Definitive Host vs. Intermediate Host: What's the Difference?
Edited by Janet White || By Harlon Moss || Updated on October 29, 2023
Definitive host harbors the adult form of a parasite, while intermediate host harbors the larval or juvenile form.
Key Differences
A definitive host is an organism that harbors the adult, sexually mature form of a parasite. Intermediate hosts, on the other hand, harbor the larval or juvenile stages of a parasite. The parasite completes its life cycle by transferring between these two types of hosts.
The definitive host is essential for the parasite's reproduction, as it is in this host that the parasite reaches maturity and reproduces. The intermediate host is necessary for the parasite's development, as it provides the environment in which the parasite grows and prepares to infect the definitive host.
In some cases, a parasite may have multiple intermediate hosts, each responsible for a different stage of the parasite's development. However, there is typically only one definitive host, in which the parasite reaches its final form.
The relationship between the definitive host and the parasite is often more complex than the relationship between the intermediate host and the parasite, as the definitive host's immune system plays a significant role in the parasite's survival and reproduction.
Understanding the roles of the definitive and intermediate hosts is essential for controlling parasitic infections, as interventions can be targeted at either host to break the parasite's life cycle and prevent its spread.
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Comparison Chart
Harbors adult form of parasite
Stage of parasite
Harbors larval/juvenile form
Essential for reproduction
Importance to life cycle
Necessary for development
Typically one per parasite
Number of hosts
May have multiple per parasite
Complex relationship with host
Relationship complexity
Simpler relationship with host
Role in controlling infections
Importance in preventing spread of parasite
Role in preventing spread of parasite
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Definitive Host and Intermediate Host Definitions
Definitive Host
There is typically one definitive host per parasite.
The definitive host for malaria is the human.
Intermediate Host
An intermediate host is an organism that harbors the larval or juvenile stages of a parasite.
The mosquito is an intermediate host for the malaria parasite.
Definitive Host
The relationship between the definitive host and the parasite is often complex.
The definitive host's immune system plays a significant role in the parasite's survival.
Intermediate Host
A parasite may have multiple intermediate hosts.
The parasite can utilize different hosts for different stages of its development.
Definitive Host
The definitive host plays a role in controlling parasitic infections.
Interventions can be targeted at the definitive host to prevent the spread of the parasite.
Intermediate Host
The relationship between the intermediate host and the parasite is often simpler than with the definitive host.
The intermediate host provides the environment necessary for the parasite's growth.
Definitive Host
Definitive host is essential for the parasite's reproduction.
In the definitive host, the parasite reproduces to complete its life cycle.
Intermediate Host
The intermediate host is necessary for the parasite's development.
In the intermediate host, the parasite grows and prepares to infect the definitive host.
Intermediate Host
The intermediate host plays a role in preventing the spread of parasitic infections.
Interventions can be targeted at the intermediate host to break the parasite's life cycle.
FAQs
What is an intermediate host?
An intermediate host is an organism that harbors the larval or juvenile stages of a parasite.
How many definitive hosts does a parasite typically have?
Typically, a parasite has one definitive host.
What is a definitive host?
A definitive host is an organism that harbors the adult, sexually mature form of a parasite.
Why is the definitive host essential for a parasite?
The definitive host is essential for the parasite's reproduction.
Why is the intermediate host necessary for a parasite?
The intermediate host is necessary for the parasite's development.
What is the relationship between the intermediate host and the parasite?
The relationship between the intermediate host and the parasite is often simpler, with the host providing the necessary environment for the parasite's growth.
What is the relationship between the definitive host and the parasite?
The relationship between the definitive host and the parasite is often complex, with the host's immune system playing a significant role in the parasite's survival and reproduction.
Can a parasite have multiple intermediate hosts?
Yes, a parasite can have multiple intermediate hosts.
What role does the definitive host play in controlling infections?
The definitive host plays a role in controlling infections by providing a target for interventions to prevent the spread of the parasite.
What role does the intermediate host play in preventing the spread of infections?
The intermediate host plays a role in preventing the spread of infections by providing a target for interventions to break the parasite's life cycle.
What is the difference between a definitive host and a reservoir host?
A definitive host harbors the adult form of a parasite, while a reservoir host harbors a parasite that can be transmitted to humans or other animals.
What is the difference between an intermediate host and a paratenic host?
An intermediate host harbors the larval or juvenile stages of a parasite, while a paratenic host harbors a parasite that does not undergo development within the host.
How can the relationship between a definitive host and a parasite be studied?
The relationship between a definitive host and a parasite can be studied through laboratory experiments, field studies, and epidemiological research.
How can the relationship between an intermediate host and a parasite be studied?
The relationship between an intermediate host and a parasite can be studied through laboratory experiments, field studies, and epidemiological research.
Can a human be an intermediate host?
Yes, a human can be an intermediate host for certain parasites, such as the malaria parasite.
What are some examples of intermediate hosts?
Examples of intermediate hosts include mosquitoes, snails, and ticks.
Can a human be a definitive host?
Yes, a human can be a definitive host for certain parasites, such as the tapeworm.
Can an intermediate host also be a definitive host?
In some cases, an intermediate host can also serve as a definitive host, depending on the parasite's life cycle.
What are some examples of definitive hosts?
Examples of definitive hosts include humans, cats, and dogs.
Can a definitive host also be an intermediate host?
In some cases, a definitive host can also serve as an intermediate host, depending on the parasite's life cycle.
About Author
Written by
Harlon MossHarlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Janet WhiteJanet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.
