NHS Greater Glasgow and Clyde's Public Health Protection Unit are continuing to work closely with NHS Lanarkshire, the procurator fiscal's office and Strathclyde Police to identify the source of the anthrax. One avenue, which continues to be investigated by Public Health and Strathclyde Police is that contaminated heroin or a contaminated cutting agent mixed with the heroin may be responsible for the infections.
Investigators are working to track down historical information about the anthrax strain. "It does attest to how rare it is," Talbot said. Talbot said the public is not in danger. Anthrax cannot be spread between people.