Congenital CMV - causes, symptoms, diagnosis, treatment, pathology

Summary

Congenital cytomegalovirus (CMV) infection is a common viral cause of birth defects, transmitted from mother to fetus during pregnancy. CMV can lead to a range of developmental issues including sensorineural hearing loss, microcephaly, and intellectual disabilities. The virus can also cause eye abnormalities and motor impairments. Diagnosis is confirmed through PCR testing of urine or saliva samples, and treatment involves antiviral medications for symptomatic infants. Although no vaccine exists, preventive measures include avoiding contact with young children who may unknowingly shed the virus. Early intervention and supportive therapies are crucial for managing long-term effects.

Takeaways

• 😀 Congenital CMV infection occurs when a pregnant woman passes cytomegalovirus (CMV) to her developing fetus, potentially causing birth defects.
• 😀 CMV is a member of the herpesvirus family, transmitted through body fluids like saliva, urine, blood, and breast milk.
• 😀 The virus can be transmitted via first-time infection, reactivation of a previous infection, or reinfection with a new strain of CMV during pregnancy.
• 😀 CMV can damage fetal cells and blood vessels, causing developmental defects, including growth restrictions and abnormalities in organ development.
• 😀 Common symptoms of congenital CMV in infants include petechiae (small skin spots), jaundice, hepatosplenomegaly (enlarged liver and spleen), and microcephaly (small head size).
• 😀 Progressive sensorineural hearing loss is a hallmark feature of congenital CMV, which can present at birth or develop later in life.
• 😀 Other potential effects of congenital CMV include eye abnormalities (such as chorioretinitis and strabismus), intellectual disability, motor disabilities, and seizures.
• 😀 Prenatal diagnosis of congenital CMV can be performed using ultrasonography, amniocentesis, or fetal blood sampling for PCR and CMV-specific antibodies.
• 😀 Postnatal diagnosis is confirmed by PCR or viral culture from urine or saliva samples taken within the first three weeks after birth.
• 😀 Treatment for symptomatic congenital CMV includes antiviral medications (ganciclovir or valganciclovir) for six months, but it does not reverse existing damage; additional therapies like physical, speech, and vision therapy are important for long-term care.

Q & A

What is congenital cytomegalovirus (CMV) infection?

Congenital CMV infection occurs when a fetus is infected with cytomegalovirus (CMV) during intrauterine life, either through primary infection in the mother, reactivation of an old infection, or reinfection with a new CMV strain.

What are some other infections included in the TORCH group, and how is CMV related?

The TORCH group includes Toxoplasma, Other pathogens (such as syphilis), Rubella, Cytomegalovirus (CMV), and Herpes simplex virus. CMV is a member of the herpesviridae family and shares similarities with these other infections in terms of causing defects in fetal development.

How is CMV transmitted?

CMV is primarily transmitted through contact with body fluids such as blood, saliva, breast milk, genital secretions, and urine of an infected person. It can also be transmitted through transplanted organs.

What are the two main mechanisms by which CMV causes fetal defects?

CMV may cause fetal defects by (1) being cytopathic, meaning it damages cells as it replicates, disrupting cell structures and causing enlarged cells with viral inclusion bodies, and (2) invading blood vessels, causing vasculitis and restricting blood flow to the fetus, resulting in abnormalities.

What are some common symptoms in newborns with congenital CMV?

Common symptoms include petechiae (tiny purple, red, or brown spots on the skin), jaundice (yellowing of the skin and eyes), hepatosplenomegaly (enlarged liver and spleen), microcephaly (abnormally small head), and sensorineural hearing loss.

What is the hallmark feature of congenital CMV infection?

The hallmark feature of congenital CMV is progressive, permanent sensorineural hearing loss, which can either present at birth or develop later in life.

How is congenital CMV diagnosed?

Diagnosis can be made prenatally through ultrasonography, amniocentesis, or fetal blood sampling, and postnatally through PCR or viral isolation from urine or saliva in newborns under three weeks of age. A full physical exam and hearing screening are also important for diagnosis.

What is the treatment for congenital CMV in symptomatic infants?

Symptomatic infants are typically treated with antiviral medications like ganciclovir or valganciclovir for six months. These medications help reduce the progression of hearing loss and improve growth and developmental milestones but do not reverse any existing damage.

What are the long-term therapies for children affected by congenital CMV?

Long-term therapies may include physical, occupational, speech, and vision therapies. For children with hearing loss, sign language, hearing aids, or cochlear implants may be necessary.

Is there a vaccine available to prevent congenital CMV?

Currently, no vaccine is available to prevent congenital CMV infection. Pregnant women can reduce their risk by avoiding contact with saliva and urine from toddlers and young children, who may be asymptomatically shedding the virus.