CMV virus




Cytomegalovirus Retinitus

Cytomegalovirus (CMV) infection is very common within the general population, but it often shows little or no symptoms in healthy people (Gateway). It infects between 50% to 85% of adults in the United States by the age of 40 (CDC). However, in the immunodepressed population, there is often an active infection that shows many possible symptoms. Within the HIV infected community, the CMV virus’ most common symptoms are retinitus and gastrointestinal problems (Gateway). In these patients, CMV retinitus usually develops when the T-cell count is below 50 cells/mm^3. CMV retinitus presents itself as an area of whitening in the retina of the eye. The whitening may be accompanied by a hemorrhage (Medscape).
CMV retinitus is particularly important to the HIV/AIDS community. Infection with CMV is a major cause of disease and death in immunocompromised patients, specifically HIV infected patients (CDC). Retinitus is one of the most common symptoms of CMV infection within the HIV community. As stated before, CMV retinitus presents itself as an area of whitening within the retina. Hemorrhages may or may not occur. If the infection involves the posterior pole of the eye where many large blood vessels, there is a strong likelihood that hemorrhaging will occur where as if the infection is in the peripheral retina where there is a small number of large blood vessels, hemorrhaging is less likely to occur. CMV retinitus most often occurs in the peripheral retina and the area around the optic nerve. Since vision is determined mostly by the fovea, which is located in the central part of the retina, a large part of the retina can be affected before the infected individual ever develops noticeable visual symptoms. These visual symptoms are floaters, photophobia, and visual field defects (Medscape). CMV retinitus spreads directly from diseased retina to healthy parts of the retina. If it is left untreated, it will result in complete blindness (CDC).
“Transmission of CMV occurs from person to person. Infection requires close, intimate contact with a person excreting the virus in their saliva, urine, or other bodily fluids. CMV can be sexually transmitted and can also be transmitted via breast milk, transplanted organs, and blood transfusions (CDC).” Although the virus is not extremely contagious, it is common for in to spread within households and among children at day care centers. Infection is preventable since most infections is caused by bodily fluids coming into contact with hands which then touch the mouth or nose spreading the virus. This can be prevented by simple washing of the hands with soap and water (CDC).
CMV infection is common in infants and children, and most often it shows no symptoms. Because of this, no extraordinary precautions are necessary. Effective hygiene is adequate for the prevention of further transmission of the virus.
There is another circumstance in which the CMV virus can cause problems excluding the immunodepressed community. For infants who are infected by their mothers before birth, there are two potential problems. One problem is that a generalized infection may occur. Symptoms may range from enlargement of the liver and spleen to possible death form illness caused by the virus. With treatment, most infants will survive, but 80% to 90% percent will experience complications including hearing loss, vision loss, and mental retardation. Around 5% to 10% of infants who are infected but show no symptoms will experience varying degrees of hearing and mental loss and coordination problems (CDC).
Most infections of CMV never diagnosed because they cause no symptoms and present no problems, however within the HIV/immunodepressed community the infection is diagnosed using serologic testing (CDC). The earlier it is detected the more effective the treatment (Medscape).
“Currently, no treatment exists for CMV infection in the healthy individual (CDC).” As of 1999 there were only six FDA-approved treatments for CMV retinitus. They are intravenous and oral ganciclovir (Cytovene), intravenous foscarnet (Foscavir), intravenous cidofovir (Vistide), the ganciclovir implant (Vitrasert), and fomivirsen (Vitravene) (Medscape). However, the use of antiretroviral therapies has been shown to reduce the progression of CMV retinitus. “There have been reports of dramatic decreases in the frequency of CMV retinitus in areas where 3- and 4-drug antiretroviral combination therapies are routinely used. In one study, the 6-month risk for new CMV disease in patients who had not taken protease inhibitors was 61% versus 9% in those