Plasmodium knowlesi

Publication Title: 
Tropical medicine & international health: TM & IH

Glutathione-S-transferase (GST) activity has been detected in rodent (Plasmodium berghei, P. yoelii), simian (P. knowlesi) and human (P. falciparum) malarial parasites, and in different intraerythrocytic stages of P. knowlesi (schizont > ring > trophozoite). In chloroquine-resistant strains of rodent and human malarial parasites GST activity significantly increases compared to sensitive strains. Further, the increase in enzyme activity is directly related to drug pressure of resistant P. berghei. Complete inhibition of chloroquine-sensitive and resistant P.

Author(s): 
Srivastava, P.
Puri, S. K.
Kamboj, K. K.
Pandey, V. C.
Publication Title: 
Zhongguo Yao Li Xue Bao = Acta Pharmacologica Sinica

AIM: To study the blood schizontocidal effect of oral artesunate on P berghei in mice and P knowlesi in monkey. METHODS: Effects of artesunate and chloroquine were detected with "4-day test" and "28-day test" on P berghei in mice and "7-day test" on P knowlesi in Macaca mudatta. RESULTS: The suppressive efficacy of oral artesunate was inferior to chloroquine on P berghei K173 strain but the time for 50% and 90% reduction and the time of clearance of parasitemia was 10-15 h shorter than that of chloroquine.

Author(s): 
Shi, Y. L.
Li, G. F.
Zhao, J. H.
Yang, J. D.
Ding, D. B.
Publication Title: 
Malaria Journal

BACKGROUND: Plasmodium knowlesi is a cause of symptomatic and potentially fatal infections in humans. There are no studies assessing the detailed parasitological response to treatment of knowlesi malaria infections in man and whether antimalarial resistance occurs. METHODS: A prospective observational study of oral chloroquine and primaquine therapy was conducted in consecutive patients admitted to Kapit Hospital, Sarawak, Malaysian Borneo with PCR-confirmed single P. knowlesi infections.

Author(s): 
Daneshvar, Cyrus
Davis, Timothy M. E.
Cox-Singh, Janet
Rafa'ee, Mohammad Z.
Zakaria, Siti K.
Divis, Paul C. S.
Singh, Balbir
Publication Title: 
Emerging Infectious Diseases

The simian parasite Plasmodium knowlesi causes severe human malaria; the optimal treatment remains unknown. We describe the clinical features, disease spectrum, and response to antimalarial chemotherapy, including artemether-lumefantrine and artesunate, in patients with P. knowlesi malaria diagnosed by PCR during December 2007-November 2009 at a tertiary care hospital in Sabah, Malaysia. Fifty-six patients had PCR-confirmed P. knowlesi monoinfection and clinical records available for review. Twenty-two (39%) had severe malaria; of these, 6 (27%) died.

Author(s): 
William, Timothy
Menon, Jayaram
Rajahram, Giri
Chan, Leslie
Ma, Gordon
Donaldson, Samantha
Khoo, Serena
Frederick, Charlie
Jelip, Jenarun
Anstey, Nicholas M.
Yeo, Tsin Wen
Publication Title: 
Malaria Journal

BACKGROUND: The simian parasite Plasmodium knowlesi is recognized as a common cause of severe and fatal human malaria in Sabah, Malaysia, but is morphologically indistinguishable from and still commonly reported as Plasmodium malariae, despite the paucity of this species in Sabah. Since December 2008 Sabah Department of Health has recommended intravenous artesunate and referral to a general hospital for all severe malaria cases of any species. This paper reviews all malaria deaths in Sabah subsequent to the introduction of these measures.

Author(s): 
Rajahram, Giri S.
Barber, Bridget E.
William, Timothy
Menon, Jayaram
Anstey, Nicholas M.
Yeo, Tsin W.
Publication Title: 
Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America

BACKGROUND: Plasmodium knowlesi commonly causes severe malaria in Malaysian Borneo, with high case-fatality rates reported. We compared risk, spectrum, and outcome of severe disease from P. knowlesi, Plasmodium falciparum, and Plasmodium vivax and outcomes following introduction of protocols for early referral and intravenous artesunate for all severe malaria. METHODS: From September 2010 to October 2011 we prospectively assessed nonpregnant patients aged ?12 years admitted to Queen Elizabeth Hospital (QEH), Sabah, with polymerase chain reaction-confirmed Plasmodium monoinfection.

Author(s): 
Barber, Bridget E.
William, Timothy
Grigg, Matthew J.
Menon, Jayaram
Auburn, Sarah
Marfurt, Jutta
Anstey, Nicholas M.
Yeo, Tsin W.
Publication Title: 
BMJ open

INTRODUCTION: Malaria due to Plasmodium knowlesi is reported throughout South-East Asia, and is the commonest cause of it in Malaysia. P. knowlesi replicates every 24?h and can cause severe disease and death. Current 2010 WHO Malaria Treatment Guidelines have no recommendations for the optimal treatment of non-severe knowlesi malaria. Artemisinin-combination therapies (ACT) and chloroquine have each been successfully used to treat knowlesi malaria; however, the rapidity of parasite clearance has not been prospectively compared.

Author(s): 
Grigg, M. J.
William, T.
Dhanaraj, P.
Menon, J.
Barber, B. E.
von Seidlein, L.
Rajahram, G.
Price, R. N.
Anstey, N. M.
Yeo, T. W.
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