What is the most likely natural method of human exposure to Brucella spp. infections?

• A. Consumption of unpasteurized milk products
• B. Inhalation of dust
• C. Insect bites
• D. Skin contact with water

Answer: (A)

The main concept here is that Brucella is most often transmitted to humans through ingestion of contaminated dairy products from infected animals. When milk from an infected animal is consumed raw or used to make unpasteurized cheeses, the bacteria can enter the body and cause infection. Pasteurization or thorough cooking kills Brucella, which is why properly processed dairy products are considered safe. While inhalation of aerosolized bacteria can occur in certain settings, it’s a less common natural route for the general population. Insect bites and skin contact with water are not typical transmission pathways for Brucella. So the most likely natural exposure is consuming unpasteurized milk products.