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Plasmodium knowlesi: Emergent Human Malaria in Southeast Asia

  • Kim-Sung Lee
  • Indra VythilingamEmail author
Chapter

Abstract

Plasmodium knowlesi is an emerging malaria parasite in humans and is unique to Southeast Asia. Since most countries in Southeast Asia are working towards elimination of malaria, it is important to have knowledge on this emerging simian malaria parasite affecting humans. The first case of simian malaria was reported in Malaysia in 1965. At that time extensive work conducted did not reveal other simian malaria cases in humans. However, in 2004, a large focus of P. knowlesi was reported from Sarawak, Malaysian Borneo and that led to many studies and cases being reported from most countries in Southeast Asia. In this chapter, the history, epidemiology, diagnosis, vectors and role of simian host are discussed. Malaria is now a zoonosis and the challenges facing the countries of Southeast in tackling the knowlesi malaria situation and the way forward have been documented.

Keywords

Lamp Assay Human Malaria Malaria Species Plasmodium Knowlesi Small Subunit rRNA Gene 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    S.M. Rich, F.J. Ayala, Evolutionary origins of human malaria parasites, in Malaria: Genetic and Evolutionary Aspects, ed. by K.R. Dronamraju, P. Arese (Springer, New York, 2006), pp. 125–146CrossRefGoogle Scholar
  2. 2.
    B. Singh et al., A large focus of naturally acquired Plasmodium knowlesi infections in human beings. Lancet 363(9414), 1017–1024 (2004)PubMedCrossRefGoogle Scholar
  3. 3.
    N.J. White, Plasmodium knowlesi: the fifth human malaria parasite. Clin. Infect. Dis. 46(2), 172–173 (2008)PubMedCrossRefGoogle Scholar
  4. 4.
    S.I. Hay et al., Estimating the global clinical burden of Plasmodium falciparum malaria in 2007. PLoS Med. 7(6), e1000290 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  5. 5.
    I. Mueller et al., Key gaps in the knowledge of Plasmodium vivax a neglected human malaria parasite. Lancet Infect. Dis. 9(9), 555–566 (2009)PubMedCrossRefGoogle Scholar
  6. 6.
    R.G. Coatney et al., The Primate Malarias (US Government Printing Office, Washington, 1971)Google Scholar
  7. 7.
    P.C.C. Garnham, Malaria Parasites and Other Haemosporidia (Blackwell, Oxford, 1966)Google Scholar
  8. 8.
    B. Singh, C. Daneshvar, Human infections and detection of Plasmodium knowlesi. Clin. Microbiol. Rev. 26(2), 165–184 (2013)PubMedCrossRefGoogle Scholar
  9. 9.
    J. Cox-Singh et al., Plasmodium knowlesi malaria in humans is widely distributed and potentially life threatening. Clin. Infect. Dis. 46(2), 165–171 (2008)PubMedCentralPubMedCrossRefGoogle Scholar
  10. 10.
    G.R. Coatney et al., Plasmodium inui, a quartan-type malaria parasite of Old World monkeys transmissible to man. J. Parasitol. 52(4), 660–663 (1966)PubMedCrossRefGoogle Scholar
  11. 11.
    P.G. Contacos et al., Man to man transfer of two strains of Plasmodium cynomolgi by mosquito bite. Am. J. Trop. Med. Hyg. 11(2), 186–193 (1962)PubMedGoogle Scholar
  12. 12.
    G.R. Coatney, Simian malarias in man: facts, implications, and predictions. Am. J. Trop. Med. Hyg. 17(2), 147–155 (1968)PubMedGoogle Scholar
  13. 13.
    B. Gupta, Transmission of P. inui to man. in Proceedings of the National Institute of Sciences of India, National Institute of Sciences of India, 1938Google Scholar
  14. 14.
    L.E. Napier, H.G.M. Campbell, Observations on a Plasmodium infection which causes haemoglobinuria in certain species of monkey. Indian Med. Gaz. 67, 151–160 (1932)Google Scholar
  15. 15.
    R. Knowles, B.M. Das Gupta, A study of monkey-malaria and its experimental transmission to man. Indian Med. Gaz 67, 301–320 (1932)Google Scholar
  16. 16.
