Time-to-detection in culture of Mycobacterium tuberculosis: performance for assessing index cases contact-positivity.

OBJECTIVES: Time-to-detection (TTD) in culture on liquid media is inversely correlated to bacillary load and should be a contributing factor for assessing tuberculosis transmission. We wanted to assess if TTD was a better alternative than smear status to estimate transmission risk. METHODS: From October 2015 to June 2022, we retrospectively studied a cohort of index cases (IC) with pulmonary tuberculosis (tuberculosis disease [TD]) from which samples were culture-positive before treatment. We studied the correlation between TTD and contact-positivity (CP) of IC contacts: CP was defined as CP = 1 (CP group) in case of TD or latent tuberculosis infection (LTI) in at least one screened contact of an IC, and CP = 0 otherwise (contact-negativity [CN] group). Univariate and multivariable analyses (logistic regression) were done. RESULTS: Of the 185 IC, 122 were included, generating 846 contact cases of which 705 were assessed. A transmission event (LTI or TD) was identified in 193 contact cases (transmission rate: 27%). At day 9, 66% and 35% of the IC had their sample positive in culture for CP and CN groups, respectively. Age and TTD ≤9 days were independent criteria of CP (odds ratio 0.97, confidence interval [0.95-0.98], P = 0.002 and odds ratio 3.52, confidence interval [1.59-7.83], P = 0.001, respectively). CONCLUSION: TTD was a more discriminating parameter than smear status to evaluate the transmission risk of an IC with pulmonary tuberculosis. Therefore, TTD should be considered in the contact-screening strategy around an IC.

Procalcitonin and C-Reactive Protein/Procalcitonin Ratio as Markers of Infection in Patients With Solid Tumors.

Objectives: The roles of procalcitonin (PCT) and C-reactive protein (CRP) in febrile cancer patients is currently unclear. Our aim was to assess these in febrile patients with solid tumors and to identify cut-off values for ruling out infection. Methods: We retrospectively evaluated patients with solid tumors admitted to hospital due to fever. They were divided into those with Fever with microbiologically documented infection (FMDI), Fever with clinically documented infection (FCDI) and Tumor-related fever (TRF). PCT and CRP levels were compared. Receiver-operating curves were plotted to define the best cut-off values for discriminating between infection-related and cancer-related fever. Results: Between January 2015 to November 2018, 131 patients were recorded (mean age 68 years, 67% male, 86% with metastasis). Patients with FMDI or FCDI had significantly higher baseline levels of PCT and lower CRP/PCT than those with TRF. A PCT cut-off value of 0.52 ng/mL for discriminating between infection and cancer-associated fever yielded 75% sensitivity, 55% specificity, 77% positive predictive value (PPV), and 52% negative predictive value (NPV). A CRP/PCT ratio with a cut-off value of 95 showed 56% sensitivity, 70% specificity, 79% NPV, and 44% PPV. Discussion: PCT is a sensitive marker of sepsis or localized infection in patients with solid tumors, but its specificity is poor. The CRP/PCT ratio improves specificity, thus providing a reliable means of ruling out infection for values above 95.

Amoxicillin/clavulanic acid+aminoglycoside as empirical antibiotic treatment in severe community-acquired infections with diagnostic uncertainty.

Diagnostic uncertainty is common in the emergency room and multidrug-resistant bacteria emerge in the community setting, implying to establish the most efficient empirical antibiotic therapy (eEAT). Our aim was to identify such eEAT, considering that in case of DU with severe clinical presentation, most prescribers would propose an empiric combination (EC). The medical dashboard of our ward records prospectively 28 characteristics of each hospitalization including hospitalization motive, final diagnosis, and all antibiotics prescribed. All patients with community-acquired bacteremia (CAB) were included. DU was defined by a discrepancy between suspected diagnosis in the emergency room and final diagnosis. eEAT was defined by in vitro activity of at least one prescribed compound. Finally, independently from the dashboard, we retrospectively compared 2 CTs: amoxicillin/clavulanic acid (AMC)+gentamicin (G) and cefotaxime (3GC)+G. One thousand thirty-four patients with a final diagnosis of CAB were identified from July 2005 to June 2018, including 357 DU (35%) at baseline. eEAT (n = 553) was associated with a trend towards a lower death rate compared to inefficient therapies: 5.4 vs 10.0% (p = 0.053), and effective antibiotic reassessment was the most protective factor against an unfavorable outcome: 0.34 (0.16-0.71). Bacteria involved in case of UD were resistant to AMC+G and to 3GC+G in 8.1% and 12.8% of patients, respectively. Diagnostic uncertainty was a frequent event requiring antibiotic reassessment. As the latter was not systematically realized, the best eEAT is required and AMC+aminoglycoside should be considered.

Adherence to antibiotic guidelines for erysipelas or cellulitis is associated with a favorable outcome.

Outside areas of S. aureus strains resistant to methicillin (MRSA) in the community, no studies showed a relationship between the treatment for erysipelas or cellulitis and the outcome. We aimed to measure the impact of an internal therapeutic protocol, based on national guidelines on patients' outcome. This study was based on the dashboard of the infectious diseases department, which prospectively includes 28 parameters for all admitted patients. We included community-acquired erysipelas and cellulitis; exclusion criteria were abscesses at admission; ear, nose, throat, or dental cellulitis; pyomyositis; and length of stay ≤ 2 days. Adherence to guidelines was defined by the use of amoxicillin, amoxicillin/clavulanic acid, clindamycin, or pristinamycin, alone or in combination or successively. A poor outcome was defined by surgical procedure or intensive care requirement or death occurring after 5 days or more of antibiotic therapy. From July 2005 to June 2017, 630 cases of erysipelas or cellulitis were included. Blood cultures performed in 567 patients (90%) were positive in 39 cases (6.9%). Adherence rate to guidelines was 65% (410 cases). A poor outcome was recorded in 54 (8.5%) patients, less frequently in case of adherence to guidelines: 26/410 (6.3%) vs 28/220 (12.7%), p = 0.007. In logistic regression analysis, two risk factors were associated with a poor outcome: peripheral arterial disease, AOR 4.80 (2.20-10.49); and bacteremia, AOR 5.21 (2.31-11.76), while guideline adherence was the only modifiable protective factor, OR 0.48 (0.26-0.89). In erysipelas and cellulitis, adherence to guidelines was associated with a favorable outcome.