Evaluation of varicella reporting to the National Notifiable Disease Surveillance System--United States, 1972-1997.

Varicella (chickenpox) is a common, highly infectious, vaccine-preventable disease. Before 1995, an estimated 4 million cases of varicella occurred each year in the United States, approximately 100 patients died, and approximately 10,000 persons were hospitalized because of varicella and related complications. Approximately 95% of cases, 66% of hospitalizations, and 45% of the varicella-related deaths occurred among persons aged <20 years (CDC, unpublished data, 1998). In 1972, varicella became nationally notifiable in the United States; subsequently, 46 states and the District of Columbia (DC) provided weekly reports to CDC's National Notifiable Disease Surveillance System (NNDSS). In 1981, varicella was deleted from the weekly morbidity report, and in 1982, states were encouraged to report varicella to NNDSS annually. In 1995, a live, attenuated varicella vaccine was licensed in the United States for routine use in children. This report describes changes in the annual reported incidence of varicella from 1972 to 1997 and discusses the need for increased surveillance with the availability of a vaccine.