Can eating with dirty hands lead to parasitic infections?

Generally speaking, eating with dirty hands may lead to parasitic infection, but it does not necessarily result in infection. Whether an infection occurs mainly depends on whether the hands are contaminated with parasite eggs and the quantity and type of those eggs. A detailed analysis is as follows:

If the hands are only exposed to small amounts of ordinary dust and have not come into contact with items contaminated by parasite eggs—such as feces, raw meat, polluted soil, or water sources—eating directly is unlikely to cause parasitic infection. In everyday environments, the probability of clean hands being contaminated with parasite eggs is low, so there's generally no need for excessive concern.

However, if the hands have touched items contaminated with parasite eggs and food is consumed without washing them, the parasite eggs may enter the digestive tract along with food, potentially causing infection. For example, handling raw vegetables or fruits, or interacting with pets without subsequent handwashing, could leave parasite eggs such as those of roundworms or pinworms on the hands.

To prevent parasitic infections, it is important to develop good hygiene habits: always thoroughly wash hands with soap or hand wash before meals and after using the toilet, and promptly clean hands after handling raw meat, soil, or pets. Additionally, maintaining food hygiene helps reduce infection risks at the source.