There are some sources on the Silliman Hospital in the Tulane University Archives, but I cannot guarantee that you will find specific information on the disease that killed Corp. Griffin. In the Manuscripts Department, Special Collections Division, at Tulane is the Joseph Jones Collection. Within the Jones papers are a "Wardmaster's Register, Silliman Hospital, 1862-1863," and "Registry of Deaths at the Silliman Hospital Commencing Oct 27th 1862."