What is brucellosis?

Brucellosis is a bacterial infection that primarily affects livestock, such as cattle, sheep, goats, and dogs, and can be transmitted to humans. It is caused by bacteria of the genus Brucella, which people can acquire through direct contact with infected animals or consumption of unpasteurized dairy products. The disease can result in significant health issues, including fever, fatigue, and musculoskeletal problems, and it tends to become chronic if not treated properly.

In contrast, the other options describe different disease mechanisms or types that do not apply to brucellosis. Viral infections transmitted through the air typically refer to diseases like influenza or the common cold. A chronic condition affecting mental health might pertain more to psychological disorders rather than infectious diseases. Lastly, while there are vaccines available for some diseases caused by bacteria, brucellosis does not currently have a widely recommended vaccine for general use in humans, making it distinctly different from infectious diseases that are preventable through vaccination.