In humans, infection of the salivary glands by a specific virus typically leads to which of the following diseases characterised by painful swelling near the ears?

Introduction / Context:
Several common childhood and adolescent illnesses are caused by viruses that target particular tissues. One such disease involves painful swelling of the salivary glands, especially the parotid glands located near the ears. Recognising which disease is associated with viral infection of salivary glands helps in understanding human infectious diseases and in interpreting clinical symptoms.

Given Data / Assumptions:

The question specifies an infection of the salivary glands caused by a virus. It asks which disease results from this type of infection. Options include tetanus, mumps, pyorrhoea, ulcers and dengue fever. We assume standard clinical descriptions of these diseases.

Concept / Approach:
Mumps is a viral illness caused by the mumps virus, a paramyxovirus. It frequently affects children and young adults and is characterised by inflammation and swelling of the parotid salivary glands, often on both sides. This leads to the classic chipmunk like facial appearance, pain when chewing and fever. Tetanus is caused by a bacterial toxin from Clostridium tetani and affects the nervous system, not specifically the salivary glands. Pyorrhoea (periodontal disease) involves bacterial infection of gums and supporting structures of teeth. Common ulcers in the stomach or duodenum are linked to factors such as Helicobacter pylori infection, acid and lifestyle, and dengue fever is a mosquito borne viral infection affecting blood vessels and platelets, not salivary glands.

Step-by-Step Solution:
Step 1: Recall that mumps is known for painful swelling of the parotid salivary glands just below and in front of the ears. Step 2: Recognise that mumps is caused by a virus and spread through respiratory droplets and saliva. Step 3: Examine tetanus, which is caused by a bacterial neurotoxin and produces muscle spasms, not salivary gland infection. Step 4: Note that pyorrhoea affects gums and supporting tissues of teeth, rather than the salivary glands themselves. Step 5: Understand that peptic ulcers and dengue fever also do not primarily involve salivary glands, confirming that mumps is the correct disease.

Verification / Alternative check:
To verify, you can think of the characteristic symptoms often mentioned in textbooks: mumps presents with swelling of one or both parotid glands, pain when eating sour foods, fever and malaise. Health campaigns for mumps vaccination highlight protection against this glandular swelling. In contrast, tetanus is associated with lockjaw, dengue with high fever and bleeding risk, and pyorrhoea with gum bleeding and tooth loosening. These clinical pictures confirm that only mumps matches the description of viral infection of the salivary glands.

Why Other Options Are Wrong:
Tetanus is not a viral disease and affects the nervous system, not salivary glands. Pyorrhoea is a periodontal disease mainly due to bacterial plaque and affects gums and tooth sockets rather than major salivary glands. Peptic ulcers involve the lining of the stomach or duodenum, producing abdominal pain and acidity, not facial gland swelling. Dengue fever is a viral infection but it targets blood and immune systems, causing high fever and low platelets rather than salivary gland enlargement. Thus, none of these alternative options fit the description given in the question.

Common Pitfalls:
Students sometimes confuse different oral and facial infections, especially if they only remember that some of them involve pain in the mouth region. Another pitfall is concentrating only on the word infection and not on which organ is infected. To avoid these errors, link keywords to specific organs: mumps with parotid salivary glands, pyorrhoea with gums, tetanus with nervous system and dengue with blood vessels and platelets. Keeping these associations clear in your mind will help you rapidly identify mumps whenever salivary gland infection is mentioned.

Final Answer:
Viral infection of the salivary glands, especially the parotid glands, typically leads to the disease called mumps.