Which of the following best describes foodborne infection?

Foodborne infection occurs when harmful organisms, such as bacteria, viruses, or parasites, are ingested through contaminated food or drink and then multiply within the body, leading to illness. This definition aligns with the correct choice, which specifically refers to the consumption of living, harmful organisms. Once these pathogens enter the gastrointestinal tract, they can cause various symptoms, typically manifesting a few hours to several days after ingestion as they multiply and release toxins in the host.

Considering the other choices, bacterial toxins ingested through food are related to foodborne intoxication rather than infection, which specifically involves live pathogens. Immediate reactions to spoiled food might imply a rapid onset of symptoms due to toxins or irritants rather than a biological infection process. Lastly, consuming allergenic ingredients would lead to allergic reactions, not foodborne infections caused by pathogens. Understanding the mechanisms through which foodborne illnesses arise helps ensure proper food safety practices.