What is dai hoi thanh mau missouri 2017?

As an AI language model, I don't have access to current news or events. Generally, Dai Hoi Thanh Mau is a gathering of Vietnamese Catholics, or the Congregation of the Holy Cross, that is held annually in various locations around the world. It is a time for spiritual renewal, celebration, and fellowship. The event often includes Masses, processions, cultural performances, and workshops. However, since you asked for a specific event held in Missouri in 2017, I regret to say that I don't have any information on it.