A man is suffering from a severe disease which includes symptoms like chills , fever and cough. On close inspection, it is found his fingernails have turned blue. An x-ray of his lungs showed an accumulation of fluid in them. Which of the following pathogens in the causative agent for this disease ?

Options

A. Plasmodium vivax
B. Klebsiella pneumoniae
C. Haemophilus influenza
D. Plasmodium ovale

Answer

To solve the question regarding the causative agent of the disease described, we can follow these steps:

### Step 1: Identify the Symptoms
The symptoms presented in the question are chills, fever, cough, and blue fingernails. Additionally, an X-ray shows fluid accumulation in the lungs.

**Hint:** Look for common diseases associated with these symptoms.

### Step 2: Recognize the Disease
The combination of symptoms, particularly the cough, fever, chills, and fluid in the lungs, suggests pneumonia. The blue fingernails indicate a lack of oxygen, which is also common in respiratory diseases.

**Hint:** Think about respiratory diseases that cause similar symptoms.

### Step 3: Determine the Causative Agent
Pneumonia can be caused by various pathogens, including bacteria and viruses. The options given are:
1. Plasmodium vivax
2. Chlamydia pneumoniae
3. Haemophilus influenzae
4. Plasmodium ovale

**Hint:** Consider which of these pathogens are known to cause pneumonia.

### Step 4: Analyze Each Option
- **Plasmodium vivax**: This is a protozoan that causes malaria, not pneumonia.
- **Chlamydia pneumoniae**: This bacterium can cause pneumonia but is less common than other pathogens.
- **Haemophilus influenzae**: This is a well-known bacterium that can cause pneumonia and fits the symptoms described.
- **Plasmodium ovale**: Like Plasmodium vivax, this is also a protozoan responsible for malaria.

**Hint:** Eliminate options that are not associated with pneumonia.

### Step 5: Conclusion
Based on the analysis, the most likely causative agent for the disease described, which includes pneumonia symptoms, is **Haemophilus influenzae**.

**Final Answer:** Haemophilus influenzae