Diabetic Foot Osteomyelitis Undergoing Amputation: Epidemiology and Prognostic Factors for Treatment Failure.

Background: When treating diabetic foot osteomyelitis (DFO), it remains difficult to determine the presence of residual infection and the optimal treatment after bone resection. In this study, we aimed to investigate the clinical characteristics of and prognostic factors in patients with DFO undergoing amputation. Methods: This retrospective study involved 101 patients with DFO who underwent amputation. Data on their demographics, clinical characteristics, tissue culture, and surgery type were collected. Patients were grouped according to primary closure status and clinical outcome postamputation. A good outcome was defined as a successful complete remission, characterized by the maintenance of complete wound healing with no sign of infection at 6 months postamputation. Multivariate logistic regression analysis was performed. Outcomes according to surgery type were also analyzed. Results: Staphylococcus aureus (17%) and Pseudomonas species (14%) were the most prevalent pathogens. Gram-negative bacteria were isolated from 62% of patients. In patients with primary closure, hemodialysis and ankle brachial index (ABI) <0.6 were associated with poor outcomes. In patients with DFO, ABI <0.6 was the only prognostic factor associated with treatment failure. Antimicrobial stewardship allows patients who underwent major amputation to reduce the duration of antibiotic therapy compared to those after minor amputation, although it did not contribute to reducing mortality. Conclusions: Peripheral artery disease and hemodialysis were associated with poor outcomes despite radical resection of the infected bone. Vigilant monitoring after amputation and antimicrobial stewardship implemented based on microbiological epidemiology, prognostic factors, and the type of surgery are important. A multidisciplinary team could assist in these activities to ensure treatment success.

Trends, clinical characteristics, antimicrobial susceptibility patterns, and outcomes of Campylobacter bacteraemia: a multicentre retrospective study.

PURPOSE: We aimed to explore the clinical characteristics of Campylobacter bacteraemia and identify the trends, risk factors for mortality, and antimicrobial susceptibility patterns from clinical samples. METHODS: This retrospective cohort study included patients confirmed to have Campylobacter bacteraemia from seven hospitals between January 2010 and June 2021. Data on demographics and underlying history, clinical manifestation, and antimicrobial susceptibility patterns were collected and analyzed. Annual cases of Campylobacter enteritis were extracted from a public database. RESULTS: A total of 108 patients were included, and five species were isolated. Campylobacter jejuni accounted for 54 (50.0%) cases and 17 (16%) patients had no symptoms other than fever. In-hospital mortality occurred in 14 (13.0%) patients. C. jejuni bacteraemia was associated with lower mortality compared to non-C. jejuni bacteraemia. Underlying cancer and septic shock were the significant factors associated with in-hospital mortality. Quinolone resistance was high (59%), whereas only 4% of isolates exhibited macrolide resistance. There has been a significant increase in the number of Campylobacter enteritis cases, which was strongly correlated with the number of Campylobacter bacteraemia cases (Pearson's coefficient: 0.953; p < 0.0001). CONCLUSION: The notably increasing incidence of Campylobacter bacteraemia and antibiotic resistance patterns can challenge the treatment, necessitating collective efforts of national surveillance and networks by many departments.

Late-Onset Granulomatous Pneumocystis jirovecii Pneumonia in A Renal Transplant Recipient: A Clinical Grand Round Conference Case in 2022.

Late-onset Pneumocystis jirovecii pneumonia (PCP) can be developed in solid organ transplant (SOT) patients. Granulomatous P. jirovecii pneumonia (GPCP) can occur in immunocompromised patients, but has rarely been reported in SOT recipients. The diagnosis of GPCP is difficult since the sensitivity of sputum and bronchoalveolar lavage is low and atypical patterns are shown. A 60-year-old man, who had undergone renal transplantation 24 years ago presented with nodular and patchy lung lesions. He was asymptomatic and stable. After empirical treatment with a fluoroquinolone, the condition partially resolved but relapsed 4 months later. The pulmonary nodule was resected, and GPCP was confirmed. The pathogenesis of GPCP remains unclear, but in SOT recipients presenting with an atypical lung pattern, GPCP should be considered. This case was discussed at the Grand Clinical Ground of the Korean Society of Infectious Disease conference on November 3, 2022.

Immunogenicity and Safety of Vaccines against Coronavirus Disease in Actively Treated Patients with Solid Tumors: A Prospective Cohort Study.

PURPOSE: We aimed to assess the humoral response to and reactogenicity of coronavirus disease 2019 (COVID-19) vaccination according to the vaccine type and to analyze factors associated with immunogenicity in actively treated solid cancer patients (CPs). Materials and Methods: Prospective cohorts of CPs, undergoing anticancer treatment, and healthcare workers (HCWs) were established. The participants had no history of previous COVID-19 and received either mRNA-based or adenovirus vector-based (AdV) vaccines as the primary series. Blood samples were collected before the first vaccination and after 2 weeks for each dose vaccination. Spike-specific binding antibodies (bAbs) in all participants and neutralizing antibodies (nAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wild-type, Delta, and Omicron variants in CPs were analyzed and presented as the geometric mean titer. RESULTS: Age-matched 20 HCWs and 118 CPs were included in the analysis. The bAb seroconversion rate and antibody concentrations after the first vaccination were significantly lower in CPs than in HCWs. After the third vaccination, antibody levels in CPs with a primary series of AdV were comparable to those in HCWs, but nAb titers against the Omicron variant did not quantitatively increase in CPs with AdV vaccine as the primary series. The incidence and severity of adverse reactions post-vaccination were similar between CPs and HCWs. CONCLUSION: CPs displayed delayed humoral immune response after SARS-CoV-2 vaccination. The booster dose elicited comparable bAb concentrations between CPs and HCWs, regardless of the primary vaccine type. Neutralization against the Omicron variant was not robustly elicited following the booster dose in some CPs, implying the need for additional interventions to protect them from COVID-19.

