Difference Between Infection and Infestation

Main Difference – Infection vs Infestation

Animals, as well as plants, can be ill due to the invasion of their body by other organisms. Infection and infestation are two types of invasion mechanisms that differ from each other based on the type of that organisms invade plant or animal bodies. The main difference between infection and infestation is that infection is the invasion of microorganisms whereas infestation is the invasion of complex organisms. Therefore, infections are caused by protozoans, fungi, bacteria, and viruses while infestations are typically caused by insects and worms.   

Key Areas Covered

1. What is an Infection
     – Definition, Facts, Infectious Agents
2. What is an Infestation
     – Definition, Facts, Causative Organisms
3. What are the Similarities Between Infection and Infestation
     – Outline of Common Features
4. What is the Difference Between Infection and Infestation
     – Comparison of Key Differences

Key Terms: Ectoparasites, Endoparasites, External Infestation, Host, Infection, Infestation, Internal Infestation, Microorganisms

What is an Infection

Infection refers to the invasion of microorganisms that causes a disease in the host. The microorganisms that cause diseases are called infectious agents. These microorganisms can be protozoans, fungi, bacteria or viruses. The microorganisms enter the tissues of the host and multiply, arresting the normal physiology of the cells during infection. As they cause diseases to the host, the infectious agents are also called pathogens. The malaria infection in the midgut epithelia of an Anopheles mosquito is shown in figure 1.

Figure 1: Malaria Infection in Anopheles Mosquito

An infection can be either mild or severe, life-threatening. The transmission of the infection can occur through body fluids, skin contact, contact with feces or airborne particles. The spread of the infection depends on the type of infectious agent. The immune system of the host serves as a protective barrier for the invasion, multiplication, and reproduction of the microorganism.

What is an Infestation

Infestation refers to the invasion of insects and worms that causes a disease to the host. These insects can be mites, ticks, fleas or lice. Worms can be roundworms, pinworms, flatworms or other helminths. The infestation of plants by mites is shown in figure 2.

Figure 2: Smallpox

Infestations can occur in two ways, either internally or externally. External infestation occurs as a result of the invasion of ectoparasites that are parasitic on the surface of the host. Head lice, mites, ticks, bed bugs, mosquitoes, and mice are examples of ectoparasites. Internal infestation occurs as a result of the invasion of endoparasites. Endoparasites such as roundworms and flatworms live inside the host.

Similarities Between Infection and Infestation

• Infection and infestation are two invasion mechanisms of parasites.
• Both infection and infestation cause illness in the host.

Difference Between Infection and Infestation

Definition

Infection: Infection refers to the invasion of microorganisms that causes disease to the host.

Infestation: Infestation refers to the invasion of insects and worms that causes disease to the host.

Caused by

Infection: Infection is caused by the invasion of microorganisms such as protozoans, fungi, bacteria, and viruses.

Infestation: Infestation is caused by the invasion of complex organisms such as insects and worms.

Process

Infection: Microorganisms enter the tissues of the host and multiply, arresting the normal physiology of the cells during infection.

Infestation: Insects or worms reproduce on the surface of the host or inside the lumens.

Conclusion

Infection and infestation are two mechanisms used by different types of parasites to invade their host. Infection is caused by the invasion of microorganisms such as protozoans, fungi, bacteria and viruses. On the contrary, an infestation is caused by an invasion of complex organisms or animals such as insects and worms. The main difference between infection and infestation is the type of organisms involved in each mechanism.

Reference:

1. Nordqvist, Christian. “Infection: Types, causes, and differences.” Medical News Today, MediLexicon International, 22 Aug. 2017, Available here.
2. “Infestation.” Wikipedia, Wikimedia Foundation, 6 Jan. 2018, Available here.

Image Courtesy:

1. “Malaria” By image by Ute Frevert;false color by Margaret Shear – (CC BY 2.5) via Commons Wikimedia
2. “1147394” (Public Domain) via pxhere