This photomicrograph shows a silver stain of Pneumocystis carinii that was obtained from an HIV patient by performing a bronchoalveolar lavage. This procedure is performed by placing a fiberoptic scope into the lung of the patient, then injecting sterile saline into the lung and removing it. The extracted saline solution contains secretions and cells from the lower respiratory tract that can be tested. The lavage was tested and a silver stain was performed in order to observe the organism.
P. carinii is a fungus that is commonly found in most humans. It is an opportunistic organism that will cause pneumonia under certain circumstances. For most people with a healthy immune system, the organism generally causes no threat. However, if the patient has HIV or any other disease that affects the immune system, the fungus can become active and cause what is known as P. carinii pneumonia, or PCP.
PCP is found to be the most prevalent opportunistic infection among HIV patients. Without treatment, 85% of HIV patients will develop PCP. People who have a CD4 T-cell count (a measure of the strength of the immune system) less than 200 have the highest risk of infection. The first signs of a PCP infection are difficulty breathing, fever, and a dry cough. Patients with PCP generally become much weaker and lose a lot of weight. PCP, however, is now almost entirely preventable and treatable with antibiotics.
Legend written by:
Aaron Nebelsick
Colorado State University
Fort Collins, Colorado 80525
anebel@holly.colostate.edu |
