While the detection of viruses is distributed over the Internet, for example, just as the cells of the immune system are spread throughout the body, there is no biological equivalent of the central analysis centre.

ECONOMIST: A thousand ills require a thousand cures

Meanwhile, Colorado voters were projected to reject an anti-abortion amendment that would have defined a "person" as "every human being from the beginning of the biological development of that human being, " according to a CNN analysis of exit poll data.

CNN: Variety of proposals on ballots in 37 states

"Only a full analysis performed at an accredited laboratory can determine the presence of a biological agent such as ricin, " according to the bureau.

CNN: Ricin scare rattles Washington