What Can Cause Pneumonia in People with HIV?

HIV-Associated Lung Infections Linked with Deterioring Immune Function

Pneumonia, conceptual artwork
Pneumonia, conceptual artwork. Getty Images/SCIEPRO/Science Photo Library

Pneumonia is defined simply as the inflammation of tissue in one or both of the lungs, primarily the microscopic air sacs called alveoli. Symptoms of pneumonia include cough, chest pain, fever, and difficulty breathing.

There are a number of pneumonial infections that affect people with HIV more than the general population, both of which are considered opportunistic as they are more likely to occur when an individual's immune function is low (a clinical feature of HIV).

Two of the most common of these are pneumocystis pneumonia (PCP) and recurrent bacterial pneumonia. Both are considered AIDS-defining conditions indicative of a fully compromised immune system.

Pneumocystis Pneumonia (PCP)

Pneumocystis jiroveci  is a fungus that can cause a potentially fatal opportunistic infection called pneumocystis pneumonia, or PCP. It is an infection that primarily affects the lungs in people with HIV whose CD4 counts are less than 200 cells/mL. 

The symptoms of PCP are often indistinguishable from other types of pneumonia and can include:

  • Dry cough
  • Fever
  • Difficulty breathing
  • Fatigue
  • Night sweats

One of the distinguishing features of PCP is that coughs are generally non-productive, mainly because sputum is too thick to be expelled from the lungs.

While there is no single test to diagnose PCP, it is characterized on a chest x-ray by an opacity on the lower section of the lungs.

The use of biopsy, tissue staining, blood analysis and a measure of arterial oxygen levels can generally help confirm infection.

PCP is typically treated with a medication called trimethoprim-sulfamethoxazole (TMP-SMX) for 21 days. There are alternative therapies available for persons with an allergic reaction to TMP-SMX, including atovaquone and dapsone.

Pentamidine, commonly used to treat PCP in the early years of the epidemic, is used often today due to the high frequency of side effects.

There is currently no vaccine for PCP, but people with HIV withCD4 counts less than 200 cell/mL are often prescribed TMP-SMX prophylactically to help prevent infection.

Moreover, initiation of antiretroviral therapy (ART) is known to reduce the likelihood of PCP in patients as immune function is restored.

Recurrent Bacterial Pneumonia

Bacterial pneumonia is a common cause of pneumonia in people with HIV. When it is recurrent —with two or more episodes within a year—is considered an AIDS-defining condition.

There are different types of bacterial pneumonias, like those caused by Streptococcus pneumoniae or Haemophilus influenzae.  Pseudomonas aeruginosa and Staphylococcus aureus are types that occur more frequently in people with HIV than those without.

Unlike PCP, the symptoms of bacterial pneumonia usually come on suddenly over the course of a few days and can include:

  • Fever
  • Chills and rigors
  • Productive cough with sputum
  • Difficulty breathing
  • Chest pain, particularly when taking a deep breath 

Bacterial pneumonia is usually diagnosed with a number of tests, including a chest x-ray that sometimes show a localized infiltrate—essentially, a ball of infection in part of the lung. Generally speaking, the infection is seen to be more diffuse in a chest x-ray than what might see in PCP.  Blood and urine tests, as well as cultures or microscopic examination of lung tissue, are helpful in diagnosis.

Antibiotics are the primary therapy for bacterial pneumonia, in addition to supportive care in a hospital setting, if needed.

In addition to ART, pneumococcal vaccination can significantly prevent infection risk, including such agents as the pneumococcal polysaccharide vaccine (PPV) and the 13-valent pneumococcal conjugate vaccine (PCV13).

Since bacterial pneumonia can occur as a result of influenza, people with HIV should also receive the inactivated influenza vaccine every eye. Smoking cessation can also greatly reduce the likelihood of bacterial pneumonia in people with HIV.


AIDSinfo. "Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents."Accessed September 18, 2015.

Centers for Disease Control and Prevention. "Pneumocystis pneumonia." Atlanta, Georgia; accessed September 18, 2015.

Kohli R, et al. "Bacterial pneumonia, HIV therapy, and disease progression among HIV-infected women in the HIV epidemiologic research (HER) study." Clin Infect Dis. July 1, 2006;43(1):90-8.

UCSF HIV Insite. (2014). "Pulmonary Manifestations of HIV." San Francisco, California; accessed September 18, 2015.

Edited by Dennis Sifris, MD and James Myhre

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