Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions
Varicella Outbreak School Surveillance, 2012-2015
J Pediatr Infect Dis Soc; ePub 2018 Mar 7; Lopez, et al
The majority of cases associated with varicella outbreaks in the US occurred in undervaccinated children (unvaccinated and 1-dose vaccine recipients), according to a recent study. Through the Centers for Disease Control and Prevention Epidemiology Laboratory Capacity funding, health departments conducted active surveillance for varicella outbreaks in schools from 2012 to 2015. Outbreaks of varicella were defined as ≥5 cases in a school within at least 1 incubation period (21 days). Researchers found:
- Georgia, Houston, Maine, Minnesota, New York City, and Philadelphia participated in all 3 years; Puerto Rico and West Virginia participated in 2012 to 2013; and Kansas and Arkansas participated in 2014 to 2015.
- 29 outbreaks, including 262 cases, were reported.
- The median size of the outbreaks was 7 cases (range, 5–31 cases), and the median duration was 31 days (range, 4–100 days).
- Of the case-patients associated with larger outbreaks (≥8 cases), 55.4% were unvaccinated, and 15.7% and 18.1% had received 1 or 2 doses of vaccine, respectively.
- In small outbreaks (5–7 cases), 33.3% of case-patients were unvaccinated, and 16.7% and 38.5% had received 1 or 2 doses of vaccine, respectively.
Lopez AS, LaClair B, Buttery V, et al. Varicella outbreak surveillance in schools in sentinel jurisdictions, 2012–2015. [Published online ahead of print March 7, 2018]. J Pediatr Infect Dis Soc. doi:10.1093/jpids/piy010.
It is important to monitor varicella outbreaks over time in order to gain information about varicella epidemiology. In 2007, a 2-dose varicella vaccine recommendation was initiated. Since varicella is a disease that can manifest during an individual’s entire lifespan (80+ years), changes in epidemiology of the disease will take time to manifest and therefore, monitoring of varicella disease and outbreaks is essential. This study, which examined school outbreaks, found that increasing vaccination rates was associated with smaller outbreaks, compared with larger outbreaks where more cases were unvaccinated. Monitoring school outbreaks can help enforce and inform public policy on vaccination for school entry.—Sarah Rawstron, MB, BS, FAAP, FIDSA
Pediatric Residency Program Director, The Brooklyn Hospital Center, NY
Clinical Associate Professor, Icahn School of Medicine, Mount Sinai, NY