developed in one patient with diabetes and normal-pressure hydrocephalus, who had an open wound following a fall, and in one patient with diabetes and a foot ulcer. Three patients with non-B/S infections had no pet and no episode of recent animal contact. The rate of moderate-to-severe comorbidities was significantly higher in patients with non-B/S infections than in those with B/S infections (100% and 14.3%, respectively, p < 0.001). In conclusion, non-B/S infections can develop in patients with chronic pulmonary disease, invasive mechanical ventilation, or open wounds, or who are immunocompromised, irrespective of obvious animal exposure. In contrast to B/S infections, non-B/S pasteurellosis should be considered opportunistic.

Changes in the Epidemiology of Rubella: The Influence of Vaccine-Introducing Methods and COVID-19.

Rubella is an infectious disease caused by the rubella virus. Congenital rubella syndrome is a risk for all newborns if pregnant women are infected with rubella, raising an important public health issue. Rubella is a vaccine-preventable disease, and routine immunization has been conducted in Japan. The timing of the vaccine approval did not differ from that in the United States. In 2004, endemic rubella was eliminated in the United States. However, recent rubella outbreaks have occurred in Japan. This may be related to differences in the introduction of routine rubella immunization. In Japan, routine rubella immunization was initially introduced only for junior high school girls, and the rate of susceptibility is high among males who have not received rubella vaccination, causing an outbreak. Therefore, in Japan, measures have been taken to decrease the number of susceptible males in the vaccination-free generation. The coronavirus pandemic has also affected the epidemiology of rubella as well as other infectious diseases.

Optimal timing for therapeutic drug monitoring of voriconazole to prevent adverse effects in Japanese patients.

BACKGROUND: The optimal timing for therapeutic drug monitoring (TDM) of voriconazole in Asians, who have higher rates of poor metabolisers than non-Asians, is unclear. This can cause unexpectedly high concentrations and delays in reaching steady-state levels. OBJECTIVES: To determine the appropriate timing of TDM in Japanese patients receiving voriconazole. PATIENTS/METHODS: Trough levels (Cmin ) were measured on days 3-5 (recommended timing, RT) and days 6-14 (delayed timing, DT) after starting voriconazole in patients receiving an appropriate dosage. Considering bioavailability, Cmin was only compared in patients receiving oral voriconazole. RESULTS: A total of 289 and 186 patients were included in the safety and pharmacokinetic analyses, respectively. There was a significant difference in Cmin measured no later than and after day 5 (3.59 ± 2.12 [RT] vs. 4.77 ± 3.88 µg/mL [DT], p = .023), whereas no significant difference was observed on cutoff day 6 (3.91 ± 2.60 vs. 4.40 ± 3.94 µg/mL, p = .465), suggesting that Cmin close to the steady-state was achieved after day 5. DT causes a delay in achieving the therapeutic range. The hepatotoxicity rates were 21.5% and 36.8% in the RT and DT groups, respectively (p = .004); DT was an independent risk factor for hepatotoxicity. CONCLUSION: Although steady-state concentrations may not be achieved by day 5, early dose optimisation using RT can prevent hepatotoxicity in Japanese patients. TDM should be performed on days 3-5 to ensure safety. However, subsequent TDM may be necessary due to a possible further increase in Cmin .

Judicious ending of isolation based on reverse transcription-polymerase chain reaction (RT-PCR) cycle threshold only for patients with coronavirus disease 2019 (COVID-19) requiring in-hospital therapy for longer than 20 days after symptom onset.

BACKGROUND: For patients with coronavirus disease 2019 (COVID-19) requiring hospitalization, extending isolation is warranted. As a cautious protocol, ending isolation based on polymerase chain reaction cycle threshold (Ct) value was introduced for patients requiring therapy for >20 days after symptom onset. METHOD: We compared a Ct-based strategy using Smart Gene® between March 2022 and January 2023 with a preceding control period (March 2021 to February 2022) when two consecutive negative reverse transcription-polymerase chain reaction tests using FilmArray® were required for ending isolation. Ct was evaluated on day 21, and ending isolation was permitted in patients with Ct ≥ 38. Although patients with Ct 35-37 were transferred to a non-COVID-19 ward, isolation was continued. RESULTS: The duration of stay on a COVID-19 ward in the Ct group was 9.7 days shorter than that in controls. The cumulative number of tests was 3.7 in controls and 1.2 in the Ct group. There was no nosocomial transmission after ending isolation in either group. The number of days from symptom onset to testing was 20.7 ± 2.1 in Ct group, and five patients had Ct < 35, nine Ct 35-37, and 71 Ct ≥ 38. No patients were moderately or severely immunocompromised. Steroid use was an independent risk factor for prolonged low Ct (odds ratio 9.40, 95% confidence interval 2.31-38.15, p = 0.002) CONCLUSIONS: The efficacy of ending isolation based on Ct values could improve bed utilization without the risk of transmission among patients with COVID-19 requiring therapy for >20 days after symptom onset.

