Diseases transmitted by droplet infection

Options

A. asthma
B. pneumonia only
C. typhoid
D. bronchitis

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for diseases that are transmitted by droplet infection. Droplet infection refers to the spread of pathogens through tiny droplets expelled when an infected person coughs, sneezes, or talks.

2. **Analyzing the Options**:
- **Asthma**: This is a chronic condition characterized by the narrowing of airways, leading to difficulty in breathing. It is primarily caused by environmental factors and is not transmitted from person to person. Hence, it cannot be classified as a disease transmitted by droplet infection.

- **Pneumonia**: This is an inflammatory condition of the lungs, often caused by bacteria such as Streptococcus pneumoniae and Haemophilus influenzae. Pneumonia can be spread through droplet infection, making it a candidate for the answer.

- **Typhoid**: This is a bacterial infection caused by Salmonella typhi, primarily transmitted through contaminated water or food. It is not spread through droplets, so it can be eliminated from consideration.

- **Bronchitis**: This condition involves inflammation of the bronchi and can be caused by various factors, including viral infections. While it can be associated with droplet transmission in rare cases, it is primarily a self-caused condition and not typically classified as a droplet infection disease.

3. **Conclusion**: After analyzing all the options, pneumonia is the only disease among the given choices that is primarily transmitted by droplet infection.

### Final Answer:
The disease transmitted by droplet infection is **Pneumonia**.

---