PATHOLOGY

Detailed explanation-1: -Note: Influenza is not categorised under bacterial disease as it is caused by a virus known as flu or influenza virus.

Detailed explanation-2: -The flu (also called influenza) is a common illness caused by a virus. Other viruses and some bacteria can cause infections with similar symptoms, but the flu is always viral.

Detailed explanation-3: -Haemophilus influenzae disease is a name for any illness caused by bacteria called H. influenzae. Some of these illnesses, like ear infections, are mild while others, like bloodstream infections, are very serious. In spite of the name, H. influenzae does not cause influenza (the flu).

Detailed explanation-4: -Typhoid is not caused by viruses.