出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2013/01/07 00:38:19」(JST)
Typhus | |
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Classification and external resources | |
Rash caused by epidemic typhus |
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ICD-10 | A75.1 |
ICD-9 | 080-083 |
DiseasesDB | 29240 |
MedlinePlus | 001363 |
eMedicine | med/2332 |
MeSH | D014438 |
Epidemic typhus (also called "camp fever", "jail fever", "hospital fever", "ship fever", "famine fever", "putrid fever", "petechial fever", "Epidemic louse-borne typhus,"[1] and "louse-borne typhus"[2]) is a form of typhus so named because the disease often causes epidemics following wars and natural disasters. The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus corporis).[3][4] Feeding on a human who carries the bacillus infects the louse. R. prowazekii grows in the louse's gut and is excreted in its feces. The disease is then transmitted to an uninfected human who scratches the louse bite (which itches) and rubs the feces into the wound. The incubation period is one to two weeks. R. prowazekii can remain viable and virulent in the dried louse feces for many days. Typhus will eventually kill the louse, though the disease will remain viable for many weeks in the dead louse.
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Symptoms include severe headache, a sustained high fever, cough, rash, severe muscle pain, chills, falling blood pressure, stupor, sensitivity to light, and delirium. A rash begins on the chest about five days after the fever appears, and spreads to the trunk and extremities. A symptom common to all forms of typhus is a fever which may reach 39 °C (102°F).
Brill-Zinsser disease, first described by Nathan Brill in 1913 at Mount Sinai Hospital in New York City, is a mild form of epidemic typhus which recurs in someone after a long period of latency (similar to the relationship between chickenpox and shingles). This recurrence often occurs in times of relative immunosuppression, which is often in the context of malnutrition and other illnesses. In combination with poor sanitation and hygiene which leads to a greater density of lice, this reactivation is why typhus forms epidemics in times of social chaos and upheaval.
Epidemic typhus is thus found most frequently during times of war and deprivation. For example, typhus killed hundreds of thousands of prisoners in Nazi concentration camps during World War II. The deteriorating quality of hygiene in camps such as Theresienstadt and Bergen-Belsen created conditions where diseases such as typhus flourished. Situations in the twenty-first century with potential for a typhus epidemic would include refugee camps during a major famine or natural disaster. In the periods between outbreaks, when human to human transmission occurs less often, the flying squirrel serves as a zoonotic reservoir for the Rickettsia prowazekii bacterium.
Henrique da Rocha Lima in 1916 then proved that the bacterium Rickettsia prowazekii was the agent responsible for typhus; he named it after H. T. Ricketts and Stanislaus von Prowazek, two zoologists who had died from typhus while investigating epidemics. Once these crucial facts were recognized, Rudolf Weigl in 1930 was able to fashion a practical and effective vaccine production method[5] by grinding up the insides of infected lice that had been drinking blood. It was, however, very dangerous to produce, and carried a high likelihood of infection to those who were working on it.
A safer mass-production-ready method using egg yolks was developed by Herald R. Cox in 1938.[6] This vaccine was widely available and used extensively by 1943.
The infection is treated with antibiotics. Intravenous fluids and oxygen may be needed to stabilize the patient. The mortality rate is 10% to 60%, but is vastly lower (close to zero) if intracellular antibiotics such as tetracycline are used before 8 days. Infection can also be prevented by vaccination.
The first description of typhus was probably given in 1083 at a convent near Salerno, Italy.[7] In 1546, Girolamo Fracastoro, a Florentine physician, described typhus in his famous treatise on viruses and contagion, De Contagione et Contagiosis Morbis.[8]
Before a vaccine was developed during World War II, typhus was a devastating disease for humans and has been responsible for a number of epidemics throughout history.[9] These epidemics tend to follow wars, famine, and other conditions that result in mass casualties.
During the second year of the Peloponnesian War (430 BC), the city-state of Athens in ancient Greece was hit by a devastating epidemic, known as the Plague of Athens, which killed, among others, Pericles and his two elder sons. The plague returned twice more, in 429 BC and in the winter of 427/6 BC. Epidemic typhus is a strong candidate for the cause of this disease outbreak, supported by both medical and scholarly opinions.[10][11]
Typhus also arrived in Europe with soldiers who had been fighting on Cyprus. The first reliable description of the disease appears during the Spanish siege of Moorish Granada in 1489. These accounts include descriptions of fever and red spots over arms, back and chest, progressing to delirium, gangrenous sores, and the stench of rotting flesh. During the siege, the Spaniards lost 3,000 men to enemy action but an additional 17,000 died of typhus.
