Howard's End: Anthrax Backgrounder

The World Health Organisation surveillance network has gone to a higher level of alert following confirmed and suspected outbreaks on anthrax across the world. Scoop offers some background information on anthrax. Maree Howard writes.

1. Anthrax is NOT listed as an infectious disease. It is not like the plague or cholera.

2. Anthrax is the name for a disease caused by a germ, Bacillus anthracis, which can be found in ruminant animals such as cows, sheep, goats, camels and antelopes. Outbreaks among these animals is more likely to occur in Asia, Africa and Latin America, than in Western Europe, the U.S. and Australia and New Zealand.

3. The germs can form spores, a protective capsule which enables them to resist degradation in nature. Fields where anthrax-infected cattle have been buried can harbour spores for more than 40 years. If anthrax spores enter the body. the bacteria proliferates, producing poisonous toxins that cause sickness or sometimes death.

4. Human casualties of anthrax are historically rare. Those most at risk are people who handle dead animals or their products, such as abattoir workers, tanners, or wool sorters. Sixty-eight people were killed in Sverdlovsk, Russia in 1979 when a military unit accident accidentally released spores into the air.

5. Anthrax spores are absorbed through one of three ways, with the symptoms usually showing up after three to five days of infection:

(a) through the skin, via a cut or and abrasion (about 95% of cases). A raised itchy bump, rather like an insect bite, develops into a painless lesion about one to three centimetres across, with a characteristic area of blackish dying flesh in the centre. Among untreated cases, the death rate is about 20 percent.

(b) by eating contaminated, undercooked meat. Early symptoms are nasea, vomiting, acute abdominal pain and diarrhoea, followed by blood poisoning and shock. Intestinal anthrax results in death in 25-60 percent of cases.

(c) by being inhaled. Initial symptoms resemble those of a cold, which after several days develop into breathing problems and shock, often followed by coma. Inhaled anthrax is usually fatal.

It is inhaled anthrax which authorities recognise is the most dangerous possibility since it could be distributed throughout an auditorium or an enclosed building through the air-conditioning system.

Lapsed time detectors using mercury vapour lamps, pulse lasers and strobes and mass spectrometers are used for detection. These are called BIDS, an acronym for Biological Integrated Detection System.

They take an air-sample and cultivate them. That gives an ability to detect if something lethal can be determined but the kind of agent would still be unknown. False positives are a concern. Moreover, it is not real time detection. Nevertheless, an alarm would be sounded.

External distribution of anthrax is highly unlikely to have a major impact because of widely variable meterological conditions.

Person to person spread of anthrax is extremely unlikely.

Treatment: Anthrax patients can be cured with antibiotics, but provided the disease is spotted quickly enough especially in respiratory or intestinal infections. The problem is that symptoms of anthrax are often difficult to distinguish from those of colds, the flu, or food poisoning.

Vaccine: There is a vaccine against anthrax, which is usually routinely administered to military personnel but is not otherwise recommended except for people considered at high risk, such as meat industry workers and scientists handling the disease. The vaccine is reported to give 93 percent protection against anthrax. However, it does not give permanent protection - boosters are needed - and it can have side-effects.

Pregnant women should only be vaccinated if absolutely necessary. Test results for inhaled anthrax have been sketchy.

Anthrax has been developed by several states as a biological weapon as it is relatively easy to develop and produce in large quantities and can be stored for long periods. It is also cheap to manufacture.

Terrorist groups seeking to cause mass death face several major hurdles, notably devising a way of delivering spores in an aerosol form.

However, even though there are "PUSH" packs with enough antidotes and antobiotics to treat around 10,000 people per PUSH pack, the best alternative is likely to be to quarantine an area and then begin to try to produce as much antibiotic as you can.

There are 17 available substances for chemical weapons. Whereas there are 47 infections and viruses available for biological weapons.

Another problem is that infections and viruses can be multiple-mixed into a cocktail so that nobody can really know what they are dealing with for some time. That makes any treatment extremely difficult.

Intelligence officials are aware that throughout the 90's, hundreds of scientists in Russia and elsewhere were developing antidote-resistant biologicals along with the cocktail mixes. Many biologicals have similar initial symptoms so diagnosing which biological you are dealing with in a cocktail mix can be very difficult.

Hybridised biologicals are becoming a real concern. Intelligence officials believe that smallpox - only at two locations in the world - has not been sufficiently security- controlled and some has moved to other sites and been hybridised. If just 10 people became infected with smallpox which takes about 10 days to incubate, the calculations would be disasterous.

The good news is that unless you inhale anthrax you can survive.

ENDS

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