Gold (SST - Clot activator & gel)
2 ml blood
1 ml serum
If multiple viral serologies are being requested from the same specimen, the general rule is to collect a total of 2-4 ml of blood for every 2-3 tests ordered. A single serum specimen is required to determine the immune status of an individual or to test for viral-specific IgM antibodies. Paired sera specimens, collected two to three weeks apart, are required for the diagnosis of a current or recent viral infection when examining specimens for IgG antibody. Obtain the acute phase serum as soon as possible after the onset of illness. The most useful results are obtained by submitting acute and convalescent phase sera together to be tested simultaneously. Evaluation of serum for antibodies to TORCH (Toxoplasma, Rubella, CMV, HSV, etc) agents can be used to detect congenital and perinatal infections in newborns. Two serum specimens should be submitted for testing; one from the mother and the other from her infant. Serological testing is not usually available for body fluids other than serum. However, in patients with viral neurologic disease, cerebrospinal fluid (CSF) may be tested for viral antibody if paired with a serum specimen from the same date.
86747 x 2
Erythema infectiosum (Fifth disease) is the most common manifestation of parvovirus B19 infection. The disease is characterized by a distinctive slapped-cheek" rash that gives the child a flushed look. The rash may also involve the limbs and trunk but can fluctuate in intensity for weeks to months with changes in temperature and exposure to sunlight. Arthralgia and arthritis is common among adults infected with parvovirus B19, particularly women. Polyarthropathy of knees, fingers, and other joints is common. In transient aplastic crisis, the patient has severe anemia characterized by lethargy, pallor, and weakness. Condition occurs as a complication in individuals with chronic hemolytic anemias. Normally lasts 7 to 10 days with complete recovery; however, can be life threatening and blood transfusions may be required to prevent death. Chronic infection resulting in severe anemia has been observed in AIDS patients. Infection during pregnancy can cause fetal hydrops, intrauterine growth retardation, congestive heart failure, and death.
Results are reported as negative, equivocal, or positive for parvovirus B19 IgM and/or IgG antibody.
Negative or no parvovirus B19 IgM or IgG antibody detected
The preferred diagnostic test for Fifth disease (erythema infectiosum) and acute arthritis due to parvovirus B19 is detection of parvovirus B19-specific IgM in a single serum specimen. For patients with transient aplastic crisis, serum or plasma PCR for parvovirus B19 DNA should be performed as a supplement to IgM testing since parvovirus B19-specific IgM antibodies may not be detectable until some days after onset of the crisis. Detection of fetal infection or chronic infection in immunocompromised patients is best accomplished by PCR for detection of parvovirus B19 DNA because a serologic response to B19 infection may not occur in this setting.
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