### Key Points: - **Clinical Diagnosis:** Early diagnosis w…

### Key Points:
- **Clinical Diagnosis:** Early diagnosis was based on symptoms and epidemiological context.
- **Virological Confirmation:** Later, methods such as virus isolation and serological tests were used to confirm polio cases.
- **Global Standardization:** The Global Polio Eradication Initiative standardized diagnostic criteria and surveillance protocols globally.
- **No Evidence:** There is no evidence provided in the sources about a change in the definition of polio from 3 days to 60 days of paralysis post-Salk vaccine to manipulate statistics.