Comparison of antibiotic use and antibiotic resistance between a community hospital and tertiary care hospital for evaluation of the antimicrobial stewardship program in Japan.

Assessment of risk-adjusted antibiotic use (AU) is recommended to evaluate antimicrobial stewardship programs (ASPs). We aimed to compare the amount and diversity of AU and antimicrobial susceptibility of nosocomial isolates between a 266-bed community hospital (CH) and a 963-bed tertiary care hospital (TCH) in Japan. The days of therapy/100 bed days (DOT) was measured for four classes of broad-spectrum antibiotics predominantly used for hospital-onset infections. The diversity of AU was evaluated using the modified antibiotic heterogeneity index (AHI). With 10% relative DOT for fluoroquinolones and 30% for each of the remaining three classes, the modified AHI equals 1. Multidrug resistance (MDR) was defined as resistance to ≥ 3 anti-Pseudomonas antibiotic classes. The DOT was significantly higher in the TCH than in the CH (10.85 ± 1.32 vs. 3.89 ± 0.93, p < 0.001). For risk-adjusted AU, the DOT was 6.90 ± 1.50 for acute-phase medical wards in the CH, and 8.35 ± 1.05 in the TCH excluding the hematology department. In contrast, the DOT of antibiotics for community-acquired infections was higher in the CH than that in the TCH. As quality assessment of AU, higher modified AHI was observed in the TCH than in the CH (0.832 ± 0.044 vs. 0.721 ± 0.106, p = 0.003), indicating more diverse use in the TCH. The MDR rate in gram-negative rods was 5.1% in the TCH and 3.4% in the CH (p = 0.453). No significant difference was demonstrated in the MDR rate for Pseudomonas aeruginosa and Enterobacteriaceae species between hospitals. Broad-spectrum antibiotics were used differently in the TCH and CH. However, an increased antibiotic burden in the TCH did not cause poor susceptibility, possibly because of diversified AU. Considering the different patient populations, benchmarking AU according to the facility type is promising for inter-hospital comparisons of ASPs.

Correlation between Antimicrobial Resistance and the Hospital-Wide Diverse Use of Broad-Spectrum Antibiotics by the Antimicrobial Stewardship Program in Japan.

Increased antibiotic use and antibiotic homogeneity cause selective pressure. This study investigated the correlation between antibiotic diversity and antimicrobial resistance (AMR) in Gram-negative organisms. The days of therapy/100 patient-days (DOT) for four broad-spectrum antibiotic classes were evaluated for 2015-2022. The antibiotic heterogeneity index (AHI) for the equal use of four classes (25%) and the modified AHI for the equal use of three classes (30%), excluding fluoroquinolones (10%), were measured (target: 1.0). Quarterly antibiotic use markers and the resistance rates against ≥2 anti-Pseudomonas antibiotics were compared. The DOT value was 9.94, and the relative DOT were 34.8% for carbapenems, 32.1% for piperacillin/tazobactam, 24.3% for fourth generation cephalosporins/ceftazidime/aztreonam, and 8.9% for fluoroquinolones. Although no correlation was found between the total DOT and the resistance rate for any bacterium, a significant negative correlation was found between the heterogeneity indices and resistance rates for Pseudomonas aeruginosa and Klebsiella pneumoniae. The significant cutoffs that discriminate the risk of resistance were 0.756 for the AHI and 0.889 for the modified AHI for K. pneumoniae. Antibiotic diversity is more important in preventing AMR than overall antibiotic use. The ideal ratio of broad-spectrum antibiotics should be studied for diversified use to prevent AMR.

Efficacy of surgical skin preparation with chlorhexidine in alcohol according to the concentration required to prevent surgical site infection: meta-analysis.

