Viruses are responsible for which types of diseases?

The selection of poliomyelitis and infectious hepatitis is justified as both of these diseases are primarily caused by viruses. Poliomyelitis, commonly known as polio, is caused by the poliovirus and can lead to severe complications, including paralysis. Infectious hepatitis, specifically hepatitis A, is caused by the hepatitis A virus and can result in liver inflammation.

Viruses are distinct pathogens that can cause a wide variety of diseases, particularly those affecting specific systems of the body, such as the gastrointestinal system in the case of hepatitis. By focusing on viral infections, you can identify the distinct types of diseases that these pathogens can cause, which underpins the rationale for why this choice is correct.

Other choices, while they do list significant health concerns, primarily involve diseases caused by bacteria or other types of pathogens rather than being exclusively viral. For instance, diarrhea and dysentery can result from various bacterial infections, while pneumonia can be caused by bacteria, viruses, or even fungi, and tuberculosis is a bacterial infection entirely. Measles and mumps are also viral diseases, but the specificity of the first answer highlights more classic examples of virus-related diseases when considering public health challenges.