The Uganda strain (MR766) caused upregulation of the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), inositol requiring enzyme 1α (IRE-1α) and activating transcription factor-6 α (ATF6α) proteins, while infection with the Honduran strain induced expression of IRE-1α and ATF6α. This evidence concerns the gene ERN1 and infection.