Introduction: Although macrolides and fluoroquinolones can cause fatal arrhythmia, few studies have evaluated this risk in Japanese populations.
Aims: To assess the 30-day risk of fatal arrythmia caused by macrolides and fluoroquinolones compared with second- or third-generation cephems using a Japanese medical claims database.
Methods: We utilized Japanese medical claims data provided by JMDC Inc. for the period April 2012 to March 2021. We constructed a cohort of patients who were dispensed macrolides, fluoroquinolones, or cephems, and who met the eligibility criteria. We used the nested case-control (NCC) study design. Among the full cohort, cases were defined as patients who experienced an outcome within 30 days after exposure, and controls were sampled from the at-risk population at the time each case occurred. We sampled five control subjects per case by simple random sampling. Exposure was defined as the dispensing of macrolides or fluoroquinolones, and cephems were used as a comparator. The outcome was defined as hospitalization with a diagnosis of arrhythmia or sudden death. Hazard ratios (HRs) were estimated using an inverse probability of treatment (IPT)-weighted Cox model. The IPT weights were calculated by fitting an inverse probability of sampling-weighted generalized logistic model conditioned on sex, age, Charlson comorbidity index, medication history, and medical history.
Results: The full study cohort comprised ~2.8 million people (~1.5 million males; mean age [standard deviation]: 33.9 [18.4] years). We extracted 332 cases and 1,660 controls. Compared with cephems, for macrolides the crude HR was 0.99 (95% confidence interval: 0.76‒1.32) and the IPT-weighted HR was 0.98 (0.73‒1.34). In contrast, for fluoroquinolones the crude HR was 0.89 (0.65‒1.22) and the IPT-weighted HR was 0.79 (0.58‒1.09).
Discussion: The use of macrolides and fluoroquinolones may not increase the risks of fatal arrhythmia or other cardiovascular diseases in Japanese people, but the accumulation of further safety data is necessary.

Introduction: Defined daily dose (DDD) and days of therapy (DOT) are the widely used traditional metrics for antimicrobial stewardship. DOT only counts number of days patient received antibiotics however does not account for spectrum of antibiotics hence may not accurately measure antibiotics regimens and de-escalation strategies. Days of Antibiotic Spectrum Coverage (DASC) is a novel metric which can measure both duration and spectrum of antibiotics has gained popularity. However, it has not been utilized in cancer patients who are more susceptible to infections and often receive antibiotics.
Aim: To evaluate the antibiotic consumption via DASC and DOT among cancer patients.
Methodology: A prospective observational study was carried out in oncology wards for the duration of one year (January 2023-December 2023). DASC is the sum of antibiotic spectrum scores multiplied by duration of treatment. Data was analyzed using descriptive statistics, Karl Pearson’s and Spearman’s rank correlation coefficient.

Results: Among the 213 cancer patients, males (62.4%) predominate over female with mean age 51.5 years. The overall DOT, DASC, and de-escalation DASC score was found to be 13850.2, 12640, and 1880 respectively. The de-escalation rate was 14.8%. On correlation, we observed significant positive correlation between monthly DASC and DASC/patients (ρ=0.73, p<0.01), and between DASC and monthly DOT (ρ=0.692, p<0.05) whereas significant negative correlation was observed between DASC/DOT ratio and DOT/patients (r=0.692, p<0.05).

Discussion: The integration of DASC alongside DOT offers a more comprehensive evaluation of stewardship efforts. The monthly DASC vs DOT and monthly DASC vs DOT/patients showed parallel trends. Higher DASC/DOT ratio is indicative of broad-spectrum antibiotic use and vice-versa. There was no correlation between DASC/DOT ratio with other metric indicating it as a independent and robust metric. Thus, use of DASC can lead to more accurate measurement of AMS efforts in compared to DOT/DDD in challenging facilities like oncology wards.

