Interpretation guide: MULTI BAND tests: Difference between revisions
From MalariaETC
(Created page with "Invalid test No band appears in the control area Invalid test: do not interpret, consider if test was incorrectly performed or incorrectly stored For valid tests (1) A band appears in the species-specific area only Most common: the species is present and no other species is present Possible alternatives: There is a dual infection but the second species is not detected by the pan-species antibody* This is a false positive band* (2) No band present in species-specific...") |
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'''Navigation'''</br> | |||
<span style="font-size:90%">[[MalariaETC Index|Main Malaria Index]]''</span></br> | |||
<span style="font-size:90%">>[[Rapid diagnostic tests (RDTs)|RDT main page]]''</span></br> | |||
<span style="font-size:90%">>>This page: '''Multi band RDT tests'''</span> | |||
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<span style="font-size:160%; color:navy">Multi-band RDT tests</br></span> | |||
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{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | |||
|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''RESULT PATTERN 1''' | |||
|} | |||
<span style="font-size:90%; color:maroon">These are '''invalid tests''' No band appears in the control area (black arrow)</span>: </br></br> | |||
<gallery mode="nolines" widths=80px heights=160px> | |||
File:RDT_multi_fail1.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_fail1.jpg}} | |||
File:RDT_multi_fail2.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_fail1.jpg}} | |||
File:RDT_multi_fail3.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_fail1.jpg}} | |||
File:RDT_multi_fail4.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_fail1.jpg}} | |||
</gallery> | |||
<span style="font-size:90%">Irrespective of whether any other bands are present, this is always an invalid test: '''do not interpret.''' Report as failed test</br>Action:</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 1|test failure]] ]</span> | |||
</br> | |||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | |||
|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''RESULT PATTERN 2''' | |||
|} | |||
( | There has a '''valid control line''' (black arrow) showing a technically successful test, but '''no malaria bands are detected''' either the species specifc or pan malaria areas. | ||
There are two species present in the sample (5%) | <gallery mode="nolines" widths=80px heights=160px> | ||
File:RDT_multi_neg.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_neg.jpg}} | |||
</gallery> | |||
<span style="font-size:90%">'''Most likely interpretation:''' No malaria parasites are present</br></span> | |||
<span style="font-size:90%">'''Less likely but possible interpretations:'''</span> | |||
*<span style="font-size:90%">Malaria infection is present, but is not detected because it is below the detection limit of the test</span> | |||
*<span style="font-size:90%">Bands are present but may be faint and not seen by the operator</span> | |||
</br> | |||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | |||
|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''RESULT PATTERN 3''' | |||
|} | |||
<span style="font-size:90%">The test has '''valid control line''' (black arrow) and has bands in the '''pan-specific area''' and the '''species specific area''' (red arrows)</span> | |||
<gallery mode="nolines" widths=80px heights=160px> | |||
File:RDT_multi_posPF1.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_posPF1.jpg}} | |||
</gallery> | |||
<span style="font-size:90%">'''Most likely interpretation:''' The single species detected by the species specific band is present (this same species is also detected the pan-malaria band) | |||
<span style="font-size:90%">'''Less likely but possible interpretations:'''</span> | |||
*<span style="font-size:90%">There are two species present in the sample (likelihood depends on country of origin, but is less likely) [ [[Co-infection with two species2|Co-infection with two species]] ]</span> | |||
*<span style="font-size:90%">There is a false positive result causing both bands (unlikely) [ [[False positive reaction in RDT tests 2|False positive reaction in RDT tests]] ]</span> | |||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | |||
|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''RESULT PATTERN 4''' | |||
|} | |||
<span style="font-size:90%">The test has '''valid control line''' (black arrow) and a '''band in the species-specific area only''' (red arrow)</span> | |||
<gallery mode="nolines" widths=80px heights=160px> | |||
File:RDT_multi_posPF2.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_posPF2.jpg}} | |||
</gallery> | |||
<span style="font-size:90%">'''Most likely interpretation:''' The species detected by the test is present and is the only malaria species infecting the individual</br></span> | |||
<span style="font-size:90%">'''Less likely but possible interpretations:'''</span> | |||
*<span style="font-size:90%">There is a dual-species infection, but the second species was not detected by the pan-specific band [ [[Co-infection with two species2|Co-infection with two species]] ]</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> | |||
</br> | |||
{| class="wikitable" style="border-style: none; border-width: 2px; border-color: gainsboro; color:black" | |||
|colspan="1" style = "font-size:100%; color:black; background: gainsboro |'''RESULT PATTERN 5''' | |||
|} | |||
<span style="font-size:90%">The test has '''valid control line''' (black arrow) and a '''band in the pan-specific area only''' (red arrow)</span> | |||
<gallery mode="nolines" widths=80px heights=160px> | |||
File:RDT_multi_pan1.jpg|<span style="font-size:90%"></span>|link={{filepath:RDT_multi_pan1.jpg}} | |||
</gallery> | |||
<span style="font-size:90%">'''Most likely interpretation:''' A malaria infection is detected (pan band), but is not caused by the species detected by the specific antibody (Sp band)</br></span> | |||
<span style="font-size:90%">'''Less likely but possible interpretations:'''</span> | |||
*<span style="font-size:90%">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_effect_alt|Prozone-like effect]] ], [ [[HRP2_gene_deletion_alt|HRP2 gene deletion]] ]</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> | |||
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Latest revision as of 15:17, 14 April 2025
Navigation
Main Malaria Index
>RDT main page
>>This page: Multi band RDT tests
Multi-band RDT tests
| RESULT PATTERN 1 |
These are invalid tests 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 |
There has a valid control line (black arrow) showing a technically successful test, but no malaria bands are detected either the species specifc or pan malaria areas.
Most likely interpretation: No malaria parasites are present
Less likely but possible interpretations:
- Malaria infection is present, but is not detected because it is below the detection limit of the test
- Bands are present but may be faint and not seen by the operator
| RESULT PATTERN 3 |
The test has valid control line (black arrow) and has bands in the pan-specific area and the species specific area (red arrows)
Most likely interpretation: The single species detected by the species specific band is present (this same species is also detected the pan-malaria band)
Less likely but possible interpretations:
- There are two species present in the sample (likelihood depends on country of origin, but is less likely) [ Co-infection with two species ]
- There is a false positive result causing both bands (unlikely) [ False positive reaction in RDT tests ]
| RESULT PATTERN 4 |
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 5 |
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-like effect ], [ HRP2 gene deletion ]
- The "specific band" is a false positive result (infrequent but observed) [ False positive reaction in RDT tests ]