[Current Approaches in the Diagnosis and Management of Congenital Cytomegalovirus Infections and the Situation in Turkey].

Human cytomegalovirus (CMV) infections are common in all populations and CMV seroprevalence in women of childbearing age is in the range of 45-100% worldwide. CMV is the most common cause of congenital infections and is associated with fetal development defects and hearing loss. The risk of congenital infection is directly related to maternal immunity and is between 30-40% and 1-2% range in primary and non-primary infections, respectively. Only 5-10% of newborns with congenital infection are symptomatic at birth. Nearly 4% of these babies can die early in life, while 40-60% have to live with permanent sequelae such as sensorineural hearing loss, cognitive deficit and visual impairment. Asymptomatic newborns including those born from mothers with non-primary infections are also at risk for long-term sequelae. These sequelae often develop in the first 1-2 years of life and may extend up to 5-7 years, but the severity of damage reduces in time. CMV seroprevalence in women of childbearing age and pregnant women in Turkey is between 96% and 99.8%. Until recently, our knowledge about the frequency of congenital CMV infections in Turkey was derived from the studies based on the maternal screening tests. These studies, which were far from reflecting the true prevalence of congenital CMV infections, have begun to be replaced by newborn-based systematic screening studies. CMV DNA positivity was found to be 1.6-1.9% in saliva samples, while both saliva and urine and/or blood samples positivity was found to be 0.2-1.4% in the newborn screening studies carried out in Turkey. Glycoprotein B-1 (gB1) was the most frequently detected genotype (38.4-83.3%) in newborns in Turkey. Standard measures and preventive public health practices such as education of the mother, reducing the contact of pregnant women with virus-spreading children and the hand hygiene come into prominence in the prevention of maternal and congenital infections as a result of the absence of an approved vaccine or low protection of existing vaccines. Advanced measures, such as screening blood products especially for the people with immunodeficiency and serological screening of the in-vitro fertilization applications are also being considered. Monitoring of infected newborns and their mothers during pregnancy, postnatal diagnosis and providing counseling for the parents are also critical. Hearing loss can be detected at an early stage using screening tests that become a routine practice for all newborns. Thus, cognitive and psychosocial development of children affected by infection is supported by speech therapy, the use of hearing aids and other practices. However, it should be noted that hearing functions in infected newborns may be normal at birth, but these newborns are at risk for progressive sensorineural hearing loss. For early diagnosis of asymptomatic newborns, it is important to adopt CMV tests as a part of newborn screening programs. Another preventive approach is to treat the mother and the baby with antiviral drugs and preparations that directly target the virus. Passive immunization of the pregnant and the treatment of the symptomatic newborns with valganciclovir have yielded positive results. In this review article, maternal, fetal and newborn based current approaches used in the diagnosis and follow-up of congenital CMV infections have been discussed.