Dewanee Ranaweera A, Danansuriya Manjula N, Pahalagedera Kusumawathie, de A W Gunasekera W M Kumudunayana T, Dharmawardena Priyani, Mak Keng Wai, Wong Pei-Sze Jeslyn, Li Mei-Zhi Irene, Tan Cheong Huat, Hapuarachchi Hapuarachchige C, Herath Hema D B, Fernando Deepika
Anti Malaria Campaign, 555/5, Public Health Complex, Narahenpita, Colombo 5, Sri Lanka.
Regional Office, Anti Malaria Campaign, Dutugemunu Mawatha, Watapuluwa, Kandy, Sri Lanka.
Malar J. 2017 Mar 21;16(1):126. doi: 10.1186/s12936-017-1776-1.
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.
斯里兰卡已实现“无疟疾”状态，目前正处于预防疟疾重新传入的阶段。输入性疟疾仍然是该病再次流行的一个挑战。本文讨论了所遇到的诊断难题以及为处理一例疟原虫感染而启动的快速应对措施，该感染后来被确认为诺氏疟原虫，是斯里兰卡报告的首例病例。
一名于2016年10月从马来西亚回国的军官，在第三次前往医疗服务机构就诊时，经斯里兰卡抗疟疾运动（AMC）进行显微镜检查和快速诊断检测（RDT），发现疟原虫呈阳性。显微镜检查结果怀疑为诺氏疟原虫感染，因为涂片显示的寄生虫阶段类似于三日疟原虫和恶性疟原虫。AMC的巢式PCR确认了疟原虫属，但未确认具体种类。在未确认种类的情况下，该患者被当作恶性疟原虫病例进行治疗。后来，新加坡国家环境局环境卫生研究所进行的半巢式PCR检测确认存在诺氏疟原虫。还通过对环子孢子基因进行测序对该寄生虫菌株进行了鉴定。开展了包括寄生虫学和昆虫学监测在内的广泛病例调查。
对于从南亚地区寄生虫流行国家回国且血涂片结果不确定的患者，应怀疑感染诺氏疟原虫。
