The immune system protects the body from infections. People living with HIV/AIDS have a weakened immune system, which increases their susceptibility to a variety of infections, including pneumonia. The same germs that cause pneumonia in otherwise healthy people pose an increased risk to patients living with HIV/AIDS. Additionally, germs that people with a healthy immune system can easily defend against may cause potentially life-threatening pneumonia in a patient with HIV.
Pneumococcus
Streptococcus pneumoniae, or pneumococcus, remains a leading cause of bacterial pneumonia among people living with HIV/AIDS, reports the Centers for Disease Control and Prevention. Patients infected with HIV have a significantly increased risk for pneumococcal pneumonia compared to the general population. CDC recommends vaccination against pneumococcus for people older than age 2 living with HIV infection.
Pneumocystis Jiroveci
Pneumocystis jirovecii, previously known as Pneumocystis carinii, is a common fungus found in many environments. Although people with a healthy immune system generally do not develop Pneumocystis pneumonia, the fungus poses a significant risk to patients with HIV and a low immune cell count. The incidence of Pneumocystis pneumonia, or PCP, has declined dramatically among the HIV-infected population in the United States due to the use of combination antiretroviral therapy and antibiotics to prevent PCP in those patients at high risk for the infection, reports CDC.
Mycobacterium Tuberculosis
Mycobacterium tuberculosis causes the illness tuberculosis, or TB. People living with HIV infection have an increased risk for active pulmonary tuberculosis. Unlike other HIV-related infections that occur primarily in patients with a low immune cell count, pulmonary tuberculosis can develop in HIV-infected patients with a relatively high immune cell count, reports CDC. Untreated pulmonary tuberculosis can spread to other parts of the body, including the brain and bones.
Coccidioides
Coccidioides fungi inhabit the soil of northern Mexico and the southwestern United States. The fungal spores commonly travel in the air and may cause pneumonia and systemic disease in patients with HIV and a low immune cell count. The initial infection develops in the lungs, causing chest pain and coughing. In untreated HIV-infected patients, the fungi may spread to other organs, including the nervous system and bones, reports Dr. Judith Aberg of New York University on the medical information website HIV InSite.
Aspergillus
Aspergillus fungal species occur commonly in the environment and may cause severe pneumonia among people living with HIV. A low immune cell count increase the risk for lung invasion by Aspergillus fungi, reports the medical reference text "Principles and Practice of Infectious Diseases." The fungi may spread from the lungs to other sites in the body, including the nervous system, liver, kidneys and spleen.
References
- Centers for Disease Control and Prevention, MMWR: Prevention of Pneumococcal Disease: Recommendations of the Advisory Committee on Immunization Practices (ACIP)
- Centers for Disease Control and Prevention, Morbidity and Mortality Weekly Report: Guidelines for Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents
- University of California, San Francisco Medical Center HIV InSite: Coccidioidomycosis and HIV
- "Principles and Practice of Infectious Diseases, Sixth Edition"; Gerald L. Mandell, M.D., et al., Editors; 2004
