Diagnostic challenges and case management of the first imported case of Plasmodium knowlesi in Sri Lanka.
Sri Lanka has achieved 'malaria-free' status and is now in the phase of prevention of re-introduction of malaria. Imported malaria remains a challenge to resurgence of the disease. The diagnostic challenges encountered and the rapid response initiated to manage a Plasmodium infection, which was later confirmed as Plasmodium knowlesi, the first reported case from Sri Lanka, is discussed.



An army officer who returned from Malaysia in October 2016 was found to be positive for Plasmodium both by microscopy and rapid diagnostic test (RDT) by the Anti Malaria Campaign Sri Lanka (AMC) during his third visit to a health care provider. Microscopy findings were suspicious of P. knowlesi infection as the smears showed parasite stages similar to both Plasmodium malariae and Plasmodium falciparum. Nested PCR at AMC confirmed Plasmodium genus, but not the species. In the absence of species confirmation, the patient was treated as a case of P. falciparum. The presence of P. knowlesi was later confirmed by a semi-nested PCR assay performed at the Environmental Health Institute, National Environmental Agency in Singapore. The parasite strain was also characterized by sequencing the circumsporozoite gene. Extensive case investigation including parasitological and entomological surveillance was carried out.



Plasmodium knowlesi should be suspected in patients returning from countries in the South Asian region where the parasite is prevalent and when blood smear results are inconclusive.
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka. dranaweera90@gmail.com.
A
A
Dewanee Ranaweera
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka.
Manjula N
MN
Danansuriya
Regional Office, Anti Malaria Campaign, Dutugemunu Mawatha, Watapuluwa, Kandy, Sri Lanka.
Kusumawathie
K
Pahalagedera
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka.
W M Kumudunayana T
WM
de A W Gunasekera
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka.
Priyani
P
Dharmawardena
Environmental Health Institute, National Environmental Agency, 11 Biopolis Way, #06-05/08, Singapore, 138667, Singapore.
Keng Wai
KW
Mak
Environmental Health Institute, National Environmental Agency, 11 Biopolis Way, #06-05/08, Singapore, 138667, Singapore.
Pei-Sze Jeslyn
PJ
Wong
Environmental Health Institute, National Environmental Agency, 11 Biopolis Way, #06-05/08, Singapore, 138667, Singapore.
Mei-Zhi Irene
MI
Li
Environmental Health Institute, National Environmental Agency, 11 Biopolis Way, #06-05/08, Singapore, 138667, Singapore.
Cheong Huat
CH
Tan
Environmental Health Institute, National Environmental Agency, 11 Biopolis Way, #06-05/08, Singapore, 138667, Singapore.
Hapuarachchige C
HC
Hapuarachchi
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka.
Hema D B
HD
Herath
Department of Parasitology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
Deepika
D
Fernando
D000328:Adult; D003955:Diagnostic Tests, Routine; D019468:Disease Management; D006801:Humans; D008288:Malaria / Q000175:diagnosis* / Q000188:drug therapy* / Q000469:parasitology; D008296:Malaysia; D008297:Male; D008853:Microscopy; D008889:Military Personnel; D016790:Plasmodium knowlesi / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D013188:Sri Lanka; D014195:Travel
D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan
Imported; Malaria; Plasmodium knowlesi; Sri Lanka; Surveillance