Public health consultant Dr Syed Ahmed speaks after the anthrax revelation
Health officials have said that no new cases of anthrax have emerged 48 hours after two heroin users in Glasgow tested positive for the infection.
NHS Greater Glasgow and Clyde said officials across the country were still looking out for possible new cases.
A man and woman in the city's Victoria Infirmary tested positive for anthrax. The man died on Wednesday.
Doctors are waiting for the results of tests carried out on a third drug user at Glasgow Royal Infirmary.
At the moment, the cases are not being linked, though it is known all three had infections in areas of the body they had injected with heroin.
The last anthrax death in Scotland was in 2006
Police and health officials are investigating whether contaminated heroin or a contaminated cutting agent may be responsible.
Speaking after a meeting of the outbreak control team on Friday, Dr Syed Ahmed, consultant in public health medicine, said: "The possible presence of a batch of heroin contaminated with anthrax makes drug injecting even riskier and even more dangerous.
"Once again, I urge injecting drug users to be on their guard and to seek urgent medical advice if they have experienced an infection or other serious symptoms."
The outbreak control team was told that the female patient with anthrax remained in a stable condition at the Victoria Infirmary.
The male patient undergoing intensive care at Glasgow Royal Infirmary also remains in a stable condition.
The post-mortem examination results on the man who died at the Victoria Infirmary are expected next week.
Health authorities in the Highlands have said they have no reason to believe there is any link with the deaths of two men in Inverness from suspected drug use earlier this week.
Meanwhile, rehabilitation charity Turning Point Scotland has urged heroin users to make use of help services.
The charity's Ian Irvine said all support agencies could do in a situations like this was to promote harm reduction measures.
David, 30, has been a heroin addict for 15 years
"One thing obviously is to encourage people to use needle exchanges so addicts are only getting clean needles," he said.
"We also try and encourage them to use their own needles and not share."
Anthrax is an acute bacterial infection most commonly found in hoofed animals such as cattle, sheep and goats.
It normally infects humans when they inhale or ingest anthrax spores, but cannot be passed from person to person.
The last death from anthrax in Scotland was in 2006 when Christopher Norris died after inhaling the spores.
The 50-year-old craftsman, from Stobs, near Hawick, made drums with materials such as untreated animal hides.
Last November, drum-maker Fernando Gomez, who is thought to have inhaled anthrax spores while handling imported animal skins, died in hospital in London.
The 35-year-old Spanish folk musician had been in the intensive care unit for several days.
Five people died and 17 others were ill in a series of anthrax attacks in the US in 2001.
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