If an outbreak of smallpox were to occur today, it's likely that most doctors wouldn't realize what it was in its early stages, which would allow the disease to spread.
Even one confirmed case of smallpox would be considered an international health emergency. The Centers for Disease Control and Prevention can do definitive testing using a tissue sample taken from one of the lesions on the skin of the infected person.
No cure for smallpox exists. In the event of an infection, treatment would focus on relieving symptoms and keeping the person from becoming dehydrated. Antibiotics might be prescribed if the person also develops a bacterial infection in the lungs or on the skin.