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Malaria - and its cousin, yellow fever - had significant implications during the war and the debilitating consequences of the disease were already certain before the Civil War had started in earnest and well before its final history had been written.
Malaria vs Yellow Fever. Malaria and yellow fever are similar in the sense that they are both diseases carried by mosquitoes and move from one victim to the next. Neither malaria nor yellow fever can be transmitted between human beings.