A soldier aged 28 had an attack of malaria overseas in September 1943. He received the usual treatment and had no further attacks. He was evacuated to the United States in July 1944, not for physical reasons. While at his home in Durant, Okla., August 19, he had an attack of malaria with chills and a temperature of 105 F., which lasted about two hours. That evening, while lying in bed, he experienced an acute pain in the left shoulder and twenty or thirty minutes later the pain radiated to and became constant in the left upper quadrant of the abdomen. These pains were severe enough to require morphine and resulted in his hospitalization. He became extremely weak and stated that "he could not get enough air." He was given atabrine and was treated expectantly. On August 22 he was brought from Oklahoma to a hospital by ambulance.
Russ SE, Gaynor JS. SPONTANEOUS RUPTURE OF A MALARIAL SPLEEN. JAMA. 1945;127(13):758. doi:10.1001/jama.1945.92860130002005a