Summary
Pathogens spread by air, water, food, contact or vectors such as mosquitoes.
In depth
Routes: direct contact, droplets, airborne, faecal-oral, vector-borne, bloodborne and vertical (mother to baby). Breaking the chain: handwashing, sanitation, vaccination, vector control and isolation.
The chain of infection: agent, reservoir, portal of exit, transmission, portal of entry, susceptible host. Cutting any link stops spread. Incubation periods vary.
Key idea: sanitation and hygiene have saved more lives than most drugs.
The chain of infection includes the agent, reservoir, portal of exit, mode of transmission, portal of entry and susceptible host. Hand hygiene is one of the most effective interruptions. Fomites (surfaces) carry some pathogens. Vector-borne diseases such as malaria, dengue and Lyme disease depend on mosquitoes and ticks.
Some pathogens cause infection with few symptoms, and asymptomatic carriers may spread disease unknowingly (Typhoid Mary; COVID-19). Superspreading events cause a large share of cases. Contact tracing, isolation, quarantine, masks, ventilation and safe water cut transmission. John Snow's removal of the Broad Street pump handle in 1854 linked cholera to water.
Key idea: understanding the route of spread tells us how to break it.
Frequently asked questions
What is Infectious Disease Transmission?
Pathogens spread by air, water, food, contact or vectors such as mosquitoes.
Which area of biology covers Infectious Disease Transmission, and how advanced is it?
Infectious Disease Transmission is one of the 52 topics in Immunology & Disease. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Basic Reproduction Number, Epidemic and Pandemic, Mathematical Epidemiology.
Can you give an example of Infectious Disease Transmission?
Cholera spreads through contaminated water; John Snow's 1854 map traced a London outbreak to a pump.
What should I learn before Infectious Disease Transmission?
Infectious Disease Transmission is a Beginner topic, so no earlier topic is required. Other Beginner topics in Immunology & Disease that pair well with it include Immune System, Viruses, Innate Immunity.
What topics are related to Infectious Disease Transmission?
The closest topics to Infectious Disease Transmission are Basic Reproduction Number, Epidemic and Pandemic, Mathematical Epidemiology, Herd Immunity. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Infectious Disease Transmission?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Infectious Disease Transmission. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Infectious Disease Transmission different from Basic Reproduction Number?
Infectious Disease Transmission: Pathogens spread by air, water, food, contact or vectors such as mosquitoes. Basic Reproduction Number: R0 is the average number of new infections one case causes in a fully susceptible population. Read both side by side and note what each one explains.
How should I study Infectious Disease Transmission step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Basic Reproduction Number and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.