Fast and Reliable Trypanosoma Test for Malaria P.f./Pan Antigen

INTRODUCTION

Malaria is caused by a protozoan which invades human red blood cells.1 World Health Organization estimates that 3.3 billion were at risks of acquiring malaria in 2006, with 247 million of these developing clinical malaria (86% in Africa), and nearly 1 million (mostly African children) dying from the disease. 2 Microscopic analysis of appropriately stained thick and thin blood smears has been the standard diagnostic technique for identifying malaria infections for more than a century. The technique is capable of accurate and reliable diagnosis when performed by skilled microscopists using defined protocols. The skill of the microscopist and use of proven and defined procedures, frequently present the greatest obstacles to fully achieving the potential accuracy of microscopic diagnosis. Although there is a logistical burden associated with performing a time-intensive, labor-intensive, and equipment-intensive procedure such as diagnostic microscopy, it is the training required to establish and sustain competent performance of microscopy that poses the greatest difficulty in employing this diagnostic technology. The Malaria P.f/Pan Rapid Test Device (Whole Blood) is a rapid test to qualitatively detect the presence of the P.falciparum-specific HRP-II antigens and/or Pan-malarial Aldolase antigens found in P.falciparum(P.f), P.vivax(P.v), P.ovale(P.o) and P.malariae(P.m). The test utilizes colloid gold conjugate to selectively detect P.f-specific and Pan-malarial antigens (P.f, P.v, P.o and P.m) in whole blood.

MATERIALS

Materials Provided

Materials Required but Not provided

PROCEDURE

Allow the test device, specimen, buffer, and/or controls to equilibrate to room temperature (15-30°C) prior to testing.

Remove the test device from the foil pouch and use it as soon as possible. Best results will be obtained if the assay is performed within one hour.

Place the test device on a clean and level surface. Transfer the specimen by a pipette or a pipette:

To use a Pipette: Transfer 10 mL of whole blood to Well-1 (W1) of the test device, then add 3 full drops of buffer to Well-2 (W2), and start the timer. (See illustration ① below). Avoid trapping air bubbles in W1. At the end of 5 minutes, add 1 full drop of buffer to the W1 (See illustration ③ below).

To use a Disposable Specimen Pipette: Hold the pipette vertically; draw the specimen up to the Fill Line as shown in illustration ① below. Transfer the specimen to W1 of the test device, then add 3 full drops of buffer to W2 and start the timer. Avoid trapping air bubbles in W1. At the end of 5 minutes, add 1 full drop of buffer to W1 (See illustration ③ below).

3. Wait for the colored line(s) to appear. The result should be read at 15 minutes. Do not

interpret the result after 20 minutes.

INTERPRETATION OF RESULTS

(Please refer to the illustration above)

POSITIVE:* Two or Three distinct colored lines appear.

1. falciparum or mixed malaria infection：one line appears in the control region, one line appears in Pan line region and one line appears in P.f line region.
2. falciparum infection: one line appears in the control region, and one line appears in P.f line region.

Non-falciparum Plasmodium species infection：one line appears in the control region and one line appears in Pan line region.

*NOTE: The color intensity of P.f or Pan test lines may vary depending on the concentration of antigens, viz., HRP-II or Aldolase present in the specimen.

NEGATIVE: Only one colored line appears in the control region.

INVALID: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test with a new test device. If the problem persists, discontinue using the test kit immediately and contact your local distributor.

For Pan: 99.20% （95%CI: 95.16%～>99.99%）  

For P.f: >99.99% （95%CI: 93.02%～100.00%）

Relative Specificity: 98.94% （95%CI：96.79%～99.79%） 

Accuracy: 99.15% （95%CI：97.76%～99.75%）