I have no specific knowledge of this event, but on the surface, it doesn't seem particularly strange to me. This was the winter of '63, and if you look at the casualty rates of Walker's Texas Division during this time frame - in Confederate camps in Arkansas, with no outside influences such as prison camp - or at Burnett's Sharpshooters, another Texas unit comfortably encamped around Marksville, La. - you wouldn't think there was anything peculiar about this kind of death rate at all. Smallpox, dysentery, typhoid, etc, etc. Confederate losses to disease during early 1863 were monumental.