Abstract & Commentary
Cytomegalovirus Persists on Surfaces, Posing Risk during Pregnancy
By Hal B. Jenson, MD, FAAP, Dean, School of Medicine, Western Michigan University Western Michigan University School of Medicine, Kalamazoo, Michigan, is Associate Editor for Infectious Disease Alert
Dr. Jenson reports no financial relationship in this field of study.
Synopsis: Cytomegalovirus (CMV) app lied to various surfaces was found to be viable on rubber, cloth, and wheat cracker up to 6 hours, glass and plastic up to 3 hours, and metal and sanded wood up to 1 hour. CMV viability was shorter on poorly absorbent surfaces compared to absorbent surfaces.
Source: Stowell JD, Forlin-Passoni D, Din E, et al: Cytomegalovirus survival on common environmental surfaces: Opportunities for viral transmission. J Infect Dis 2011 Nov 23. [Epub ahead of print]
Seven types of common environmental surfaces—rubber, glass, plastic, metal, sanded wood, cloth, and wheat crackers—were studied for recovery of ~200 viable virions of CMV strain AD 169 applied to 2 cm2 replicates on each surface. Virus was applied in 200 µL aliquots of phosphate-buffered saline (PBS). At time points from 1 minute to 6 hours an additional 100 µL aliquot of PBS was used to rewet the surface and collect the sample. For cloth and cracker, the entire 2 cm2 sample area was collected and centrifuged to collect the liquid. A 100 µL aliquot of the collection was cultured for CMV for ≥2 weeks using standard methods and scored from 0 to 4+ based on the extent of cytopathic effect. The remaining collection was tested for CMV by quantitative real-time polymerase chain reaction (PCR).
The quantity of infectious virions declined over time for each surface. The duration of CMV viability was generally shorter on poorly absorbent surfaces compared with absorbent surfaces. Of the poorly absorbent surfaces, CMV viability was longest on rubber with persistence for up to 6 hours, with persistence of 3 hours on glass and plastic, 2 hours on metal, and <2 hours on sanded wood. CMV viability was 6 hours on both cloth and wheat crackers with cloth showing greatest viral viability with 4+ cytopathic effect at 3 hours after application. The cracker surface remained visibly moist throughout the 6-hour study period. There was a correlation of reduced viability with the subjective visual observation of the surface becoming dry. Results of PCR showed that CMV DNA was readily detected on all 7 surfaces throughout the 6 hours of study.
Commentary
CMV is the most common congenital infection, affecting 1-2% of all live births, and is now recognized as a leading cause of congenital hearing loss and other neurological sequelae. In the United States, approximately 6000 children each year have permanent sensorineural hearing loss and intellectual disability resulting from congenital infection.
Transmission of CMV occurs via direct contact with saliva and urine from infected individuals. Asymptomatic shedding of virus persists from weeks to months after initial infection. Children who are congenitally infected may shed virus for the first several years of life.
These results demonstrate that viable CMV persists up to at least 6 hours on a variety of types of fomites as long as they remain moist. Young children who become infected with CMV shed virus for extended periods, contaminating toys and food in the environment, which poses a risk for pregnant women. To minimize the risk of acquiring CMV during pregnancy, it is usually recommended that pregnant women take precautions to avoid sharing food or fomites with young children, and wash their hands after touching toys and other fomites that have been in contact with children's saliva. This seems reasonable and may be possible for the nulliparous pregnant woman who is not already the caretaker of another young child. However, this guidance seems impractical if not impossible for a pregnant woman who is already the mother and caretaker of a young child. The continual risk of maternal exposure to CMV, which may not be feasible to mitigate in many cases, underscores the need to develop an effective CMV vaccine to prevent the serious and frequent sequelae of congenital CMV infection.
Seven types of common environmental surfacesrubber, glass, plastic, metal, sanded wood, cloth, and wheat crackerswere studied for recovery of ~200 viable virions of CMV strain AD 169 applied to 2 cm2 replicates on each surface. Virus was applied in 200 µL aliquots of phosphate-buffered saline (PBS).You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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