Introduction: Antibiotic stewardship programmes (ASPs) are specifically important for surgical specialties due to their impact on the use of antibiotics as prophylaxis and therapy.

Aim: To assess the clinical and economic impact of clinical pharmacist-initiated Handshake Antibiotic Stewardship in surgical units of a tertiary care hospital.

Methods: This was a prospective interventional study carried out primarily by a clinical pharmacist at the Surgical units in two phases: the pre-implementation and the post-implementation phases. The clinical and economic outcomes were assessed in both the pre-implementation and the post-implementation phases of the antibiotic stewardship programme. The paired t-test and the Wilcoxon sign rank test were used to compare both phases. The chi-square test was used to determine the association between various categorical variables such as length of stay, surgical prophylaxis, SSIs, culture-susceptibility tests, etc. The data was analyzed using SPSS 26.0 version and the results with p< 0.05 were considered statistically significant.

Results: There was a statistically significant (p< 0.001) decrease in the number of days of surgical antimicrobial prophylaxis during the post-implementation phase. The post-implementation phase witnessed a statistically significant reduction in DDD per 10000 patient days and DOT per 1000 patient days of antibiotics. During the pre-implementation phase, 6.03% of culture and susceptibility tests were performed, whereas 10.27% were performed in the post-implementation phase. De-escalation of antibiotics was done in 8.31% of patients during the pre-implementation phase, whereas it was done in 16.21% of patients in the post-implementation phase. Also, there was a significant reduction in the length of stay during the post-implementation phase. A net cost saving of 784346.02 INR was achieved post-implementation. Furthermore, there was a significant reduction in the probability of length of stay and lab monitoring in the post-implementation phase.

Conclusion: ASP can improve the clinical and economic outcomes of surgical patients

Introduction. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is used in the treatment of infectious disease, which has been reported to reduce mortality, length of hospital stay, and time to effective therapy for infectious disease. However, reports on the use of MALDI-TOF MS in multicenter settings are limited in Japan.
Aims. This study aimed to survey the prevalence of MALDI-TOF MS for patients with bacteremia.
Methods. We conducted a retrospective descriptive study used inpatient claims data from fiscal year (FY) 2018 to FY 2021, collected by Medical Data Vision, Inc. Eligible patients for this study were those who: 1) were admitted for infection, 2) had blood culture collected and susceptibility testing performed during the hospitalization period, 3) were administered antimicrobials for at least three days, and 4) were 18 years or older. We investigated the prevalence of MALDI-TOF MS. In addition, the patient’s background was described by whether antimicrobials changed or no changed. Moreover, described median days to change antimicrobials and the mean daily cost of before and after the antimicrobials change.
Results. 114,820 patients were included in this study and 5% (5,741 patients) were used MALDI-TOF MS. There were 4,232 patients in the antimicrobial changed group and 1,509 patients in the no changed group. Significant differences were observed in age (p=0.0004) and sex (p=0.0005). The median (interquartile range) days to antimicrobial change was 6 (3-11) days. Mean daily antimicrobial costs before and after antimicrobial change were 11.0 USD per day and 9.4 USD per day, and the difference was 1.6 USD per day (95% Confidence Interval 0.9-2.1; p<0.001).
Conclusion. Prevalence of MALDI-TOF MS using for patients with bacteremia was not higher than anticipated. On the other hands, there is a possibility of effectiveness for infectious therapy; and therefore, more detailed research is needed in the future.

Aim: To determine the effectiveness of nirmatrelvir/ritonavir and molnupiravir among vaccinated and unvaccinated non-hospitalized adults with COVID-19.

Methods: Observational studies of nirmatrelvir/ritonavir or molnupiravir compared to no antiviral drug treatment for COVID-19 in non-hospitalized adults with data on vaccination status were included. We searched MEDLINE, EMBASE, Scopus, Web of Science, WHO COVID-19 Research database, and medRxiv for reports published between 1 January 2022 and 8 November 2023. The primary outcome was a composite of hospitalization or mortality up to 35 days after COVID-19 diagnosis. Risk of bias was assessed with ROBINS-I. Risk ratios (RR), hazard ratios (HR) and risk differences (RD) were separately estimated using random-effects models.

