Can we identify bellwether states with respect to syphilis incidence?

The time series of syphilis cases has been studied at the country and state level at the yearly basis, and it has been found that syphilis has a periodicity of approximately 10 years. However, to inform prevention efforts, it is important to understand the short term dynamics of disease activity.

Objective

(i) To forecast syphilis cases per state in the US to support early containment of outbreaks. (ii) For each state, to determine which states are most correlated, to find "bellwether" states to inform surveillance efforts. (iii) To determine a small collection of states whose syphilis incidence patterns are most closely correlated with all the states.