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How does poliovirus reach the brain and spinal cord?
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polio
A health care worker giving a polio vaccine to a child in Katsina state, Nigeria, 2014.
After the poliovirus is ingested, it initially multiplies within the lymph nodes of the intestinal tract. From there, the virus spreads throughout the body via the bloodstream. In cases where the infection progresses to the central nervous system, the virus attacks and destroys motor cells located in the spinal cord and brainstem.1