Typhus was also common in prisons (and in crowded conditions where lice spread easily), where it was known as Gaol fever or Jail fever. Gaol fever often occurs when prisoners are frequently huddled together in dark, filthy rooms. Imprisonment until the next term of court was often equivalent to a death sentence. It was so infectious that prisoners brought before the court sometimes infected the court itself. Following the Assize held at Oxford in 1577, later deemed the Black Assize, over 300 died from Epidemic typhus, including Sir Robert Bell Lord Chief Baron of the Exchequer. The outbreak that followed, between 1577 to 1579, killed about 10% of the English population. During the Lent Assize Court held at Taunton (1730) typhus caused the death of the Lord Chief Baron, as well as the High Sheriff, the sergeant, and hundreds of others. During a time when there were 241 capital offences, more prisoners died from 'gaol fever' than were put to death by all the public executioners in the realm. In 1759 an English authority estimated that each year a quarter of the prisoners had died from gaol fever.[12] In London, typhus frequently broke out among the ill-kept prisoners of Newgate Gaol and then moved into the general city population.
Epidemics occurred throughout Europe and occurred during the English Civil War, the Thirty Years' War and the Napoleonic Wars. During Napoleon's retreat from Moscow in 1812, more French soldiers died of typhus than were killed by the Russians. A major epidemic occurred in Ireland between 1816–19, and again in the late 1830s, and yet another major typhus epidemic occurred during the Great Irish Famine between 1846 and 1849. The Irish typhus spread to England, where it was sometimes called "Irish fever" and was noted for its virulence. It killed people of all social classes, since lice were endemic and inescapable, but it hit particularly hard in the lower or "unwashed" social strata. In Canada, the typhus epidemic of 1847 killed more than 20,000 people died from 1847 to 1848, mainly Irish immigrants in fever sheds and other forms of quarantine, who had contracted the disease aboard coffin ships.[13]
In America, a typhus epidemic killed the son of Franklin Pierce in Concord, New Hampshire in 1843 and struck in Philadelphia in 1837. Several epidemics occurred in Baltimore, Memphis and Washington DC between 1865 and 1873. Typhus fever was also a significant killer during the US Civil War, although typhoid fever was the more prevalent cause of US Civil War "camp fever." Typhoid is a completely different disease from typhus.
During World War I typhus caused three million deaths in Russia and more in Poland and Romania. Delousing stations were established for troops on the Western front but the disease ravaged the armies of the Eastern front, with over 150,000 dying in Serbia alone. Fatalities were generally between 10 to 40 percent of those infected, and the disease was a major cause of death for those nursing the sick. Between 1918 and 1922 typhus caused at least 3 million deaths out of 20–30 million cases. In Russia after World War I, during a civil war between the White and Red armies, typhus killed three million, largely civilians. During World War II typhus struck the German army as it invaded Russia in 1941.[6] In 1942 and 1943 typhus hit French North Africa, Egypt and Iran particularly hard.[14] Typhus epidemics killed inmates in the Nazi Germany concentration camps; infamous pictures of typhus victims' mass graves can be seen in footage shot at Bergen-Belsen concentration camp.[6] Thousands of prisoners held in appalling conditions in Nazi concentration camps such Theresienstadt and Bergen-Belsen also died of typhus during World War II,[6] including Anne Frank at the age of 15 and her sister Margot. Even larger epidemics in the post-war chaos of Europe were only averted by the widespread use of the newly discovered DDT to kill the lice on millions of refugees and displaced persons.
Following the development of a vaccine during World War II, epidemics have usually occurred in Eastern Europe, the Middle East and parts of Africa.
Typhus was one of more than a dozen agents that the United States researched as potential biological weapons before President Richard Nixon suspended all non-defensive aspects of the U.S. biological weapons program in 1969.[15]
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リンク元 | 「発疹チフス」「Rickettsia prowazekii」「epidemic louse-borne typhus」 |
関連記事 | 「epidemic」 |
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