MICROBIOLOGY AND EPIDEMIOLOGY OF INFECTIOUS DISEASES IN VULNERABLE YET UNDERSTUDIED POPULATIONS

THE PROBLEM

Multidrug resistant bacteria are a major threat to health in the United States and around the globe. The U.S. military considers these organisms to be a major threat to military readiness and a priority area of research. The microbiology of many common pediatric infections has also changed in the modern vaccine era. The rise of resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and carbapenem-resistant Enterobacteriaceae (CRE), has made initial antimicrobial decision-making challenging. Microbiologic and epidemiologic data informing early antimicrobial management for many infections in children are limited to small historical case series performed at a single institution, and therefore are significantly dated and poorly generalizable.

OUR APPROACH

The objective of our research is to evaluate the modern microbiology and epidemiologic exposures associated with infections in DoD beneficiaries, both children and adults.

Previous military health system database information has also been used to research certain viral infections in the DoD, particularly Respiratory Syncytial virus (RSV) bronchiolitis and Rotavirus gastroenteritis. These epidemiologic studies have led to publications that identified risk for factors for severe RSV disease and vaccine effectiveness data on the rotavirus vaccine. In addition, the databases were used to explore the rising number of Clostridium difficile infections (CDI) in patient populations. Clostridium difficile infections are now estimated to occur in over half a million Americans a year, making it the most common bacterial enteritis. CDI were known to be associated with antibiotic administration in adults. However beyond this, almost nothing was known about the epidemiology of CDI in children.

RESULTS & ADVANCEMENTS

Our group published the first major article reporting the increasing trend of CDI in children in the US and reported that CDI is associated with increased risk of colectomy and death in children. We have also identified an increased risk for CDI in children who are prescribed certain classes of medications such as proton pump inhibitors, histamine-2 receptor antagonists, corticosteroids, and specific classes of antibiotics. The publication resulting from this research demonstrated that with each additional class of antibiotic a child is exposed to, their risk doubles for CDI. CDI has traditionally been thought to occur only in hospitalized children. There is an increasing trend in community associated CDI in children. These findings are critically important to the understanding of this emerging infection in order to identify and execute prevention strategies in a vulnerable population, which has been previously under recognized.

LEAD FACULTY

Cade Nylund
Greg Gorman
Beth Hisle-Gorman
Apryl Susi, Matt Eberly
Jayasree Krishnamurthy
Kevin Oakley