INTRODUCTION

Enzyme immunoassay for the detection of IgG and IgM antibodies against tick-borne encephalitis (TBE) virus in human serum, plasma or CSF

TBE virus is a member of the Flaviviridae family. The virus is transmitted to humans by hard ticks, with Ixodes ricinus as the most important species in Europe. Transmission by virus infected milk from goat, sheep or cow is only rarely observed.

The major part of all TBE virus infections is without any clinical symptoms. The incubation time is 4 - 6 days. About 30 % of infected persons show a mono- or biphaseal course of the disease: typical symptoms of the first viremia phase are flue like symptoms (mild fever, headache and vomitus). After an afebril period of about one week about 10% of infected persons are showing an isolated Meningitis or Menigoencephalitis accompanied by high fever and vomitus. Lethality in Europe varies between 0,5 % and 2 %.

Active vaccination is the most effective form of prophylaxis against TBE infection. At least four different vaccines are currently available which are all made from purified and formaldehyde-inactivated virus. In Germany, cases in which the virus is detected either directly or indirectly are notifiable according to § 7, para 1 IfSG.

Enzyme immunoassays like the recomWell FSME / TBE Virus are mainly used for serological testing in routine labs.

PRODUCT ADVANTAGES

• recomWell FSME / TBE Virus and recomWell Borrelia, the diagnosis of tick-borne diseases from a single source
• Test procedure and reagents identical in all MIKROGEN ELISA - reagents exchangeable
• Standardised CSF serum analysis available - CE certified instruction for use
• Software for the calculation of the antibody index
• Easy to quantify
• Break-a-part: single sample examination possible
• Easy test procedure; automation possible
• CE label: The recomWell FSME /TBE Virus tests meet the high standard of the EC directive 98/79/EC on in vitro diagnostic medical devices

TESTPRINCIPLE AND PROCEDURE

Indirect sandwich test.
Recombinant antigens are bound to the solid phase.

1^st Incubation
Add patient samples diluted 1:101 (sample: 10 µl of serum or plasma), incubate for 1 h at 37 °C.

Wash 4 times

2^nd Incubation
Add peroxidase conjugated anti-human IgG or IgM antibodies (conjugate), incubate for 30 min at 37 °C.

Wash 4 times

Color reaction
Add ready-to-use TMB solution and incubate for 30 min at room temperature. Stop the substrate reaction with H₃PO₄ and measure the extinction at 450 nm.

EVALUATION

Diagnostic sensitivity and specificity

¹Clinically defined samples consistently tested reactive (i.e. positive or borderline) by 5 commercially available comparative tests (ELISA), Origin: Landesamt für Gesundheit und Lebensmittelsicherheit, Oberschleißheim.
²Consistently tested negative by 2 commercially available comparative tests (ELISA), Origin: Bavarian Red Cross, Wiesentheid.

Relative agreement

¹Positive and negative agreement was determined using a legally marketed ELISA.
²Samples with a „borderline“ test result were regarded as positive.

Seroprevalence

Seroprevalence for FSME / TBE Virus in the examined blood donors was determined by two commercially available comparative tests (ELISA) for IgG with 32,5% and 36,5% and for IgM with 1,0% and 1,5% respectively. Origin of the samples: Bavarian Red Cross, Wiesentheid. Seroprevalence is strongly dependent on the origin of the samples. For IgG it may also depend on vaccination titre.

STORAGE AND SHELF LIVE

At 4 °C 18 months from the date of production

COMMERCIAL PRODUCT