My thoughts on the Future of Infectious Disease and Medicine

http://outbreaknewstoday.com/laboratory-testing-sepsis-63349/

https://soundcloud.com/outbreak-news-this-week/outbreak-news-this-week-082717

http://outbreaknewstoday.com/sepsis-interview-steven-larosa-md-52322/

Procalcitonin (PCT) is the prohormone of Calcitonin. It is also released by monocytes and macrophages rapidly in response to bacterial infections. Unlike the typically used biomarkers of inflammation (CRP and ESR), it does not rise in malignancies (or non-infectious inflammatory conditions with the following exceptions: medullary thyroid cancer, small cell lung cancer, administration of OKT3 and ATG, in the first 24 hours after trauma or surgery, in the first 48 hours of life, Adult Onset Still's Disease (AOSD), Wegener's granulomatosis and Kawasaki's Disease. As a clinical lab test PCT has been found to be useful in the following settings: 1) Antimicrobial Stewardship - numerous studies have shown that ability to use PCT as part of clinical decision making in stopping antibiotic therapy. In these studies antibiotic use mas discouraged if the PCT was < 0.5ng/ml and strongly discouraged if the PCT was < 0.25ng/ml. An important caveat is that a single PCT measu...

As an adult Infectious Disease physician many of the calls I receive stem from concerning labs. The most common calls are concern for sepsis in a patient with leukocytosis and “bandemia”. Leukocytosis while a reliable marker of bacteremia in the pediatric population is woefully non-specific for sepsis in adults with AUC ROC of about .500. Similarly, the presence of immature band forms in not predictive of sepsis or bacteremia. It turns out that much more can be cleaned about the likelihood of sepsis and bacteremia from other components of the WBC differential. A neutrophil to lymphocyte count ratio greater than 10 has been demonstrated in numerous studies to be almost as good as serum Procalcitonin at predicting bacteremia. Additionally an absolute lymphocyte count < 1000 is highly predictive of bacteremia. While physicians tend to notice eosinophilia as a marker of allergic reactions or fungal infection, eosinopenia with an absolute eosinophil count < 40 cells/ microliter r...

Cytomegalovirus (CMV) is a member of the Herpesviridiae family and is endemic throughout the world. Approximately 60% of adults are seropositive for past CMV infection. Reactivation of CMV is a source of significant morbidity in immunocompromised hosts. CMV can cause direct organ injury, activate the coagulation cascade as well as act as an endogenous immunosuppressant leading to secondary bacterial, fungal and viral infections. In the immunocompetent critically ill ICU population, CMV viremia is found in approximately 30%   of CMV seropositive patients and is associated with a poor outcome. It is unclear if CMV leads to poor outcome or is a disease severity marker. In the current issue of JAMA 2017; 318 (8): 731-740 Ajit Limaye and colleagues begin to address in the question. They performed a double-blind, placebo controlled trial in patients who had either sepsis or severe trauma and were seropositive for past CMV infection. A total of 160 patients were randomized to re...