Diagnosis

Diagnostic measures depend on the immune status of the patient and the clinical picture. As a rule, detection and staging of B19 infection are best achieved by combined

Table 2 Methods for detection of parvovirus B19 DNA in clinical material

Method Indication Sensitivity/detection limita Reference

DNA hybridization Large-scale ca. 106 (1 pg) [23]

quantitative screening

In situ hybridization Noncanonical symptoms Single cells [12]

Single-round PCR Initial individual 105 [24] (agarose gel, ethidium bromide) diagnosis, screening

Single-round PCR-EIA Large-scale screening 1.6 x 103 [7,25]

(DIG-labeled or DNP-labeled probes) (plasma pools, factor concentrates) (colorimetric);

6 x 102

(chemoluminometric)

Nested multiplex PCR Differential diagnosis of ca. 102 [26] (agarose gel, ethidium bromide) exanthematic viral infections

Quantitative real-time PCR Initial individual diagnosis of 102-109(linear [21,27]

(TaqMan and LightCycler, chronic/relapsing infections; quantification range) internal standard) follow-up studies, therapeutic guidance;

contagiosity estimates aAll values represent genome equivalents per milliliter (gEq/mL); 0.65 gEq equals approximately 1 IU (WHO standard).

testing for B19-specific IgM (and IgG) and DNA in serum.[20] Various commercially available formats for antibody detection are available, all based on recombinant VP1/VP2 proteins. Elaborate qualitative and quantitative DNA amplification techniques for detection of B19 DNA abound (Table 2). However, being tailored to detection of B19 genotype 1, they might require adaptation to the newly discovered genotypes 2 and 3. Quantification of B19 DNA, now based on a World Health Organization (WHO) standard, is appropriate to guide therapeutic planning and to assess the contagiosity of pooled plasma and other blood products. In situ detection of B19 DNA is indicated if noncanonical forms of B19-associated disorders, such as myocarditis and chronic joint disorders, are suspected.[12]

B19 diagnostic techniques need to be modified to factor the sequence variation of the two recently discovered new human Erythrovirus genotypes. Quantification of the B19 virus load can help to guide therapeutic planning for immunocompromised patients and to facilitate the assessment of the contagiosity of B19-contaminated blood products.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

Get My Free Ebook


Post a comment