    J.A. Sinton, H.W. Mulligan, A critical review of the literature relating to the identification of the malarial parasites recorded from monkeys of the families Cercopithecidae and Colobidae. Rec. Malar. Surv. India 3, 381–443 (1932)Google Scholar
  17. 17.
    J.A. Sinton, H.W. Mulligan, A critical review of the literature relating to the identification of the malarial parasites recorded from monkeys of the families Cercopithecidae and Colobidae. Rec. Malar. Surv. India 3, 381–443 (1933)Google Scholar
  18. 18.
    C. Ionesco-Mihaiesti et al., Transmission experimentale a l’homme du paludisme propre des singes. Compt. Rend. Soc. Biol 115, 1311–1313 (1934)Google Scholar
  19. 19.
    C.E. Van Rooyen, G.R. Pile, Observations on infection by Plasmodium knowlesi (ape malaria) in the treatment of general paralysis of the insane. Br. Med. J. 2, 662–666 (1935)PubMedCentralPubMedCrossRefGoogle Scholar
  20. 20.
    R.N. Chopra, B.M. Das Gupta, A preliminary note on the treatment of neurosyphilis with monkey malaria. Indian Med. Gaz. 77, 187–188 (1936)Google Scholar
  21. 21.
    M. Ciuca et al., Contribution a l’etude de la virulence du Pl knowlesi chez l’homme. Carateres de la maladie et biologie du parasite. Arch. Roum. Pathol. Exp. Microbiol. 10, 5–28 (1937)Google Scholar
  22. 22.
    W. Chin et al., A naturally acquitted quotidian-type malaria in man transferable to monkeys. Science 149(3686), 865 (1965)PubMedCrossRefGoogle Scholar
  23. 23.
    Y.L. Fong et al., A presumptive case of naturally occurring Plasmodium knowlesi malaria in man in Malaysia. Trans. R. Soc. Trop. Med. Hyg. 65(6), 839–840 (1971)PubMedCrossRefGoogle Scholar
  24. 24.
    Q. Liu et al., Sequence variation in the small-subunit rRNA gene of Plasmodium malariae and prevalence of isolates with the variant sequence in Sichuan, China. J. Clin. Microbiol. 36(11), 3378–3381 (1998)PubMedCentralPubMedGoogle Scholar
  25. 25.
    K.S. Lee et al., Plasmodium knowlesi from archival blood films: further evidence that human infections are widely distributed and not newly emergent in Malaysian Borneo. Int. J. Parasitol. 39(10), 1125–1128 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  26. 26.
    I. Vythilingam et al., Plasmodium knowlesi in humans, macaques and mosquitoes in peninsular Malaysia. Parasit. Vectors 1(1), 26 (2008)PubMedCentralPubMedCrossRefGoogle Scholar
  27. 27.
    W.F. Joveen-Neoh et al., Incidence of malaria in the interior division of Sabah, Malaysian Borneo, based on nested PCR. J. Parasitol. Res. 2011, 104284 (2011)PubMedCentralPubMedCrossRefGoogle Scholar
  28. 28.
    T.Y. Lau et al., High incidence of Plasmodium knowlesi infection in the interior division of Sabah, Malaysian Borneo. Int. J. Biosci. Biochem. Bioinform. 1(2), 163–167 (2011)Google Scholar
  29. 29.
    B.E. Barber et al., Epidemiology of Plasmodium knowlesi malaria in north-east Sabah. Malar. J. 11, 401 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  30. 30.
    T. William et al., Severe Plasmodium knowlesi malaria in a tertiary care hospital, Sabah, Malaysia. Emerg. Infect. Dis. 17(7), 1248–1255 (2011)PubMedCrossRefGoogle Scholar
  31. 31.
    B.E. Barber et al., Plasmodium knowlesi malaria in children. Emerg. Infect. Dis. 17(5), 814–820 (2011)PubMedCrossRefGoogle Scholar
  32. 32.
    Y.L. Lau et al., Plasmodium knowlesi reinfection in human. Emerg. Infect. Dis. 17(7), 1314–1315 (2011)PubMedCrossRefGoogle Scholar
  33. 33.
