背景:基于青蒿素的联合疗法(ACT)治疗恶性疟原虫的有效性,对全球疟疾控制工作至关重要,特别是在撒哈拉以南非洲。对来自流行地区的输入病例的检查对全球范围的疟疾化疗具有影响。
方法:一名45岁男性高烧,干咳,腹泻和全身肌肉疼痛,在莫桑比克为期两周的旅行之后。确诊恶性疟原虫感染伴寄生虫血症,患者最初接受奎宁和强力霉素治疗,然后静脉注射青蒿琥酯.为了评估药物敏感性,进行离体半最大抑制浓度测定,并对分离的恶性疟原虫基因组进行了深度测序。
结果:临床分离物对双氢青蒿素表现出升高的离体半最大抑制浓度值,lumefantrine,甲氟喹和哌喹。基因组分析确定了恶性疟原虫Kelch13(PF3D7_1343700)基因中的I416V突变,和Kelch13相互作用候选基因的几个突变,pfkics(PF3D7_0813000,PF3D7_1138700,PF3D7_1246300),包括泛素羧基末端水解酶1,pfubp1(PF3D7_0104300)。还存在与下一代抗疟疾药物抗性相关的药物转运蛋白和基因的突变。
结论:这个案例突出了莫桑比克携带青蒿素耐药相关基因突变的恶性疟原虫菌株的出现,对ACT药物的离体敏感性降低。必须持续监测与耐药性相关的突变,并定期监测药物敏感性,以预测莫桑比克出现的潜在耐药菌株的传播,并维持有效的疟疾控制策略。
The effectiveness of artemisinin-based combination therapies (ACT) in treating Plasmodium falciparum, is vital for global malaria control efforts, particularly in sub-Saharan Africa. The examination of imported cases from endemic areas holds implications for malaria chemotherapy on a global scale.
A 45-year-old male presented with high fever, dry cough, diarrhoea and generalized muscle pain, following a two-week trip to Mozambique. P. falciparum infection with hiperparasitemia was confirmed and the patient was treated initially with quinine and doxycycline, then intravenous artesunate. To assess drug susceptibility, ex vivo half-maximal inhibitory concentration assays were conducted, and the isolated P. falciparum genome was deep sequenced.
The clinical isolate exhibited elevated ex vivo half-maximal inhibitory concentration values to dihydroartemisinin, lumefantrine, mefloquine and piperaquine. Genomic analysis identified a I416V mutation in the P. falciparum Kelch13 (PF3D7_1343700) gene, and several mutations at the Kelch13 interaction candidate genes, pfkics (PF3D7_0813000, PF3D7_1138700, PF3D7_1246300), including the ubiquitin carboxyl-terminal hydrolase 1, pfubp1 (PF3D7_0104300). Mutations at the drug transporters and genes linked to next-generation antimalarial drug
resistance were also present.
This
case highlights the emergence of P. falciparum strains carrying mutations in artemisinin
resistance-associated genes in Mozambique, couple with a reduction in ex vivo susceptibility to ACT drugs. Continuous surveillance of mutations linked to drug
resistance and regular monitoring of drug susceptibility are imperative to anticipate the spread of potential resistant strains emerging in Mozambique and to maintain effective malaria control strategies.