BACKGROUND: A combination of chlorhexidine gluconate and alcohol (CHG-alcohol) is recommended for surgical skin preparation to prevent surgical site infection (SSI). Although more than 1 per cent CHG-alcohol is recommended to prevent catheter-related bloodstream infections, there is no consensus regarding the concentration of the CHG compound for the prevention of SSI. METHODS: A systematic review and meta-analysis was performed. Four electronic databases were searched on 5 November 2020. SSI rates were compared between CHG-alcohol and povidone-iodine (PVP-I) according to the concentration of CHG (0.5 per cent, 2.0 per cent, 2.5 per cent, and 4.0 per cent). RESULTS: In total, 106 of 2716 screened articles were retrieved for full-text review. The risk ratios (RRs) of SSI for 0.5 per cent (6 studies) and 2.0 per cent (4 studies) CHG-alcohol were significantly lower than those for PVP-I (RR = 0.71, 95 per cent confidence interval (c.i.) 0.52 to 0.97; RR = 0.52, 95 per cent c.i 0.31 to 0.86 respectively); however, no significant difference was observed in the compounds with a CHG concentration of more than 2.0 per cent. CONCLUSIONS: This meta-analysis is the first study that clarifies the usefulness of an alcohol-based CHG solution with a 0.5 per cent or higher CHG concentration for surgical skin preparation to prevent SSI.

Comparison of the Hemagglutination Inhibition Titers against Influenza Vaccine Strains in Japan from the 2017/2018 to 2021/2022 Seasons Using a Single Set of Serum Samples.

In Japan, inactivated influenza vaccines are used. We measured titers of antibodies to vaccine strains of three influenza types-influenza A (H1N1), influenza A (H3N2), and influenza B/Victoria-from the 2017/2018 to 2021/2022 seasons, but not for influenza A (H3N2) from the 2018/2019 season, using a single set of serum samples from 34 healthy volunteers, and assessed the consistency in antibody positivity between seasons. The antibody titers in the 2017/2018 season were used as a reference. The influenza A (H1N1) antibody titer in 2019/2020 did not differ significantly from that in the 2017/2018 season, but the titers varied in the two subsequent seasons. The influenza A (H3N2) antibody titers toward the 2019/2020, 2020/2021, and 2021/2022 seasonal viruses differed significantly from that in the 2017/2018 season. The influenza B/Victoria antibody titer toward the 2019/2020 seasonal antigen differed from that in the 2017/2018 season, and the antibody positivity was inconsistent between seasons; however, the antibody titer in the 2020/2021 season did not differ significantly from those in the prior two seasons, and the antibody positivity was consistent between seasons. Antibody titers and their consistency can be used to evaluate cross-immunity of antibodies.

Correction of thrombocytopenia caused by linezolid with scheduled sequential tedizolid use in patients with vertebral osteomyelitis by antibiotic resistant Gram-positive organisms.

INTRODUCTION: Because of thrombocytopenia, linezolid treatment tends to be stopped before the completion of therapy for complicated infections that require prolonged antimicrobial administration. In contrast, tedizolid shows a favorable hematologic profile. The primary end-point of this study was to evaluate the efficacy of switching treatment to tedizolid in patients who developed thrombocytopenia during linezolid therapy. METHODS: This retrospective study was conducted in patients with vertebral osteomyelitis (VO) caused by antibiotic-resistant Gram-positive bacteria. Treatment failure was defined as the reappearance of infection signs within 2 weeks after stopping tedizolid and discontinuation of tedizolid because of continued thrombocytopenia or other adverse effects. RESULTS: Eight patients with native VO (n = 3) and postoperative VO (n = 5) were included in the study. The causative organisms were MRSA in all patients except one. Platelet counts decreased from 35.2 ± 11.5 × 104/mm3 to 17.8 ± 6.2 × 104/mm3 during linezolid therapy and improved without washout period in all patients after switching to tedizolid on days 5-7 (28.6 ± 4.9 × 104/mm3, p = 0.002). Tedizolid therapy was completed and treatment failure was not observed in any patient. The duration of treatment was 20.0 ± 11.2 days for linezolid and 30.3 ± 9.5 days for tedizolid (total, 50.3 ± 10.7 days). One patient died because of underlying disease, and there was no recurrence in the remaining 7 patients (median follow-up 501 days). CONCLUSIONS: Switching therapy to tedizolid improved thrombocytopenia that occurred during linezolid therapy, and it enabled the completion of therapy for VO patients.

Association between preoperative biologic use and surgical morbidity in patients with Crohn's disease.

