Blog Post
Interesting and Relevant Articles on Infection Control
What is the mode of transmission in the chain of infection?
An infectious agent living in a reservoir and then finding a way of that reservoir represent the first, second, and third links in the chain of infection. The fourth link is the mode of transmission, the manner in which an infectious agent is passed from one person to another.
The transmission of the infectious agent can be done either directly or indirectly. Direct transmission methods are more immediate and often involve close contact, while indirect methods can involve various pathways that don't necessarily require direct physical interaction. This understanding helps public health officials and healthcare workers develop targeted strategies for preventing transmission in different scenarios.
Direct methods involve a sick person coming into physical contact with someone else and include:
-
Direct contact: Transmission through direct contact involves situations such as a healthy person touching, kissing, or engaging in sexual activity with an infected person or a pregnant woman transmitting an infectious agent to her fetus.
-
Transmission through droplets: Transmission through droplets involves a sick person sneezing, coughing or speaking near another person. Droplets containing the infectious agent leave the infected person and land on the healthy person before the droplets have a chance to fall to the ground. This type of transmission does not require touching, but it does require the two people to be near to one another.
Indirect methods include:
-
Transmission through the air: Transmission through the air involves infectious agents remaining suspended in the air carried by dust particles or other residue that can move as a result of air currents instead of falling to the ground. Unlike transmission through direct contact, the transmission of infectious agents through the air does not require the infect person to be in the same location as another person.
-
Transmission through a vector: Transmission through a vector involves an insect usually those that suck blood, such as a mosquito carrying an infectious disease between two people. The insect becomes a carrier of the disease when it bites an infected person, and it then spreads the disease when it subsequently bites someone else.
-
Transmission through a vehicle: Transmission through a vehicle involves infectious agents being transmitted in, on, or as part of another substance or object, such as water, food, blood, or surgical instruments.