Woolsorters’ Disease

Hugh Pennington

The big puzzle about anthrax is that terrorists have so far used it so little. After all, the bulk of the world’s population lives in countries where it occurs naturally, and where it isn’t difficult to get live material to start a culture. The notion that you need to be trained in biological warfare to grow it is ludicrous. In principle, any doctor, dentist, vet, microbiology graduate or hospital bacteriology lab technologist could produce it. In Britain, at least 100,000 people have the knowledge, and even if they’ve forgotten some of it, they know which textbook contains the necessary details. Preparing spores is easy: biological warfare researchers used to grow them on Marmite agar, which incorporated that well-known yeast extract. ‘Weaponising’ the spores isn’t difficult either. It’s true that something has to be added to spore suspensions to stop them clumping when they are prepared and dried, but as David Henderson from Porton Down said in 1952, in a journal to be found in any medical school library, ‘fortunately many substances added to the suspension will prevent clumping. The simplest and most effective that has been found is sodium alginate used in concentrations of about 0.1 per cent.’ Laboratory-quality sodium alginate costs £42 per half-kilo – enough to treat 200,000 billion spores – and is available from laboratory suppliers. It comes from seaweed and is widely used in the food industry – in ice cream, for example, to stop ice crystals forming.

Scientists optimise their chances of making a discovery by picking on problems that are ripe for resolution, often because the necessary laboratory techniques have just come on stream. Robert Koch’s choice of anthrax in 1873 is a brilliant instance of this. Thanks to anthrax, he founded bacteriology as a science and in little over a decade catapulted himself from the life of a rural doctor in a small town in Posen – a province of the Second Reich east of the Oder described in the contemporary Baedeker as ‘uninteresting’ – to a chair and institute directorship at the University of Berlin and, eventually, a Nobel Prize. His choice was inspired for the same reason that anthrax is so amenable to use by terrorists: growing it is not a sophisticated undertaking. Koch made his own glass culture chambers and filled them with liquid taken from inside the eyes of cattle killed at his local slaughterhouse. The bacteria grew beautifully and made spores. To test the virulence of his cultures he used wild mice from the stables, then white mice from the small but rapidly breeding colony kept as pets by his daughter. He made his own constant temperature incubator by carefully adjusting the height of a kerosene flame under the dishes of sand on which his cultures rested.

Koch invented these methods as he went along because other equipment wasn’t commercially available; and since he didn’t have a laboratory, he carried out the experiments in his consulting room. The room faced south-west, and the sun provided the light for his microscope. He worked alone. His first paper on anthrax, ‘Die Aetiologie der Milzbrand-Krankheit, begründet auf die Entwicklungsgeschichte des Bacillus Anthracis’, was published in 1876, and was recognised by the scientific community for the masterpiece it was. For the first time there was incontrovertible evidence that a specific disease was caused by a specific organism. The paper described his discovery of anthrax spores – the extremely resistant but still infectious stage of the bacterium’s life history which allowed it to survive harsh environments and stay in the soil for years as a threat to farm animals. If Koch could do all these things with home-made apparatus, there is surely nothing to prevent a contemporary terrorist, with the results of more than a hundred years of research on anthrax at his disposal, from setting up a spore factory and scaling up the procedure.

According to the book of Exodus, Moses was the first practitioner of biological warfare, having been advised by the Lord to ‘sprinkle ashes toward the heaven in the sight of Pharaoh’; Moses did so and the ashes ‘became a boil breaking forth with blains upon man, and upon beast’. This sounds like anthrax. Mercifully, few individuals have so far followed Moses’ example. During the 20th century, however, governments spent large sums on anthrax research in military or quasi-military laboratories. They were influenced by its ease of production, but more important was the spores’ ability to survive extremely well in infectious form when blown on the wind, and to cause lethal human infection when breathed in. A further advantage is that the victim dies but is not infectious to anyone else: your own side, in other words, is safe – and can be protected additionally by vaccination. For the spore-makers and the politicians who order their use this is important, given that the wind might change.

The spores were discovered by the greatest of German bacteriologists, and immunisation was developed by his French counterpart, the incomparable Pasteur. This, too, was a revolutionary advance and its staging was masterful. On the afternoon of 2 June 1881, Pasteur travelled by train to Melun, and from there to a large farm at Pouilly-le-Fort, where two groups of 25 sheep had been assembled. One group had already been immunised some time before with Pasteur’s new vaccine. On 31 May, they had been injected – along with the other, unimmunised group of 25 animals – with a culture of virulent anthrax bacilli. International observers, politicians, farmers, Army officers, Government officials and reporters were in Pouilly-le-Fort on 2 June. De Blowitz, the Paris correspondent of the Times, filed his copy worldwide later that day: the immunised animals were well, 23 of the unimmunised ones had died, and the other two were dying.

