Cytomegalovirus infection

Cytomegalovirus infection, or cytomegalovirus, is a chronic anthroponotic disease of viral etiology, characterized by a variety of forms of the pathological process from latent infection to clinically expressed generalized disease.

ICD-10 codes

• B25. Cytomegalovirus disease.
• B27.1. Cytomegalovirus mononucleosis.
• B35.1. Congenital cytomegalovirus infection.
• B20.2. HIV-associated disease with manifestations of cytomegalovirus disease.

What causes cytomegalovirus infection?

Cytomegalovirus infection is caused by cytomegalovirus (CMV, human herpesvirus type 5), which can cause infection of varying severity. The infectious syndrome is similar to infectious mononucleosis, but there is no pronounced pharyngitis. Severe local manifestations, including retinitis, develop in HIV-infected patients and, less commonly, after organ transplantation and in other immunocompromised patients. Severe systemic involvement occurs in neonates or immunocompromised individuals. Cultivation, serologic testing, biopsy, and determination of antigens or nucleic acids are useful for laboratory diagnosis. Ganciclovir and other antiviral drugs are used in severe cases of the disease, particularly retinitis.

Cytomegalovirus is widespread. Infected individuals excrete the virus in urine or saliva for many months; the virus is present in biological fluids, blood; donor organs can cause disease in susceptible recipients. Cytomegalovirus infection is transmitted through the placenta, during childbirth. In the general population, infection increases with age: from 60 to 90% of adults are infected with cytomegalovirus. High infection rates are observed among groups with low socioeconomic levels.

What are the symptoms of cytomegalovirus infection?

Congenital cytomegalovirus infection can be latent, without consequences; cause a disease manifested by fever, hepatitis, pneumonia and, in newborns, severe brain damage; lead to stillbirth or death in the perinatal period.

Acquired cytomegalovirus infection can be asymptomatic; it can cause a disease characterized by fever (CMV mononucleosis), hepatitis with elevated aminotransferases, atypical lymphocytosis similar to infectious mononucleosis, and splenomegaly.

Postperfusion/posttransfusion syndrome may develop within 2-4 weeks after transfusion of blood products contaminated with cytomegalovirus infection. Fever lasting 2-3 weeks and CMV hepatitis develop.

In immunocompromised patients, cytomegalovirus infection is the main cause of morbidity and mortality.

In patients with cytomegalovirus infection (acquired or developed due to activation of a latent pathogen), lesions of the lungs, gastrointestinal tract, central nervous system, and kidneys are possible. After organ transplantation, these complications occur in 50% of cases and are highly lethal. Generalized CMV infection usually manifests itself as retinitis, encephalitis, and ulcerative disease of the colon or esophagus in the terminal stage of AIDS.

How is cytomegalovirus infection diagnosed?

Cytomegalovirus infection is suspected in healthy individuals with mononucleosis-like syndromes; in immunocompromised individuals with gastrointestinal, CNS, or ocular symptoms; and in neonates with systemic symptoms. Differential diagnosis of acquired CMV infection includes viral hepatitis and infectious mononucleosis. The absence of pharyngitis and lymphadenopathy and a negative reaction to heterophile antibodies are more characteristic of primary mononucleosis caused by CMV rather than Epstein-Barr virus. Serologic tests help differentiate CMV infection from viral hepatitis. Laboratory confirmation of CMV infection is necessary only in the case of differential diagnosis with other diseases that produce a similar clinical picture. CMV can be isolated from urine, other body fluids, and tissues. Cytomegalovirus can be excreted for many months and years after infection, which is not evidence of active infection. Seroconversion is indicated by a change in the titer of antibodies to cytomegalovirus. In immunocompromised patients, biopsy is often necessary to prove CMV-induced pathology; PCR, which allows determination of the viral load, is also useful. In children, the diagnosis can be confirmed by obtaining a urine culture.

How is cytomegalovirus infection treated?

In patients with AIDS, the symptoms of CMV retinitis are relieved by antiviral drugs. Most patients receive ganciclovir 5 mg/kg intravenously twice daily for 2 to 3 weeks or valganciclovir 900 mg orally twice daily for 21 days. If initial treatment for CMV infection is ineffective even once, a change in drug should be made. After the initial dose, the patient should receive maintenance or suppressive therapy with valganciclovir 900 mg orally once daily to stop disease progression. Maintenance treatment of CMV infection with valganciclovir 5 mg/kg intravenously once daily is useful in preventing relapses. Alternatively, foscarnet may be used with or without ganciclovir, at a starting dose of 90 mg/kg intravenously every 12 hours for 2-3 weeks, followed by maintenance therapy of 90-120 mg/kg intravenously once daily. Side effects of intravenous foscarnet are significant and include nephrotoxicity, hypocalcemia, hypomagnesemia, hypokalemia, hyperphosphatemia, and CNS involvement. Combination therapy with ganciclovir and foscarnet increases the risk of side effects. Treatment of cytomegalovirus infection with sidovir is carried out at a starting dose of 5 mg/kg intravenously once a week for 2 weeks, followed by administration of the drug once every two weeks (maintenance dose). Efficacy is similar to that of ganciclovir or foscarnet. The use of sidovir is limited by significant side effects, such as renal failure. To reduce nephrotoxicity, probenecid should be administered with each dose and the body should be hydrated. It should be remembered that probenecid itself can cause significant side effects (rash, fever, headache).

For prolonged treatment of patients, ocular implants with ganciclovir can be used. Intraocular injections into the vitreous body are useful when other therapeutic measures are ineffective or when they are contraindicated (desperate therapy). Such treatment of cytomegalovirus infection includes injections of ganciclovir or foscarnet. Potential side effects of such treatment may include retinotoxicity, vitreous hemorrhage, endophthalmitis, retinal detachment, papilledema of the optic nerve, and cataract formation. Sidovir can lead to the development of iritis or ocular hypotony. But even with such therapy, patients need systemic use of antiviral drugs to prevent damage to the second eye or extraocular tissues. In addition, increasing the level of CD4 + lymphocytes to a level of more than 200 cells / μl in combination with systemic antiretroviral drugs allows limiting the use of ocular implants.

Anti-CMV drugs are used to treat more severe conditions than retinitis, but their effectiveness is much lower than in the treatment of retinitis. Ganciclovir in combination with immunoglobulin is used to treat cytomegalovirus pneumonia in patients who have undergone bone marrow transplantation.

Prevention of cytomegalovirus infection is necessary for recipients of solid organs and hematopoietic cells. The same antiviral drugs are used.

What is the prognosis for cytomegalovirus infection?

Cytomegalovirus infection has a favorable prognosis if the diagnosis of cytomegalovirus pneumonia, esophagitis, colitis, retinitis, polyneuropathy is made early and etiotropic therapy is started in a timely manner. Late detection of cytomegalovirus retinal pathology and the development of its extensive damage leads to persistent vision loss or its complete loss. Cytomegalovirus damage to the lungs, intestines, adrenal glands, brain and spinal cord can cause disability in patients or lead to death.