Dengue Fever Rapid Test Kits: Principles & Procedures

Definition

Dengue Fever Rapid Test Kits or devices, also known as one-step Dengue tests, are a solid phase immuno-chromatographic assay for the rapid, qualitative and differential detection of Dengue IgG and IgM antibodies to dengue fever virus in human serum, plasma or whole blood. This is a common test used to detect presence of dengue antibodies in the blood of a suspected dengue case.

These IgG/IgM test kit is a rapid membrane based screening test to detect the presence of antibodies produced by the body to the Dengue virus. The test can either be used with serum or whole blood and employs the use of antibody binding protein conjugated to a colloidal gold particle and a unique combination of Dengue antigen immobilized on the membrane.

How Does it Work?

  • Once the sample is added to the test cassette along with the diluents, the mixture passes through the antibody binding/gold complex, which then binds the immunoglobulins in the sample.
  • As this complex passes over the immobilized antigens on the membrane, if any antibodies to Dengue are present, the antigens capture them.
  • In turn, this produces a pink/purple band in the T (test) zone of the test strip.
  • The remaining complex continues to migrate to a control area in the test strip and produces a pink/purple band in the C (controlled) area.
  • This band indicates that the test has been performed properly.

Components of the Kit

  • Test cassette
  • Diluent in dropper vial
  • Directions for use

Storage

  • Dengue test kit is stable at any room temperature between 8-30 oC when in the unopened pouches.
  • Do not freeze the kit or expose to extreme temperatures
  • Stable until 24 months from the date of manufacture

Precautions

  • Test is for In Vitro Diagnostic use only
  • Appropriate infection control measures should be followed
  • All materials should be considered infectious and must be discarded or disinfected properly.
  • Do not use test beyond the expiration date indicated.

Sample Collection

  • Dengue IgG/IgM test can be run on serum or whole blood.
  • The test works best on fresh samples.
    • If testing cannot be done immediately, samples should be stored at 2-8 C after collection, and may remain in storage for up to 3 days.
    • If testing cannot be done within 3 days, serum can be stored frozen at -20C or colder.
    • Whole blood samples cannot be frozen, nor samples collected in EDTA, and it is recommended that finger prick blood be used.
  • Plasma may be used depended on anticoagulant.

Test Procedure

  1. Remove test cassettes from the pouches as needed. Lay on a clean flat surface.
  2. For whole blood–add 10micro of sample to Sample Well labeled A of the test cassette using measuringpipette.
    For serum–add 5micro sample to the sample well labeled A of the test casette.
  3. Follow sample addition with 3 drops of the diluent provided in the dropper bottle by holding the bottle vertically over the (S) well.
  4. Results are then read in after 5 minutes for strong positives, or up to 30 minutes for weaker positives and to make sure negatives are confirmed.

Note: If the dye has not cleared the membrane, or blood is still present, one or two more drops of diluents may be added
to the (S) well.

Reading the Results

NEGATIVE

Only 1 (one) pink/purple band appears in the C (control) line area of the test casette.

POSITIVE

Two pink/purple bands appear, one in the C (control line), and one in the T (test line) area of the test strip.

INDETERMINATE

If only one band appears in the T well – Test area, or no band appears at all in the C well –Control area, it is then recommended that a fresh device be used and the test repeated, carefully following the directions in this insert. Test should be repeated.

Other Information

  • A clinical evaluation of patient’s signs and symptoms should be established and correlated with the test resultsbefore making a final diagnosis.
  • Using rapid test alone is not sufficient to diagnose Dengue fever even if antibodies are present. Also, a negative results does not preclude the possibility of infection with Dengue virus.

Nursing Responsibilities

  • Observe proper hand hygiene
  • Infection control measures should be observed
  • Establish baseline data,  obtain a nursing assessment
  • Prompt referral

References & Sources

  1. Health Chem Diagnostics
  2. Dengue Fever Rapid Test Kit

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