183. Decrease in Invasive Pneumococcal Disease in 7 United States Children’s Hospitals during the COVID-19 Pandemic

Background During the 2020 SARS-CoV-2 pandemic, physical distancing and mask use guidelines were implemented resulting in a decline in the number of infections caused by influenza, respiratory syncytial virus and otitis media. A surveillance analysis from England and Taiwan showed a decline in invasive pneumococcal disease (IPD) (Clin Infect Dis. 2021;72: e65-75 and J Infect. 2021;82:296-297). We hypothesized that COVID mitigation efforts resulted in a decrease in incidence of pediatric IPD within the U.S. during 2020 compared to previous years. Methods We reviewed all cases of IPD among 7 children’s hospitals from the U.S. Pediatric Multicenter Pneumococcal Surveillance Group from 2017-2020. IPD was defined by the isolation of Streptococcus pneumoniae from normally sterile sites (eg. blood, cerebrospinal, pleural, synovial or peritoneal fluid). Pneumococcal pneumonia was defined as an abnormal chest radiograph in the presence of a positive blood, pleural fluid or lung culture. Mastoiditis was identified by positive middle ear, subperiosteal abscess or mastoid bone culture. Serotypes were determined by the capsular swelling method. Hospital admission numbers were obtained for incidence calculations. Statistical analyses were performed using STATA11. A p< 0.05 was considered significant. Results A total of 410 IPD cases were identified. The cumulative incidence of IPD (0-22 years of age) decreased from 99.2/100,000 admissions in 2017-2019 to 53.8/100,000 admissions in 2020 (risk ratio 0.54, CI: 0.40-0.72, p< 0.00001). Pneumococcal bacteremia and pneumonia decreased significantly in 2020 (p< 0.05), and although not statistically significant, there were fewer cases of meningitis and mastoiditis when compared to previous years (p=0.08) (Figure 1). Sex, race, age or presence of comorbidities were not significantly different between groups. Most common serotypes in 2020 were 35B, 3 and 15B/C (Figure 2). Conclusion The observed decline in IPD cases during the first year of the SARS-CoV-2 pandemic is likely associated with mask use and physical distancing limiting transmission of S. pneumoniae via droplets and viral infections frequently preceding IPD. These precautions might be useful in the future to decrease IPD, especially in high-risk patients. Disclosures Sheldon L. Kaplan, MD, Pfizer (Research Grant or Support) Tina Q. Tan, MD, GSK (Individual(s) Involved: Self): Advisor or Review Panel member, Grant/Research Support; ILiAD (Individual(s) Involved: Self): Advisor or Review Panel member; Merck (Individual(s) Involved: Self): Advisor or Review Panel member, Grant/Research Support; Moderna (Individual(s) Involved: Self): Advisor or Review Panel member; Pfizer (Individual(s) Involved: Self): Advisor or Review Panel member Pia S. Pannaraj, MD, MPH, Pfizer (Grant/Research Support)Sanofi-Pasteur (Advisor or Review Panel member)Seqirus (Advisor or Review Panel member) Larry Givner, MD, AstraZeneca (Advisor or Review Panel member) Kristina G. Hulten, PhD, Pfizer (Research Grant or Support)

Specific Magnetic Resonance Imaging Findings as Predictors of Osteomyelitis in Routine Clinical Practice

Background: The gold standard for the diagnosis of osteomyelitis is histopathology combined with positive bone cultures. Magnetic Resonance Imaging (MRI) is often used to aide diagnosis and guide treatment decisions. The purpose of the study was to examine the association of MRI findings with, and their sensitivity and specificity in identifying osteomyelitis as proven by bone histopathology and bone culture in routine clinical practice. Materials and Methods: A retrospective analysis of patients with bone specimens obtained by biopsy or at resection for suspected osteomyelitis during 2010-2014 at an academic medical center in New York City. We used bivariate analysis to compare findings of patients who did or did not have osteomyelitis confirmed on histopathology (Analysis 1) and those who had either bone histopathology demonstrating osteomyelitis, positive bone cultures or both or who had neither (Analysis 2). Results: We identified 103 patients with an MRI in the week prior to bone biopsy or bone resection. In Analysis 1, 52 (50.5%) of 103 patients had osteomyelitis confirmed on histopathology. In Analysis 2, 72 (70%) patients had proven osteomyelitis. These groups with and without osteomyelitis did not differ significantly with respect to the frequency of marrow edema, cortical erosions, decreased T1 signal or increased T2 signal in either analysis and the sensitivity and specificity of MRI findings for detecting osteomyelitis was lower than reported in prior studies. Conclusions: Based on the above results, clinicians should be aware that the sensitivity and specificity of MRI findings for histologic and microbiologic osteomyelitis may be less in real world practice than is reported in formal studies.