Pasteur’s achievement was very big and very real. But like many scientists before and after, he was also a master of spin. The results had been telegraphed through to him before he caught the train, so he knew what to expect on his triumphant arrival. (A fall-back position had been planned in case the experiment failed: his assistant would attend in his place.) According to the revisionist science historian, Gerald Geison, the story told about the vaccine and its manufacture was almost certainly economical with the truth. A rival anthrax vaccine had been produced by Jean-Joseph Toussaint, a young professor at Toulouse Veterinary School, who treated the bacteria with antiseptic to kill them. His approach, in other words, was fundamentally different from Pasteur’s, which was to enfeeble, but not kill, the organisms by growing them at high temperatures and exposing them to atmospheric oxygen. But Pasteur’s notebooks show that this method was dropped at Pouilly-le-Fort in favour of a product prepared by chemical treatment: a method with strong Toussaintian overtones. Pasteur never admitted this, leaving instead the very strong impression that his oxygen method was used. As Geison says, ‘he did not quite go so far as flatly to lie,’ but he denied Toussaint the possibility of receiving proper credit for his pioneering work.

As a Göttingen graduate, Koch benefited from the best aspects of the Humboldtian educational tradition, while Pasteur was a product of the Ecole Normale’s Napoleonic legacy. Thoroughness, attention to detail and intellectual rigour marked Koch’s work: Pasteur’s was more impressionistic, and conducted on a far larger canvas. There is good evidence that the two men disliked each other intensely: Koch criticised Pasteur publicly for not giving credit to Toussaint; and Pasteur hated all Prussians on principle. (On the other hand, it was Koch who kept a young mistress and Pasteur who never deviated from an irreproachably petit-bourgeois lifestyle.) They had important things in common which distinguished them from British workers on anthrax. In particular, their fame brought them enormous state support. They were also able to address anthrax as a veterinary problem since it killed enough farm animals in Europe to be of real economic significance.

British interest in anthrax developed for a different reason. Thanks to our climate, it had never been a serious animal health problem here. From the late 1840s, however, a new disease had appeared among workers in the woollen mills of Bradford, which mainly affected those who opened bales and sorted imported wools, particularly alpaca and mohair. It came to be called ‘woolsorters’ disease’, though apart from its occupational connection it had no distinctive features save the rapidity of its course and its lethality: fever, rapid breathing, coughing and chest pain often occurred for only a day or two before the victim’s death. Many never had time to call a doctor; some dropped dead without having shown any symptoms at all. The notion that this might be anthrax was put forward in the 1870s by doctors in Bradford, notably J. Henry Bell. In 1880, the local medical society set up a commission to investigate the cause of the disease, the Local Government Board appointed one of its inspectors to look at wool, and the Board of Agriculture asked a university scientist to investigate because anthrax had occurred on a farm through which woollen mill effluent passed.

It was eventually concluded that woolsorters’ disease was indeed anthrax, caused by workers breathing in spores released when they handled contaminated wool. Excellent recommendations to prevent it were made, even if, in the familiar British tradition, many years passed before they became enshrined in law. Most of the firms handling dangerous wools didn’t wait for the law to be passed. Some did, however, and cases of anthrax continued to appear, though there were fewer of them. Public pressure did not abate.

Improved local rules were introduced in Bradford in 1884 and Government regulations promulgated in 1897 and 1909. Woolsorters’ disease continued all the same. In 1919, an Act of Parliament came into force banning importation of the most dangerous materials – goat hair from anywhere, and wool and hair from Egypt. A large disinfecting plant was built in Liverpool, using chemicals and heat in a process known as Duckering, after one of its inventors, Elmhirst Duckering, a factory inspector. Although there’s no doubt that it killed anthrax spores and didn’t spoil the wool, Duckering was not a success. Most imported wool never went near the plant, because mill owners had to pay for the treatment. Three operatives there contracted skin anthrax, but even so it was closed only in 1972.

To the student of science and medicine, the anthrax story is a powerful indicator of the different ways in which nations conduct their scientific affairs and reward their savants. Both Koch and Pasteur went on to do even greater things, but anthrax brought them big rewards. It’s hard to imagine Arthur Conan Doyle saying of any late 19th-century British bacteriologist, as he did of Koch in 1890, that

his name is on every lip, his utterances are the constant subject of conversation, but like the Veiled Prophet, he remains unseen . . . the stranger must content himself by looking up at the long grey walls of the Hygiene Museum . . . and knowing that within them the great master mind is . . . rapidly bringing under subjection those unruly tribes of deadly micro-organisms which are the last creatures in the organic world to submit to the sway of man.

