What type of contact involves transmission through objects or surfaces?

Indirect contact involves the transmission of pathogens through objects or surfaces, typically referred to as fomites. When a person comes into contact with contaminated surfaces, such as equipment, cages, or bedding, and then touches their face or another mucous membrane, they can introduce pathogens into their body. This concept is crucial in laboratory settings, as maintaining a clean and sanitized environment helps prevent the spread of diseases among animals and between animals and personnel.

The other options represent different modes of transmission. Direct contact refers to the immediate transfer of pathogens from one animal or person to another through physical interaction. Horizontal transmission involves the spread of infectious agents between organisms of the same generation, such as from one animal to another. Vertical transmission refers to the passing of pathogens from parent to offspring, either during gestation, birth, or through breastfeeding. Understanding these distinctions is essential for implementing appropriate biosecurity measures in animal research and veterinary care.