Which of the following is NOT a factor in determining zoonotic disease risk?

• A. A Type of pathogen
• B. B Presence of biologics
• C. C Transmission route
• D. D Host range

Answer: (B)

Zoonotic disease risk comes from factors that affect whether a pathogen can move from animals to humans and spread among hosts. The type of pathogen matters because different organisms have different abilities to survive outside a host, evade defenses, and infect new species. The transmission route is key since routes that bring pathogens into close contact with humans or involve vectors increase the chance of spillover. The host range is also important; a pathogen capable of infecting many species can bridge species barriers more easily and sustain transmission across reservoirs. The presence of biologics, however, does not influence a pathogen’s ability to cross species barriers or propagate in new hosts, so it isn’t a factor in determining zoonotic disease risk.