Quality Control and Precautions of Dengue Rapid Test Kit

Ⅰ. Collection and preparation of dengue fever test kit samples

1. Venous blood clumps at room temperature (20-25ºC) and is centrifuged according to the NCCLS (approved standard procedure for collecting diagnostic venous blood, H3-A4, 1998).

Serum should be separated and refrigerated (2-8ºC) or frozen (-20ºC) as soon as possible. If the dengue rapid test kit is not tested within two days, it should be frozen at a lower temperature. Serum with jaundice, hemolysis, lipemia, or bacterial growth is not recommended

2. The use of self-thawing refrigerators for sample storage is not recommended, as it can cause samples to produce false results by going through freeze-thaw cycles and reducing antibody levels.

3. Rapid diagnostic test for dengue should be performed immediately after finger blood collection. Whole blood containing EDTA or heparin as an anticoagulant can be used immediately without centrifugation or stored at 2-8ºC for 72 hours.

4. The sample collection time after the heating determines the accuracy of dengue fever test kit. Samples taken between 6 and 14 days after the onset of fever yield the best results.

Ⅱ. Quality control of dengue fever test kit

1. If there is no control line, the test is invalid and must be redone. If the test is invalid, patient results cannot be reported.

2. The whole blood sample may have a red background value in the window. The result is valid if the background value does not cover the test line of rapid diagnostic test for dengue.

3. Quality control requirements must comply with local state or national laws or mandates and your laboratory's standard quality procedures. Users are advised to refer to the appropriate quality control practice guidelines in NCLSI C24-A and 42 CFR 493.1202(c)

Ⅲ. Secondary infection in dengue fever test kit

Pink bands were found in the IgM, IgG and control areas, indicating positive IgM and IgG antibodies and secondary dengue infection.

Ⅳ. Limitations of dengue fever test kit

1. The analysis of a single test sample cannot be the sole criterion for diagnosis.

2. Detectable levels of IgM antibodies may be low in early infection and some secondary infections. Some patients may not produce detectable levels of antibodies for the first 7-10 days after infection. As long as symptoms persist, it is recommended that patients be re-tested for rapid diagnostic test for dengue 3-4 days after the first sample.

3. Serological cross-reactions with flaviviruses are common (i.e., between dengue 1, 2, 3, 4 and St. Louis Encephalitis, West Nile, Japanese Encephalitis, Yellow Fever Virus, etc.).

4. Final diagnosis should be based on the combination of test results and other clinical and laboratory findings.

5. This IVD kit cannot be used to screen the general population. The positive prediction depends on the probability of the virus present. Tests can only be performed on patients with clinical symptoms or suspicious exposures.

6. The continued presence or absence of antibodies cannot be used to determine the success of treatment.

7. Results from immunosuppressed patients should be interpreted with caution.

8. The best results for rapid diagnostic test for dengue are obtained from samples collected 6-14 days after fever.