Nor have we ever known any equivalent of the ‘Pasteurisation’ France underwent, with innumerable streets and a Métro station named after him. We have to be satisfied with the tribute paid by the French to the sufferers and investigators of woolsorters’ disease: they called it the ‘maladie de Bradford’.

Not all anthrax-related events have been publicly recognised. The KGB did its best to suppress knowledge of the outbreak in Sverdlovsk (now Ekaterinburg) in 1979. There were 96 cases and 64 deaths. Officially ascribed to contaminated meat, compelling evidence has emerged that it was caused by an escape of spores from Compound 19, a military microbiology facility. Once again, anthrax proved a fine indicator of different national scientific practices: here it exploited the weaknesses in Soviet safety systems, management and culture that were laid bare so dramatically in Chernobyl seven years later.

For most of its history, anthrax’s importance has been as a naturally occurring disease in farmed and wild herbivores, and in humans only as a by-product of interaction with them. In Britain, it has been recorded as an occupational disease not just of woolsorters but of butchers, slaughtermen, dock labourers, fellmongers, hair curlers, carpet makers, brush makers, keepers in zoos and tanners. Those who make charcoal from bones have suffered, as well as the gardeners who used fertiliser made from the powder left over from the bone-crusher. One of the very few fatal cases in the US in the 20th century was that of a piano key maker from Hartford, Connecticut, who cut the keys from elephant tusks with an electric saw.

The overwhelming majority of occupationally acquired cases of anthrax affect the skin. The lesion is big and black in its centre (anthrax is Greek for ‘coal’), and is surrounded by a ring of blisters and a lot of swelling. The name for the lesion, the ‘malignant pustule’, is unjustified because it contains no pus, is almost painless, and because even in the pre-antibiotic era 85 per cent or more of patients recovered completely. Early improvements in treatment rates were produced by anthrax’s redesignation as a medical disease – previously surgeons had scraped, incised and excised the pustules, with disastrous consequences. Anthrax is usually very sensitive to penicillin, whose use has reduced mortality from the malignant pustule to very low levels. Modern experience of treating inhalation anthrax with antibiotics is so limited that reliable statements about its success are difficult to make. The essential problem is that the interval between the onset of illness and the infliction of irreversible damage can be very short. A much rarer and equally deadly form can be caused by ingestion of meat from an animal that has died of the disease: in Africa, outbreaks have occurred after people have feasted on dead hippopotamuses. And, although anthrax is said not to be infectious to others, under particular circumstances it can be. In the Gambia between 1970 and 1974, an outbreak affected nearly five hundred people, the use of communal loofahs having spread the infection. This was an important outbreak not only because of its size but because the immune responses of victims and their relatives were studied in detail. This showed that not everyone who had had a malignant pustule made a vigorous antibody response – so immunity does not automatically follow infection; some people who had not been ill had antibodies, proving that they had been infected without visible manifestations.

Anthrax is a stochastic disease, i.e. one that operates according to the rules of chance. For inhalation anthrax – woolsorters’ disease – this is expressed by saying that the ID50 (the infectious dose required to cause disease in 50 per cent of those exposed) is ten thousand spores. In practice, this means that although exposure to a few spores may cause disease, the more that are inhaled the more likely infection will be. But out of a group exposed to the ID50, it’s not possible to say who will fall ill. All that can be predicted with any confidence is that half of them are likely to die.

As a weapon of mass destruction, anthrax is far from ideal. The essential problem is delivery – getting enough spores to enough victims and relying on the wind to do it. A carefully planned, well-resourced, state-sponsored mass attack would probably have about as much success as the first gas warfare attack in April 1915, when with the benefit of surprise and meticulous preparation over many months (masterminded by Fritz Haber, who later won the Nobel Prize for his work on nitrogen fixation), the Germans killed five thousand Franco-Algerian soldiers at Ypres with 168 tonnes of chlorine released from more than five thousand steel cylinders arranged along a six-kilometre front.

Anthrax’s outstanding attribute as a weapon is its cost-effectiveness. The British planned to kill the German cattle herd in the 1940s by dropping anthrax-laced cattle cakes from the air. Had they been used, they would have been the cheapest smart bombs ever invented: no need for precise aiming when the target is mobile and walks up to the weapons. And events this autumn in the United States have shown that a few days’ growth of spores distributed in a handful of letters can dominate thinking and close down major parts of the Government. The US establishment currently resembles the mill-owners of Bradford, who were never likely to get woolsorters’ disease themselves, but were slow to prevent it in their employees. Perhaps we should rename it ‘mailsorters’ disease’.