    S. Jongwutiwes et al., Naturally acquired Plasmodium knowlesi malaria in human, Thailand. Emerg. Infect. Dis. 10(12), 2211–2213 (2004)PubMedCrossRefGoogle Scholar
  34. 34.
    C. Putaporntip et al., Differential prevalence of Plasmodium infections and cryptic Plasmodium knowlesi malaria in humans in Thailand. J. Infect. Dis. 199(8), 1143–1150 (2009)PubMedCrossRefGoogle Scholar
  35. 35.
    F. Lambrecht et al., Isolation of Plasmodium knowlesi from Philippine macaques. Nature 191, 1117–1118 (1961)PubMedCrossRefGoogle Scholar
  36. 36.
    M. Tsukamoto et al., Surveys on simian malaria parasites and their vector in Palawan Island, the Philippines. Trop. Biomed. 20, 39–50 (1978)Google Scholar
  37. 37.
    J. Luchavez et al., Human infections with Plasmodium knowlesi, the Philippines. Emerg. Infect. Dis. 14(5), 811–813 (2008)PubMedCrossRefGoogle Scholar
  38. 38.
    K. Goh, Eradication of malaria from Singapore. Singapore Med. J. 24(5), 255 (1983)PubMedGoogle Scholar
  39. 39.
    W.P. Jeslyn et al., Molecular epidemiological investigation of Plasmodium knowlesi in humans and macaques in Singapore. Vector Borne Zoonotic Dis. 11(2), 131–135 (2011)PubMedCrossRefGoogle Scholar
  40. 40.
    O.T. Ng et al., Naturally acquired human Plasmodium knowlesi infection, Singapore. Emerg. Infect. Dis. 14(5), 814–816 (2008)PubMedCrossRefGoogle Scholar
  41. 41.
    C.W. Ong et al., Monkey malaria in humans: a diagnostic dilemma with conflicting laboratory data. Am. J. Trop. Med. Hyg. 80(6), 927–928 (2009)PubMedGoogle Scholar
  42. 42.
    P. Van den Eede et al., Human Plasmodium knowlesi infections in young children in central Vietnam. Malar. J. 8, 249 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  43. 43.
    P. Van den Eede et al., Plasmodium knowlesi malaria in Vietnam: some clarifications. Malar. J. 9, 20 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  44. 44.
    J. Cox-Singh, Knowlesi malaria in Vietnam. Malar. J. 8, 269 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  45. 45.
    R.P. Marchand et al., Co-infections of Plasmodium knowlesi, P. falciparum, and P. vivax among Humans and Anopheles dirus Mosquitoes, Southern Vietnam. Emerg. Infect. Dis. 17(7), 1232–1239 (2011)PubMedCrossRefGoogle Scholar
  46. 46.
    L. Cui et al., Malaria in the Greater Mekong Subregion: heterogeneity and complexity. Acta Trop. 121, 227–239 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  47. 47.
    H. Zhu et al., [Human natural infection of Plasmodium knowlesi]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 24(1), 70–71 (2006)PubMedGoogle Scholar
  48. 48.
    N. Jiang et al., Co-infections with Plasmodium knowlesi and other malaria parasites, Myanmar. Emerg. Infect. Dis. 16(9), 1476–1478 (2010)PubMedCrossRefGoogle Scholar
  49. 49.
    M. Figtree et al., Plasmodium knowlesi in human, Indonesian Borneo. Emerg. Infect. Dis. 16(4), 672–674 (2010)PubMedCrossRefGoogle Scholar
  50. 50.
    E. Sulistyaningsih et al., Diagnostic difficulties with Plasmodium knowlesi infection in humans. Emerg. Infect. Dis. 16(6), 1033–1034 (2010)PubMedCrossRefGoogle Scholar
  51. 51.
    N. Khim et al., Plasmodium knowlesi infection in humans, Cambodia, 2007–2010. Emerg. Infect. Dis. 17(10), 1900–1902 (2011)PubMedCrossRefGoogle Scholar
  52. 52.
    D. Eyles et al., Malaria parasites of the Malayan leaf monkeys of the genus Presbytis. Med. J. Malaya 17, 85–86 (1962)Google Scholar
  53. 53.
    J. Fooden, Ecogeographic segregation of macaque species. Primates 23(4), 574–579 (1982)CrossRefGoogle Scholar
  54. 54.
