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Respiratory symptoms in HIV-infected individuals increase in frequency as the CD4 cell count declines below 200 cells/FL. Cough occurs at a frequency of 27%, shortness of breath at 23%, and fever at 9%.
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Spectrum of Respiratory Illnesses in HIV-Infected Patients |
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Bacterial Infections Streptococcus pneumoniae |
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Mycobacterial Infections Mycobacterium tuberculosis |
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Fungal Infections Pneumocystis carinii |
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Viral Infections Cytomegalovirus |
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Parasitic Infections Toxoplasma gondii |
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Neoplasms Kaposi's sarcoma Non-Hodgkin's lymphoma Bronchogenic carcinoma |
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Upper Respiratory Illnesses Upper respiratory tract infection |
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Lower Respiratory Tract Disorders Lymphocytic interstitial pneumonitis (LIP) |
Diagnosis
FL, episodes of bacterial pneumonia may be recurrent, and mycobacteria other than M. tuberculosis (e.g. M. kansasii).As the CD4 cell count declines below 500 cells/
At a CD4 cell count below 200 cells/
FL, bacterial pneumonia is often accompanied by bacteremia and sepsis, and M. tuberculosis infection is often extrapulmonary or disseminated. Pneumocystis carinii pneumonia and pneumonia/pneumonitis due to Cryptococcus neoformans become significant considerations.Below 100 cells/FL, bacterial pathogens, such as Staphylococcus aureus and Pseudomonas aeruginosa, and pulmonary involvement from Kaposi's sarcoma or Toxoplasma gondii are increasingly diagnosed.
At CD4 cell count <50 cells/FL, respiratory diseases caused by endemic fungi (Histoplasma capsulatum, Coccidioides immitis), Cytomegalovirus, M. avium complex, and nonendemic fungi (Aspergillus, Candida).
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CD4 Cell Count Ranges for Selected HIV-Related |
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Any CD4 cell count Upper respiratory tract illness |
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CD4 cell count <500 cells/ FLBacterial pneumonia (recurrent) |
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CD4 cell count <200 cells/ FLPneumocystis carinii pneumonia |
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CD4 cell count <100 cells/ FLPulmonary Kaposi's Sarcoma |
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CD4 cell count <50 cells/ FLDisseminated Histoplasma capsulatum |
Symptoms
Pneumocystis carinii pneumonia and pneumonia due to bacterial pathogens (most commonly Streptococcus pneumoniae and Haemophilus influenzae) are the two most likely HIV-related syndromes producing significant respiratory symptoms.
Past medical history
Injection drug users are at risk for developing bacterial pneumonia and tuberculosis. Kaposi's sarcoma is seen almost exclusively in men who engage in sex with other men. Injection drug use or other illicit drugs.
Cigarette smokers are at an increased risk for bacterial bronchitis, bronchopneumonia, and chronic obstructive lung disease.
Travel to or residence in a geographic region that is endemic for one of the endemic fungi (Histoplasma capsulatum, Coccidioides immitis).
Tuberculosis exposure is more common in Asia and Latin America. HIV-infected patients from a country with a high prevalence of TB and patients who are homeless, unstably housed, or previously incarcerated.
History of Pneumocystis carinii pneumonia increases the risk for recurrence of PCP, and secondary P. carinii prophylaxis should be given to these patients. HIV-infected patients with a history of cryptococcosis, coccidioidomycosis, or histoplasmosis are at high risk for relapse.
Physical examination
HIV-infected patients with pneumonia may be febrile, tachycardic, and tachypneic. Hypotension suggests a fulminant disease process. Pulse oximetry often reveals a decreased oxygen saturation.
Laboratory tests
White blood cell count (WBC) is frequently elevated relative to the patient's baseline value in persons with bacterial pneumonia. HIV-infected patients with neutropenia are at higher risk.
Serum lactate dehydrogenase (LDH) may suggest Pneumocystis carinii pneumonia. The serum LDH is frequently elevated in 83% of patients with Pneumocystis carinii pneumonia.
Arterial blood gas (ABG). Hypoxemia, an increased alveolar-arterial oxygen difference.