Varicella outbreak reporting, response, management, and national surveillance.

Two national surveys were conducted to evaluate the status of varicella case-based surveillance and outbreak response. Although progress toward national surveillance has been significant, a large number of jurisdictions are still without case-based surveillance. For jurisdictions beginning case-based surveillance with limited resources, a staged approach is recommended. The national outbreak survey showed that a significant number of varicella outbreaks continue to occur. The majority of jurisdictions respond to these outbreaks, although the response varies considerably. Depending on the outbreak-response approach, costs per outbreak ranged from $3000 for a typical, or passive, response to $6000 for a more active response. As varicella surveillance and outbreak control improves, jurisdictions may benefit from more-standardized outbreak-control practices. The recent recommendation by the Advisory Committee on Immunization Practices for a routine second dose of varicella vaccine should lead to better varicella disease control, making case-based surveillance and appropriate outbreak response even more feasible.