The second leading reason for death at Camp Chase was small-pox. Although I have not crunched the numbers yet it will be more than 30%. At Fort Delaware it has been estimated that about 20% died of small-pox. From what I've saw where the majority of the prisons in both North and South separated the prisoners with small-pox as soon as possible and took them to a Pest House far from the prison population. And both North and South vaccinated prisoners from small-pox sometimes giving the disease to prisoners.

What is startling to me is the number of deaths that occurred at Camp Sumter aka Andersonville. According to the park ranger I spoke to only 67 Union soldiers died of small-pox and because 12,996 Union soldiers were reported as died there this would come to about 1/2 of one percent due to death of small-pox.

Fort Delaware would be forty times as bad and Chase at least 60 times as bad as Andersonville due to small-pox.

At Andersonville the Union dead due to small-pox were buried in a separate burial location. At Camp Chase they were buried as normal Confederate dead in the Chase Cemetery from my understanding. I cannot speak of Fort Delaware only that many of the Confederate dead were buried at Finns Point in New Jersey much like a mass grave with boxes piled on top of each other.

The explanation may be as simple as the 19th century doctors did not fully realize the reasons of how the small-pox was transmitted. The Federal government provided one blanket per soldier at Camp Chase if they did not have one. Another Confederate coming into the camp may have been issued a blanket at one time belonging to a small-pox victim. At Andersonville the Confederates had no such blankets to issue to the Union soldiers.