High proportion of knowlesi malaria in recent malaria cases in Malaysia

Yusof, Ruhani; Lau, Yee Ling; Mahmud, Rohela; Fong, Mun Yik; Jelip, Jenarun; Ngian, Hie Ung; Mustakim, Sahlawati; Hussin, Hani Mat; Marzuki, Noradilah; Ali, Marlindawati Mohd

doi:10.1186/1475-2875-13-168

Cited by 116 publications

(148 citation statements)

References 27 publications

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“…In countries such as Malaysia where other malaria parasites are being controlled effectively, P. knowlesi infections are the dominant cause of human malaria (3,4). In all malaria parasite species, disease is caused by cyclic parasite multiplication within RBCs, releasing invasive merozoites that invade new RBCs.…”

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confidence: 99%

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasite Plasmodium knowlesi

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Sharaf

Hastings

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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The dominant cause of malaria in Malaysia is now Plasmodium knowlesi, a zoonotic parasite of cynomolgus macaque monkeys found throughout South East Asia. Comparative genomic analysis of parasites adapted to in vitro growth in either cynomolgus or human RBCs identified a genomic deletion that includes the gene encoding normocyte-binding protein Xa (NBPXa) in parasites growing in cynomolgus RBCs but not in human RBCs. Experimental deletion of the NBPXa gene in parasites adapted to growth in human RBCs (which retain the ability to grow in cynomolgus RBCs) restricted them to cynomolgus RBCs, demonstrating that this gene is selectively required for parasite multiplication and growth in human RBCs. NBPXa-null parasites could bind to human RBCs, but invasion of these cells was severely impaired. Therefore, NBPXa is identified as a key mediator of P. knowlesi human infection and may be a target for vaccine development against this emerging pathogen.

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mentioning

confidence: 99%

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasite Plasmodium knowlesi

Moon

Sharaf

Hastings

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…In Malaysia, P. falciparum and P. vivax cases have declined over the past five years and P. knowlesi has now become the most common cause of human malaria 6,7 . The true incidence of knowlesi malaria is not known in other parts of Southeast Asia since not many large-scale studies have been undertaken with molecular detection assays.…”

Section: Epidemiology and Risk Factors Of Acquiring Knowlesi Malariamentioning

confidence: 99%

Plasmodium knowlesi: an update

Singh

2016

Microbiol. Aust.

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There were only four species of Plasmodium that were thought to cause malaria in humans until a large number of human infections by Plasmodium knowlesi, a malaria parasite typically found in long-tailed and pig-tailed macaques, were reported in 2004 in Malaysian Borneo. Since then, cases of knowlesi malaria have been reported throughout South-east Asia and also in travellers returning from the region. This article describes the molecular, entomological and epidemiological data which indicate that P. knowlesi is an ancient parasite that is primarily zoonotic, and there are three highly divergent sub-populations. It also describes the detection methods for P. knowlesi, which is morphologicaly similar to P. malariae, and the clinical features and treatment of this malaria parasite that is potentially fatal. Malaria parasites and discovery of large focus of human knowlesi malaria casesMalaria is caused by parasites that belong to the genus Plasmodium and there are more than 150 species of Plasmodium that infect reptiles, birds and mammals 1 . These parasites, in general, tend to be host-specific. Long-tailed and pig-tailed macaques (Macaca fascicularis and M. nemestrina respectively) are hosts to five species (P. knowlesi, P. inui, P. cynomolgi, P. fieldi and P. coatneyi). Only four species of Plasmodium, namely P. falciparum, P. vivax, P. malariae and P. ovale, were thought to cause malaria in humans until a large number of human cases due to P. knowlesi were reported in Sarawak, Malaysian Borneo over 11 years ago 2 . The study in Kapit was prompted by observations that cases diagnosed by microscopy as P. malariae had high parasitaemias, required hospitalization and that 95% of patients were adults. This was in contrast to P. malariae infections which typically are asymptomatic with low parasitaemia and occur in all age groups. When blood samples from 208 malaria patients at Kapit Hospital were analysed by PCR assays, none were identified as P. malariae, although 141had been diagnosed as P. malariae by microscopy. Fifty-eight percent (120) were either single P. knowlesi infections or mixed infections of P. knowlesi with P. falciparum and P. vivax. Misdiagnosis had occurred because the blood stages of P. knowlesi and P. malariae are morphologically indistinguishable

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“…In some areas of Malaysian Borneo where molecular genetic typing methods have been applied, all locally acquired malaria cases were attributable to P. knowlesi [9••]. In a recent study assessing parasites species in 453 samples positive for malaria parasites in 22 hospitals all over Malaysia, P. knowlesi was identified in 56 % of the samples followed by P. vivax (29 %), P. falciparum (11 %), Plasmodium ovale (<1 %) and P. malariae (<1 %) [18].…”

Section: Introductionmentioning

confidence: 99%

Plasmodium knowlesi malaria: Overview Focussing on Travel-Associated Infections

Cramer

2015

Curr Infect Dis Rep

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In 2004, Plasmodium knowlesi was first recognised as a relevant cause of human malaria in Southeast Asia. Since then, P. knowlesi has been described from all Southeast Asian countries except Laos and has become well-established as the fifth human malaria parasite and the first significant zoonotic Plasmodium species. As countries endemic for P. knowlesi malaria are among the most popular and most highly visited international destinations, travel medicine experts should be aware about disease and risks including prophylactic and therapeutic measures. Between 2005 and 2012, 15 cases of P. knowlesi malaria have been recognised and published in international travellers. Male gender and travel to rural/forested areas with contact to wild monkeys are risk factors for P. knowlesi infection. The present review gives an overview on current literature on the P. knowlesi parasite and summarises recent findings related to epidemiology, diagnostics, treatment and prophylaxis focussing on travellers.

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High proportion of knowlesi malaria in recent malaria cases in Malaysia

Cited by 116 publications

References 27 publications

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasite Plasmodium knowlesi

Normocyte-binding protein required for human erythrocyte invasion by the zoonotic malaria parasite Plasmodium knowlesi

Plasmodium knowlesi: an update

Plasmodium knowlesi malaria: Overview Focussing on Travel-Associated Infections

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