TORCH is an acronym that stands for toxoplasmosis, rubella, CMV, and HSV. These pathogens are frequently implicated in congenital or neonatal infections that are not clinically apparent but that may result in serious CNS impairment of the newborn.
Both mothers and newborn infants are tested for exposure to these agents. The test differentiates acute, congenital, and intrapartum infections caused by T. gondii, rubella virus, CMV, and HSV. The presence of IgM-associated antibodies in newborns reflects actual fetal antibody production. High levels of IgM at birth indicate fetal in utero response to an antigen. In this instance, an intrauterine infection should be considered. TORCH is more useful in excluding than in establishing etiology.
Negative for toxoplasmosis, rubella, CMV, and HSV antibodies
Collect a 7-mL blood serum sample in a red-topped tube. Observe standard precautions.
Label the specimen with the patient’s name, date, and test(s) ordered and place in a biohazard bag for transport to the laboratory.
Persistent rubella antibodies in an infant older than 6 months highly suggest congenital infection. Congenital rubella is characterized by neurosensory deafness, heart anomalies, cataracts, growth retardation, and encephalitic symptoms.
A marked and persistent rise in CF antibody titer over time is consistent with a diagnosis of rubella in infants younger than 6 months.
A diagnosis of toxoplasmosis is established through sequential testing rather than by a single positive result. Sequential examination reveals rising antibody titers, changing titers, and the conversion of serologic tests from negative to positive. A titer of 1:256 suggests recent infection. About one third of infants who acquire infection in utero show signs of cerebral calcifications and chorioretinitis at birth; the rest are born without symptoms.
Presence of herpes antibodies in CSF, together with signs of herpetic encephalitis and persistent HSV-1 or HSV-2 antibody levels in a newborn showing no obvious external lesions, is consistent with a diagnosis of HSV.
Pretest Patient Care
Explain test purpose and procedure.
Follow guidelines in Chapter 1 for safe, effective, informed pretest care.
Posttest Patient Care
Review test results; report and record findings. Modify the nursing care plan as needed. Counsel the parent or caregiver regarding abnormal findings; explain the need for possible follow-up testing and treatment for intrauterine and congenital infections. See Interpreting Results of Immunologic Tests.
Follow guidelines in Chapter 1 for safe, effective, informed posttest care.