Nosema Apis - Transmission

Transmission

Newly emerged bees are always free from infection. Spores must be swallowed by a bee for the infection to be initiated. Spores germinate quickly after entering the ventriculus, and the epithelial cells of the ventriculus are infected when the vegetative stage is introduced by way of the hollow polar filament. Once inside a cell, the vegetative stage increases in size and multiplies, effecting an apparent concurrent reduction of RNA synthesis in the host cell. In 6–10 days the infected host epithelial cell becomes filled with new spores. Epithelial cells are normally shed into the ventriculus where they burst – releasing digestive enzymes. When infected cells are shed similarly, they release 30–50 million infective spores when they burst.