There are six common modes for the transmission of infectious disease.
Those six are subdivided into two main categories: contact and non-contact transmission.
Contact transmission refers to spreading infection through physical interaction with the infectious agent. For example:
- Direct physical contact between the infected individual and yourself. Sexually transmitted diseases work this way. Flu virus transmits itself in this way too. You could shake hands with someone that is suffering from flu, and you could become infected.
- Indirect contact. The infected person touches something and deposits the infectious agent onto that object. Then a second person interacts with that object and picks up the agent. This is why my kids get sick every time that I check them into nursery at church.
- Droplet transmission. An infected person sneezes, and you inhale the tiny droplets of infected fluid.
Non-contact transmission refers to infection that is not transmitted through person to person interactions. For example:
- Airborne transmission. This would be an agent that is capable of moving through ventilation systems or being spread through aerosols. Chicken pox and smallpox are this kind of disease.
- Vehicle transmission refers to diseases that spread through contaminated sources. A common vehicle is contaminated food sources.
- Vector-borne transmission are diseases that are transmitted to a person from some kind of animal or insect (the vector). Mosquitoes are the vector for malaria. Another example is Hantavirus. Vietnam soldiers contracted Hantavirus, and it was traced back to the urine of mice and rats.