Objective: To identify 10 imported cases of Plasmodium ovale wallikeri infection in Sichuan Province from January to April in 2018, and to analyze the P. ovale wallikeri infection status of 1 079 malaria cases reported in this area from 2013 to 2017.
Methods: The 10 cases collected in 2018 were examined by microscopy, RDT, nested PCR and sequencing. Meanwhile, the retrospective detections of P. ovale wallikeri of the 1 079 blood samples from past 5 years were conducted by nested PCR using wallikeri-specific primers.
Results: For the 10 cases, the microscopic examinations were all positive for P. ovale, of which 2 were mixed infection with P. falciparum, and the results of RDT were all positive for Plasmodium. Except for 2 cases of P. falciparum infection, the routine nested PCR showed negative results for rest of the samples. The nested PCR for the specific detection of P. ovale wallikeri showed the 10 cases were all positive, and the following sequencing confirmed that the 10 cases were all infected with P. ovale wallikeri. The retrospective tests discovered 2 cases both reported in 2017 and recorded as simple P. falciparum infection tuned out to be mixed infection with P. falciparum and P. ovale wallikeri.
Conclusions: This is the first time that imported P. ovale wallikeri infection is founded in Sichuan Province.
[摘要] 目的 鉴定四川省疑似输入性卵形疟原虫感染病例wallikeri 亚种感染情况, 并对2014-2017年全省1 079份复 核血样卵形疟原虫wallikeri 亚种感染情况进行分析。方法 对2018年1-4月四川省10例疑似输入性卵形疟原虫感染病 例进行血涂片镜检、快速诊断试纸条 (RDT) 检测和巢式PCR检测并进行测序分析, 同时回顾性检测2014-2017年全省 1 079份复核血样卵形疟原虫wallikeri 亚种感染情况。结果 2018年1-4月四川省10例疑似输入性卵形疟原虫感染病 例镜检结果均为卵形疟原虫阳性, 其中2例存在恶性疟原虫混合感染; RDT检测结果均为疟原虫阳性; 常规巢式PCR检 测除2例结果为恶性疟原虫阳性外, 其余均为阴性; 采用卵形疟原虫wallikeri 亚种特异性引物进行PCR检测, 10例均为阳 性, 序列分析结果显示为卵形疟原虫wallikeri 亚种。对2014-2017年全省1 079份复核血样进行回顾性检测, 发现2例卵 形疟原虫wallikeri 亚种与恶性疟原虫混合感染病例, 均为2017年报告, 此前检测结果为单纯恶性疟原虫感染。结论 四 川省首次鉴定发现输入性卵形疟原虫wallikeri 亚种感染病例。.
Keywords: Imported malaria; Laboratory diagnosis; Nested PCR; Plasmodium ovale wallikeri; Sichuan Province.