'Eleventh Hour's' smallpox outbreak: How accurately does it portray the disease?

"Containment" episode CBS, Nov. 6

The premise: Dr. Jacob Hood (Rufus Sewell) is a biophysicist and a science advisor to the U.S. government who investigates crises. An old friend, Dr. Calvert Rigdon (Oded Fehr), virologist and director of the Pennsylvania Health Department, asks Hood to come to a demolition site to help investigate an infectious outbreak.

Twenty-one construction workers are being isolated by men in contamination suits because some have fallen ill with a severe respiratory infection, fever and fatigue, some with a blistery rash. One man escapes but coughs up blood and collapses, then is recaptured.

The group is moved to Rigdon's lab, a Level 3 Biosafety research facility. Hood suspects a smallpox outbreak and thinks he has tracked it to a group of extremely ill Guatemalans who have entered the country. But when Rigdon looks at their viral isolate under the electron microscope, he discovers that their virus is round in shape, characteristic of the chickenpox virus, rather than square as expected with severe smallpox (variola major).

Hood confirms smallpox in the workers. He discovers that Rigdon has been hiding variola major samples in a storage area to produce a better vaccine -- but the boxes were moved, samples were stolen, and one was opened, leading to the outbreak.

The medical questions: Is a smallpox outbreak described accurately? The virus seems to be spreading almost instantaneously, but how long does it really take smallpox to spread? Would people potentially exposed to smallpox be moved to a Level 3 Biosafety facility? Are there still specimens of variola major in the world that could be mishandled and cause a new outbreak? Is it square-shaped as opposed to round?

The reality: Outbreaks of variola major have not been seen in the world since 1977 (in Somalia) and in the U.S. since 1949 (the virus still exists in some high-security labs). "The show's clinical description is not entirely accurate for smallpox," says Dr. Joel Ernst, chief of infectious diseases at the New York University Langone Medical Center. "Smallpox is characterized by fever and rash -- respiratory symptoms are not prominent." Dr. Shawn Skerrett, infectious disease specialist and associate professor of pulmonary medicine at the University of Washington, says "casual contact is usually not sufficient for infection. Smallpox is not nearly as infectious as chickenpox."