The search is on to find cause of parasite that has sickened over 3000 

No specific source has yet been identified for a growing nationwide outbreak of cyclosporiasis, a parasitic illness often tied to contaminated food that has now surpassed 3000 cases in 31 states. Many of the cases are clustered in New York City, which is also dealing with a Legionnaires' outbreak. NBC News' Erika Edwards reports.