Limitations in the immunologic response predispose the infant to certain viral and bacterial infections acquired during the prenatal, perinatal, and immediate postpartum periods. The development of the immune system and the mechanisms of response to both bacterial and viral infections are discussed in Chapter 182. Common viral and bacterial infections of neonates are discussed in this chapter.
NEONATAL VIRAL PATHOGENS
Viral pathogens can infect the fetus or neonate in utero via transplacental or ascending transmission of microorganisms; in the peripartum period at delivery by passage through an infected birth canal; or in the postpartum period by acquisition within the first several weeks of life. Human cytomegalovirus (CMV) and rubella virus can cause significant sequelae when acquired in utero, whereas herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) and enteroviruses can cause life-threatening disease when acquired in the peripartum and postpartum periods.
The usual timing of transmission, clinical presentation, diagnosis, treatment, and prevention of common neonatal viral infections are discussed in the following sections and summarized in Table 225-1.
Table Graphic Jump Location TABLE 225-1NEONATAL VIRAL PATHOGENS AND TREATMENT ||Download (.pdf) TABLE 225-1NEONATAL VIRAL PATHOGENS AND TREATMENT
|Organism ||Usual Time of Transmission ||Clinical Manifestations ||Diagnosis ||Antiviral Treatment ||Prevention |
|Herpes simplex virus (HSV) ||Perinatal, postnatal ||Hepatitis, disseminated intravascular coagulation (DIC), pneumonitis, seizures (focal or generalized), lethargy, irritability, tremors, poor feeding, temperature instability, bulging fontanel, skin vesicles ||Culture of lesions, surface sites; polymerase chain reaction (PCR) from CSF and whole blood; ALT ||Acyclovir (IV) ||Cesarean delivery, Suppressive acyclovir in the pregnant woman may be useful |
|Enterovirus ||Perinatal, postnatal ||Fever, irritability, anorexia, lethargy, rash, emesis, diarrhea, abdominal distention, jaundice, hepatomegaly, seizures, apnea, bulging anterior fontanel ||Culture or PCR of CSF, blood, culture of surface sites ||Consider intravenous immune globulin (IVIG); pleconaril is an experimental therapy ||Hand washing |
|Cytomegalovirus (CMV) ||Prenatal ||Petechiae, jaundice, hepatosplenomegaly, purpura, microcephaly, periventricular calcifications, lethargy, hypotonia, poor suck, seizures, intrauterine growth restriction, hearing impairment ||Shell vial or tissue culture or PCR of urine, saliva ||Valganciclovir (PO) or ganciclovir (IV) for infants born with symptomatic congenital CMV disease ||Unproven, experimental therapies include CMV hyperimmune globulin and a vaccine now in development |
|Rubella ||Prenatal ||Dermal erythropoiesis (“blueberry muffin” rash), chronic rash, thrombocytopenic purpura, hemolytic anemia, generalized lymphadenopathy, interstitial pneumonitis, hepatitis, hepatosplenomegaly, nephritis, myositis, myocarditis, bone radiolucencies, meningoencephalitis, structural defects of the cardiovascular system, cataracts, retinopathy, microphthalmia, deafness ||Culture of blood, urine, CSF, saliva, rubella-specific IgM in neonatal serum ||None ||Vaccination |
PATHOGENESIS AND EPIDEMIOLOGY
HSV infections can be acquired in utero (5%) or in the peripartum (85%) or postpartum (10%) periods. Peripartum or postpartum disease can be classified as disseminated disease involving multiple visceral organs, including lung, liver, adrenal glands, skin, and eye, ...