Which socio-economic conditions facilitate the spread of poliovirus?

• A. Poor sanitation and crowded living conditions.
• B. High vaccination rates
• C. Clean water access
• D. Rural isolation only

Answer: (A)

Spread of poliovirus hinges on the fecal-oral route. When sanitation is poor, sewage can contaminate water and food, and the virus shed in feces can persist in the environment. Crowded living conditions amplify transmission because close contact and shared facilities increase the chance that an infected person passes the virus to others, especially young children who may have less immunity. In such settings, repeated exposure sustains transmission cycles and can spark outbreaks. This is why poor sanitation plus crowding is the key socio-economic factor that facilitates spread. By contrast, high vaccination rates cut transmission by creating herd immunity, access to clean water interrupts ingestion of contaminated material, and rural isolation can limit contacts and thus reduce spread.