Impact of Valve Culture Positivity on Prognosis in Patients with Infective Endocarditis Who Underwent Valve Surgery.

INTRODUCTION: Infective endocarditis (IE) is a severe and fatal infection with high in-hospital and overall mortality rates of approximately up to 30%. Valve culture positivity was associated with in-hospital mortality and postoperative complications; however, few studies have analyzed the relationship between valve cultures and overall mortality over a long observation period. This study aimed to compare the association of valve culture positivity with overall mortality in patients with IE who underwent valve surgery. METHODS: A total of 416 IE patients admitted to a tertiary hospital in South Korea from November 2005 to August 2017 were retrospectively reviewed. A total of 202 IE patients who underwent valve surgery and valve culture were enrolled. The primary endpoint was long-term overall mortality. Kaplan-Meier curve and Cox proportional hazards model were used for survival analysis. RESULTS: The median follow-up duration was 63 (interquartile range, 38-104) months. Valve cultures were positive in 22 (10.9%) patients. The overall mortality rate was 15.8% (32/202) and was significantly higher in valve culture-positive patients (36.4%, p = 0.011). Positive valve culture [hazard ratio (HR) 3.921, p = 0.002], Charlson Comorbidity Index (HR 1.181, p = 0.004), Coagulase-negative staphylococci (HR 4.233, p = 0.001), new-onset central nervous system complications (HR 3.689, p < 0.001), and new-onset heart failure (HR 4.331, p = 0.001) were significant risk factors for overall mortality. CONCLUSIONS: Valve culture positivity is a significant risk factor for long-term overall mortality in IE patients who underwent valve surgery. The importance of valve culture positivity needs to be re-evaluated, as the valve culture positivity rate increases with increasing early surgical intervention.

Comparing Treatment Outcomes of Ampicillin-Sulbactam, Other ß-Lactams, and Vancomycin in Blood Culture-Negative Infective Endocarditis.

Selection of proper antibiotics for blood culture-negative infective endocarditis (BCNIE) is difficult due to limited data on antibiotic regimens for BCNIE in existing literature. The aim of this study was to compare ampicillin-sulbactam, other ß-lactams antibiotics, and vancomycin among patients with BCNIE to determine the proper antibiotic regimens. This retrospective study included adult patients with BCNIE admitted to Severance Hospital from November 2005 to August 2017. Patients were classified into three groups as, treated with ampicillin-sulbactam, other ß-lactams, and vancomycin. The primary outcome was 1-year all-cause mortality. A total of 74 cases with BCNIE were enrolled in this study. There were no statistically significant differences in clinical characteristics between the three groups. One-year mortality did not significantly differ between the study groups either. Further, in-hospital mortality, 28-day mortality and overall mortality showed no difference. However, Cox-regression analysis showed nosocomial infective endocarditis as an independent risk factor and a protective effect of surgery on 1-year mortality. This study showed no clear difference in the outcomes of BCNIE as per the antibiotic therapy but suggested the beneficial effect of surgical treatment. With increasing global concern of antimicrobial resistance, it might be reasonable to select ampicillin-sulbactam-based antibiotic therapy while actively considering surgical treatment in BCNIE.

A mathematical model of COVID-19 transmission in a tertiary hospital and assessment of the effects of different intervention strategies.

Novel coronavirus (named SARS-CoV-2) can spread widely in confined settings including hospitals, cruise ships, prisons, and places of worship. In particular, a healthcare-associated outbreak could become the epicenter of coronavirus disease (COVID-19). This study aimed to evaluate the effects of different intervention strategies on the hospital outbreak within a tertiary hospital. A mathematical model was developed for the COVID-19 transmission within a 2500-bed tertiary hospital of South Korea. The SEIR (susceptible-exposed-infectious-recovered) model with a compartment of doctor, nurse, patient, and caregiver was constructed. The effects of different intervention strategies such as front door screening, quarantine unit for newly admitted patients, early testing of suspected infected people, and personal protective equipment for both medical staff and visitors were evaluated. The model suggested that the early testing (within eight hours) of infected cases and monitoring the quarantine ward for newly hospitalized patients are effective measures for decreasing the incidence of COVID-19 within a hospital (81.3% and 70% decrease of number of incident cases, respectively, during 60 days). Front door screening for detecting suspected cases had only 42% effectiveness. Screening for prohibiting the admission of COVID-19 patients was more effective than the measures for patients before emergency room or outpatient clinic. This model suggests that under the assumed conditions, some effective measures have a great influence on the incidence of COVID-19 within a hospital. The implementation of the preventive measures could reduce the size of a hospital outbreak.