PURPOSE: We evaluated the influence of preoperative treatments with biologics on surgical morbidity in patients with Crohn's disease (CD). METHODS: We reviewed the surveillance data of patients with CD who underwent surgery between April 2018 and April 2021. The possible risk factors for morbidity were analyzed. RESULTS: A total of 305 surgically treated patients were included. Anti-TNF alpha agents and ustekinumab were used in 92 and 27 patients, respectively, within 12 weeks before surgery. There were no cases of mortality. In total, 70/305 (23.0%) patients developed a complication, and 42/305 (13.8%) patients developed a surgical site infection (SSI) (17 incisional SSIs and 35 organ/space SSIs). Current smoking status (OR 3.44), emergent/urgent surgery (OR 6.85), and abdominoperineal resection (APR) (OR 14.93) were identified as risk factors for total complications. Penetrating disease (OR 14.55) was identified as a risk factor for incisional SSIs. Current smoking status (OR 7.09), an American Society of Anesthesiologists (ASA) score greater than 3 (OR 5.85), a postoperative blood sugar level over 155 mg/dL (OR 4.37), and APR (OR 207.95) were identified as risk factors for organ/space SSIs. CONCLUSIONS: No correlation between preoperative treatment with biologics and surgical mortality or morbidity was found. However, we should perform further analyses on a larger number of patients because the analyses may be limited by selection bias for treatment and several confounding factors.

Clinical Practice Guidelines for Therapeutic Drug Monitoring of Vancomycin in the Framework of Model-Informed Precision Dosing: A Consensus Review by the Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring.

BACKGROUND: To promote model-informed precision dosing (MIPD) for vancomycin (VCM), we developed statements for therapeutic drug monitoring (TDM). METHODS: Ten clinical questions were selected. The committee conducted a systematic review and meta-analysis as well as clinical studies to establish recommendations for area under the concentration-time curve (AUC)-guided dosing. RESULTS: AUC-guided dosing tended to more strongly decrease the risk of acute kidney injury (AKI) than trough-guided dosing, and a lower risk of treatment failure was demonstrated for higher AUC/minimum inhibitory concentration (MIC) ratios (cut-off of 400). Higher AUCs (cut-off of 600 µg·h/mL) significantly increased the risk of AKI. Although Bayesian estimation with two-point measurement was recommended, the trough concentration alone may be used in patients with mild infections in whom VCM was administered with q12h. To increase the concentration on days 1-2, the routine use of a loading dose is required. TDM on day 2 before steady state is reached should be considered to optimize the dose in patients with serious infections and a high risk of AKI. CONCLUSIONS: These VCM TDM guidelines provide recommendations based on MIPD to increase treatment response while preventing adverse effects.

Validation of Vancomycin Area under the Concentration-Time Curve Estimation by the Bayesian Approach Using One-Point Samples for Predicting Clinical Outcomes in Patients with Methicillin-Resistant Staphylococcus aureus Infections.

Area under the concentration-time curve (AUC)-guided vancomycin treatment is associated with decreased nephrotoxicity. It is preferable to obtain two samples to estimate the AUC. This study examined the usefulness of AUC estimation via trough concentration (Cmin)-only sampling of 260 adults infected with methicillin-resistant Staphylococcus aureus (MRSA) who received vancomycin. The exact Cmin sampling time was used for Bayesian estimation. A significantly higher early treatment response was observed in patients with a day 2 AUC ≥ 400 µg·h/mL than those with <400 µg·h/mL, and a significantly higher early nephrotoxicity rate was observed in patients with a day 2 AUC ≥ 600 µg·h/mL than those with <600 µg·h/mL. These AUC cutoff values constituted independent factors for each outcome. In sub-analysis, the discrimination ability for early clinical outcomes using these AUC cutoffs was confirmed only in patients with q12 vancomycin administration. A significant difference in early treatment response using the 400 µg·h/mL cutoff was obtained only in patients with low-risk infections. The usefulness of the vancomycin AUC target to decrease nephrotoxicity while assuring clinical efficacy was even confirmed with a single Cmin measurement. However, assessment with two samples might be required in patients with q24 administration or high/moderate-risk MRSA infections.

Enhanced loading dose of teicoplanin for three days is required to achieve a target trough concentration of 20 µg/mL in patients receiving continuous venovenous haemodiafiltration with a low flow rate.