The role of remnant bone microbiological cultures in managing diabetic foot osteomyelitis

Aim: Effective treatment of diabetic foot osteomyelitis can reduce the risk of major amputations. Our primary aim was to compare the yield in cultures from the proximal and distal segments of bone excised intraoperatively and the impact on antibiotic choice and duration.Methods: Patients with a confirmed diagnosis of osteomyelitis on bone culture results, where both proximal and distal bone segment samples had been collected, were retrospectively reviewed. Microbiological data were examined to identify true pathogens and studied against antimicrobial choice and duration of prescribing.Results: A total of 47 forefoot amputation cases were studied. In 89% of cases, definite or likely pathogens were isolated from the deep tissues cultured. Definite pathogens (Staphylococcus aureus, Group B streptococcus, Group G streptococcus and Streptococcus anginosus) were identified in 32% of cases; in 73% of these, definite pathogens were grown in both the proximal and distal bone segments.Conclusion: Sampling of remnant bone culture can help in reducing the duration of antibiotic treatment in patients (27% of cases in our series) as it is challenging to correctly estimate intraoperatively whether clear surgical margins have been adequately achieved when resecting infected bone.

Are surrogate markers for diabetic foot osteomyelitis remission reliable?

Background: The aim of this study was to evaluate surrogate markers commonly used in the literature for diabetic foot osteomyelitis remission after initial treatment for diabetic foot infections. Methods: Thirty-five patients with diabetic foot infections were prospectively enrolled and followed for 12 months. Osteomyelitis was determined from bone culture and histology initially and for recurrence. Chi square and Fischer's exact test were used for dichotomous variables and the student's t-test and Mann-Whitney U test for continuous variables with an alpha of 0.05. Results: Twenty-four patients were diagnosed with osteomyelitis and eleven patients with soft-tissue infections. 16.7% (n=) of patients with osteomyelitis had a re-infection based on bone biopsy. The success of osteomyelitis treatment varied based on the surrogate marker used to define remission: osteomyelitis infection (16.7%), failed wound healing (8.3%), re-ulceration (20.8%), re-admission (16.7%), amputation (12.5%). There was no difference in outcomes among patients who were initially diagnosed with osteomyelitis and soft tissue infections. There were no differences in osteomyelitis re-infection (16.7% vs 45.5%, p=0.07), wounds that failed to heal (8.3% vs 9.1%, p=0.94), re-ulceration (20.8% vs 27.3%, p=0.67), re-admission for diabetic foot infections at the same site (16.7% vs 36.4%, p=0.20), amputation at the same site after discharge (12.5% vs 36.4%, p=0.10). Osteomyelitis at the index site based on bone biopsy indicated that failed therapy was 16.7%. Indirect markers demonstrated a failure rate ranging from 8.3-20.8%. Conclusions: Most osteomyelitis markers were similar to markers in soft tissue infection subjects. Commonly reported surrogate markers were not shown to be specific to identify patients that failed osteomyelitis treatment when compared with patients that had soft tissue infections. Given this, these surrogate markers are not reliable for use in practice to identify osteomyelitis treatment failure.

