Zoology - Human Health and Diseases Question with Solution | TestHub

Polioviruses are more stable than most other viruses and can remain infectious for a relatively long period in water and food. The primary mode of transmission is ingestion of water contaminated with the virus. Its primary area of multiplication is the throat and small intestine. Next, the virus invades the tonsils and lymph nodes of the neck and ileum. From the lymph nodes the virus enters to blood and by penetrating the capillary walls enters the central nervous system. The virus displays high affinity for particularly motor nerve cells and multiplies within the cytoplasm of motor nerve cells. Hence, the cells die resulting in paralysis.