This should be a cause for concern and care. It may be nothing but it may be significant. I for one am quite thankful that it is being investigated. As for all the other means of disseminating smallpox I presume they would be workable. The most infamous case of smallpox being used as a weapon was when General Braddock diistributed the blankets from smallpox victims to Indian tribes. the resultant epidemic was far more deadly than any actual military actions undertook against these tribes. I presume there are a number of days that the virus remains active and that the CDC website would have the detained information.
Stay well - Stay safe- Stay armed - Yorktown