Chain of Infection

Chain of Infection

A series of steps that must occur for the spread of an infectious disease.

Reservoir of Infection

The natural habitat of a pathogen, which may be an animal, human, or environment like soil or water.

Portal of Exit

The route through which an infectious agent leaves its reservoir.

Portal of Entry

The route through which an infectious agent enters a new host.

Fecal-Oral Transmission

Transfer of pathogens from fecal matter to the mouth, leading to infection.

Infected Host

An individual carrying an infectious agent that can be transmitted to others.

Susceptible Host

An individual who is at risk of contracting an infectious disease due to lack of immunity.

Pathogen

An infectious agent, such as bacteria or virus, that causes disease.

Vector Control

Methods implemented to control or eliminate disease-carrying organisms, particularly arthropods.

Handwashing

A practice that reduces the spread of infectious diseases by removing pathogens from hands.

Droplet Transmission

Spread of pathogens through respiratory droplets expelled by coughing or sneezing.

Infectious Dose

The number of microbial cells required to cause infection in a susceptible host.

Mechanical Vector

An organism that carries pathogens on its body without being affected by them.

Biological Vector

An organism that not only carries pathogens but also allows them to multiply or change within its body.

Microbiota

The collection of microorganisms that normally live in or on the human body, often harmless.