As a result of single-dose varicella vaccination, daycare outbreaks have become rare. We investigated a daycare outbreak resulting from a misdiagnosed varicella case in an unvaccinated attendee. Of 25 attendees aged 12–32 months without evidence of immunity, 7 (28%) were unvaccinated due to religious/philosophical opposition or recent 1st birthday. Single-dose vaccination reduced disease by 92% compared with no vaccination.
From the *Division of Disease Control, Philadelphia Department of Public Health; †Department of Pediatrics, Drexel University College of Medicine; ‡Department of Pediatrics, St Christopher’s Hospital for Children, Philadelphia, PA; and §Centers for Disease Control and Prevention, Atlanta, GA.
Accepted for publication October 9, 2013.
The Centers for Disease Control and Prevention funded this study through cooperative agreement 3U01IP000019 with the Philadelphia Department of Public Health for active varicella surveillance and epidemiologic studies. The authors have no other funding or conflicts of interest to disclose.
Address for correspondence: Irini Daskalaki, MD, St Christopher’s Hospital for Children, Erie Ave at Front St, Philadelphia, PA 19134. E-mail: firstname.lastname@example.org.