Pneumocystis carinii pneumonia

Pneumocystis carinii pneumonia (PCP) was the first pneumonia to be associated with AIDS. In North America and Western Europe, PCP remains the primary cause for AIDS-related deaths. Preventative treatment (prophylaxis) and antiretroviral therapy have dramatically decreased the number of cases of PCP in the United States in recent years.

HIV-infected patients are at risk for developing PCP when their CD4 counts drop below 200. PCP causes a persistent, dry, hacking cough, and the patient usually feels very ill and feverish. Patients who have PCP generally became very short of breath when walking or engaging in any sort of light activity. Often, they are unable to take a deep breath and hold it without coughing.

PCP usually is treated with one of three medications: trimethoprim sulfamethoxazole (Bactrim®), pentamadine, or atovaquone. Often a steroid (e.g., prednisone) also is prescribed, especially if the blood oxygen level is low. In most cases, PCP can be prevented by combining antiretroviral therapy and one of these medications. In the United States and Western Europe, most patients who develop PCP are not being treated for HIV infection.

Bacterial pneumonias are common HIV-related infections; in fact, these infections are so common that two bacterial pneumonias within 6 months are considered an AIDS-defining condition. Most bacterial pneumonias are caused by the bacterium pneumococcus. These infections can be life-threatening, especially in patients with untreated HIV infection or those who have only recently begun treatment.

Bacterial pneumonia is treated with antibiotics. Many types can be prevented by receiving pneumoccal vaccination, taking antiretroviral therapy, and by not smoking. Smoking weakens the lungs and makes the body more susceptible to pneumonia. Patients who are HIV positive and smoke should speak with a physician or other health care provider about quitting.

Tuberculosis (TB) is one of the oldest and deadliest infections. About one-third of the world's population is infected with Mycobacterium tuberculosis, the bacterium that causes TB. Tuberculosis is the number one cause of death by infectious disease worldwide. It is also the most common infection risk for HIV-infected people with normal T-cell counts. TB is the leading cause of death among HIV-infected patients, accounting for about one-third of all AIDS-related deaths worldwide.

In the industrialized world, TB is no longer a great public health problem because of dramatic improvements in living conditions and sanitation, and the development and use of effective anti-TB drugs since the 1940s. In the developing world, however, TB remains a serious public health problem.

Not everyone who is infected with M. tuberculosis develops "active tuberculosis." In fact, only about 10% of people who are infected and are otherwise healthy develop TB symptoms during their lifetime. Patients with HIV are much more susceptible to developing active tuberculosis. In the United States, people who are infected with HIV and TB are 100 times more likely to develop active tuberculosis than people who are infected with TB but not HIV, according to the American Association for World Health.

The annual rate of TB cases in the United States is 40 times greater among people who are infected with HIV than in the general population. Therefore, all patients who are HIV positive should have a screening PPD (purified protein derivative) skin test and chest x-ray. The PPD skin test is used to detect M. tuberculosis infection.