Respiratory neonatal CIS Brandau Flashcards
CMV Infection in the Fetus and Newborn
Human CMV is a DNA virus of the herpevirus group
CMV infection results in characteristic massive enlargement of the affected cells that contain intranuclear and cytoplasmic inclusions
most common congenital viral infection
More than 8,000 of these infants have mental retardation, cerebral palsy and most commonly, hearing impairment
CMV epidemiology
Person to person transmission occurs through close contact with infected body fluids and secretions
Virus can be isolated from tears, saliva, human milk, urine, stool, semen, cervical secretions, amniotic fluid, blood and transplanted organs
After an active replication stage, CMV enters a latent stage in leucocytes and other tissues
Latent virus can reactivate during periods of immunocompromise such as pregnancy
Viral excretion persists for years after congenital and perinatal infections and primary infections in older children and adults
CMV transmission- prenatal
Prenatal:
Fetal infection more common after primary infection in the mother
Transmission can occur at any time during pregnancy
Overall only 10%-15% of infected infants manifest clinical signs at birth
Maternal reinfection with a different strain can result in symptomatic congenital infection
CMV transmission: natal
Occurs when seropositive pregnant women shed virus in cervical and vaginal secretions
Approximately 50% become infected with disease that becomes manifest at 4-6 weeks of age
CMV transmission: postnatal
CMV is shed in breast milk in anywhere from 9%-88% of seropositive women
50%-60% of infants fed infected breast milk become infected
Transmission also occurs through blood transfusion
clinical manifestations of congenital CMV infections
**Sensorineural hearing loss-Occurs in 30% to 65% of symptomatic infants and 5% to 15% in asymptomatic infants
Ultrasonography has documented fetal abnormalities such as hepatosplenomegaly, echogenic bowel, ventriculomegaly and intracranial calcifications
Umbilical blood sampling as shown thrombocytopenia, anemia and elevated liver enzymes
Most infant infected with CMV have no clinical findings at birth or in the neonatal period hence are classified as asymptomatic
Those having clinical, laboratory or radiographic findings include
Intrauterine growth restriction
Hepatosplenomegaly
Jaundice
Petechiae or purpura
“blueberry muffin” spots
Microcephaly
Chorioretinitis
Sensorineural hearing loss-Occurs in 30% to 65% of symptomatic infants and 5% to 15% in asymptomatic infants
Cerebral calcifications
Other Findings in congenital CMV infections
Poor feeding, pneumonia, lethargy, hypotonia and seizures
Laboratory findings
Coombs (-) hemolytic anemia
Elevated liver enzymes
Elevated CSF protein
Bronchopulmonary Dysplasia (BPD)
chronic lung disease occurring in premature infants with RDS that were treated with mechanical ventilation and supplemental oxygen that developed chest X-rays that showed “coarse, streaky infiltration with small areas of emphysema and occasionally appeared cystic”
Changing Picture of BPD
With advent of surfactant therapy, antenatal glucocorticoids and refinements in ventilation BPD is rare infants with a gestational age > 30 weeks and weights of > 1200 grams
Currently a study showed that 30% of infants with a birth weight of less than 1000 grams developed BPD but the radiographic appearance is different from the early description leading to the new name as Chronic Lung disease of Infancy that appears to be a disease of only very immature infants ( < 1000 grams and less than 32 weeks gestation
Consensus Definition of BPD
An infant at 36 weeks post-menstrual age (PMA) born at less than 32 weeks gestation who has required supplemental oxygen for at least 28 days.
Radiographic Stages of BPD
Stage I-(2-3) days after birth Chest X-ray shows typical granular appearance of RDS
Stage II-(4-10) days after birth X-ray shows complete opacifcation of the lung
Stage III-(10-20) days after birth X-ray shows round cystic lucencies with alternating opacities
Stage IV-after 1 month X-ray shows enlargement of the lucencies with increasing strands of opacity (Bubbly Lung)
