Malaria causes: Difference between revisions
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__NOTOC__ | __NOTOC__ | ||
{{Malaria}} | {{Malaria}} | ||
{{CMG}} | {{CMG}}; {{AE}} {{AJL}} | ||
==Overview== | ==Overview== | ||
Malaria is a [[Vector (biology)|vector]]-borne [[infectious disease]] caused by [[protozoan]] parasites.'' [[P. vivax]]'' is the most common cause of infection, responsible for about 80 % of all malaria cases. | Malaria is a [[Vector (biology)|vector]]-borne [[infectious disease]] caused by [[protozoan]] parasites. '' [[P. vivax]]'' is the most common cause of infection, responsible for about 80% of all malaria cases. ''P. falciparum'', the most significant cause of disease, is responsible for about 15% of infections and 90% of deaths.<ref>{{cite journal | author = Mendis K, Sina B, Marchesini P, Carter R |title = The neglected burden of Plasmodium vivax malaria. |url=http://www.ajtmh.org/cgi/reprint/64/1_suppl/97.pdf | journal = Am J Trop Med Hyg |volume = 64 | issue = 1-2 Suppl | pages = 97-106 | year = 2001 | pmid = 11425182}}</ref><ref>{{cite journal | author = Mendis K, Sina B, Marchesini P, Carter R | title = The neglected burden of Plasmodium vivax malaria. | url=http://www.ajtmh.org/cgi/reprint/64/1_suppl/97.pdf | journal = Am J Trop Med Hyg | volume = 64 | issue = 1-2 Suppl | pages = 97-106 | year = 2001 | pmid = 11425182}}</ref> | ||
==Causes== | ==Causes== | ||
'' [[P. vivax]]'' is the most common cause of infection, responsible for about 80 % of all malaria cases. | '' [[P. vivax]]'' is the most common cause of infection, responsible for about 80% of all malaria cases. ''[[P. falciparum]]'', the most significant cause of disease, is responsible for about 15% of infections and 90% of deaths.<ref>{{cite journal | author = Mendis K, Sina B, Marchesini P, Carter R | title = The neglected burden of Plasmodium vivax malaria. | url=http://www.ajtmh.org/cgi/reprint/64/1_suppl/97.pdf | journal = Am J Trop Med Hyg | volume = 64 | issue = 1-2 Suppl | pages = 97-106 | year = 2001 | pmid = 11425182}}</ref> The remainder of human malaria infections are caused by ''[[P. ovale]]'', ''[[P. malariae]]'', and ''[[P. knowlesi]].'' | ||
The following table distinguishes between the different strains of ''[[Plasmodium]]'' species, all of which are causative agents of | The following table distinguishes between the different strains of ''[[Plasmodium]]'' species, all of which are causative agents of malarial infection. | ||
{| style="border: 0px; font-size: 90%; margin: 3px;" align=center | {| style="border: 0px; font-size: 90%; margin: 3px;" align=center | ||
|+'''''Comparison of ''Plasmodium'' Species Implicated in Human Malaria''''' ({{cite web |url=http://www.cdc.gov/dpdx/malaria/dx.html |title= Malaria |date= Nov. 29 2013 |website= Center for Disease Control and Prevention|publisher= Center for Disease Control and Prevention (CDC)|accessdate=Jul 24 2014}}) | |+'''''Comparison of ''Plasmodium'' Species Implicated in Human Malaria''''' ({{cite web |url=http://www.cdc.gov/dpdx/malaria/dx.html |title= Malaria |date= Nov. 29 2013 |website= Center for Disease Control and Prevention|publisher= Center for Disease Control and Prevention (CDC)|accessdate=Jul 24 2014}}) | ||
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*Clump of mass and dark pigment: Trophozoite and schizont forms | *Clump of mass and dark pigment: Trophozoite and schizont forms | ||
*Crescent or sausage shape: Gametocyte form | *Crescent or sausage shape: Gametocyte form | ||
