Smallpox was a systemic disease, officially eradicated since 1979 (WHO), caused by infection with the Variola major virus, whose only reservoir was infected humans.
Hantaviruses are rodent-borne viruses can be transmitted to humans by contact with faeces/urine from infected rodents or with dust containing infective particles. They may cause severe diseases. Eliminating contact with rodents is the best way to prevent infection.