Results: We included 30 cohort studies on adults treated with nirmatrelvir/ritonavir (n=462,279) and molnupiravir (n=48,008) in the systematic review and 22 studies in the quantitative synthesis. Nirmatrelvir/ritonavir probably reduced the composite outcome (RR 0.62, 95% CI 0.55–0.70; I²=0%; moderate certainty) with no evidence of effect modification by vaccination status (Psubgroup=0.47). In five studies, RD estimates against the composite outcome for nirmatrelvir/ritonavir were 1.21% (95% CI 0.57% to 1.84%) in vaccinated and 1.72% (95% CI 0.59% to 2.85%) in unvaccinated subgroups.

Molnupiravir may slightly reduce the composite outcome (RR 0.75, 95% CI 0.67–0.85; I²=32%; low certainty). Evidence of effect modification by vaccination status was inconsistent among studies reporting different effect measures (RR Psubgroup=0.78; HR Psubgroup=0.08). In two studies, RD against the composite outcome for molnupiravir were −0.01% (95% CI −1.13% to 1.10%) in vaccinated and 1.73% (95% CI −2.08% to 5.53%) in unvaccinated subgroups.

Conclusion: Among cohort studies of non-hospitalized adults with COVID-19, nirmatrelvir/ritonavir is effective against the composite outcome of severe COVID-19 independent of vaccination status. Further research and a reassessment of molnupiravir use among vaccinated adults are warranted.

Keywords: Antiviral drugs, COVID-19, effectiveness, vaccination status

Introduction. Staphylococcus aureus is a kind of commensal bacteria that potentially increase the risk of staphylococcal infections especially among children who with a weaker immune system. Prolonged carriage in child may lead to potential serious invasive bacterial infection.

Aims. To study the epidemiology and risk factors for bacterial carriages of S.aureus and MRSA in Hong Kong children and adolescent.

Methods. We recruited and obtained nasal swabs from children and adolescents, aged 0-18 years during their clinical follow-up visit in Hong Kong Children’s Hospital specialist out-patient clinic along with surveys completed by caregivers regarding information on recent antibiotic usage, travel and infection history. Bacterial colonization test was freshly performed after receiving the samples. Subjects with S.aureus colonization were case, while the subject without colonization acting as a control. Risk factors were analysed using logistic regression models.

Results. Of all 207 subjects, 62 were case (30%); 4% were MRSA carrier; with 52.9% of male; mean age 8.39; 79.6% prior antibiotic use; 52.4% prior pneumococcal vaccination; 80.1% prior respiratory symptoms and 54.5% with chronic medical condition.

Female and younger age when comparing age 0-3, 4-12 and 13-18 years old have a lower risk of S.aureus and MRSA colonization (OR: 0.48, 95%CI: 0.37-0.61; OR: 0.03, 95%CI: 0.02-0.04). Other significant risk factors for S.aureus and MRSA carriage including increase in household size (OR:1.6, 95%CI: 1.21-2.02 ; OR:5.64, 95%CI: 4.37-7.29), having any domestic pets (OR: 1.14, 95%CI: 0.89-1.48; OR: 1.71, 95%CI: 1.33-2.21), prior respiratory symptoms (OR: 1.08, 95%CI: 0.84-1.34; OR: 1.98, 95%CI: 1.53-2.55), overseas travel history in past 12 months (OR: 4.33, 95%CI: 3.36-5.59; OR: 5.71, 95%CI: 4.42-7.37).

Discussion. Prevalence of S.aureus and MRSA carriage higher than previously reported. The risk factors identified in this study will help inform the profile of potential high risk for S. aureus and MRSA carriage.

Keywords: MRSA, Staphylococcus aureus