Unsanitary conditions may cause typhoid fever, cholera and dysentery.
The phrase "filth diseases" was coined in 1858 by British physician Charles Murchison to describe a class of conditions, mostly caused by infectious pathogens, that were associated with squalid living conditions—the overcrowded, unsanitary, and vermin-infested dwellings that were all too numerous in urban areas in the nineteenth century. It was an evocative phrase, popular with social reformers and pioneers of the Public Health movement and the Sanitary Revolution. It was not so much pejorative as accusatory, attributing blame for these diseases to the living conditions rather than to the people forced to live that way. Its use was a political lever that moved public opinion in favor of reforming the conditions that led to so much disease, disability, and premature death.
The filth diseases included infections of the gastrointestinal and respiratory tracts—diarrhea and dysentery, typhoid, croup, bronchitis, pneumonia, and tuberculosis—and skin diseases such as scabies and ringworm. Conditions associated with verminous bedding and clothing, such as louse-borne typhus, also turned out to be filth diseases although they may have not been identified as such at the time. Bubonic plague, long associated with rat-infested dwellings, was another filth disease, though fortunately its visitations were uncommon. One of the goals of nineteenth-century public health reformers was the eradication of filth diseases, which meant improving the housing and living conditions of working people. This in turn depended on better wages and working conditions, so social and economic reform were inseparable from public health reform.