A focus of infection is a place containing whatever epidemiological factors are needed for transmission of an infection. Any focus of infection will have a source of infection, and other common traits of such a place include a human community, a vector population, and environmental characteristics adequate for spreading infection.

Examples of focus of infection

Water pump in 1854 London

In 1854 London physician John Snow discovered that people who drank from a particular water pump contracted cholera, and proposed that drinking this water from this pump was the cause of the illness. At the time people did not readily believe

germ theory of disease The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can lead to disease. These small organisms, too small to be seen without magnification, invade ...

, instead favoring miasma theory. The discovery of the water pump as a source of infection set a precedent which helped establish epidemiology as a science.

Gay bathhouses, particularly in 1980s

gay bathhouse A gay bathhouse, also known as a gay sauna or a gay steambath (uncommonly known as a gay spa), is a commercial space for gay, bisexual, and other men to have sex with men. In gay slang, a bathhouse may be called just "the baths", "the sauna", ...

is a place where

men who have sex with men Men who have sex with men (MSM) are male persons who engage in sexual activity with members of the same sex. The term was created in the 1990s by epidemiologists to study the spread of disease among all men who have sex with men, regardless of ...

meet for sex. In the 1980s at the advent of

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

many men who used bathhouses for sex developed AIDS as a consequence of their having sex without using safe sex practices for the

prevention of HIV/AIDS HIV prevention refers to practices that aim to prevent the spread of the human immunodeficiency virus (HIV). HIV prevention practices may be undertaken by individuals to protect their own health and the health of those in their community, or may ...

. Consequently, public health policies found bathhouses to be a place to target for public health intervention.

Child daycare

Childcare infection is the spread of infection during

childcare Child care, otherwise known as day care, is the care and supervision of a child or multiple children at a time, whose ages range from two weeks of age to 18 years. Although most parents spend a significant amount of time caring for their child(r ...

, typically because of contact among children in

daycare Child care, otherwise known as day care, is the care and supervision of a child or multiple children at a time, whose ages range from two weeks of age to 18 years. Although most parents spend a significant amount of time caring for their child(r ...

or school. This happens when groups of children meet in a childcare environment, and there any individual with an infectious disease may spread it to the entire group. Commonly spread diseases include influenza-like illness and enteric illnesses, such as diarrhea among babies using diapers. It is uncertain how these diseases spread, but

hand washing Hand washing (or handwashing), also known as hand hygiene, is the act of cleaning one's hands with soap or handwash and water to remove viruses/bacteria/microorganisms, dirt, grease, or other harmful and unwanted substances stuck to the hands ...

reduces some risk of transmission and increasing hygiene in other ways also reduces risk of infection.

References

{{reflist Epidemiology Public health