Fatalities were generally between 10% and 40% of those infected and the disease was a major cause of death for those nursing the sick.In 1922, the typhus epidemic reached its peak in Soviet territory, with some 20 to 30 million cases in Russia. Although typhus had ravaged Poland with some 4 million cases reported, efforts to stem the spread of disease in that country had largely succeeded by 1921 through the efforts of public health pioneers such as Hélène Sparrow and Rudolf Weigl. In Russia during the civil war between the White and Red Armies, epidemic typhus killed 2–3 million people, many of whom were civilians. In 1937 and 1938 there was a typhus epidemic in Chile.During World War II, many German POWs after the loss at Stalingrad died of typhus. Typhus epidemics killed those confined to POW camps, ghettos, and Nazi concentration camps who were held in unhygienic conditions. Pictures of mass graves including people who died from typhus can be seen in footage shot at Bergen-Belsen concentration camp. Among thousands of prisoners in concentration camps such as Theresienstadt and Bergen-Belsen who died of typhus were Anne Frank, age 15, and her sister Margot, age 19 in the latter camp. The first typhus vaccine was developed by the Polish zoologist Rudolf Weigl in the interwar period; the vaccine did not prevent the disease but reduced its mortality. 21st century
Beginning in 2018, a typhus outbreak spread through Los Angeles County primarily affecting homeless people.
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, as lice were endemic and inescapable, but it hit particularly hard in the lower or "unwashed" social strata.In the United States, a typhus epidemic broke out in Philadelphia in 1837 and killed the son of Franklin Pierce (14th President of the United States) in Concord, New Hampshire, in 1843. Several epidemics occurred in Baltimore, Memphis, and Washington, DC, between 1865 and 1873. Typhus 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 fever is caused by the bacterium Salmonella enterica Serovar Typhi.In Canada alone, the typhus epidemic of 1847 killed more than 20,000 people from 1847 to 1848, mainly Irish immigrants in fever sheds and other forms of quarantine, who had contracted the disease aboard the crowded coffin ships in fleeing the Great Irish Famine. Officials neither knew how to provide sufficient sanitation under conditions of the time nor understood how the disease spread. 20th century
Typhus was endemic in Poland and several neighboring countries prior to World War I (1914–1918), but became epidemic during the war. Delousing stations were established for troops on the Western Front during World War I, but typhus ravaged the armies of the Eastern Front, where over 150,000 died in Serbia alone.