Comparing Active to Passive Surveillance In Philadelphia, 2005–2009: Implications for the Transition to Nationwide Passive Varicella Disease Surveillance
Kendra Viner, PhD, MPH1, Michael Nguyen, MD2, Dana Perella, MSPH1, Adriana Lopez3, Niya Spells, BA1 and Barbara Watson, MBChB, FRCP, FAAP1, 1Division of Disease Control, Philadelphia Department of Public Health, Philadelphia, PA, 2Center for Biologics Evaluation and Research, FDA, Rockville, MD, 3CDC