Interpretation guide: MULTI BAND tests: Difference between revisions
From MalariaETC
No edit summary |
No edit summary |
||
| Line 26: | Line 26: | ||
*<span style="font-size:90%">Repeat the test</br></span> | *<span style="font-size:90%">Repeat the test</br></span> | ||
*<span style="font-size:90%">Consider the reasons for [ [[Practical reasons for test failure|test failure]] ]</span> | *<span style="font-size:90%">Consider the reasons for [ [[Practical reasons for test failure|test failure]] ]</span> | ||
</br> | </br> | ||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | {| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | ||
| Line 45: | Line 44: | ||
*<span style="font-size:90%">There is no active malaria, but patient recently received successful treatment and the antigen has not yet cleared [ [[Clearance of parasite antigens from blood 2|Clearance of parasite antigens from blood]] ]</span> | *<span style="font-size:90%">There is no active malaria, but patient recently received successful treatment and the antigen has not yet cleared [ [[Clearance of parasite antigens from blood 2|Clearance of parasite antigens from blood]] ]</span> | ||
*<span style="font-size:90%">The "specific band" is a false positive result (infrequent but observed) [ [[False positive reaction in RDT tests 2|False positive reaction in RDT tests]] ]</span> | *<span style="font-size:90%">The "specific band" is a false positive result (infrequent but observed) [ [[False positive reaction in RDT tests 2|False positive reaction in RDT tests]] ]</span> | ||
</br> | |||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | {| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | ||
Revision as of 20:45, 13 October 2024
Navigation
Main Malaria Index
>RDT main page
>>This page: Single band RDT tests
Multi-band RDT tests
| RESULT PATTERN 1
|
Failed test: No band appears in the control area (black arrow):
Irrespective of whether any other bands are present, this is always an invalid test: do not interpret. Report as failed test
Action:
- Repeat the test
- Consider the reasons for [ test failure ]
| RESULT PATTERN 2 |
The test has valid control line (black arrow) and a band in the species-specific area only (red arrow)
Most likely interpretation: The species detected by the test is present and is the only malaria species infecting the individual
Less likely but possible interpretations:
- There is a dual-species infection, but the second species was not detected by the pan-specific band [ Co-infection with two species ]
- There is no active malaria, but patient recently received successful treatment and the antigen has not yet cleared [ Clearance of parasite antigens from blood ]
- The "specific band" is a false positive result (infrequent but observed) [ False positive reaction in RDT tests ]
| RESULT PATTERN 3 |
The test has valid control line (black arrow) and a band in the pan-specific area only (red arrow)
Most likely interpretation: A malaria infection is detected (pan band), but is not caused by the species detected by the specific antibody (Sp band)
Less likely but possible interpretations:
- The species detected by the specific band is present (as a single infection or dual infection), but has not been detected by the specific band [ prozone, mutation ]
- The patient recently received successful treatment, but the antigen has not yet cleared [ Clearance of parasite antigens from blood ]
- The "specific band" is a false positive result (infrequent but observed) [ False positive reaction in RDT tests ]
(2) No band present in species-specific area Most common: the species is not present Possible alternatives: A faint band was present but not seen by observer* The species is present but not detected due to low parasite concentration (link to reasons) The species is present but not detected for technical reasons The species is present, but there is gene deletion of the target antigen (HRP2 tests) The species is present but exceeds test capacity due to very high parasite Pyrome effect (mainly HRP2 tests)
(3) A band appears in the pan-malaria area only The most common cause is infection is present with a malaria species not detected by the specific antibody Possible alternatives: The specific band has failed (see causes above) but pan-malaria antigen still detects that species No malaria is present and the band in the pan-malaria area is a false positive (cross reaction)
(4) A band appears in both the species-specific and pan malarial area
A single specific species and is detected by specific and pan-malaria antigens (95%) There are two species present in the sample (5%) False positive result in both bands (least common cause)