Pediatric Cytomegalovirus Infection Follow-up

Updated: Jan 27, 2015
  • Author: Mark R Schleiss, MD; Chief Editor: Russell W Steele, MD  more...
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Follow-up

Deterrence/Prevention

Ultimately, control of cytomegalovirus (CMV) infection, particularly the devastating sequelae of congenital cytomegalic inclusion disease (CID), depends on immunization.

The major target population for a CMV vaccine is women of childbearing age. Although immunization is unlikely to prevent all congenital infection, the hope is that immunization can have a significant and major impact on the prevalence of CID.

A vaccine may also be useful in controlling CMV disease in organ transplant recipients. A live-attenuated vaccine, the Towne vaccine, showed promise for prevention of CMV disease in studies involving renal transplant recipients reported in the 1980s. However, the Towne strain of CMV is poorly immunogenic, probably because it has been overly attenuated during the process of tissue culture passage.

Newer technologies using recombinant chimeric viruses that represent genetic hybrids between Towne virus and a low-passage clinical isolate, the Toledo strain, are currently under investigation as the next generation of live-virus CMV vaccines.

Subunit vaccine approaches are also being explored. These use molecularly cloned, eucaryotically expressed forms of the major immunogenic CMV envelope protein, gB, and are being actively investigated in clinical trials.

A phase II, placebo-controlled, randomized, double-blind trial by Pass et al evaluated a recombinant CMV vaccine (envelope glycoprotein B with MF59 adjuvant). Three doses of the CMV vaccine or placebo were administered at 0, 1, and 6 months to 464 CMV-seronegative women within 1 year after they had given birth. After a minimum of 1 year of follow-up, 49 confirmed infections were noted, 18 in the vaccine group and 31 in the placebo group. One congenital infection among infants of the study subjects occurred in the vaccine group, and 3 infections occurred in the placebo group. Ongoing research continues to evaluate the potential for a CMV vaccine to decrease maternal and congenital CMV infection. [45] Another study of this vaccine in solid organ transplant patients at risk for CMV infection and disease also indicated efficacy in seronegative transplant recipients. [46]

A prospective, multicenter birth-cohort study was conducted to estimate the risk of postnatal CMV transmission from transfusion of CMV-seronegative and leukoreduced blood and also maternal breast milk. The study concluded that transfusion of CMV-seronegative and leukoreduced blood products effectively prevents transmission of CMV to very low-birth-weight (VLBW) infants. The study further concluded that among infants whose care is managed with the transfusion of CMV-seronegative and leukoreduced blood, maternal breast milk is the primary source of postnatal CMV infection. [47]

A vectored vaccine approach in a genetically engineered poxvirus vector, canarypox, is also under evaluation. In addition to gB, this approach targets the major cytotoxic T-cell (CTL) target, the UL83 gene product.

DNA vaccines have also shown promise for prevention of CMV infection, and they have demonstrated some degree of efficacy in the transplantation setting. [48]

CMV has been demonstrated to enter epithelial and endothelial cells by different pathways than those used for entry into fibroblasts, and a complex of CMV proteins (ie, gH/gL/UL128/130/131 complex) is essential for this process. This discovery has provided a new potential target for vaccines. [28]

Until the goal of a CMV vaccine is realized, educating women of childbearing age about the risks of CMV and about how to avoid disease transmission are the only control strategies available.

Seronegative women who regularly come in close contact with large numbers of young children, particularly in daycare environments, may be at particularly high risk.

Acquisition of primary cytomegalovirus (CMV) infection during pregnancy is a major concern. Women at high risk include those with extensive daycare contact, particularly individuals who work in large daycare facilities in which repeated exposures are common. [49]

Behaviors known to be associated with transmission of infection, particularly kissing and sharing eating utensils, can be avoided, and careful handwashing after diaper changes should be stressed.

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Patient Education

Increased awareness of the complications of congenital cytomegalovirus (CMV) infection is needed.

With a greater educational effort, women of childbearing age can be better prepared to anticipate risk factors for CMV transmission during pregnancy. [50]

A national CMV registry provides education and support for families affected by congenital CMV infection. Contact the National Congenital CMV Disease Registry at Feigin Center, Suite 1150, 1102 Bates Street, MC 3-2371, Houston, TX, 77030-2399, (832) 824-4387, or visit the Web site at http://www.bcm.tmc.edu/pedi/infect/cmv/ .

Better education of the risks of CMV infection for young women is a must. The CDC is also an excellent educational resource.

Other foundations provide education and resources for parents interested in learning more about congenital CMV, including the CMV Foundation.

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