Cmv Virus Essay, Research Paper
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 patients who had taken protease inhibitors (Medscape).” In addition to this, there have been reports that described improved outcomes in patients with CMV retinitus who have received antiretroviral therapy in addition to antiviral therapy. Also, it has been shown that only HAART or oral ganciclovir were associated with a decreased risk of CMV retinitus relapse (Medscape). In many patients with CMV retinitus that has healed in response to HAART, anti-CMV therapy has been discontinued without a reoccurrence of the retinitus (Medscape).
Overall, CMV has a relatively small affect on society even though there is a high infection rate. In Healthy individuals, the virus rarely shows any symptoms at all. However, in the HIV/immunodepressed community, CMV has a very large affect. CMV is very common and can be deadly to immunodepressed individuals, therefore it should not be taken lightly (CDC).
The future of CMV is unknown. “Vaccines are still in the research and development stage (CDC).” HAART has been shown to be effective in treating and preventing CMV retinitus (Medscape), but in my opinion I think the virus will be around for a long time.
I chose to research and write about CMV and particularly CMV retinitus because I am planning on becoming an optometrist. Diseases of the eye interest me and there is a good possibility in today’s society that when I do begin to practice optometry that I will run across and possibly even diagnose a case of CMV retinitus. My father is currently practicing optometry and he told me that he has one patient that is HIV positive and that she has been diagnosed with CMV and she is on specific drugs to prevent the development of CMV retinitus. My father is in continued contact with the ladies HIV doctor to ensure that he eyesight is not damaged. Currently the lady is not showing any signs of retinitus, but there is no assurance that she never will. There is a good chance that when I enter optometry school I will study CMV as a cause for retinitus. My father did not study CMV while he was in optometry school but AIDS had not even been discovered during the time he was in school.
I find the information I have found about CMV retinitus to be very interesting. I have always been interested in eyes and how they work so obviously I am interested in learning more about diseases that can possibly take the wonderful gift of sight away from us. The information I found included some photographs of the retina of infected individuals and I found this very interesting as well. Overall, my opinion of the time I spent researching is very good. It was time well spent.