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<span style="font-size:90%">>[[Rapid diagnostic tests (RDTs)|RDT main page]]''</span></br>
<span style="font-size:90%">>[[Rapid diagnostic tests (RDTs)|RDT main page]]''</span></br>
<span style="font-size:90%">>>[[Interpretation guide: SINGLE BAND tests|Single Band Tests]]''</span></br>
<span style="font-size:90%">>>[[Interpretation guide: SINGLE BAND tests|Single Band Tests]]''</span></br>
<span style="font-size:90%">>>>Current page: '''C0-infection with two species'''</span>
<span style="font-size:90%">>>>Current page: '''Co-infection with two species'''</span>
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In short, mixed-species malaria infections occur, but may go unrecognised. Their precise frequency will vary according to the case-mix in the area concerned. They may only be detected during convalescence.  
<span style="font-size:90%">Mixed-species malaria infections certainly occur. Their precise frequency will vary according to the case-mix in the area concerned.</br></br>In endemic areas where multiple malarial species circulate estimates of prevalence may be as high as 30%, but in other areas this is far lower and would often be regarded as forming fewer than 5% of infections.</span>


In endemic areas where multiple malarial species circulate estimates of prevalence may be as high as 30%, but in other areas this is far lower and would often be regarded as forming fewer than 5% of infections.
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<span style="font-size:90%">Recogition by morphology requires the presence of parasite forms that have recognisable species-specific features for two separate species. This may sometimes be easy, but can be challenging when one species predominates. Some examples are shown below:</br></br></span>
 
<gallery mode="nolines" widths=250px heights=250px>
File:Dual1.jpg|<span style="font-size:90%"></span>|A|link={{filepath:Dual1.jpg}}
File:Dual2.jpg|<span style="font-size:90%"></span>|B|link={{filepath:Dual2.jpg}}
</gallery>


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<span style="font-size:90%">'''Image A''': two gametocytes in separate red cells. These clearly have different appearances - one has the elongated and curved form typical of ''P.falciparum'', while the second is "round" with visible round bametocytecytoplasmic dots and fimbriation of the red cell - appearances of ''P.ovale''.</br<</br>'''Image B''': a large parasite within the red cell is clearly seen and has the chacteristics of a microgametocyte of ''P.ovale'', but note also a small fine early "double dot" ring form  of ''P.falciparum'' that is within the same erythocyte - an unusual "dual-parasite" erythrocyte!</span>

Latest revision as of 13:30, 21 November 2024

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Dual species infection


Mixed-species malaria infections certainly occur. Their precise frequency will vary according to the case-mix in the area concerned.

In endemic areas where multiple malarial species circulate estimates of prevalence may be as high as 30%, but in other areas this is far lower and would often be regarded as forming fewer than 5% of infections.

Recogition by morphology requires the presence of parasite forms that have recognisable species-specific features for two separate species. This may sometimes be easy, but can be challenging when one species predominates. Some examples are shown below:

  • A

    A

  • B

    B

Image A: two gametocytes in separate red cells. These clearly have different appearances - one has the elongated and curved form typical of P.falciparum, while the second is "round" with visible round bametocytecytoplasmic dots and fimbriation of the red cell - appearances of P.ovale.</br<
Image B: a large parasite within the red cell is clearly seen and has the chacteristics of a microgametocyte of P.ovale, but note also a small fine early "double dot" ring form of P.falciparum that is within the same erythocyte - an unusual "dual-parasite" erythrocyte!

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