    J. Fooden, Comparative review of fascicularis-group species of macaques (Primates: Macaca). Fieldiana Zool. 107, 1–43 (2006)Google Scholar
  55. 55.
    K.S. Lee et al., Plasmodium knowlesi: reservoir hosts and tracking the emergence in humans and macaques. PLoS Pathog. 7(4), e1002015 (2011)PubMedCentralPubMedCrossRefGoogle Scholar
  56. 56.
    C. Putaporntip et al., Ecology of malaria parasites infecting Southeast Asian macaques: evidence from cytochrome b sequences. Mol. Ecol. 19(16), 3466–3476 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  57. 57.
    M.A.M. Sallum et al., Revision of the Leucosphyrus group of Anopheles (Cellia) (Diptera, Culicidae). Rev. Bras. Entomol. 49, 1–152 (2005)CrossRefGoogle Scholar
  58. 58.
    R.H. Wharton, D.E. Eyles, Anopheles hackeri, a vector of Plasmodium knowlesi in Malaya. Science 134(3474), 279 (1961)PubMedCrossRefGoogle Scholar
  59. 59.
    M.W. Warren, R.H. Wharton, The vectors of simian malaria: identity, biology, and geographical distribution. J. Parasitol. 49, 892–904 (1963)PubMedCrossRefGoogle Scholar
  60. 60.
    W.H. Cheong et al., Anopheles balabacensis balabacensis identified as vector of simian malaria in Malaysia. Science 150(3701), 1314 (1965)PubMedCrossRefGoogle Scholar
  61. 61.
    I. Vythilingam et al., Natural transmission of Plasmodium knowlesi to humans by Anopheles latens in Sarawak, Malaysia. Trans. R. Soc. Trop. Med. Hyg. 100(11), 1087–1088 (2006)PubMedCrossRefGoogle Scholar
  62. 62.
    C.H. Tan et al., Bionomics of Anopheles latens in Kapit, Sarawak, Malaysian Borneo in relation to the transmission of zoonotic simian malaria parasite Plasmodium knowlesi. Malar. J. 7, 52 (2008)PubMedCentralPubMedCrossRefGoogle Scholar
  63. 63.
    C.H. Tan, Identification of vectors of Plasmodium knowlesi and other malaria parasites, and studies on their bionomics in Kapit, Sarawak, Malaysia. MSc Thesis, University Malaysia, Sarawak (UNIMAS), 2008Google Scholar
  64. 64.
    M.S. Chang et al., Changes in abundance and behaviour of vector mosquitoes induced by land use during the development of an oil palm plantation in Sarawak. Trans. R. Soc. Trop. Med. Hyg. 91(4), 382–386 (1997)PubMedCrossRefGoogle Scholar
  65. 65.
    A.I. Jiram et al., Entomologic investigation of Plasmodium knowlesi vectors in Kuala Lipis, Pahang, Malaysia. Malar. J. 11(1), 213 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  66. 66.
    S. Nakazawa et al., Anopheles dirus co-infection with human and monkey malaria parasites in Vietnam. Int. J. Parasitol. 39(14), 1533–1537 (2009)PubMedCrossRefGoogle Scholar
  67. 67.
    E. Vargas-Serrato et al., Phylogenetic analysis of CSP and MSP-9 gene sequences demonstrates the close relationship of Plasmodium coatneyi to Plasmodium knowlesi. Infect. Genet. Evol. 3(1), 67–73 (2003)PubMedCrossRefGoogle Scholar
  68. 68.
    D.A. Joy et al., Early origin and recent expansion of Plasmodium falciparum. Science 300(5617), 318–321 (2003)PubMedCrossRefGoogle Scholar
  69. 69.
    S. Krief et al., On the diversity of malaria parasites in African apes and the origin of Plasmodium falciparum from Bonobos. PLoS Pathog. 6(2), e1000765 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  70. 70.
    A.A. Escalante et al., A monkey’s tale: the origin of Plasmodium vivax as a human malaria parasite. Proc. Natl. Acad. Sci. USA 102(6), 1980–1985 (2005)PubMedCrossRefGoogle Scholar
  71. 71.
