Table of Contents
Journal of Mycology
Volume 2013 (2013), Article ID 413874, 11 pages
http://dx.doi.org/10.1155/2013/413874
Research Article

Optimizing Containment and Control of Candida parapsilosis Fungemia among Neonates in the Outbreak Setting Using a Mathematical Modeling Approach

Department of Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences (USUHS), 4301 Jones Bridge Road, Bethesda, MD 20814, USA

Received 7 January 2013; Accepted 18 February 2013

Academic Editor: Thierry Jouault

Copyright © 2013 Anil A. Panackal. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Candida is the second leading cause of sepsis related death in the neonatal intensive care unit (NICU). Using the C. parapsilosis paradigm, the endogenous and exogenous routes of infection were simulated in order to enhance prevention among neonates at highest risk. A deterministic model was constructed with transmission parameters calculated from the basic reproductive number ( ), derived from the mean serial interval from two published outbreaks. Uncertainty and sensitivity analyses were performed via Latin hypercube sampling. Prevention measure effects were ascertained by incorporating percent coverage and efficacies into the existing model. The colonized and infected neonatal prevalence peaked at 17.4% and 39.4%, respectively, and reduction was achieved by compartmental replacement with susceptibles. Containment of greater than 60% of the cohort had minimal effect on the effective reproductive number ( ) unless hand hygiene compliance dropped below 40% at a fixed ratio of nurses to neonates. Antifungal prophylaxis in combination with hand hygiene and cohorting extinguished an outbreak 14 days sooner than baseline. The critical proportion ( ) requiring prophylaxis in order to stop an outbreak increases, as rises, and the prophylaxis efficacies decrease. Internal and external sources of Candida lead to invasive disease in neonates differentially. Optimal prevention is dependent upon understanding the dynamics of this disease process under diverse circumstances.