Summary
Pathogens jump from animals to humans, as with coronaviruses, Ebola and avian influenza.
In depth
Over 60 percent of human infectious diseases are zoonotic. Drivers: land use change, wildlife trade, intensive farming. Reservoir hosts include bats (Nipah, SARS-related viruses). One Health surveillance aims for early detection.
Spillover requires exposure, compatibility with host receptors and capacity for human-to-human spread. Risk reduction: preventing deforestation, regulating wildlife trade and surveillance.
Remember: most spillovers do not lead to pandemics.
Spillover requires exposure, ability to infect human cells and then onward transmission. Bats host many viruses (Ebola relatives, SARS-like coronaviruses, Nipah, Hendra) possibly due to their unusual immune tolerance and flight physiology. Influenza spills from birds and pigs; Nipah involves fruit bats and pigs or date palm sap; MERS involves camels; HIV came from chimpanzee SIV in Cameroon around 1920.
The One Health approach combines human, animal and environmental health, including surveillance in wildlife and livestock, reducing risky practices and conserving habitat. Antimicrobial use in livestock and deforestation increase risk. Predicting the next pandemic pathogen remains difficult.
Example: avian influenza H5N1 has infected humans with high fatality but limited human-to-human spread so far, and it has spread in wild birds and mammals.
Frequently asked questions
What is Zoonotic Spillover?
Pathogens jump from animals to humans, as with coronaviruses, Ebola and avian influenza.
Which area of biology covers Zoonotic Spillover, and how advanced is it?
Zoonotic Spillover is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Virus Evolution, Antigenic Variation, Autoimmune Disease.
Can you give an example of Zoonotic Spillover?
HIV came from chimpanzee SIV.
What should I learn before Zoonotic Spillover?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Zoonotic Spillover. Advanced topics assume the Intermediate vocabulary.
What topics are related to Zoonotic Spillover?
The closest topics to Zoonotic Spillover are Virus Evolution, Antigenic Variation, Autoimmune Disease, Epidemic and Pandemic. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Zoonotic Spillover?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Zoonotic Spillover. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Zoonotic Spillover different from Virus Evolution?
Zoonotic Spillover: Pathogens jump from animals to humans, as with coronaviruses, Ebola and avian influenza. Virus Evolution: High mutation rates and reassortment allow viruses like influenza to evolve and jump species. Read both side by side and note what each one explains.
How should I study Zoonotic Spillover 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 Virus Evolution and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.