cytomegalovirus (CMV)
المؤلف:
Kathleen Deska Pagana, Timothy J. Pagana, Theresa Noel Pagana.
المصدر:
Mosbys diagnostic and laboratory test reference
الجزء والصفحة:
15th edition , p323-324
2025-12-04
65
Type of test Blood
Normal findings
No virus isolated
Test explanation and related physiology
CMV is part of the viral family that includes herpes simplex, Epstein–Barr, and varicella-zoster viruses. CMV infection is widespread and common. Infections usually occur in the fetus, during early childhood, and in the young adult. Certain populations are at increased risk. Male homosexuals, transplant patients, and AIDS patients are particularly susceptible. Infections are acquired by contact with body secretions or urine. Blood trans fusions are a common form of spread for CMV.
CMV is the most common congenital infection. Pregnant mothers can get the disease during pregnancy, or a previous CMV infection can become reactivated. Approximately 10% of infected newborns exhibit permanent damage, usually mental retardation and auditory damage. Fetal infection can cause microcephaly, hydrocephaly, cerebral palsy, mental retardation, or death. The term TORCH (toxoplasmosis, other, rubella, cytomegalovirus, herpes) has been applied to infections with recognized detrimental effects on fetuses.
Virus culture is the most definitive method of diagnosis. Antibodies reveal much more information about the activity of the infection. CMV IgG antibody levels persist for years after infection. Identification of IgM antibodies, however, indicates a relatively recent primary infection. Three different CMV anti gens can be detected immunologically. They are called early, intermediate-early, and late antigens and indicate onset of infection. A fourfold increase in CMV titer in paired sera drawn 10 to 14 days apart is usually indicative of an acute infection.
More recently, measurement of CMV-specific IgG avidity is able to distinguish primary from nonprimary CMV infections. In this test, the strength with which the IgG attaches to the CMV antigen is measured. IgG avidity matures with the length of time after primary infection. Therefore IgG produced in the first few months after primary CMV infection will exhibit “low avidity.” IgG produced more than 6 to 8 months after CMV infection will have “high avidity” and represent nonprimary chronic CMV infection.
Procedure and patient care
• See inside front cover for Routine Blood Testing.
• Fasting: no
• Blood tube commonly used: red or gold
• For culture specimens, a urine, sputum, or mouth swab is the specimen of choice. Fresh specimens are essential.
• The specimens are cultured in a virus laboratory, which takes about 3 to 7 days.
• For antibody or antigen titer, collect a venous blood sample in a gold- or red-top tube.
• Collect a specimen from a mother with suspected acute infection as early as possible.
• Collect the convalescent specimen 2 to 4 weeks later.
Abnormal findings
- CMV infection
الاكثر قراءة في التحليلات المرضية
اخر الاخبار
اخبار العتبة العباسية المقدسة
