What is the primary route of infection for Brucella spp.?

Brucella spp. primarily causes infections through the consumption of contaminated milk and dairy products, particularly from animals like cattle, goats, and sheep. The bacteria are often present in unpasteurized milk, which can harbor the pathogen as it is shed from infected animals. When individuals consume such products, the bacteria can enter the bloodstream, leading to brucellosis, a disease characterized by fever, fatigue, and other systemic symptoms.

In contrast, while contaminated water can be a route for various pathogens, Brucella infections are most strongly associated with dairy. Airborne transmission and vector-borne transmission are not significant routes for Brucella spp. infection, making contaminated milk the key source through which humans typically acquire the disease.