Question

Known case of HIV with cough of sputum production & fever with examination finding of consolidation in right infrascapular area with x-ray showing right lower consolidation with CD4 of 55. What is the most common cause of this in these?

• A. Staph aureus
• B. Strep pneumonia
• C. Mycoplasma
• D. P. jiroveci

Answer 1

The Correct Option is B

In a patient with HIV presenting with respiratory symptoms such as cough, sputum production, fever, and examination findings suggestive of pneumonia, it is important to consider the common pathogens responsible. The radiographic evidence of right lower lobe consolidation combined with a low CD4 count of 55 is crucial in identifying the probable cause of pneumonia in this immunocompromised patient.

For individuals with HIV/AIDS, especially those with low CD4 counts (below 200 cells/mm³), certain opportunistic infections become prevalent. However, some common bacterial infections still remain the main culprits causing pneumonia. In this scenario, we have to differentiate between typical bacterial, atypical bacterial, and opportunistic infections.

The options provided are:

• Staph aureus
• Strep pneumonia
• Mycoplasma
• P. jiroveci

Strep pneumoniae (Streptococcus pneumoniae) is the most common cause of community-acquired pneumonia (CAP) in both healthy individuals and those who are immunocompromised, including HIV patients. Although opportunistic infections like Pneumocystis jiroveci pneumonia (PCP) might occur in patients with CD4 counts less than 200, Strep pneumonia remains the leading cause of bacterial pneumonia in HIV patients regardless of the CD4 count. Clinical presentation with fever, productive cough, and lobar consolidation is highly suggestive of bacterial pneumonia, most commonly caused by Streptococcus pneumoniae.

Therefore, based on the presentation and the CD4 count, the most likely and common cause of pneumonia in this HIV patient is Strep pneumonia.