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Hyperparasitaemic human Plasmodium knowlesi infection with atypical morphology in peninsular Malaysia

Wenn-Chyau Lee1, Pek-Woon Chin2, Yee-Ling Lau1*, Lit-Chein Chin1, Mun-Yik Fong1, Chee-Jiek Yap2, Raymond Raj Supramaniam2 and Rohela Mahmud1

Author Affiliations

1 Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia

2 Department of Medicine, Hospital Enche’ Besar Hajjah Khalsom, Kluang, Johor, Malaysia

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Malaria Journal 2013, 12:88  doi:10.1186/1475-2875-12-88

Published: 6 March 2013


Plasmodium knowlesi is a potentially life-threatening zoonotic malaria parasite due to its relatively short erythrocytic cycle. Microscopic identification of P. knowlesi is difficult, with “compacted parasite cytoplasm” being one of the important identifying keys. This report is about a case of hyperparasitaemic human P. knowlesi infection (27% parasitaemia) with atypical amoeboid morphology. A peninsular Malaysian was admitted to the hospital with malaria. He suffered anaemia and acute kidney function impairment. Microscopic examination, assisted by nested PCR and sequencing confirmed as P. knowlesi infection. With anti-malarial treatment and several medical interventions, patient survived and recovered. One-month medical follow-up was performed after recovery and no recrudescence was noted. This case report highlights the extreme hyperparasitaemic setting, the atypical morphology of P. knowlesi in the patient’s erythrocytes, as well as the medical interventions involved in this successfully treated case.

Plasmodium knowlesi; Mainland Southeast Asian strain; Malaria; Hyperparasitaemia; Amoeboid morphology; Treatment