CMV stands for cytomegalovirus. Cytomegalovirus is a member of the herpesvirus family. Viruses have been around for thousands of years and there are many kinds of viruses. A virus can't live on its own or spread on its own, but needs human cells to live and grow. Most people are infected with some kind of virus, but the immune system usually keeps them from causing active disease.

When the immune system is not working well, a virus like CMV can cause illness. T4 cell counts are one way to measure how well the immune system is working in people with HIV. The risk of developing illness due to CMV is greatest when theT4 cell count is less than 100.

The most common illness caused by CMV in people with AIDS is retinitis. CMV retinitis is an infection of the eye that can lead to blindness. Other forms of CMV disease are colitis (CMV in the intestine), esophagitis (in the mouth or throat), myelitis (spine), and sometimes encephalopathy (brain), and pneumonitis (in the lungs). Left untreated, CMV can spread throughout the body, infecting one or more organs at once and resulting in a great variety of symptoms.

Symptoms
The signs of CMV retinitis are vision problems, such as moving black spots known as "floaters," or blind spots. These indicate an inflammation of the retina of the eye. A doctor that specializes in eye problems, called an ophthalmologist, can check for CMV by doing a simple eye examination. If you have a low T4 cell count, it's important to get regular eye exams to check for early signs of CMV retinitis.

The main symptom of CMV colitis is diarrhea. CMV colitis is diagnosed by biopsy, which means taking a small piece of tissue from the intestine and testing it for CMV in the laboratory. CMV esophagitis can make swallowing painful and difficult. A biopsy taken from the throat can diagnose CMV esophagitis. CMV myelitis can cause numbness at the base of the spine, which can spread to the legs and cause difficulty walking. A small sample of spinal fluid can be tested to diagnose CMV myelitis. Encephalitis and pneumonia are only rarely caused by CMV. CMV encephalitis causes symptoms similar to other brain infections such as personality changes, difficulty concentrating and headaches. CMV encephalitis can only be diagnosed for certain by biopsy, requiring surgery. CMV pneumonia can cause shortness of breath and dry cough, but it is extremely unusual for CMV to be the main cause of pneumonia in people with AIDS.

Treatments
There are three drugs approved for the treatment of CMV retinitis, ganciclovir, foscarnet and cidofovir. Ganciclovir and foscarnet are also commonly used to treat CMV in other parts of the body. Ganciclovir, foscarnet and cidofovir have been shown to slow down the progression of CMV, although they cannot cure the illness. Until recently, all anti-CMV drugs had to be given by intravenous infusion, which means into a vein. With ganciclovir and foscarnet, intravenous treatment requires having a permanent catheter placed in the chest for daily infusions. The Network has information on the different types of catheters used for these CMV treatments. Cidofovir does not require a catheter, because it only requires infusions every other week.

Ganciclovir is now available in two other formulations. A pill form can sometimes be used after receiving two weeks of intravenous therapy, called induction therapy. Induction therapy is used to bring the CMV retinitis under control. The pill form of ganciclovir can then be taken daily for maintenance therapy. A device that releases ganciclovir directly into the eye is approved for the treatment of CMV retinitis. This device is called Vitrasert. Treatment with Vitrasert is localized, meaning it only treats the eye and can't be used for treating CMV in other parts of the body.

Other anti-CMV treatments are in clinical trials.

The side effects of ganciclovir can be neutropenia (a low number of white blood cells called neutrophils), nausea, vomiting, and lowered levels of a hormone called testosterone. Foscarnet can cause kidney problems due to dehydration and sodium depletion which can slow down the passage of fluid through the kidneys and cause decreased function and sometimes failure. Side effects from foscarnet should be watched for in the third week of treatment. Cidofovir can cause kidney problems and has to be given with a drug called probenicid to reduce the risk of kidney failure.

The Simple Facts Project is a program of The Network. If you need help finding out whether or not a specific drug or therapy is covered by private or public insurance, contact The Network at (800) 734-7104. This information does not intend to promote or endorse any specific treatment for any health related condition.