325. Invasive and Non-Invasive Osteomyelitis Caused by Group B Streptococcus Infection Among Veterans

Background Epidemiological studies that assess invasive Group B Streptococcus (GBS) infections may not capture cases of osteomyelitis diagnosed using non-invasive cultures in combination with imaging, laboratory tests, and clinical assessment. Here, we compare GBS osteomyelitis among individuals diagnosed using invasive and non-invasive cultures. Methods Using the Veterans Health Administration corporate data warehouse, we studied a national retrospective cohort review of Veterans diagnosed with GBS osteomyelitis between 2008 – 2017. Invasive cases were defined as an International Classification of Disease (ICD) code for osteomyelitis accompanied by a blood or bone culture positive for GBS within 2 weeks. Non-invasive cases were defined as an ICD code for osteomyelitis and a non-invasive culture positive for GBS from a concordant site within 2 weeks. We compared demographics, comorbid conditions, mortality, and time to below- or above-knee amputation among patients with invasive and non-invasive GBS osteomyelitis. Results We identified 1167 cases of invasive osteomyelitis among 1077 patients and 692 cases of non-invasive osteomyelitis among 644 patients. Most patients were male (98%) with an average age of 63.2 years (± standard deviation (SD) 10.1 years). The Charlson Comorbidity Index (CCI) was similar among patients with invasive and non-invasive disease (3.85 ± SD 2.3 and 3.83 ± SD2.4, respectively). Among those with lower extremity osteomyelitis, 11% of invasive cases had an amputation at 30 days while 2% of non-invasive cases had an amputation in the same time frame (Figure 1). Mortality was similar among those with invasive and non-invasive GBS osteomyelitis at 30-days (1% and 1%, respectively) and at 1-year (11% and 9%, respectively) (Figure 2). Figure 1: Time to Amputation Figure 2: Survival Conclusion Over 1/3 of the cases of osteomyelitis caused by GBS do not meet the case definition for invasive disease. Whether diagnosed using invasive or non-invasive microbiological cultures, survival outcomes for people with GBS osteomyelitis were similar. These findings suggest that non-invasive GBS osteomyelitis is as clinically important as invasive GBS osteomyelitis and that the rates of GBS osteomyelitis may be higher than previously reported. Disclosures Federico Perez, MD, MS, Accelerate (Research Grant or Support)Merck (Research Grant or Support)Pfizer (Research Grant or Support) Robin Jump, MD, PhD, Accelerate (Grant/Research Support)Merck (Grant/Research Support)Pfizer (Grant/Research Support, Advisor or Review Panel member)Roche (Advisor or Review Panel member)

Feasibility of Percutaneous Bone Biopsy as Part of the Management of Diabetic Foot Osteomyelitis in a 100% Neuropathic, Grade 3 IDSA/IWGDF Population on an Outpatient Basis

The present study aimed to evaluate the feasibility of percutaneous bone biopsy in an ambulatory setting as part of the management of diabetic foot osteomyelitis (DFO) on an outpatient basis. DFO may complicate some cases of apparently nonsevere foot infections in patients with diabetes and greatly increase the risk of a lower extremity amputation. It has been suggested that bone culture–based antibiotic therapy is a predictive factor of success in patients with diabetes treated nonsurgically for osteomyelitis of the foot. It is recommended to identify the causative microorganism(s) by the means of either a surgical or percutaneous bone biopsy taken appropriately to select the proper antibiotic therapy. Percutaneous bone biopsy in patients not requiring surgery is, however, not performed in everyday practice as it should be according to the current recommendations. In the present retrospective study, we report a series of 23 consecutive patients with a suspicion of DFO in whom 28 bone samples were collected by percutaneous biopsy at the bedside in an outpatient setting. The percentage of positive cultures was in accordance with that reported in the literature. The mean number of isolates per specimen was 1.04. After a mean 12-month follow-up, the remission was almost of 78%. No adverse event related to the bone biopsy was noted. After a 1-year follow-up, no recurrence was recorded among the patients in remission. The results of the present study suggest that bedside percutaneous bone biopsy performed in the ambulatory setting is a valuable and safe tool in the management of DFO on an outpatient basis.

Informativeness of bone intraoperative culture for diagnose osteomyelitis in diabetic foot patients.

BACKGROUND: Diagnosis of osteomyelitis in diabetic foot patients is frequently not obvious due to similar clinical and X-ray signs of bone infection and Sharcot osteopathy, but it is very important because of opposite approach to treatment of these conditions. Today we do not have reliable parameters to determine the devastation of bone infection and, therefore, the rational volume of bone resection and debridement. AIMS: To determine the diagnostic value of bone culture for osteomyelitis in diabetic foot patients. MATERIALS AND METHODS: 177 patients underwent surgery due to different forms of diabetic foot. In 131 of them clinical signs of osteomyelitis were revealed and this diagnosis was confirmed by histology. 46 patients with diabetes who underwent high-level amputation without bone infection formed the control group. Intraoperative bone cultures and histological samples were taken in all cases. RESULTS: We found similar microbial landscape in various forms of diabetic foot and in control group. The frequency of positive intraoperative cultures in patients without osteomyelitis was detected as 63%. The sensitivity of bone culture was counted as 86,3%, the specificity as 37%, the accuracy 73.5%. CONCLUSIONS: Our findings suggest that bone culture is not reliable sign of bone infection in diabetic foot patients due to its low specificity. In our judgment, the only way to determine rational level of bone resection is visual intraoperative assessment and clinical signs such as development of granulation tissue and wound healing.