Varicella in the prison setting: A report of three outbreaks in Rhode Island and a review of the literature.

Background: The prison setting carries unique risks for varicella outbreaks and the disease in adults, particularly those who are immunocompromised, can be life-threatening. In 2016-17, there were three outbreaks of varicella at three different correctional facilities in Rhode Island. The Centers for Disease Control and Prevention (CDC) recommend post-exposure vaccination within three to five days for affected populations however the Federal Bureau of Prisons (BOP) notes the logistical challenges of vaccinating exposed incarcerated individuals.

Material And Methods: A descriptive analysis was performed for each outbreak along with an overview of the response. Varicella serologies were obtained from the exposed population at each facility and the results compiled for comparative analysis. A literature review was then performed to identify and analyze other reported varicella outbreaks in incarcerated populations.

Results: In each outbreak, the sentinel event was an inmate with herpes zoster. In prison A, there were 432 inmates exposed to the virus leading to 5 cases of varicella, while the outbreak in Prison B exposed 46 inmates and led to 3 cases. In Prison C, there was one case of primary varicella and 97 inmates were exposed.

Discussion: It is remarkable that there were 3 unrelated outbreaks in a short time and, although corroborating data would be necessary to establish a trend, it may signal an increased risk of varicella transmission within this population. Correctional facilities should remain vigilant and have plans for managing the disease including isolation protocols, serology testing and post-exposure vaccination when indicated. While the BOP does not provide clear recommendations on the use of post-exposure prophylaxis during an outbreak response in this population, the experience in Rhode Island and the review of the literate demonstrate steps that can be taken to facilitate a response including post-exposure vaccination in line with CDC recommendations.