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Hepatitis A virus (HAV) Rapid Test

Hepatitis A virus (HAV) rapid test uses for detection immunoglobulin G(IgG) and immunoglobulin M (IgM) of past and present infection respectively as shown above picture. Hepatitis A is an acute, usually self-limiting disease of the liver caused by HAV.  It is transmitted from person to person, primarily by the feco-oral route. The incidence of hepatitis A is closely related to socioeconomic development, and seroepidemiological studies show that the prevalence of anti-HAV antibodies in the general population varies from 15% to close to 100% in different parts of the world. This HAV IgG/IgM test is a simple, visual qualitative test that detects Hepatitis A Virus antibodies in human serum or plasma. The test is based on immunochromatography and can give a result within 15 minutes. It indicates protective immunity by detecting HAV IgG titers ≥70 mIU/mL. High confidence as it is traceable to the 2nd WHO International Standard for HAV and IgM is in agreement with market-leading ELISA test: Sensitivity: 94.8%; Specificity: 96.7% (Ctkbiotech). Small sample volume (5 µL) enables multiple tests on the same specimen without having to re-draw the patient. Initial patient care action can begin during the patient’s visit as test results are available in 15 minutes. Easily transported, and can be stored for 24 months at 2-30°C. This test provides only a preliminary test result. Therefore, isolation of the virus, PCR, and RT-PCR, more specific alternative diagnosis methods must be used in order to obtain a confirmation of Hepatitis A virus infection.

Test Principle of HAV Test

immunoglobulin G  to Hepatitis A virus  (IgG to HAV): This kit makes use of colloidal gold immune chromatography principle, coated IgG monoclonal antibody and IgG monoclonal antibody on the nitrocellulose membrane for test line, the control line is coated with anti-rabbit Hepatitis A virus antibody, fix HAV antigen on the colloidal gold pad. If the sample contains HAV-IgG antibody, can combine with colloidal gold marked Hepatitis A virus antigen, anti-human IgG monoclonal antibody to form sandwich complex, form two red reaction lines that naked-eye can see in the test area, otherwise, only one red reaction line appears in the control line(C).
immunoglobulin M  to Hepatitis A virus (IgM to HAV): This kit makes use of colloidal gold immune chromatography principle, coated IgM monoclonal antibody and IgM monoclonal antibody on the nitrocellulose membrane for test line, the control line is coated with anti-rabbit Hepatitis A virus antibody, fix HAV antigen on the colloidal gold pad. If the sample contains HAV-IgM antibody, can combine with colloidal gold marked Hepatitis A virus antigen, anti-human IgM monoclonal antibody to form sandwich complex, form two red reaction lines that naked-eye can see in the test area, otherwise, only one red reaction line appears in the control line(C).

Test Requirements for HAV Test

1. Test kit contains

• Individually sealed foil pouches containing:
  One cassette device
  One desiccant
• 5 µL capillary tubes
• Sample diluent
• Buffer
• Instruction manual

2 . Specimen (serum/plasma)

3. Wastebin

Test Procedure of HAV test

1. Take off the foil bag, put the cassette onto the desk with the sample window of the cassette up.
2. Take 50 µl Serum/Plasma and dispense in sample diluent. Mix it properly.
3. Drop 5µl diluted sample vertically onto the membrane of the sample well.
4. Add about 2 drops of sample buffer onto the sample pad of the buffer well of the cassette.
5. Observe the test results immediately within 15-20 minutes, the result is invalid over 20 minutes.

Result Interpretation of HAV Test

Test Positive: Two distinct red lines appear. One line should be in the control region (C) and the other line should be in the test region (T).
Test Negative: One red line appears in the control region(C). No red or pink line appears in the test region (T).
Test Invalid: No red lines appear or control line fails to appear, indicating that the operator error or reagent failure. Verify the test procedure and repeat the test with a new testing device.

Test Result: Negative

Limitation

1. This reagent is designed for the qualitative screening test. Concentration of
   Hepatitis A virus -IgM and HAV-IgG cannot be determined by this qualitative test.
2. The results of the reagent are only for clinical reference, which is not the only basis for clinical diagnosis and treatment. A confirmed diagnosis and treatment should only be made by a physician, after all, clinical and laboratory findings have been evaluated.
3.  Sensitivity can be lowered by the competition between high titers of
   HAV-IgG and HAV-IgM antibodies to the antigen-binding site. Results of this kind of sample should be analyzed cautiously.
4.  A negative result may occur when detecting short-term infected samples,
   indicate that the specific antibodies of Hepatitis A virus do not exist or the concentration is below the detection limit. If HAV infection is still suspected, the sample should be collected 1-2 weeks later and carry the parallel detection with the first sample.
5.  Results of patients who used to receive immunosuppressive therapy or with
   immune function damage may have a low serology reference value.
6. Positive results of the patients who used to receive blood transfusions or
   other blood products therapy should be analyzed cautiously.
7.  Abnormal results may occur according to operator error or drug use. If Hepatitis A virus infection is still suspected, the sample should be collected later and carry the parallel detection with the first sample.

Precaution

• The instructions must be followed to obtain accurate results. Anyone performing an assay with this product must be trained in its use and laboratory procedures.
•  Wear protective gloves while handling specimens. Wash hands thoroughly afterward.
•  The sample must be fresh for the test, avoiding freezing repeatedly.
• The test result is invalid over 20 minutes.
• Do not use after the expiration.
•  If the patient, for the first time, is infected in less than 5 days, with no
  detected specific antibody, the result will be negative when testing.
• The parent antibody can be detected from the samples of a yearling baby,
  therefore, it is not appropriate to take this test to evaluate the baby’s history
  of infection and immunization.
• Do not use other kinds of quality control samples to test the reagent.
  Components of different batches cannot be exchanged for use to avoid
  the erroneous result
• For in vitro diagnostic use only. Do not re-use test device
• Do not eat or smoke while handling specimens.
• Avoid splashing or aerosol formation
• Clean up spills thoroughly using an appropriate disinfectant
• Decontaminate and dispose of all specimens, reaction kits, and potentially contaminated materials, as if they were an infectious waste, in a biohazard container.
•  Do not mix with other specimens.

Keynotes

1. Allow the test device controls to equilibrate to room temperature for 30 minutes (20°C -30°C) prior to testing.
2. Do not open the inner packaging until ready, it must be used in one hour if opened.
3. Internal Quality Control: The “Control Line” is used for procedural control. The Control line should always appear if the test procedure is performed properly and the test reagents of the control line are working. It confirms sufficient specimen volume and correct procedural technique. A clear background is also required
4. Some manufacturer’s test kits may detect antibodies even from whole blood.
5. The rate of sensitivity and specificity also vary according to from vendor to vendor.

References

1. https://ctkbiotech.com/product/hav-igg-igm-rapid
2. http://img.creative-diagnostics.com/pdf/DTS649,HAV.pdf
3. https://www.biogatelab.com/uploads/3/4/4/1/34413460/
4. https://www.globalpointofcare.abbott/en/product-details/sd-bioline-hav-igg-igm-rapid-test.html
5. https://www.accubiotech.com/product-hav-igg-igm-rapid-test-(serum-plasma).html
6. https://www.biochromescientific.com/rapid-hepatitis-tests.html
7. https://www.biopanda.co.uk/php/products/rapid/infectious_diseases/hav.php
8. https://www.mybiosource.com/hav-igg-rapid-test-kits/hepatitis-a-virus-hav-igg/2548640