Germs, Genes, & Civilization: How Epidemics Shaped Who We Are Today

by David P. Clark

  Note that typhus and typhoid are quite distinct. Historically, they were confused because both cause fever and a rash. An unfortunate consequence of this is the use of two variants of the same original name for the two diseases. However, typhus results from the bacteria known as Rickettsias, which can grow only inside animal cells. Typhoid is the result of virulent Salmonella, which can be grown in culture. Typhus is transmitted by lice or ticks, whereas typhoid is spread by water or food contaminated with human waste.

  Typhus is at home in cooler climates because the lice that spread it thrive in warm, dirty clothing, especially fur or wool. It is difficult today to imagine just how lousy and verminous our predecessors were—even the upper classes. Archbishop Thomas á Becket was assassinated in December 1170, and his body lay overnight in Canterbury cathedral awaiting burial the next day. He had on “a large brown mantle; under it, a white surplice; below that, a lamb’s-wool coat; then another woolen coat; and a third woolen coat below this; under this, there was the black, cowled robe of the Benedictine Order; under this, a shirt; and next to the body a curious hair-cloth, covered with linen.” As the body grew cold, the inhabitants of these multiple layers began to evacuate. “The vermin boiled over like water in a simmering cauldron, and the onlookers burst into alternate weeping and laughter.”

  In 1542, 30,000 soldiers fighting for the Holy Roman Empire against the Turks were lost to typhus. In 1556, Maximillian II of Germany took 80,000 men to fight the Sultan of Hungary, but abandoned the campaign after losing most of his army to typhus. Assorted European wars supplied typhus with a steady stream of victims for the next few centuries.

  Typhus was carried aboard ships and took a steady, massive toll among the sailors of the competing European imperial powers. It was especially lethal when allied to the poor nutrition and vitamin deficiency typical of long ocean voyages. The British navy stripped, scrubbed, and shaved its sailors before issuing clean clothes. They also issued lime juice to prevent scurvy (vitamin C deficiency). The British consequently lost far fewer sailors than their enemies, especially the French and Spanish.

  The most famous outbreak of typhus was the destruction of Napoleon’s Grand Army in Russia. We have already noted Napoleon’s Haitian fiasco, but this was not his first brush with disease. In 1798, Napoleon invaded and occupied Egypt briefly. More than 40% of his men died, mostly from bubonic plague. Napoleon’s army was so weakened that the British easily ejected him from Egypt. However, Napoleon’s biggest bacteriological disaster came during his attempt to conquer Russia in 1812. The French Grand Army started with about 450,000 men. By October, only about 80,000 were fit to fight, and Napoleon began his retreat from Moscow. A mere 6,000 men made it back to France. Of course, the cold, poor nutrition, and the Russians didn’t help; nonetheless, typhus caused most deaths, with dysentery as runner-up.

  After the Napoleonic era, the Western nations got cleaner. During World War I, typhus was confined to the eastern front. The Serbians lost 150,000 to typhus in the first six months of the war, including more than half of their 60,000 Austrian prisoners of war. Paradoxically, this aided the Serbs because the Austrians were so frightened by the typhus epidemic that they stayed out of Serbia for fear of infection. Overall, the Russians suffered most from typhus. During World War I and the Russian revolution that it triggered, the Russians encountered roughly 25 million cases of typhus and suffered 3 million deaths from typhus. (Among all other combatants in World War I, there were five million cases and about half a million deaths.) The typhus outbreak during the Russian revolution was so severe that Lenin stated, “Either socialism will defeat the louse, or the louse will defeat socialism.” In World War II, scattered outbreaks of typhus occurred, especially in concentration camps, but the use of insecticides such as DDT to eliminate the lice that carry typhus virtually eradicated the disease.

