The Pharmaceutical Journal Vol 267 No 7171 p590
27 October 2001

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Responding to biological terrorism

The recent anthrax attacks in the United States have made the threat of biological terrorism seem real to many people. Clare Bellingham finds out what advice pharmacists can give to worried members of the public

Biological terrorism strikes fear in the hearts of many people. The number of anthrax cases in the United States is rising and has caused alarm in the United Kingdom. A number of hoax incidents have occurred in the UK but, importantly, there has not been a single confirmed attack here. This, however, has not eased public concern. In recent weeks, pharmacists, who are often the most readily accessible health care professional, have found themselves answering queries about the symptoms of anthrax, its treatment and the need for precautions for people travelling to the US. And anthrax is not the only potential biological weapon: others include smallpox, plague and botulism.

Pharmacists have a role in providing advice to people who are concerned about the threat. The Department of Health says that the Public Health Laboratory Service's website (www.phls.co.uk) should be used as the main source of information. The public should be reassured that taking antibiotics as a precautionary measure is unnecessary, unless known exposure has been confirmed.

The Government's line on biological terrorism is that people should not panic. Although the Department of Health will not discuss the details of the precautions taken against biological terrorism, it will confirm that supplies of antibiotics and vaccines have been secured. It will not comment on which antibiotics or how much of each. Pharmacists have reported stock problems recently with two drugs used in the treatment and prophylaxis of anthrax — ciprofloxacin and doxycycline — suggesting that both have been purchased in larger quantities than normal.

In the US, the American Pharmaceutical Association says that pharmacists have been called upon to assume responsibilities for the distribution of vaccines, antidotes, antimicrobials, and other pharmaceutical agents, administering vaccines and in the clinical care of casualties. A Department of Health spokeswoman said that, in the UK, victims of biological warfare would access drugs in the normal way, via their general practitioners, but added that this may differ in emergencies according to individual health authority's contingency plans.

Anthrax

Anthrax is caused by the bacterium Bacillus anthracis. It occurs rarely in the UK: the last death from anthrax was in 1974 and 14 cases were notified between 1981 and 2000.

Anthrax occurs in three forms: cutaneous, pulmonary and gastrointestinal. Cutaneous anthrax begins as an itchy area of skin followed by the appearance of a small bump that develops into an ulcer with a black, necrotic centre. The ulcer is surrounded by marked swelling but is rarely painful. If untreated, it is fatal in between 5 and 20 per cent of cases. However, with treatment it is rarely fatal. Pulmonary (or inhalation) anthrax is more serious. It begins with an influenza-like illness with symptoms such as fever, tiredness, mild non-productive cough and chest pain. This is followed by abrupt onset of acute respiratory distress and sepsis. Gastrointestinal anthrax is the most rare form. It causes severe abdominal pain, nausea and vomiting, watery or bloody diarrhoea, fever and blood poisoning.

Pulmonary anthrax is caused by inhaling anthrax spores. Airborne transmission between people does not occur. Cutaneous anthrax is caught through direct contact with the skin of an infected animal or person. Symptoms of pulmonary anthrax begin within 48 hours of inhaling spores but cutaneous anthrax may take several weeks to develop.

Anthrax is treatable with antibiotics, although to be successful treatment needs to begin as soon as possible after infection. The treatment of choice for pulmonary anthrax is intravenous ciprofloxacin or penicillin. Cutaneous anthrax is treated with oral ciprofloxacin. Prophylaxis against anthrax with ciprofloxacin or doxycycline is effective. Although no drug is licensed in the UK for the treatment of anthrax, doctors are able to prescribe antibiotics for the infection on a named-patient basis.

A vaccine against anthrax has been licensed in the UK since 1979 although its use is reserved for people at occupational risk (eg, tannery workers). In addition, researchers at the Centre for Drug Delivery Research at the School of Pharmacy, University of London, are currently developing a novel vaccine for anthrax. The vaccine offers advantages over the currently available vaccine in that it requires fewer doses and does not include toxin components known to cause side effects.

According to guidance from the Public Health Laboratory Service, people who have recently travelled to the US, and people planning trips there, do not need to be given antibiotics or vaccination.

Two papers to be published in next week's Nature examine the structure of anthrax toxin. Application of this knowledge could lead to better treatments and vaccines.

Other threats

The threat of smallpox is perhaps more worrying than anthrax for two reasons: it can be transmitted from person to person and it is not treatable. It is perhaps for these reasons that the World Health Organization announced on 19 October that it is to review guidelines on smallpox vaccination in light of the concern that populations might be deliberately infected.

Smallpox is caused by the variola virus and it is fatal in up to 30 per cent of cases. Symptoms begin with fever, tiredness, headache and backache followed by a rash that appears all over the body, including the mouth. The rash consists of vesicles that form crusts after a couple of weeks. Smallpox can be distinguished from chickenpox by the fact that it is more severe, is not itchy in the first few days (chickenpox is), the presence of vesicles and the fact that the first spots of the rash appear on the forehead, face, scalp, neck, hands and wrists as opposed to the trunk in chickenpox.

Smallpox cannot be treated but vaccination in the first four days of the incubation period can reduce the severity of the attack, including reducing mortality by 50 per cent.

Smallpox has been eradicated worldwide since 1980 and routine immunisation for smallpox in children stopped in the UK in 1971. Vaccination of individuals at risk of exposure (eg, laboratory workers) has continued. However, vaccination is not without problems. It can cause adverse reactions including potentially life-threatening complications in people with eczema and still-birth, and it is not always effective. How often the vaccine needs to be given is unclear because it tends to only be given to people working on short-term laboratory projects. The PHLS says that studies indicate that successful immunisation in the past two to three years reduces the attack rate to below 10 per cent. A spokeswoman said that it would be advisable to have a booster after three years. Although individual's levels of immunity decrease at different rates, it seems unlikely that those people vaccinated before 1971 would be protected now.

The Department of Health said on 22 October that because there is no specific threat of smallpox in the UK there are no plans at present to introduce vaccination.

If it was decided that mass immunisation was needed, sourcing large quantities of the vaccine is likely to be problematic.

Other biological terrorism threats include plague and botulism. Both could be used in an aerosol weapon and botulinum toxin could also be used to contaminate food and water supplies.

The threat of biological terrorism is likely to remain with us for some time. Fast and effective reaction to any attack depends on being prepared.

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Clare Bellingham is on the staff of The Pharmaceutical Journal