Routes of microbial contamination of food

Bacteria are a major source of microbial contamination of food, i.e. the undesired presence in food of harmful microorganisms or the harmful substances they produce. Viruses, parasites and fungi are also able to contaminate food and cause foodborne illnesses in humans. Microorganisms can enter food through different routes.

Look at the figure below and notice that eating contaminated food is a component of many transmission routes. The most common routes of entry are discussed below.