INTRODUCTION: Because of its lower risk of renal toxicity than vancomycin, teicoplanin is the preferred treatment for methicillin-resistant Staphylococcus aureus infection in patients undergoing continuous venovenous haemodiafiltration (CVVHDF) in whom renal function is expected to recover. The dosing regimen for achieving a trough concentration (Cmin) of ≥20 µg/mL remains unclear in patients on CVVHDF using the low flow rate adopted in Japan. METHODS: The study was conducted in patients undergoing CVVHDF with a flow rate of <20 mg/kg/h who were treated with teicoplanin. We adopted three loading dose regimens for the initial 3 days: the conventional regimen, a high-dose regimen (four doses of 10 mg/kg), and an enhanced regimen (four doses of 12 mg/kg). The initial Cmin was obtained at 72 h after the first dose. RESULTS: Overall, 60 patients were eligible for study inclusion. The proportion of patients achieving the Cmin target was significantly higher for the enhanced regimen than for the high-dose regimen (52.9% versus 8.3%, p = 0.003). In multivariate analysis, the enhanced regimen (odds ratio [OR] = 39.93, 95% confidence interval [CI] = 5.03-317.17) and hypoalbuminaemia (OR = 0.04, 95% CI = 0.01-0.44) were independent predictors of the achievement of Cmin ≥ 20 µg/mL. CONCLUSIONS: An enhanced teicoplanin regimen was proposed to treat complicated or invasive infections by methicillin-resistant Staphylococcus aureus in patients receiving CVVHDF even with a low flow rate.

Changes in Cell-Mediated Immunity (IFN-γ and Granzyme B) Following Influenza Vaccination.

Interferon gamma (IFN-γ) is considered a key moderator of cell-mediated immunity. However, little is known about its association with granzyme B, which plays an important role in the effector function of cytotoxic T lymphocytes (CTLs). In the present study, we collected blood samples from 32 healthy adults before and after vaccination with inactivated influenza vaccine in 2017/18 to measure the levels of IFN-γ and granzyme B, which play roles in cell-mediated immunity, and hemagglutination inhibition (HAI) antibody, which plays a role in humoral immunity. The levels of IFN-γ and granzyme B were significantly correlated both before and after vaccination. Furthermore, the post-vaccine fold increases in the IFN-γ and granzyme B levels were significantly correlated. The levels of IFN-γ and granzyme B decreased five months after vaccination in more than half of the subjects who exhibited an increase in IFN-γ and granzyme B at two weeks post-vaccination. This is the first study to investigate the correlation between IFN-γ and granzyme B levels following influenza vaccination. Our study suggests that both IFN-γ and granzyme B can be used as markers of cell-mediated immunity.

Change in antimicrobial susceptibility of pathogens isolated from surgical site infections over the past decade in Japanese nation-wide surveillance study.

Inappropriate antimicrobial therapy for surgical site infections (SSIs) can lead to poor outcomes and an increased risk of antibiotic resistance. A nationwide survey was conducted in Japan from 2018 to 2019 to investigate the antimicrobial susceptibility of pathogens isolated from SSIs. The data were compared with those obtained in 2010 and 2014-2015 surveillance studies. Although the rate of detection of extended-spectrum ß-lactamase producing strains of Escherichia coli was increased from 9.5% in 2010 to 23% in 2014-2015, the incidence decreased to 8.7% in 2018-2019. Although high susceptibility rates were detected to piperacillin/tazobactam (TAZ), the geometric mean MICs were substantially higher than to meropenem (2.67 vs 0.08 µg/mL). By contrast, relatively low geometric mean MICs (0.397 µg/mL) were demonstrated for ceftolozane/TAZ. Although the MRSA incidence rate decreased from 72% in the first surveillance to 53% in the second, no further decrease was detected in 2018-2019. For the Bacteroides fragilis group species, low levels of susceptibility were observed for moxifloxacin (65.3%), cefoxitin (65.3%), and clindamycin (CLDM) (38.9%). In particular, low susceptibility against cefoxitin was demonstrated in non-fragilis Bacteroides, especially B. thetaiotaomicron. By contrast, low susceptibility rates against CLDM were demonstrated in both B. fragilis and non-fragilis Bacteroides species, and a steady decrease in susceptibility throughout was observed (59.3% in 2010, 46.9% in 2014-2015, and 38.9% in 2018-2019). In conclusion, Japanese surveillance data revealed no significant lowering of antibiotic susceptibility over the past decade in organisms commonly associated from SSIs, with the exception of the B. fragilis group.