    J. Mu et al., Host switch leads to emergence of Plasmodium vivax malaria in humans. Mol. Biol. Evol. 22(8), 1686–1693 (2005)PubMedCrossRefGoogle Scholar
  72. 72.
    M.Y. Fong et al., Sequence analysis on the mitochondrial COXI gene of recent clinical isolates of Plasmodium knowlesi in Klang Valley, peninsular Malaysia. Trop. Biomed. 28(2), 457–463 (2011)PubMedGoogle Scholar
  73. 73.
    A. Pain et al., The genome of the simian and human malaria parasite Plasmodium knowlesi. Nature 455(7214), 799–803 (2008)PubMedCentralPubMedCrossRefGoogle Scholar
  74. 74.
    B. Singh, Molecular methods for diagnosis and epidemiological studies of parasitic infections. Int. J. Parasitol. 27(10), 1135–1145 (1997)PubMedCrossRefGoogle Scholar
  75. 75.
    K.S. Lee et al., Morphological features and differential counts of Plasmodium knowlesi parasites in naturally acquired human infections. Malar. J. 8, 73 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  76. 76.
    B. Singh et al., A genus-and species-specific nested polymerase chain reaction malaria detection assay for epidemiologic studies. Am. J. Trop. Med. Hyg. 60, 687–692 (1999)PubMedGoogle Scholar
  77. 77.
    B. Singh et al., Detection of malaria in Malaysia by nested polymerase chain reaction amplification of dried blood spots on filter papers. Trans. R. Soc. Trop. Med. Hyg. 90(5), 519–521 (1996)PubMedCrossRefGoogle Scholar
  78. 78.
    G. Snounou et al., The importance of sensitive detection of malaria parasites in the human and insect hosts in epidemiological studies, as shown by the analysis of field samples from Guinea Bissau. Trans. R. Soc. Trop. Med. Hyg. 87(6), 649–653 (1993)PubMedCrossRefGoogle Scholar
  79. 79.
    M. Imwong et al., Spurious amplification of a Plasmodium vivax small-subunit RNA gene by use of primers currently used to detect P. knowlesi. J. Clin. Microbiol. 47(12), 4173–4175 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  80. 80.
    N.W. Lucchi et al., A new single-step PCR assay for the detection of the zoonotic malaria parasite Plasmodium knowlesi. PLoS One 7(2), e31848 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  81. 81.
    C.H. Chew et al., Hexaplex PCR detection system for identification of five human Plasmodium species with an internal control. J. Clin. Microbiol. 50(12), 4012–4019 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  82. 82.
    G.A. Farcas et al., Evaluation of the RealArt Malaria LC real-time PCR assay for malaria diagnosis. J. Clin. Microbiol. 42(2), 636–638 (2004)PubMedCentralPubMedCrossRefGoogle Scholar
  83. 83.
    F. Perandin et al., Development of a real-time PCR assay for detection of Plasmodium falciparum, Plasmodium vivax, and Plasmodium ovale for routine clinical diagnosis. J. Clin. Microbiol. 42(3), 1214–1219 (2004)PubMedCentralPubMedCrossRefGoogle Scholar
  84. 84.
    H. Swan et al., Evaluation of a real-time polymerase chain reaction assay for the diagnosis of malaria in patients from Thailand. Am. J. Trop. Med. Hyg. 73(5), 850–854 (2005)PubMedGoogle Scholar
  85. 85.
    F. de Monbrison et al., Simultaneous identification of the four human Plasmodium species and quantification of Plasmodium DNA load in human blood by real-time polymerase chain reaction. Trans. R. Soc. Trop. Med. Hyg. 97(4), 387–390 (2003)PubMedCrossRefGoogle Scholar
  86. 86.
    N.E. Babady et al., Detection of Plasmodium knowlesi by real-time polymerase chain reaction. Am. J. Trop. Med. Hyg. 81(3), 516–518 (2009)PubMedGoogle Scholar
  87. 87.
    P.C. Divis et al., A TaqMan real-time PCR assay for the detection and quantitation of Plasmodium knowlesi. Malar. J. 9, 344 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  88. 88.
    O. Oddoux et al., Identification of the five human Plasmodium species including P. knowlesi by real-time polymerase chain reaction. Eur. J. Clin. Microbiol. Infect. Dis. 30(4), 597–601 (2011)PubMedCrossRefGoogle Scholar
  89. 89.
