Yes that is all true.

At Camp White Sulphur Springs in August and September of 1862 in a regiment of Arkansas newly conscripted young soldiers the death rate was more like 1 out of every 10 soldiers died.

This would be 100 times higher than what would be concidered normal from measles of 1 in 1,000. However, This may have been a records keeping fluke because it would seem that all of the new conscript not previously assign to a regiment prior to becoming ill and being placed in the hospital were eventually assigned to that regiment (24th Arkansas). But that is still a pretty high percentage. Of all the men who went to a hospital because of illness, 10% died as a results of that illness. And far more were not fit for service for as long as 6 months afterwards.

A large portion of the Arkansas Regiments captured at Arkansas Post were not there because they were still ill in the hospital at White Sulphur Springs. So may so that a new regiment (Hardy's Regiment of Arkansas Infantry) was formed from those men who were not at Arkansas Post when their parent regiments were captured.

In Col Robert Garlands Texas Brigade (6th Texas Inf, 24th and 25th Texas Cav. Dis) was in little better shape. The 25th Texas Cavalry (dismounted) may have had less than 250 men fit for duty when Arkansas Post surrendered, due to illness. The 25th having lost a lot of its men left sick in the hospital at Shrevesport.