[4][5] Though typhus has been responsible for millions of deaths throughout history, it is still considered a rare disease that occurs mainly in populations that suffer unhygienic extreme overcrowding.

[7] The causative organism is Rickettsia prowazekii, transmitted by the human body louse (Pediculus humanus corporis).

Signs/Symptoms may include:[6] After 5–6 days, a macular skin eruption develops: first on the upper trunk and spreading to the rest of the body (rarely to the face, palms, or soles of the feet, however).

[6] 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 that recurs in someone after a long period of latency (similar to the relationship between chickenpox and shingles).

In combination with poor sanitation and hygiene in times of social chaos and upheaval, which enable a greater density of lice, this reactivation is why typhus generates epidemics in such conditions[11].

For example, typhus killed millions of prisoners in German Nazi concentration camps during World War II.

Situations in the twenty-first century with potential for a typhus epidemic would include refugee camps during a major famine or natural disaster.

In 1916, Henrique da Rocha Lima proved that the bacterium Rickettsia prowazekii was the agent responsible for typhus.

Once these crucial facts were recognized, Rudolf Weigl in 1930 was able to fashion a practical and effective vaccine production method.

Clothes left unworn and unwashed for 7 days also result in the death of both lice and their eggs, as they have no access to a human host.

Epidemic typhus is proposed as a strong candidate for the cause of this disease outbreak, supported by both medical and scholarly opinions.

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.

Following the Black Assize of Oxford 1577, over 510 died from epidemic typhus, including Speaker Robert Bell, Lord Chief Baron of the Exchequer.

[citation needed] During the Lent assize held at Taunton (1730), typhus caused the death of the Lord Chief Baron of the Exchequer, the High Sheriff of Somerset, the sergeant, and hundreds of other persons.

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.

[24] In London, typhus frequently broke out among the ill-kept prisoners of Newgate Gaol and moved into the general city population.

Many historians believe that the typhus outbreak among Napoleon's troops is the real reason why he stalled his military campaign into Russia, rather than starvation or the cold.

In Canada, the 1847 North American typhus epidemic killed more than 20,000 people, mainly Irish immigrants in fever sheds and other forms of quarantine, who had contracted the disease aboard coffin ships.

[citation needed] Rudolph Carl Virchow, a physician, anthropologist, and historian attempted to control an outbreak of typhus in Upper Silesia and wrote a 190-page report about it.

[citation needed] Typhus was endemic in Poland and several neighboring countries prior to World War I (1914–1918).

Even larger epidemics in the post-war chaos of Europe were averted only by the widespread use of the newly discovered DDT to kill lice on the millions of refugees and displaced persons.

[citation needed] Following the development of a vaccine during World War II, Western Europe and North America have been able to prevent epidemics.

[citation needed] In one of its first major outbreaks since World War II, epidemic typhus reemerged in 1995 in a jail in N'Gozi, Burundi.

[38] The vaccine was tested extensively in Poland between the two world wars and used by the Germans for their troops during their attacks on the Soviet Union.

[38] They gave live Rickettsia prowazekii to concentration camp prisoners, using them as a control group for the vaccine tests.

[38] The use of DDT as an effective means of killing lice, the main carrier of typhus, was discovered in Naples.

[citation needed] Because the typhus-infected lice live in clothing, the prevalence of typhus is also affected by weather, humidity, poverty and lack of hygiene.

In these seasons, people tend to wear multiple layers of clothing, giving lice more places to go unnoticed by their hosts.

This fear of typhus and resulting quarantine and sanitation protocols dramatically hardened the border between the US and Mexico, fostering scientific and popular prejudices against Mexicans.