  Jails, workhouses, and concentration camps

  Jails and workhouses resemble refugee camps and concentration camps in many ways. In all of these, helpless humans are herded together, usually under unhygienic conditions. During the eighteenth and nineteenth centuries, typhus spread like wildfire in the overcrowded jails of industrial Europe. Cool, damp conditions, dirty clothes crawling with lice, and malnutrition combined to promote constant epidemics of typhus. Workhouses and orphanages for those without jobs or homes of their own were almost as bad. Ships carrying European emigrants to America or Australia often took aboard more passengers than they were intended for and suffered similar outbreaks of disease. Camps for refugees and prisoners of war were often overcrowded. Any overcrowded institution, whatever its original motivation, is vulnerable to typhus if hygiene lapses. Of course, other diseases also had a field day, but typhus was the biggest killer.

  Although overcrowding is the most important factor, such institutions, whether barracks, prisons, nursing homes, or orphanages, have another serious drawback: Their inmates all share resources. They breathe the same air, drink the same water, and eat the same food prepared in the institution kitchens. Consequently, they also share any infectious agents that use air, water, or food as their mechanism for distribution. The steady increase in population, coupled with the tendency to share resources for economic reasons, has made modern society increasingly vulnerable to waterborne and foodborne disease, whether spread naturally or deliberately.

  Germ warfare

  Burning crops and poisoning the water supply were probably the earliest forms of biological warfare. Tossing dead or rotting animals into wells or waterholes was doubtless reasonably effective. Throughout history, there have been occasional sporadic attempts to deliberately spread infection for military purposes. These have mostly been ineffective or irrelevant. For example, the attempts of white settlers to spread smallpox to American Indians were largely irrelevant because smallpox had already spread by itself.

  By medieval times in Europe, cattle infected with anthrax were being hurled over the walls into castles or walled cities to break sieges by spreading disease. Anthrax is a highly infectious cattle disease that is readily transmitted to humans. It causes a high death rate and was probably reasonably effective. Nonetheless, given the state of hygiene in most medieval towns or castles, there was little need to provide outside sources of infection. With plague, typhoid, smallpox, tuberculosis, dysentery, diphtheria, and measles always around, all that was usually necessary was to let nature take its course.

  The reason germ warfare has been of little account until recently is that plenty of dangerous infections were already in circulation. If the enemy is crowded and unhygienic, some natural disease will undoubtedly attempt a biological assault without waiting for artificial prompting. Only in our modern disinfected age has deliberately spreading disease become a meaningful threat.

  Psychology, cost, and convenience

  During the Vietnam War, the Viet Cong guerillas dug camouflaged pits as booby traps. Within these, they often positioned sharpened bamboo stakes or splinters smeared with human waste. Although it was possible to contract a nasty infection from these, the main purpose was psychological. Worrying about possible booby traps slowed the movements of American troops out of all proportion to actual casualties. Thus, the threat of chemical or biological warfare might have great psychological effect.

  Taking protective measures is costly and inconvenient. Vaccinating soldiers against all possible diseases that might be used is expensive and time-consuming. Moreover, vaccines often have side effects. Consider the anthrax vaccine used by the U.S. army. It was approved in 1971, has been thoroughly tested, and is considered relatively safe. It produces swelling and irritation at the injection site in 5% to 8%, and causes severe local reactions in about 1% of those inoculated. Major systemic reactions are “rare,” but the vaccine has not been widely used. Vaccination requires six inoculations, plus annual boosters. Although it works against “natural” exposure, it is uncertain whether it would protect against a concentrated aerosol of anthrax spores.

  Even without germ warfare,
drugs given to troops from temperate countries to ward off malaria and other tropical infections can damage health if taken over a long period. Constant exposure to insecticides can damage the nervous system. Dressing infantry in protective clothing and respirators hampers mobility. In hot climates, extra clothing can also cause heat stress.

