目的 探讨广州市1例输入性恶性疟病例的流行病学特征,以明确其传播风险.方法 选择2016年4月9日,于广州血液中心进行全血捐献后第14天后被确诊为恶性疟的1例无偿献血者,以及接受由本例献血者所捐献全血制备的红细胞输注的1例受血者为研究对象.收集2例受试者的流行病学资料,开展流行病学调查.2016年4月27日,采集本例献血者全血样本5mL;2016年4月27日和2016年5月12日,分别采集本例受血者全血样本各5 mL,共计3份全血样本.采用血涂片镜检对3份全血样本进行疟原虫病原学检查,采用巢氏PCR法对3份全血样本进行疟原虫核酸检测.根据巢氏PCR扩增产物的DNA测序结果.对疟原虫基因进行基因分型和构建分子系统进化树.结果 ①本例献血者有境外疟疾流行区务工史,回国后出现畏寒、发热等类似疟疾的临床表现.根据其全血样本血涂片镜检结果,诊断为恶性疟疾.②本例受血者并未出现疟疾典型临床症状,其2份全血样本血涂片镜检结果,均未发现疟原虫.③本研究献血者与受血者全血样本巢式PCR检测结果均为恶性疟原虫阳性;献血者和受血者的3份全血样本疟原虫18S rRNA基因序列的序列同源性比对结果显示,3条基因序列相似度为100%,并且均为恶性疟原虫基因序列,与临床血涂片镜检结果一致.④分子系统进化树构建结果显示,本研究献血者和受血者3份全血样本的疟原虫18S rRNA基因分型均为恶性疟原虫基因型,并且基因序列处于同一根部,这进一步证实本例受血者的疟疾感染来自本例献血者.结论 本例献血者为非洲输入性恶性疟,受血者因输注由该例献血者所捐献全血制备的红细胞,亦发生恶性疟原虫感染,但是并未出现疟疾典型临床症状.
Objective To investigate the epidemiological characteristics of one imported falciparum malaria case in Guangzhou City,in order to clarify its risk of transmission.Methods One volunteer blood donor who was diagnosed as falciparum malaria 14 d after whole blood donationin Guangzhou Blood Center on 9 April 2016,and one blood recipient who received red blood cell transfusion from this blood donor were enrolled in this study.Epidemiological data of those two subjects were collected and epidemiological investigations were conducted on them.On 27 April 2016,one whole blood sample with 5 mL was collected from blood donor.And on 27 April 2016 and 12 May 2016,two whole blood samples with 5 mL each time were collected from the blood recipient respectively.Three whole blood samples were detected for Plasmodium etiological test by blood smear microscopy.And nested PCR method was used to test Plasmodium nucleic acid of three whole blood samples.According to DNA sequencing results of the nested PCR amplification products,the gene of Plasmodium was genotyped and phylogenetic tree was constructed.Results ① The blood donor in this study had a history of migrant workers in the endemic areas of malaria.After returning to China,he had similar clinical manifestations of malaria,such as chills and fever.According to the blood smear microscopy results of his whole blood sample,he was diagnosed as falciparum malaria.② The blood recipient in this study did not show typical symptoms of malaria.And blood smear microscopy results of his two whole blood samples showed that no Plasmodium was found.③ The nested PCR results of whole blood samples from the blood donor and recipient in this study were all Plasmodium falciparum positive.The sequence of homology comparison results of Plasmodium 18S rRNA gene in the three blood samples from the blood donor and recipient in this study showed that the similarity of three gene sequences was 100%,which conformed to the results of clinical blood smear microscopy.④ The constructed results of phylogenetic tree showed that Plasmodium 18S rRNA genotypings of three whole blood samples all were Plasmodium falciparum genotypes and the gene sequences were on the same root,further confirmed that the blood recipient infected Plasmodium falciparum via blood transfusion from the blood donor.Conclusions In this study,the blood donor was infected with Plasmodium falciparum imported from Africa.The recipient was also infected with Plasmodium falciparum via blood transfusion from this blood donor,but no typical malaria symptoms were found.