cytomegalovirus infection

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Cytomegalovirus infection

A common asymptomatic infection caused by cytomegalovirus, which can produce life-threatening illnesses in the immature fetus and in immunologically deficient subjects.

Cytomegalovirus is a member of the herpesvirus group, which asymptomatically infects 50–100% of the normal adult population. Such infections usually take place during the newborn period when the virus can be transmitted from the mother to the baby if the virus is present in the birth canal or in breast milk. Toddlers may also acquire the infection in nurseries. Later in life, the virus may be transmitted by heterosexual or male homosexual activity. After infection, cytomegalovirus remains latent in the body because it cannot be completely eradicated even by a competent immune system. It may be activated and cause illnesses when there is a breakdown of the immune system.

Congenital or transplacental cytomegalovirus infection is also a fairly common event. With rare exceptions, it too is usually asymptomatic. Congenital cytomegalovirus disease results from transplacental transmission of the virus, usually from a mother undergoing initial or primary cytomegalovirus infection, during pregnancy. Its manifestations range from subtle sensory neural hearing loss detectable only later in life, to a fulminating multisystem infection and eventual death of the newborn. This important congenital disease occurs in about 1 in 1000 pregnancies.

The only cytomegalovirus illness clearly described in mature, immunologically normal subjects is cytomegalovirus mononucleosis. This is a self-limited illness like infectious mononucleosis, the main manifestation of which is fever. See Infectious mononucleosis

Otherwise, cytomegalovirus illnesses are usually seen only when cellular immunity is deficient. They constitute the most important infection problem after bone marrow and organ transplantations. Manifestations vary from the self-limited cytomegalovirus mononucleosis to more serious organ involvement such as pneumonia, hepatitis, gastrointestinal ulcerations, and widespread dissemination. The virus causing these illnesses may come from activation of the patient's own latent infection, or it may be transmitted from an outside source, usually from latent cytomegalovirus infecting the graft from a donor. See Immunological deficiency, Transplantation biology

Cytomegalovirus illnesses are also serious, fairly frequent complications of the acquired immunodeficiency syndrome (AIDS). One reason is that most individuals with human immunodeficiency virus (HIV) infection are already infected with cytomegalovirus. Disease manifestations are similar to what is seen in transplant cases, except they may be more severe. Cytomegalovirus retinitis is a typical problem associated with advanced AIDS. Without treatment, the retina is progressively destroyed such that blindness of one or both eyes is inevitable. See Acquired immune deficiency syndrome (AIDS)

Cytomegalovirus diseases can be treated with two antivirals, ganciclovir or foscarnet, with varying degrees of success. Cytomegalovirus pneumonia in the bone marrow transplant recipient cannot be cured by antivirals alone because it probably has an immunopathologic component. Cytomegalovirus diseases in persons with AIDS can be contained but not cured by specific treatment. For example, ganciclovir treatment of cytomegalovirus retinitis is effective only as long as maintenance therapy is continued. See Animal virus

cytomegalovirus infection

[‚sīd·ō¦meg·ə·lō‚vī·rəs in′fek·shən]
A common asymptomatic infection caused by cytomegalovirus, which can produce life-threatening illnesses in the immature fetus and in immunologically deficient subjects.
References in periodicals archive ?
Although the majority of the histologic findings seen in CMV are not specific, any of the above features should prompt further evaluation for congenital CMV infection with immunohistochemical studies.
The major challenge with linking CMV testing with newborn hearing screening is whether treatment with valganciclovir would be of value in congenital CMV infection and isolated hearing loss.
(20) Sellar et al demonstrated that in recipient seropositive/donor seronegative (R+/D-) patients, CMV-specific CD8 T cells detected early following transplant were entirely derived by the recipient and were protective against CMV infection. (20) This data indicates that recipient-derived CMV-specific CD8 T cells which had survived ablation treatment could establish a rapid reconstitution of anti-viral protection.
Hence, it is recommended that in order to prevent congenital CMV infection, pregnant women should be educated about preventive measures, strict hygiene practices such as hand washing and careful cleansing of environmental surfaces.
CMV infections generally increase immune activity but also diminish antibodies responding to influenza vaccination.
Studies on CT findings of CMV infections have reported a combination of GGO, consolidation, nodules, poorly defined small centrilobular nodules, bronchial dilatation, and thickened interlobular septa [10,11].
Assessment criteria were developed to evaluate the appropriateness of Ganciclovir and Valganciclovir use, by applying the recent standard treatment protocols for CMV infection in transplanted patients [19,21].
Our patient had prepapillary CBD stricture along with papillary stenosis and papillitis secondary to CMV infection with no evidence of sclerosing cholangitis.
Because CMV infections commonly occur after allogenic stem cell transplant, these serologic tests are used pretransplant to establish the serostatus which predicts the risk of developing disease, and guides the use of preemptive antiviral therapy.
In the west HCMV infects 2 to 4% of pregnant women for the first time as a primary infection during pregnancy, and it is transmitted to the foetus, resulting in a congenital infection in 40% of these pregnant women.5,8 However, in Pakistan the number of pregnant women infected during pregnancy is not known, but is most probably much higher.2 Congenital CMV in low-and middle-income countries and is mostly due to secondary maternal infections; whereas, in western settings with moderate levels of seroprevalence (70% in USA) 25% of congenital CMV are due to primary and 75% due to secondary maternal infections, in countries where seroprevalence is relatively low (50% European countries), primary and secondary infections contribute equally for occurrence of congenital CMV infection.9
Systemic CMV infection is more widespread in developing countries and in communities with a lower socioeconomic status, and it represents the most significant viral cause of birth defects in industrialised countries.