World Health Organization Workers with the World Health Organization distribute mosquito nets in a Cambodian village to protect against malaria. (more) infection biology Ask the Chatbot a Question More Actions Share Share Share to social media Facebook X URL https://www.britannica.com/science/infection Feedback Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login). Feedback Type Select a type (Required) Factual Correction Spelling/Grammar Correction Link Correction Additional Information Other Your Feedback Submit Feedback Thank you for your feedback Our editors will review what you’ve submitted and determine whether to revise the article.

　　External Websites Ask the Chatbot a Question Written by Kara Rogers Kara Rogers is the senior editor of biomedical sciences at Encyclopædia Britannica, where she oversees a range of content from medicine and genetics to microorganisms. She joined Britannica in 2006 and... Kara Rogers Fact-checked by The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... The Editors of Encyclopaedia Britannica Last Updated: Aug 29, 2025 • Article History Table of Contents Table of Contents Ask the Chatbot Key People: Leonard Colebrook Heinz L. Fraenkel-Conrat (Show more) { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type" : "Question", "name" : " What are types of infectious organisms? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "Infectious organisms include bacteria, viruses, fungi, and parasites. Examples are the bacterium Escherichia coli, influenza viruses, fungi in the genus Candida, and the malaria parasite (Plasmodium)." } } , { "@type" : "Question", "name" : " How do pathogens spread from one host to another? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "Pathogens spread in various ways, including through airborne transmission, direct contact, indirect contact, vector-borne transmission, vertical transmission, and transfusion-transmitted infection." } } , { "@type" : "Question", "name" : " What are some examples of bacterial infections? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "Examples of bacterial infections include gastroenteritis, strep throat, pneumonia, and sepsis." } } , { "@type" : "Question", "name" : " What measures can reduce the risk of infection? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "Measures to prevent infection include practicing proper hygiene, consuming clean food and water, handwashing, and vaccination. Agents such as antibiotics, antivirals, antifungals, and antiparasitic drugs can help treat infections. Control measures include surveillance, isolation, quarantine, and vector management." } } , { "@type" : "Question", "name" : " What is vector-borne transmission? ", "acceptedAnswer" : { "@type" : "Answer", "text" : "Vector-borne transmission occurs when insects or other animals transfer pathogens between hosts." } } ] } Top Questions What are types of infectious organisms? Infectious organisms include bacteria, viruses, fungi, and parasites. Examples are the bacterium Escherichia coli, influenza viruses, fungi in the genus Candida, and the malaria parasite (Plasmodium).

　　How do pathogens spread from one host to another? Pathogens spread in various ways, including through airborne transmission, direct contact, indirect contact, vector-borne transmission, vertical transmission, and transfusion-transmitted infection.

　　What are some examples of bacterial infections? Examples of bacterial infections include gastroenteritis, strep throat, pneumonia, and sepsis.

　　What measures can reduce the risk of infection? Measures to prevent infection include practicing proper hygiene, consuming clean food and water, handwashing, and vaccination. Agents such as antibiotics, antivirals, antifungals, and antiparasitic drugs can help treat infections. Control measures include surveillance, isolation, quarantine, and vector management.

　　What is vector-borne transmission? Vector-borne transmission occurs when insects or other animals transfer pathogens between hosts.

　　infection, the process by which harmful microorganisms such as bacteria, viruses, fungi, or parasites enter cells and tissues in the body and cause disease. Infection may be localized or systemic (spread throughout the body), and its outcome depends on both the type of pathogen and the host’s immune response. Although many bacteria are harmless or essential to health, certain species, referred to generally as pathogenic bacteria, are capable of causing infections. Examples of pathogenic bacteria include Escherichia coli, Staphylococcus aureus, and certain species of Streptococcus. Infection with these organisms produces illnesses that range from gastroenteritis to strep throat to life-threatening ...(100 of 394 words)

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