27th June 2023

Pneumonia

Bacterial pneumonia is the most common cause of infection and admission in HIV. Consequently, patients with reduced CD4+ T-cell counts are recommended to have pneumococcal vaccines. Risk factors for bacterial pneumonia in HIV include:

• Intravenous drug use
• Smoking
• Increasing age
• Lower CD4+ T-cell count

The most common organism in community-acquired pneumonia (CAP) in HIV is Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa and Staphylococcus aureus are also common. Legionella infection is more common but remains a relatively small proportion of cases. CAP in HIV presents similarly to in seronegative individuals. Chest radiography usually features unilateral consolidation in Streptococcus or Haemophilus infection, or cavitation in Pseudomonas aeruginosa or Staphylococcus aureus. Management is similar, however, macrolides (e.g. clarithromycin) need to be given alongside a beta-lactam rather than alone because of increased resistance in Streptococcus pneumoniae.