Miasma theory in the context of "Chlamydia infection"

The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can cause disease. These small organisms, which are too small to be seen without magnification, invade animals, plants, and even bacteria. Their growth and reproduction within their hosts can cause disease. "Germ" refers not just to bacteria but to any type of microorganism, such as protists or fungi, or other pathogens, including parasites, viruses, prions, or viroids. Diseases caused by pathogens are called infectious diseases. Even when a pathogen is the principal cause of a disease, environmental and hereditary factors often influence the severity of the disease, and whether a potential host individual becomes infected when exposed to the pathogen. Pathogens are disease-causing agents that can pass from one individual to another, across multiple domains of life.

Basic forms of germ theory were proposed by Girolamo Fracastoro in 1546, and expanded upon by Marcus von Plenciz in 1762. However, such views were held in disdain in Europe, where Galen's miasma theory remained dominant among scientists and doctors.

A severe outbreak of cholera occurred in 1854 near Broad Street (now Broadwick Street) and Golden Square in Soho, London, England, during the worldwide 1846–1860 cholera pandemic. The outbreak (also known as Golden Square outbreak), which killed 616 people, is best known for the physician John Snow's study of its causes and his hypothesis that germ-contaminated water was the cause, rather than something in the air called "miasma". This discovery influenced public health and the construction of improved sanitation facilities beginning in the mid-19th century. Later, the term "focus of infection" was used to describe sites, such as the Broad Street pump, where conditions are favourable for transmission of infection. Snow unknowingly took advantage of a natural experiment during his endeavours to identify the cause of cholera transmission.

The Great Stink was an event in Central London during July and August 1858 in which the hot weather exacerbated the smell of untreated human waste and industrial effluent that was present on the banks of the River Thames. The problem had been mounting for some years, with an ageing and inadequate sewer system that emptied directly into the Thames. The miasma from the effluent was thought to transmit contagious diseases, and three outbreaks of cholera before the Great Stink were blamed on the ongoing problems with the river.

The smell, and fears of its possible effects, prompted action by the national and local administrators who had been considering possible solutions to the problem. The authorities accepted a proposal from the civil engineer Joseph Bazalgette to move the effluent eastwards along a series of interconnecting sewers that sloped towards outfalls beyond the metropolitan area. Work on high-, mid- and low-level systems for the new Northern and Southern Outfall Sewers started at the beginning of 1859 and lasted until 1875. To aid the drainage, pumping stations were built to lift the sewage from lower levels into higher pipes. Two of the more ornate stations, Abbey Mills in Stratford and Crossness on the Erith Marshes, with architectural designs by the consultant engineer, Charles Driver, are listed for protection by English Heritage. Bazalgette's plan introduced the three embankments to London in which the sewers ran: the Victoria, Chelsea and Albert Embankments.

Broadwick Street (formerly Broad Street) is a street in Soho, City of Westminster, London. It runs for 0.18 miles (0.29 km) approximately west–east between Marshall Street and Wardour Street, crossing Berwick Street. The street extends across four separate estates, Colman Hedge Close, Little Gelding's, Pawlett's Garden and Pesthouse.

Broad Street was notorious as the centre of an 1854 outbreak of cholera. This outbreak killed a total of 700 people and only twelve escaped. Physician John Snow traced the outbreak to a public water pump on the street, and disabled the pump. Before this time, the disease was widely thought to be caused by air-borne 'miasma'; Snow's findings showed it to be water-borne.

Sanitary engineering or sanitation engineering, also known as public health engineering or wastewater engineering, is the application of engineering methods to improve sanitation of human communities, primarily by providing the removal and disposal of human waste, and in addition to the supply of safe potable water. Traditionally a branch of civil engineering and now a subset of building services engineering and environmental engineering, in the mid-19th century, the discipline concentrated on the reduction of disease, then thought to be caused by miasma. This was accomplished mainly by the collection and segregation of sewerage flow in London specifically, and Great Britain generally. These and later regulatory improvements were reported in the United States as early as 1865.

It is also concerned with environmental factors that do not have an immediate and clearly understood effect on public health. Areas outside the purview of sanitary engineering include aesthetic concerns such as landscaping, and environmental conservation as it pertains to plants and animals.