  Anthrax as a biological weapon

  Anthrax is a virulent disease of cattle that infects humans quite easily, causing a high death rate. It is caused by a bacterium, Bacillus anthracis, which is easy to culture and forms spores that can survive harsh conditions that would kill most bacteria. The spores can lie dormant in the soil for years before germinating upon contact with a suitable host. In some ways, anthrax is the ideal biological weapon: lethal, highly infectious, and cheap to produce, with spores that store well. As noted, during the Middle Ages, cattle infected with anthrax were sometimes hurled into castles or walled cities to break sieges.

  The problem with anthrax is that the spores are so tough and long-lived that getting rid of them after hostilities are over is almost impossible. After your enemy has been eliminated, the idea is to move in and occupy his territory. Unfortunately, anthrax spores persist so long in the soil that they are likely to infect the invaders. Off Scotland is the tiny island of Gruinard, which the British used to test anthrax during World War II. Thousands of sheep were used as victims, and large amounts of anthrax spores were scattered around. Although the island has been fire-bombed and disinfected, it remains uninhabitable even today because anthrax spores still survive in the soil.

  Amateurs with biological weapons are rarely effective

  In 1995, the American Type Culture Collection (ATCC) shipped a culture of Yersinia pestis (bubonic plague) to a member of a group of white supremacists. The activist was convicted of falsifying a federal certification number that he used to fool the ATCC into thinking he was associated with a bona fide institution. In 1998, the FBI arrested the same individual for possessing Bacillus anthracis (anthrax). However, it turned out to be a harmless vaccine strain! Ironically, U.S. Army researchers isolated these harmless, nonsporing derivatives of anthrax for use in immunization.

  Even more farcical was the report in July 1998 of a plot by Republic of Texas separatists to assassinate President Clinton. Their plan was to use a cactus thorn coated with the AIDS virus, anthrax, and botulism. A modified cigarette lighter would have fired the projectile. This incident illustrates another weakness of germ warfare: the introduction of needless complications. If you are going to shoot someone, why not use an unmodified gun with an ordinary bullet?

  The ATCC received a lot of publicity for supplying white supremacists with plague and Iraq with anthrax in the 1990s. Not surprisingly, a variety of proposals for more regulations were put forward. However, any country that possesses hospitals with microbiological laboratories can wage germ warfare. Major hospitals and research centers in all nations possess stocks of lethal microorganisms that are needed for diagnostic comparisons and to prepare vaccines and antisera. This is especially true of poor nations where virulent infections are frequent. Thus, any reasonably informed hospital microbiologist or clinical technician could obtain cultures of dangerous biological agents if desired. This situation makes both export controls and intensified security procedures for research laboratories futile. Indeed, in many third-world countries, the germs of lethal diseases could be directly isolated from infected people or animals during outbreaks.

  Which agents are used in germ warfare?

  Among the bacterial diseases, anthrax, brucellosis, tularemia, glanders, melioidosis, and bubonic plague have all been considered for use by the military. Assorted viruses have been suggested, including emerging diseases such as Lassa fever and Ebola virus, but the only consistent choice among viruses is smallpox. If we stick to the idea that germ warfare should be cheap and simple, we can eliminate the viruses. Although they seem more intimidating because they cannot be cured by antibiotics, viruses are difficult to culture because they replicate only in cells of other creatures. Although viruses can be cultured in egg yolks or cultured mammal cells, this requires high technology and trained staff. Granted, substantial batches of virus are grown for vaccines in advanced nations, and a relatively small volume of virus preparation could infect millions. Nonetheless, for quick-and-dirty backyard operations, we should stick to bacteria that can grow by themselves in culture.

  Brucellosis, caused by Brucella, is a disease of cattle, camels, goats, and related animals. The United States developed it as a biological weapon from 1954 to 1969, although its choice seems curious. In humans, brucellosis behaves erratically, and although victims often fall severely ill for several weeks, it is rarely fatal, even if untreated. Tularemia, caused by Francisella tularensis, is a disease of rodents, with a death rate of 5% to 10% in humans, if untreated. Melioidosis, caused by Burkholderia pseudomallei, is related to glanders (Burkholderia mallei), a disease of horses. Melioidosis is a rare disease of rodents from the Far East that is spread by rat fleas. Despite being only “pseudo”-mallei, melioidosis is worse than glanders and is fatal around 95% of the time in humans.

