Which contagious disease is spread by droplets in the air and is caused by a specific bacterium?

The selected answer identifies tuberculosis as the contagious disease spread by droplets in the air and caused by a specific bacterium. Tuberculosis (TB) is primarily caused by the bacterium Mycobacterium tuberculosis, and it is transmitted when an infected person coughs, sneezes, or talks, releasing tiny droplets into the air. These droplets can then be inhaled by others, leading to new infections.

Understanding tuberculosis's transmission method is critical in public health as it highlights the need for proper respiratory hygiene, ventilation, and prompt medical attention for individuals exhibiting symptoms. This is particularly important given TB's potential severity and the fact that it can remain latent in some individuals, complicating containment efforts.

Other diseases listed, although they may be spread through different mechanisms, do not meet the specific criteria of being caused by a bacterium and transmitted through airborne droplets in the same way that tuberculosis does. For example, pneumonia can be caused by bacteria or viruses and may not always spread through air droplets in the same infectious manner. Similarly, influenza is caused by a virus, and scarlet fever, while caused by bacteria, is transmitted primarily through direct contact or respiratory droplets but does not typically spread as airborne as tuberculosis does.