Sorted By Test Name - Mayo Medical Laboratories

TORC
80804
Med 1997 Aug 21;337(8):509-515 10. Lafferty WE, Coombs RW, Benedetti J, et al: Recurrences after
oral and genital herpes simplex virus infection. Influence of site of infection and viral type. N Engl J Med
1987 June 4;316(23):1444-1449 11. Binnicker MJ, Jespersen DJ, Harring JA: Evaluation of three
multiplex flow immunoassays to enzyme immunoassay for the detection and differentiation of IgG-class
antibodies to Herpes Simplex Virus types 1 and 2. Clin Vac Immunol 2010 Feb;17(2):253-257
TORCH Profile IgM
Clinical Information: Toxoplasma: Toxoplasma gondii is an obligate intracellular parasite that is
capable of infecting a variety of intermediate hosts, including humans. Infected definitive hosts (cats)
shed oocysts in feces that rapidly mature in soil and become infectious. Toxoplasmosis is acquired by
humans via ingestion of food or water contaminated with cat feces or undercooked meats containing
oocysts. Infection of the normal adult is commonly asymptomatic. In cases with clinical manifestations,
the most common symptom is lymphadenopathy, which may be accompanied by an array of other
symptoms making differential diagnosis difficult. Severe-to-fatal infections do occur in adults
immunocompromised by cancer chemotherapy or other immunosuppressive treatment and in patients with
AIDS. These infections are thought to be caused by reactivation of latent infections and often involve the
central nervous system. Transplacental transmission of the parasites resulting in congenital toxoplasmosis
can occur during the acute phase of acquired maternal infection. The risk of fetal infection is a function of
the time at which acute maternal infection occurs during gestation. The incidence of congenital
toxoplasmosis increases as pregnancy progresses; conversely, the severity of congenital toxoplasmosis is
greatest when maternal infection is acquired early during pregnancy. A majority of infants infected in
utero are asymptomatic at birth, particularly if maternal infection occurs during the third trimester, with
sequelae appearing later in life. Congenital toxoplasmosis results in severe generalized or neurologic
disease in about 20% to 30% of the infants infected in utero; approximately 10% exhibit ocular
involvement only and the remainder are asymptomatic at birth. Subclinical infection may result in
premature delivery and subsequent neurologic, intellectual, and audiologic defects. Cytomegalovirus
(CMV): CMV is a significant cause of morbidity and mortality, especially in organ transplant recipients
and individuals with AIDS. CMV is also responsible for congenital disease of the newborn. Infections
with CMV result from reactivation of latent virus from a previous infection, transmission of the virus
from a donor organ or blood product, or initial or primary contact with the virus in a seronegative patient.
Infection in immunologically normal patients can cause mononucleosis similar to that produced by
infection with Epstein-Barr virus. Infection in immunocompromised hosts commonly results in more
severe disease. Herpes Simplex Virus (HSV): HSV types 1 and 2 produce infections that are expressed in
various clinical manifestations ranging from mild stomatitis to disseminated and fatal disease. The more
common clinical conditions include gingivostomatitis, keratitis, encephalitis, vesicular skin eruptions,
aseptic meningitis, neonatal herpes, genital tract infections, and disseminated primary infection. Infections
with HSV types 1 and 2 can differ significantly in their clinical manifestations and severity. HSV type 2 is
the cause of the majority of urogenital infections and is almost exclusively found in adults. Type 1 HSV is
associated closely with orolabial infection, although genital infection with this virus can be common in
some populations.
Useful For: Aids in the diagnosis of both congenital and acute acquired toxoplasmosis,
cytomegalovirus, and herpes simplex virus
Interpretation: Toxoplasma: Diagnosis of acute central nervous system, intrauterine, or congenital
toxoplasmosis is difficult by routine serological methods. Active toxoplasmosis is suggested by the
presence of IgM antibodies, but elevated anti-IgM titers are often absent in immunocompromised patients.
In addition, elevated IgM can persist from an acute infection that may have occurred as long ago as 1
year. A suspected diagnosis of acute toxoplasmosis should be confirmed by further testing at a
toxoplasmosis reference laboratory or by detection of Toxoplasma gondii DNA by PCR analysis of
cerebrospinal fluid or amniotic fluid specimens (PTOX/81795 Toxoplasma gondii, Molecular Detection,
PCR). For confirmation of a diagnosis, the FDA issued a Public Health Advisory (7/25/1997) suggesting
that sera found to be positive/equivocal for Toxoplasma gondii IgM antibody be sent to a Toxoplasma
reference laboratory. CDC or Jack Remington, M.D., Palo Alto Medical Foundation, 860 Bryant Street,
Palo Alto, CA 94301, were recommended. (reviewed 12/2011) Specimens interpreted as equivocal may
contain very low levels of IgM. A second specimen should be drawn and tested. Cytomegalovirus (CMV):
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 1769