  During and just after World War II, bubonic plague was popular. Although normally transmitted by fleas, Yersinia pestis can be grown easily in culture and can be distributed by spraying. In July 1948, the Red Star, the official Soviet Army newspaper, described a captured Japanese germ warfare facility located in Manchuria. It produced nearly a ton of bubonic plague bacteria per month. The Russians claimed that the Japanese had used prisoners for testing, generally with fatal results. The British biological warfare center at Porton Down also kept large-scale bubonic plague cultures on hand for several years after World War II. In the 1960s, the United States might have experimented with spreading plague among rodents in Vietnam, Laos, and Cambodia. As with much information about biowarfare, this is disputed and uncertain. In 1969, President Nixon announced a ban on chemical and biological warfare research. Since then, interest in bubonic plague has faded.

  The Soviet germ warfare program is supposed to have concentrated on anthrax and smallpox (including artificial mutants and hybrids). For an industrial nation, preparation of a virus whose particles are fairly stable and long-lived, such as smallpox, is feasible. In addition, the eradication of smallpox led to the abandonment of smallpox vaccination and, hence, the emergence of vulnerable populations. For a third-world nation, a virus would be a dubious choice. Anthrax is a good deterrent, but occupation of territory after anthrax release is hazardous. For the Soviet Union, with its vast expanses of thinly populated land, this consideration was perhaps minimal.

  World War I and II

  The Germans made some amateurish attempts to infect animals in World War I. German agents inoculated cattle and horses shipped to the Allies from the United States in 1915 with anthrax and glanders, respectively. Similar schemes were tried in France in 1917. German agents based in Zurich were accused of spreading cholera in Italy. No significant effects can be traced to these attempts; whether they were technical failures or the accusations were mere propaganda is debatable.

  The Japanese have been accused of spreading bubonic plague in China during World War II. The Japanese probably had the capacity to grow large cultures of plague. There are accounts of attacks by small numbers of Japanese aircraft that dropped cotton rags, rice grains, and other materials supposedly carrying plague bacteria or perhaps plague-infested fleas. Undoubtedly, minor outbreaks of bubonic plague occurred in central China during the war years. Some 100 to 200 cases of plague were reported, mostly fatal. The Chinese government claimed that these were due to biological warfare, and the U.S. Surgeon General at the time apparently accepted this.

  The evidence is not convincing. Bubonic plague has been endemic among the rodents of southern China for centuries. The dislocation caused by war easily accounts for sporadic appearances of plague among humans, even in areas distant from the major plague reservoirs. Furthermore, plague bacteria were not isolated from the material drop
ped by the Japanese, although several attempts were made to do so. In any case, plague is caught either from flea bites or by breathing in airborne bacteria. Most bacteria are killed by stomach acid, so contaminated rice is useless in spreading plague. Contaminating cotton rags was also pointless. Spraying a culture of plague would be the only efficient way to infect large numbers of people, as the Japanese must surely have known. What the Japanese were doing is puzzling, but it seems unlikely to have been an effective form of germ warfare.

  Germ warfare against rabbits

  The Australian attempt to destroy rabbits with myxomatosis in the 1950s received much publicity. But rabbits have the distinction of being the first animal targeted for scientific germ warfare by no less a celebrity than Louis Pasteur. This happened in France in 1887. The rabbits had been burrowing above a wine cellar belonging to Madame Pommery of the city of Rheims. Dislodged stones had fallen, smashing bottles of champagne. Pasteur dispatched his assistant with a culture of fowl-cholera. Three days later, 32 dead rabbits were found and the rest had disappeared. Pasteur then sent his assistant to Australia. Here he met with dismal failure. The infection failed to spread among the rabbits. In addition, the cattle breeders were frightened that their herds might be infected and opposed the program. The project was abandoned.