Time series analysis of syphilis surveillance data

To manage a public health programme effectively it is necessary to set objectives and priorities according to the resources available. To utilize available resources optimally in a disease control programme we should both estimate the present and predict the future magnitude of the health problem. The CDC has an effective programme to control syphilis, a sexually transmitted disease. To keep track of control activities, CDC receives the number of syphilis cases from all states every three months. Primary and secondary syphilis cases declined from an all time high of 106,539 cases in 1947 to 6399 cases in 1956. Since then, syphilis cases increased to 27,921 in 1986. Congenital syphilis cases declined from 17,600 in 1941 to 239 in 1983, but increased to 408 in 1986. We built time series models for primary and secondary syphilis cases in men and women and congenital syphilis cases in children under one year of age. These models were used to forecast syphilis cases in all three categories. This analysis suggests that no change in the trend of male syphilis cases has occurred, but syphilis cases in women and congenital syphilis cases in children under one year of age during 1987 have increased.