| style="padding: 5px 5px; background: #F5F5F5;" | Tertian/subtertian [[fever]] (every 48 hours), causes severe malaria in up to 24% of cases, and is | | style="padding: 5px 5px; background: #F5F5F5;" | Tertian/subtertian [[fever]] (every 48 hours), causes severe malaria in up to 24% of cases, and is frequently drug resistant. | ||
|- | |- | ||
| style="padding: 5px 5px; background: #DCDCDC;" |'''''P. vivax''''' | | style="padding: 5px 5px; background: #DCDCDC;" |'''''P. vivax''''' | ||
| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
*Normal with fine Schüffner dots: Ring form | *Normal with fine Schüffner dots: Ring form | ||
*Enlarged with fine Schüffner dots: Trophozoite, schizont, and gametocyte forms | *Enlarged with fine Schüffner dots: [[Trophozoite]], [[schizont]], and gametocyte forms | ||
| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
*Large cytoplasm with pseudopods: Ring form | *Large cytoplasm with pseudopods: Ring form | ||
*Large ameboid cytoplasm with yellow-brown pigment: Trophozite form | *Large ameboid cytoplasm with yellow-brown pigment: Trophozite form | ||
*Large mass that fills | *Large mass that fills [[RBC]] with yellow-brown coalescent pigment: [[Schizont]] form | ||
*Large mass that fills | *Large mass that fills [[RBC]] with scattered brown pigment: Gametocyte form | ||
| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
Tertian fever (every 48 hours), | Tertian fever (every 48 hours), results in severe malaria in up to 22% of cases, and is frequently drug resistant. Relapse is common due to the dormant liver phase. | ||
|- | |- | ||
| style="padding: 5px 5px; background: #DCDCDC;" |'''''P. ovale''''' | | style="padding: 5px 5px; background: #DCDCDC;" |'''''P. ovale''''' | ||
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| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
*Sturdy cytoplasm and large chromatin: Ring form | *Sturdy cytoplasm and large chromatin: Ring form | ||
*Compact cytoplasm with dark-brown pigment: Trophozoite form | *Compact [[cytoplasm]] with dark-brown pigment: Trophozoite form | ||
*Large nuclei clustered around mass of dark-brown pigment: Schizont form | *Large [[nuclei]] clustered around mass of dark-brown pigment: Schizont form | ||
*Round to oval form that fills | *Round to oval form that fills [[RBC]] with scattered brown pigment: Gametocyte form | ||
| style="padding: 5px 5px; background: #F5F5F5;" |Tertian fever (every 48 hours), rarely causes severe malaria or drug resistance. Relapse is common due to dormant liver phase. | | style="padding: 5px 5px; background: #F5F5F5;" |Tertian fever (every 48 hours), rarely causes severe malaria or drug resistance. Relapse is common due to dormant liver phase. | ||
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| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
*Sturdy cytoplasm and large chromatin: Ring form | *Sturdy cytoplasm and large chromatin: Ring form | ||
*Compact cytoplasm with occasional band forms and coarse dark-brown pigment: Trophozoite form | *Compact cytoplasm with occasional band forms and coarse dark-brown pigment: [[Trophozoite]] form | ||
*Large nuclei clustered around mass of coarse, dark-brown pigment and occasional rosettes: Schizont form | *Large nuclei clustered around a mass of coarse, dark-brown pigment and occasional rosettes: [[Schizont]] form | ||
*Round to oval form that fills | *Round to oval form that fills [[RBC]] with scattered brown pigment: Gametocyte form | ||
| style="padding: 5px 5px; background: #F5F5F5;" | Quartan fever (every 72 hrs), rarely | | style="padding: 5px 5px; background: #F5F5F5;" | Quartan [[fever]] (every 72 hrs), rarely results in severe malaria or drug resistance. Although dormant liver phase is uncommon, infection persistence is frequently demonstrated. | ||
|- | |- | ||
