7. Usually, the ‘Pv’ and ‘Pan’ bands turn negative after successful anti-malarial therapy. However, since treatment duration and medication used affect the

 

Or

 In case finger prick blood is being used, touch the sample

loop to the blood on the finger prick. Ensuring that a loop

full of blood is retrieved, immediately blot the specimen

on to the sample pad in the sample port ‘A’. (care should

be taken that the blood sample has not clotted and the

transfer to the sample pad is immediate).

Or

 Alternatively, 5 µL of the anti coagulated or finger prick

specimen may be delivered to the sample pad in the

sample port ‘A’ using a micro pipette.

 Note: Ensure that the blood from the sample loop has

been completely taken up by the sample pad.

5. Dispense four drops of the clearing buffer into port ‘B’,

by holding the plastic dropper bottle vertically.

6. At the end of 15 minutes, read the results as follows.

Negative for Malaria

• Only one pink-purple band appears at the control

region ‘C’.

Positive for Malaria

¾ P. falciparum malaria: In addition to the control band,

a pink-purple band appears at the ‘Pf’ and ‘Pan’ regions

respectively.

¾ P. vivax malaria: In addition to the control band, a

pink-purple band appears at ‘Pv’ and ‘Pan’ regions

respectively.

¾ Other species: In addition to the control band, one

pink-purple band appears only at ‘Pan’ region.

¾ Mixed infection: In addition to the control band, a

pink-purple band appears at ‘Pf’, ‘Pv’ and ‘Pan’ regions

respectively.

7. The test should be considered invalid if no bands

appear on the device. Repeat the test with a new device

ensuring that the test procedure has been followed

accurately.

Limitation of the Test

1. As with all diagnostic tests, the test result must

always be correlated with clinical findings.

2. The results of test are to be interpreted within the

epidemiological, clinical and therapeutic context.

When it seems indicated, the parasitological

techniques of reference should be considered (microscopic examination of the thick smear and thin blood

films).

3. Any modification to the above procedure and/or use

of other reagents will invalidate the test procedure.

4. The device and buffer of different lots must not be

mixed and used.

5. In case of infection due to P.vivax or P. falciparum, or

due to mixed infection by these species, the ‘Pan’ malaria

band will also be positive. Hence, differentiation of

infection due to P. ovale or P.malariae cannot be done.

6. While monitoring therapy, if the reaction of the test

remains positive with the same intensity after 5 to

10 days, post-treatment, the possibility of a resistant

strain of malaria has to be considered.

7. Usually, the ‘Pv’ and ‘Pan’ bands turn negative after

successful anti-malarial therapy. However, since

treatment duration and medication used affect the

clearance of parasites, the test should be repeated

after 5–10 days of start of treatment.

8. In P. falciparum malaria infection, HRP-2 is not

secreted in gametogony stage. Hence, in “Carriers”,

the HRP-2 band may be absent.

9. The HRP-2 levels, post-treatment, persist up to 15

days, the ‘Pan’ band can be used to monitor success

of therapy, in P. falciparum malaria cases.

10. In a few cases, where the HRP-2 band is positive and

the ‘Pan’ malaria band is negative, it may indicate

650 Concise Book of Medical Laboratory Technology: Methods and Interpretations a case of post-treatment malaria. However, such

a reaction pattern may also be obtained in a few

cases of untreated malaria. Retesting after 2 days is

advised, in such cases.