The human immunodeficiency virus, or HIV, primarily weakens the immune response by depleting disease fighting blood cells called CD4+. According to MayoClinic.com, HIV makes a person more susceptible to certain types of cancers and to infections the body would normally resist, such as pneumonia and meningitis. Patients who are infected with HIV are susceptible to mycobacterial, fungal, bacterial and viral pneumonia.
Tuberculosis
According to MayoClinic.com, having HIV makes a person more susceptible to tuberculosis and much more likely to progress from inactive to active HIV infection. Tuberculosis can appear at any stage of HIV infection, but requires a high index of suspicion in late-stage HIV infection due to atypical findings on chest X-rays, according to "Harrison's Principles of Internal Medicine."
Pneumocystis Jirovecii Pneumonia
According to "Harrison's Principles of Internal Medicine," Pneumocystis is an opportunistic fungal pathogen. The risk of developing Pneumocystis carinii, renamed P. jirovecii pneumonia, in HIV patients increases sharply when CD4+ cell counts drop below 200/mL.
Even though anti-retroviral drugs have reduced the number of cases of P. jirovecii pneumonia, it remains one of the most common opportunistic infections affecting people with AIDS in the United States, according to MayoClinic.com. P. jirovecii infects the lungs, causing difficulty breathing. Signs and symptoms include a cough that doesn't go away, fever and trouble breathing.
Streptococcus Pneumoniae Pneumonia
HIV patients are also more susceptible to bacterial pneumonia, most commonly S. pneumoniae, or pneumococcus. As with P. jirovecii pneumonia, the risk of developing bacterial pneumonia in HIV patients increases sharply when CD4+ cell counts drop below 200/mL, states an article in the July 1, 2006 issue of the journal "Clinical Infectious Diseases."
Influenza Pneumonia
According to U.S. Centers for Disease Control and Prevention, people with HIV/AIDS have an increased of serious influenza-related complications. An increased risk for heart- and lung-related hospitalizations occurs in people infected with HIV during influenza season and a higher risk of influenza-related death. Vaccination with a flu shot produces an immune response against influenza viruses in some people infected with HIV.
Rhodococcus Equi Pneumonia
As stated in an article in the April 2010 issue of "AIDS Patient Care STDS," Rhodococcus equi, a bacterium that causes infection mainly in horses and foals, occasionally infects humans causing a cavitary pneumonia, or holes in the lungs. HIV-infected patients are more susceptible to R. equi infection.
References
- MayoClinic.com: HIVAIDS Complications; Aug. 9, 2008;
- "Harrison's Principles of Internal Medicine;" Dennis Kasper, M.D.; 2005
- Clinical Infectious Diseases: Bacterial Pneumonia, HIV Therapy, and Disease Progression; R. Kohli; Jul. 1, 2006;43(1):90-8.
- AIDS Patient Care STDS; Rhodococcus Equi Infection in HIV-infected Individuals; S. Topino; April 2010;24(4):211-22.
- U.S. Centers for Disease Control and Prevention: HIV/AIDS and the Flu