| style="padding: 5px 5px; background: #DCDCDC;" |'''''P. knowlesi''''' | | style="padding: 5px 5px; background: #DCDCDC;" |'''''P. knowlesi''''' | ||
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| style="padding: 5px 5px; background: #F5F5F5;" | | | style="padding: 5px 5px; background: #F5F5F5;" | | ||
*Delicate cytoplasm with appliqué (accolé) forms: Ring form | *Delicate cytoplasm with appliqué (accolé) forms: Ring form | ||
*Compact cytoplasm and large chromatin with band forms and dark-brown pigment: Trophozoite form | *Compact cytoplasm and large chromatin with band forms and dark-brown pigment: [[Trophozoite]] form | ||
* | *Segmentation with large nuclei around a mass of coarse brown pigment and occasional rosettes: [[Schizont]] form | ||
*Round to oval form that fills | *Round to oval form that fills [[RBC]] with scattered brown pigment: Gametocyte form | ||
| style="padding: 5px 5px; background: #F5F5F5;" | Daily fevers, may | | style="padding: 5px 5px; background: #F5F5F5;" | Daily fevers, may result in severe malaria in up to 10% of cases, although resistance is rare. | ||
|- | |- | ||
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Revision as of 14:37, 25 July 2014
Malaria Microchapters |
Diagnosis |
---|
Treatment |
Case studies |
Malaria causes On the Web |
American Roentgen Ray Society Images of Malaria causes |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alison Leibowitz [2]
Overview
Malaria is a vector-borne infectious disease caused by protozoan parasites. P. vivax is the most common cause of infection, responsible for about 80% of all malaria cases. P. falciparum, the most significant cause of disease, is responsible for about 15% of infections and 90% of deaths.[1][2]
Causes
P. vivax is the most common cause of infection, responsible for about 80% of all malaria cases. P. falciparum, the most significant cause of disease, is responsible for about 15% of infections and 90% of deaths.[3] The remainder of human malaria infections are caused by P. ovale, P. malariae, and P. knowlesi.
The following table distinguishes between the different strains of Plasmodium species, all of which are causative agents of malarial infection.
Strain | Appearance of Erythrocyte (RBC) | Appearance of Parasite | Clinical Significance |
---|---|---|---|
P. falciparum |
|
|
Tertian/subtertian fever (every 48 hours), causes severe malaria in up to 24% of cases, and is frequently drug resistant. |
P. vivax |
|
Tertian fever (every 48 hours), results in severe malaria in up to 22% of cases, and is frequently drug resistant. Relapse is common due to the dormant liver phase. | |
P. ovale | Normal with fine Schüffner dots | Tertian fever (every 48 hours), rarely causes severe malaria or drug resistance. Relapse is common due to dormant liver phase. | |
P. malariae | Normal with Ziemann's stippling |
|
Quartan fever (every 72 hrs), rarely results in severe malaria or drug resistance. Although dormant liver phase is uncommon, infection persistence is frequently demonstrated. |
P. knowlesi | Normal with Sinton and Mulligan stippling |
|
Daily fevers, may result in severe malaria in up to 10% of cases, although resistance is rare. |
References
- ↑ Mendis K, Sina B, Marchesini P, Carter R (2001). "The neglected burden of Plasmodium vivax malaria" (PDF). Am J Trop Med Hyg. 64 (1-2 Suppl): 97–106. PMID 11425182.
- ↑ Mendis K, Sina B, Marchesini P, Carter R (2001). "The neglected burden of Plasmodium vivax malaria" (PDF). Am J Trop Med Hyg. 64 (1-2 Suppl): 97–106. PMID 11425182.
- ↑ Mendis K, Sina B, Marchesini P, Carter R (2001). "The neglected burden of Plasmodium vivax malaria" (PDF). Am J Trop Med Hyg. 64 (1-2 Suppl): 97–106. PMID 11425182.