What is a common route of transmission of Coxiella burnetii to humans?

What is a common route of transmission of Coxiella burnetii to humans?

• A. Inhalation of aerosolized bacteria
• B. Direct milk consumption
• C. Human-to-human contact via blood
• D. Skin contact with contaminated surfaces

Answer: (A)

The main idea is that Q fever most often spreads through inhalation of aerosolized Coxiella burnetii. Infected animals shed the bacteria in birth fluids, placentas, urine, and feces, and dust containing these materials can become aerosolized and inhaled by people. This makes occupational exposure—such as farming, veterinary work, or working in abattoirs—a primary risk. Because the organism can survive in the environment and only a small number of organisms are needed to cause infection, inhalation is the efficient route for humans. Milk transmission can occur if unpasteurized dairy products are consumed, but this is far less common than inhalation. Human-to-human transmission via blood is not a recognized route, and skin contact with contaminated surfaces is not a typical way the infection is acquired.

The main idea is that Q fever most often spreads through inhalation of aerosolized Coxiella burnetii. Infected animals shed the bacteria in birth fluids, placentas, urine, and feces, and dust containing these materials can become aerosolized and inhaled by people. This makes occupational exposure—such as farming, veterinary work, or working in abattoirs—a primary risk. Because the organism can survive in the environment and only a small number of organisms are needed to cause infection, inhalation is the efficient route for humans.

Milk transmission can occur if unpasteurized dairy products are consumed, but this is far less common than inhalation. Human-to-human transmission via blood is not a recognized route, and skin contact with contaminated surfaces is not a typical way the infection is acquired.