CHAPTER 5 An outbreak of anthrax infection in drug users in Scotland
In December 2009 and the first part of 2010, Scotland experienced a large outbreak of Anthrax infection. Anthrax is a very rare but serious bacterial infection caused by the organism 'bacillus anthracis'. The disease occurs most often in wild and domestic animals in Asia, Africa and parts of Europe. The organism can exist as spores that survive in soil and the environment for many years. Humans are rarely infected usually by direct contact with skin or tissues of infected animals. People can also be infected by inhaling or swallowing anthrax spores.
It was apparent early in the outbreak that those affected were drug users. These individuals presented to GPs and hospitals with inflammation or abscesses at the sites in their body where they had injected heroin. Heroin users may sometimes smoke or 'snort' heroin but many will inject it into their body with needle and syringe. The regular injection of heroin and other substances into veins eventually leads to their damage and disappearance. When this happens users may inject heroin directly into muscle or into the skin (skin or muscle 'popping').
In this outbreak anthrax symptoms usually began between one and two days after injection of heroin. The affected individual was usually admitted to hospital some 4 days later. The range of symptoms was wide with no consistent type of presentation to clinicians.
The first cases presented to hospital in Glasgow. NHS Greater Glasgow initially established an Outbreak Control Team ( OCT) to determine the size and source of this outbreak. This OCT investigated this outbreak with the intention of establishing the numbers affected, to establish the cause and then act to control the outbreak. Those involved in the OCT included microbiologists, Strathclyde Police, Health Protection Scotland, and the Health Protection Agency ( HPA) Special Pathogens Reference Unit ( SPRU) at Porton Down and others. The OCT considered that contaminated heroin or a contaminated 'cutting agent' was the most likely vehicle of the anthrax infection. It regarded the risk to the general public as very low.
Over the following weeks more individuals across Scotland were diagnosed with Anthrax and Health Protection Scotland established a National Outbreak Control Team. Representatives of the Scottish Drugs Forum and National Forum on Drug Related Deaths were important additions to the OCT at this stage as it was vital to communicate the risk effectively to the many people who use heroin in Scotland.
The OCT released information though a number of routes advising the drug using community of this additional serious risk of taking heroin and that they should seek urgent medical advice if they developed an infection. The Scottish Drugs Forum worked with the OCT to develop special information leaflets and posters.
The key messages to reduce harm included:
- Avoid the use of any form of heroin if possible
- Seeking alternatives via drug treatment services
- Highlighting the symptoms and signs of infection.
It was considered that smoking (or snorting) heroin could lead to breathing in anthrax spores and the risk of inhalational anthrax. This combined with the risk of injecting anthrax spores into veins, muscles and skin meant that the OCT advised addiction services and pharmacies that it was not possible to advocate any 'safe route' of administration of heroin. This approach was in contrast to the outbreak of Clostridium novyi infection affecting Intravenous drug users in Scotland in 2000 (McGuigan et al 2002, Taylor et al 2005). This organism did not have the same potential for infection by inhalation.
The Chief Medical Officer alerted all general practitioners, hospital accident and emergency departments, intensive care and high dependency units, microbiologists, the ambulance service, NHS 24, services for drug users and others, to be aware of the potential for anthrax in those presenting with symptoms consistent with this disease.
The Outbreak Control Team identified three possible reasons for this anthrax outbreak.
First, Anthrax may have entered the heroin at any point in the supply chain from its original source to the point when it was bought by the drug user. Heroin is often transported in skin carrier bags in Afghanistan and other heroin producing areas. The animal skins may be the source of the anthrax spores.
Secondly, the dissolving agent or cutting agent was contaminated with anthrax.
Thirdly, there was a undiscovered link between the cases.
Although the majority of cases were identified in Scotland, a drug user in Germany died from anthrax in December 2009 and, since then a further 4 anthrax cases have been diagnosed in England. The OCT has not been able to identify any direct links between these cases to any Scottish case so far. Despite intensive investigations, working with other agencies and countries, the OCT has not been able to identify a specific cause for the outbreak or any source of contamination of heroin. Those infected with anthrax apparently took heroin by intramuscular, intravenous or subcutaneous injection and/or by smoking or snorting.
The National Outbreak Control Team has worked closely with the Health Protection Agency, colleagues in other parts of the UK and the European Centre for Disease Control. The OCT has also worked closely with anthrax experts from the Centre for Disease Control ( CDC) in Atlanta USA.
Diagnosis has been confirmed by a combination of isolation of Bacillus anthracis in blood cultures in some patients, supported by PCR (Polymerase Chain Reaction) testing of blood or tissues at the Health Protection Agency ( HPA) Special Pathogens Reference Unit ( SPRU) at Porton Down, England.
Those infected with anthrax have been given intensive medical treatment with intravenous antibiotics, guided by expert microbiologist advice. A significant number of patients have required surgical treatment due to the loss, because of infection, of skin, muscle and other tissues. Some patients were treated with specialist anthrax immunoglobulin ( AIG) supplied by the United States Centres for Disease Control and Prevention ( USCDC). CDC experts have actively assisted the investigation and continue to provide advice based on recent US experience with human anthrax infection.
At the time of writing 47 people in Scotland have been confirmed as having contracted anthrax. 35 men and 12 women. The average age was 35 years for both men and women. The first patient was admitted to hospital in Glasgow on 7 December. The majority (39) lived in the west of Scotland with only 11 cases in the east (Table 1).
Table 1: Cumulative Total of Anthrax cases in Scotland by NHS Board, 6 August 2010
Ayrshire and Arran
Dumfries and Galloway
Greater Glasgow and Clyde
Interestingly this distribution mirrors the geographical pattern of the Clostridium Novyi outbreak in 2000.
Although rare, there have been outbreaks or cases of illness among intravenous drug users in recent years. In 2000 Scotland experienced such an outbreak with 60 cases and 20 deaths. The organism, Clostridium Novyi, was considered to have been the cause probably transmitted in a contaminated batch of heroin (Taylor et al 2005, Ringerz et al 2000). In 2000 a heroin-injecting drug user in Norway was identified as suffering from 'injectional' anthrax and contaminated heroin was considered the source of infection (Brazier et al 2004).
This tragic loss of life and disabling illness in young men and women again highlights the enormous risks faced by the large number of people in Scotland who take drugs and, in particular, those who inject drugs.
I would like to thank all those involved in the response to this complex and long lasting outbreak. I would highlight the continuing work of HPS. We are also particularly grateful to CDC in providing experts who travelled over to Scotland in the new year period and for their supply of the specialist anthrax immunoglobulin ( AIG) for treatment of Scottish patients.
The investigation is ongoing. The outbreak has not been declared over. The Outbreak Control Team will publish a final report on this outbreak in due course.