    T. Notomi et al., Loop-mediated isothermal amplification of DNA. Nucleic Acids Res. 28(12), e63 (2000)PubMedCentralPubMedCrossRefGoogle Scholar
  90. 90.
    Y. Mori, T. Notomi, Loop-mediated isothermal amplification (LAMP): a rapid, accurate, and cost-effective diagnostic method for infectious diseases. J. Infect. Chemother. 15(2), 62–69 (2009)PubMedCrossRefGoogle Scholar
  91. 91.
    D.H. Paris et al., Loop-mediated isothermal PCR (LAMP) for the diagnosis of falciparum malaria. Am. J. Trop. Med. Hyg. 77(5), 972–976 (2007)PubMedGoogle Scholar
  92. 92.
    L.L. Poon et al., Sensitive and inexpensive molecular test for falciparum malaria: detecting Plasmodium falciparum DNA directly from heat-treated blood by loop-mediated isothermal amplification. Clin. Chem. 52(2), 303–306 (2006)PubMedCrossRefGoogle Scholar
  93. 93.
    H. Iseki et al., Evaluation of a loop-mediated isothermal amplification method as a tool for diagnosis of infection by the zoonotic simian malaria parasite Plasmodium knowlesi. J. Clin. Microbiol. 48(7), 2509–2514 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  94. 94.
    Y.L. Lau et al., Specific, sensitive and rapid detection of human Plasmodium knowlesi infection by loop-mediated isothermal amplification (LAMP) in blood samples. Malar. J. 10, 197 (2011)PubMedCentralPubMedCrossRefGoogle Scholar
  95. 95.
    A. Moody, Rapid diagnostic tests for malaria parasites. Clin. Microbiol. Rev. 15(1), 66–78 (2002)PubMedCentralPubMedCrossRefGoogle Scholar
  96. 96.
    T.F. McCutchan et al., Use of malaria rapid diagnostic test to identify Plasmodium knowlesi infection. Emerg. Infect. Dis. 14(11), 1750–1752 (2008)PubMedGoogle Scholar
  97. 97.
    A. Berry et al., Imported Plasmodium knowlesi malaria in a French tourist returning from Thailand. Am. J. Trop. Med. Hyg. 84(4), 535–538 (2011)PubMedCrossRefGoogle Scholar
  98. 98.
    J.J. van Hellemond et al., Human Plasmodium knowlesi infection detected by rapid diagnostic tests for malaria. Emerg. Infect. Dis. 15(9), 1478–1480 (2009)PubMedCrossRefGoogle Scholar
  99. 99.
    U. Bronner et al., Swedish traveller with Plasmodium knowlesi malaria after visiting Malaysian Borneo. Malar. J. 8, 15 (2009)PubMedCentralPubMedCrossRefGoogle Scholar
  100. 100.
    T.T. Ta et al., First case of detection of Plasmodium knowlesi in Spain by Real Time PCR in a traveller from Southeast Asia. Malar. J. 9, 219 (2010)PubMedGoogle Scholar
  101. 101.
    L. Link et al., Molecular detection of Plasmodium knowlesi in a Dutch traveler by real-time PCR. J. Clin. Microbiol. 50(7), 2523–2524 (2012)PubMedCentralPubMedCrossRefGoogle Scholar
  102. 102.
    A. Hoosen, M.T. Shaw, Plasmodium knowlesi in a traveller returning to New Zealand. Travel Med. Infect. Dis. 9(3), 144–148 (2011)PubMedCrossRefGoogle Scholar
  103. 103.
    J. Cox-Singh et al., Severe malaria – a case of fatal Plasmodium knowlesi infection with post-mortem findings: a case report. Malar. J. 9, 10 (2010)PubMedCentralPubMedCrossRefGoogle Scholar
  104. 104.
    J. Cox-Singh et al., Anti-inflammatory cytokines predominate in acute human Plasmodium knowlesi infections. PLoS One 6(6), e20541 (2011)PubMedCentralPubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Wien 2013

Authors and Affiliations

  1. 1.Environmental Health InstituteNational Environment AgencySingaporeSingapore
  2. 2.University of MalayaKuala LumpurMalaysia

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