Malaria is caused by a parasite which is spread by the bite of mosquitoes. The outbreak of malaria in Brigham City, UT, around Bushnell Hospital led to efforts to quarantine soldiers with tropical diseases and eradicate local mosquitoes.
Many patients at Bushnell came from battlefields in the Pacific where they had been exposed to malaria and other tropical diseases, and some brought these diseases with them to Utah. In 1943, malaria spread from Bushnell to Brigham City. The local epidemic prompted mosquito eradication programs in the area to keep it free from the tropical diseases being imported from the Pacific Theater.