Cytomegalovirus Culture
The cytomegaloviruses are members of the herpes virus group. They are ubiquitous and may cause infections in all age groups. By adulthood, 60-90% of persons have serologic evidence of prior infection, most of which are asymptomatic. However, the incidence and spectrum of disease in newborns and immunocompromised individuals establish CMV as an important human pathogen.
Infections can be classified as those acquired before birth (congenital), at the time of delivery (perinatal), or later in life (postnatal). Congenital infections have been detected in 0.5-2.5% of newborns. Many are asymptomatic, but symptoms may include hepatitis with jaundice, hemorrhage or purpura, growth retardation, brain damage, or death. Infants infected perinatally are usually asymptomatic. Most postnatal infections are also asymptomatic, although infected persons may excrete virus at high titers in urine and other body fluids for months. CMV in adults may cause a syndrome characterized by fever, splenomegaly, atypical lymphocytosis and a negative heterophile antibody. CMV infections are common and may be severe in debilitated and immunosuppressed individuals.
During early and acute phases of illness, CMV infections are best detected by viral culture. CMV can be isolated from urine, saliva, tears, stool, cervical and vaginal secretions, biopsy and autopsy specimens, blood, and respiratory specimens. Positive blood cultures are particularly significant for immunocompromised patients, because viral isolation from blood cells is a better indicator of symptomatic CMV infection than the presence of shed virus in urine.
Specimen Requirements:
- Respiratory - Nasopharyngeal: These specimens are best obtained using a disposable feeding tube. Place aspirate in viral transport media. Alternatively, a sputum trap may be used. After collection, aspirate viral transport media through the collection tube. Store and transport sample and media in the trap.
- Swabs (respiratory, cervical): Swab the area thoroughly then place swab in viral transport media.
- Stool: Place pea sized sample of stool in viral transport media.
- CSF: Place in a sterile tube without viral transport media.
- Urine:Collect as first morning void in sterile container without viral transport media. Urine should accompany all blood specimens.
- Vesicles: Aspirate vesicle contents into viral transport media. After fluid collection, remove top of vesicles and swab the basal membrane. Place swab in the transport media with vesicle contents.
- Lesions or ulcers: Remove several scabs and place in viral transport media along with a basal membrane swab.
- Eye: Collect fluid or swab exudate and place in viral transport media.
- Blood: Plasma. 5 mL green top tube.
