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Cytomegalovirus (CMV) is a common virus that infects people of all ages. So common, in fact,
that over half of all adults by age 40 have been infected with CMV1. Most people infected with
CMV show no signs or symptoms. However, latent CMV can be reactivated and become
symptomatic. An infected person with symptomatic CMV may experience fever, swollen lymph
nodes, and fatigue, with more severe symptoms like liver failure inflicting immunosuppressed
individuals. People infected with CMV shed the virus in bodily fluids, and can spread the virus
through urine or saliva, breast milk, sexual contact, organ transplants and blood transfusions, and
from mother to child during pregnancy (congenital CMV).
In the United States, nearly half of all women have already been infected with CMV before their
first pregnancy1. According to a report by the CDC, around 20,000-40,000 infants are born with
CMV every year, and at least 20 percent have or will develop symptoms and permanent
disabilities. Congenital CMV can occur when a pregnant woman experiences an infection with
CMV for the first time, is infected with a different strain of CMV, or experiences a reactivation
of a virus from a previous infection that occurred prior to becoming pregnant. Babies born with
CMV often suffer from microcephaly, hearing loss, vision abnormalities, intellectual deficits,
seizures and premature death1. At present, there is no vaccine or standard treatment for CMV.
According to Dr. Veronica Miller, a Senior Researcher and Lecturer at UC Berkeley’s School of
Public Health, damage resulting from CMV disease exceeds that of down syndrome, spina
bifida, congenital rubella, haemophilus influenza, and HIV combined4.
Screening for prenatal primary CMV infections is not routinely performed in the United States.
In fact, the American Congress of Obstetricians and Gynecologists states that pregnant women
would find CMV prevention “impractical and burdensome”1. CMV infection is usually detected
using serological testing, viral cell culture, or PCR4. However, most laboratory tests available
cannot detect conclusively if a primary CMV infection has occurred1. Additionally, the lack of a
proven treatment to treat CMV reduces the potential benefit of prenatal screening.
Promising research suggests that symptomatic Congenital CMV Disease can be improved.
Valganciclovir, an oral antiviral drug, was shown to improve hearing and developmental
outcomes modestly when used for 6 months2. Antiviral drugs can inhibit the replication and
development of the virus, but they do not remove the virus from an infected person’s system.
Because viruses use the host cell to replicate in, antiviral drugs are often dangerous. The drug
must target the virus without harming the host. Valganciclovir is not without its aversive side
effects; treatment with the antiviral drug risks myelosuppression, hallucination, and neurotoxic
effects in high doses3.
In the U.S., Zika is widely publicized, and nearly everyone knows a thing or two about the
mosquito-borne disease. However, its presence is quite rare in the states. CMV, if not for its
severe impairments then for its greater presence, should be every bit a priority as Zika, argues
Dr. Mark Schleiss, the Director of Pediatric Infectious Diseases at the University of Minnesota
Medical School. In combatting the global burden of cytomegalovirus, the strategy must include
determining the best screening, diagnostic, and treatment regimen with robust data for regulatory
approval, generating a consensus on an appropriate time for introducing medication to both the
pregnant mother and the infant as well as on an appropriate endpoint for treatment, and must
ensure global access by integration with maternal/child wellness programs and local and regional
governments, and established affordable pricing.
References
1. Centers for Disease Control and Prevention. Cytomegalovirus and Congenital CMV
Infection. National Center for Immunization and Respiratory Diseases, Division of Viral
Diseases. June 2016.
2. Kimberlin, David MD et al. Valganciclovir for Symptomatic Congenital
Cytomegalovirus Disease. New England Journal of Medicine 2015; 372:933-943.
3. McIntosh, Hauschild, Miller. Human cytomegalovirus and transplantation: drug
development and regulatory issues. J Virus Erad. 2016 Jul. 2(3): 143-148.
4. Veronica Miller, PhD. Lectures on Public Health Microbiology: Cytomegalovirus.
December 2016.