How do viruses typically grow?

Viruses are unique among pathogens in that they do not grow or reproduce on their own. Instead, they require a host organism to replicate and proliferate. When a virus enters a host, it hijacks the host's cellular machinery to produce new viral particles. This characteristic is fundamental to understanding how viral infections spread, particularly in food safety and public health contexts.

The other choices do not accurately represent the nature of viruses. For instance, while viruses can be transmitted through contaminated water and food contact surfaces or even found in food, they do not specifically grow in these environments. Instead, they must infect a living host to replicate, making the requirement for a host the defining characteristic of their growth. Understanding this is crucial for preventing foodborne illnesses linked to viruses.