The two major typhus fevers are murine or endemic typhus and epidemic typhus caused by the rickettsia Rickettsia typhi and Rickettsia prowazkeii. Rats, mice, and flying squirrels are asymptomatic carriers of the typhus rickettsia, and the disease is spread to human populations through ticks, chiggers, fleas, and lice. Epidemic typhus is spread by the body louse while scrub typhus is spread by chiggers and murine typhus spread by fleas from rats. The tick borne typhus fever is also known as Rocky Mountain Spotted Fever. Natural outbreaks of typhus always accompanied wars and famines, spread by armies and squalor. The disease also found a permanent home in squalid prisons. The word 'typhus' comes from the Greek 'typho,' which means smoke, perhaps a reference to the mental state of the victim who suffers from high fevers, but also a reference to the miasma cloud that was thought to spread the disease.
History of Typhus Fever
Some disagreement existed among bacteriologists and epidemiologists as to when typhus fever first appeared in recorded history. Some believe the plague of Athens during the Peloponnesian War ravaged the city and killed its leader, Pericles, was an outbreak of typhus fever. In 1083, typhus fever was described in a convent near Salerno, Italy. An outbreak of typhus fever devastated the Spanish at the siege of Granada in 1489. Soldiers arriving from Crete brought the disease and the fever spread throughout the crowded army encampment. During the siege, the Spanish army suffered 3,000 casualties from battle and 17,000 from disease, particularly typhus fever.
During the Thirty Years' War, the armies that traversed Europe left disease, particularly typhus fever, in their wake in German towns such as Metz and Nuremburg. Death rates in German towns during the war were 2-3 times higher than usual. An estimated 8 million Germans fell victim to the disease. Some historians have contended that typhus fever rather than starvation or cold was the main reason for Napoleon's stalled campaign into Russia. Typhus fever spread to Ireland during the Great Famine of the 19th century, and Irish immigrants further spread the disease worldwide as they left Ireland to escape the famine. During the Crimean War, as many as 900,000 deaths were attributed to typhus fever. During World War I, typhus spread through the Balkans and Russian. An estimated 150,000 Serbs and 3 million Russians died of typhus. Lenin is quoted as commenting that "either socialism will defeat the louse, or the louse will defeat socialism." During World War II, typhus ravaged Nazi prison camps and concentration camps killing thousands including Anne Frank.
In 1909, Charles-Jean-Henri Nicolle at the Pasteur Institute in Tunis, Tunisia, discovered that louse was the carrier of typhus rickettsia. Nicolle noticed that while typhus spread outside the hospital area, the disease stopped spreading once patients were inside the hospital. Louse became the prime suspect when he learned that all who entered the hospital were stripped and scrubbed down. Nicolle won the 1928 Nobel Prize for his work with typhus fever.
In 1905, Howard T. Ricketts discovered that Rocky Mountain Spotted Fever was spread by ticks to humans. In 1908, he discovered the causative agent in the blood of animals and in ticks. Ricketts suspected that typhus fever spread through similar mechanisms as Rocky Mountain Spotted Fever. In 1910, as Ricketts was studying typhus fever in Mexico City, he contracted the disease and died at the age of 39.
In 1915, Henrique da Rocha-Lima and Stanislaus Josef Mathias von Prowazek were sent to Cottbus near the Polish border to investigate an outbreak of typhus fever among Russian prisoners. Both da Rocha-Lima and von Prowazek contracted the fever. While da Rocha-Lima recovered, von Prowazek died of the disease. In 1916, when da Rocha-Lima identified the agent of typhus fever, it was named Rickettsia prowazekii to commemorate the two scientists, Ricketts and von Prowazek, who died of typhus while studying the disease.
The use of DDT (Dichlorodiphenyltrichloroethane) in the years leading up to World War II began to limit spread of typhus. The first typhus vaccine was produced in 1930 by Professor Rudolf Stepfan Weigl of the University of Jan Kazimierz in Poland. Professor Weigl's vaccine consisted of Rickettsia prowazekii cultivated in the midgut cells (there were no suitable artificial medias for cultivating Rickettsia prowazekii) of live lice and killed with 0.5% phenol. Lice were placed in small wooden cages with screen walls. These wooden cages were tied to a volunteer's thigh or calf for 45 minutes a day for about 10 days for the lice to grow. Then the lice are dissected. 150 lice intestines made one dose of vaccine.
Without Weigl's knowledge, one of Weigl's assistants, Michal Martynowicz, tested the vaccine on his wife Rozalia with her consent and provided the effectiveness of the vaccine. However the process was painfully slow. In 1938, bacteriologist Herald Rea Cox of the Rocky Mountain Laboratory developed a method to cultivate Rickettsia prowazekii in the yolks of fertile, six-day-old chicken eggs. This process markedly sped up the production of typhus vaccines.
Typhus as a Biological Weapons Agent
Typhus fever was categorized by the Center for Disease Control (CDC) as a Category B biological weapons agent. Rickettsia prowazekii is highly infectious and could be fatal but cannot be passed from person to person. The US, German, Japanese, Soviet biological weapons programs all studied typhus fever as a possible biological agent. The Soviet biological weapons program Biopreparat's first project in 1928 with attempts to weaponize typhus. Canada studied Rocky Mountain Spotted Fever as a possible agent. It was reported that in the early 1980s, the North Korean biological weapons program produced Rickettsia prowazekii as a potential weapon.
In 1976, letters containing ticks were found in various US cities. The letter that accompanied the ticks warned of a 'dangerous disease' that the ticks carried. It was suspected that the 'dangerous disease' carried by ticks was typhus fever.
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