PCR and Rtpcr Diagnostics of Viral Encephalitis

Molecular detection of pathogenic viruses by PCR has become a very important tool in diagnostics. Although PCR provides the most sensitive and fastest method for virus genome detection, there are some very important issues that must be considered when using this method. Because of the high sensitivity, contaminations by traces of positive amplification products could cause false-positive results. These problems are partially overcome by the new real-time PCR technology which avoids contamination of the amplified viral genome sequences. The other aspect that must be considered is that the virus load could be very different in the course of the different diseases, within different organs, or different specimens (blood, liquor, sputum, etc.), which could cause problems regarding the interpretation of the results. Therefore, a negative result cannot be interpreted as an exclusion of the respective viral infection. For Flavivirus infection such as JE, SLE, and TBE the majority of patients show a very mild course of disease and very often only a low viremia. Only in severe cases with encephalitis symptomatic is it likely to get positive results by PCR in the acute phase of the disease. The introduction of PCR in the diagnosis of this kind of diseases will lead to more information on the pathogenesis and course of disease in these patients. Presently, most of the JE, SLE, and TBE infections are still diagnosed by conventional detection of IgM and IgG antibodies in serology assays such as immunofluores-cence, ELISA, and/or neutralization tests.

Typical for the diagnosis of TBE are the following methods:

• Detection of virus antibody by ELISA in serum or liquor (IgM in acute phase serum; IgG);

• Virus isolation and detection of nucleic acid in blood or liquor in the first phase of the disease (PCR, cell culture);

• Western blot in special laboratories.'6,13,14-

Typical for the diagnosis of JE are the following methods:

• Virus isolation from tissues;

• Detection of viral nucleic acid from liquor by RT-PCR and confirmation of the sequenced RT-PCR product;

• Detection of virus antibody (IgM, IgG) by indirect immunofluorescence (from blood or other body fluid);

• Detection of virus antibody by ELISA (specific IgM in acute phase serum or IgG);

• Virus antibody by neutralization test;

• Immunohistochemistry and laboratory findings (mild leukocytosis).1-7'36-39-1

Typical for the diagnosis of SLE are the following methods:

• Virus isolation from the brain and detection of viral nucleic acid by RT-PCR and confirmation of the sequenced RT-PCR product;

• Virus antibody (IgM, IgG) by indirect immunofluorescence, by ELISA or by neutralization test;

• Immunohistochemistry findings from the brain;

• Laboratory diagnosis (mild leukocytosis).1-40-42-1

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