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Biology Quiz A Q1: Difference between revisions

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! colspan="1" |<span style="font-size:90%">Explanation of correct answer (click "Expand").</span>
! colspan="1" |<span style="font-size:90%">Explanation of correct answer (click "Expand").</span>
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|</b> <span style="font-size:90%">''Short answer taken from section "Main RDT page" (see the section for full details and links)''.</br></br>The different malaria species are detected with different sensitivity. The table below provides an overall summary of the sensitivity that can be expected for RDT tests (the specific section in the main section provides more detail)''.</span></br></br>
|</b> <span style="font-size:90%">''Short answer taken from section "Initial Infection in the Malaria Biology page" (see the section for full details and links)''.</br></br>The hepatic stage is the period where parasites begin to replicate and cause infection - this corresponds to an incubation period before symptoms begin; this will typically last between 1-4 weeks, and during this time parasites will not be detected in blood. The number of bites required for infection may be only 1 if the mosquito is heavily infected (hence cases of airport malaria where the infection is acquired from a mosquito passenger in luggage).</br></br>For two malaria species (P.ovale and P.vivax) the hepatic stage may lie dormant for a period of time - this is the hynozoite (“sleeping animal”). This hyponozoite may reactivate - typically in less than a year although occasionally longer, causing clinical malaria symptoms long after the initial infection.
 
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!colspan="1" style = "background:#e1f1fd; border:solid; border-width: 3px;"|<span style="font-size:90%">''' ''P.falciparum'''</br>
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!colspan="1" style = "background:white; border:solid; border-width: 1px; color:black"|<span style="font-size:90%">At high parasitaemia expect high sensitivity (90-95%). This declines when parasite levels are lower (45-70%)
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!colspan="1" style = "background:#e1f1fd; border:solid; border-width: 3px;"|<span style="font-size:90%;">''' ''P.vivax'' '''</span></br>
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!colspan="1" style = "background:white; border:solid; border-width: 1px; color:black"|<span style="font-size:90%">Expect moderate to high sensitivity at high parasitaemia (70-90%). This declines markedly when parasite levels are lower (30-60%)
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!colspan="1" style = "background:#e1f1fd; border:solid; border-width: 3px;"|<span style="font-size:90%;">''' ''P.ovale & P.malarae'' '''</span></br>
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!colspan="1" style = "background:white; border:solid; border-width: 1px; color:black"|<span style="font-size:90%">Generally sensitivity is poor (approximately half the sensitivity shown for ''P.vivax'')
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!colspan="1" style = "background:#e1f1fd; border:solid; border-width: 3px;"|<span style="font-size:90%;">''' ''P.knowlesi'' '''</span></br>
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!colspan="1" style = "background:white; border:solid; border-width: 1px; color:black"|<span style="font-size:90%">Reports suggest variable sensitivity that may depend on test used, RDTs are reported tp detect this species well when parasitaemia is high.
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|colspan="1" style = "font-size:90%; color:black|<span style="color:black>[[Biology_Quiz_A_Q2|Go to next question (2 of 5)]]</span>
|colspan="1" style = "font-size:90%; color:black|<span style="color:black>[[Biology_Quiz_A_Q2|Go to next question (2 of 5)]]</span>

Revision as of 13:48, 27 November 2024


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Malaria Biology Quiz A Q1


Following a mosquito bite the newly introduced malarial parasite will first enter the liver cells and replicate - only after this do they enter blood. In some species parasites may remain dormant in this liver stage (as a "hypnozoite") before re-emerging to cause a late or recurrent infection after weeks, months or perhaps longer.

In which species can late infection emerge from dormant parasites in liver?? Make one or more selections

P.falciparum
P.vivax
P.ovale
P.malariae
P.knowlesi


Explanation of correct answer (click "Expand").
Short answer taken from section "Initial Infection in the Malaria Biology page" (see the section for full details and links).

The hepatic stage is the period where parasites begin to replicate and cause infection - this corresponds to an incubation period before symptoms begin; this will typically last between 1-4 weeks, and during this time parasites will not be detected in blood. The number of bites required for infection may be only 1 if the mosquito is heavily infected (hence cases of airport malaria where the infection is acquired from a mosquito passenger in luggage).

For two malaria species (P.ovale and P.vivax) the hepatic stage may lie dormant for a period of time - this is the hynozoite (“sleeping animal”). This hyponozoite may reactivate - typically in less than a year although occasionally longer, causing clinical malaria symptoms long after the initial infection.
Go to next question (2 of 5)