Shelby County's measles outbreak has been declared over.
Media outlets report that the outbreak began April 5 and sickened seven people, all of whom have recovered. The Shelby County Health Department wasn't able to discover the source of the outbreak.
Health officials say the outbreak is considered over because it's been 42 days -- or two full incubation cycles for the virus -- since the last case was confirmed.
Measles starts with a high fever, runny nose, cough and red eyes, followed by a rash. Roughly one in 1,000 measles cases results in death.
According to the Centers for Disease Control and Prevention, the seven Shelby County measles cases were among 19 confirmed in nine states nationwide as of May 21.