背景:复发性巴贝斯虫病通常发生在高度免疫功能低下的患者中,并且归因于对常用于治疗的药物(例如atovaquone)的耐药性的获得,阿奇霉素,和克林霉素。他非诺喹,被批准用于间日疟原虫疟疾的疟疾预防和推定抗复发治疗,在几种急性感染的动物模型和一例复发性巴贝斯虫病的单个人类病例中显示出针对微巴贝斯虫的活性。这里,我们报告5例复发性巴贝西虫病用他非诺喹治疗,包括前一个案例,并开始确定他非诺喹在复发性巴贝西虫病中的最佳使用条件。
方法:通过显微镜检查Giemsa染色的薄血涂片或针对寄生虫18SrRNA基因的实时聚合酶链反应(PCR)来确定巴贝斯虫病的诊断。通过使用血液涂片和实时PCR确定B.microti感染的清除。
结果:他非诺喹的起始剂量为600mg。每周维持剂量为200mg或300mg;较低的剂量与B.microti的延迟清除有关。在两种情况下,除他非诺喹以外的所有抗菌药物均在感染清除前停用.在其他两种情况下,在他非诺喹与其他抗微生物药物一起给药的同时实现了清除率.在这4个案例中,他非诺喹与阿托伐醌-丙胍联合使用。其他药物包括atovaquone,阿奇霉素,和/或克林霉素。在1种情况下,他非诺喹单独给药,未能预防复发.
结论:他非诺喹可能是治疗由B.microti引起的复发性巴贝斯虫病的高度免疫功能低下患者的有用辅助药物。
BACKGROUND: Relapsing
babesiosis often occurs in highly immunocompromised patients and has been attributed to the acquisition of resistance against drugs commonly used for treatment such as atovaquone, azithromycin, and clindamycin. Tafenoquine, which is approved for malaria prophylaxis and presumptive antirelapse treatment of Plasmodium vivax malaria, has shown activity against Babesia microti in several animal models of acute infection and in a single human
case of relapsing
babesiosis. Here, we report 5 cases of relapsing
babesiosis treated with tafenoquine, including the previous
case, and begin to define the conditions for optimal use of tafenoquine in relapsing babesiosis.
METHODS: A definitive diagnosis of babesiosis was made by microscopic examination of Giemsa-stained thin blood smears or a real-time polymerase chain reaction (PCR) that targets the parasite 18S rRNA gene. Clearance of B. microti infection was ascertained by use of blood smear and real-time PCR.
RESULTS: Tafenoquine was initiated with a loading dose of 600 mg. A weekly maintenance dose consisted of 200 mg or 300 mg; the lower dose was associated with a delayed clearance of B. microti. In 2 cases, all antimicrobial agents but tafenoquine were discontinued prior to clearance of infection. In 2 other cases, clearance was achieved while tafenoquine was administered along with other antimicrobial agents. In 3 of these 4 cases, tafenoquine was used in combination with atovaquone-proguanil. Other agents included atovaquone, azithromycin, and/or clindamycin. In 1
case, tafenoquine was administered alone and failed to prevent relapse.
CONCLUSIONS: Tafenoquine can be a useful adjunct for the treatment of highly immunocompromised patients experiencing relapsing babesiosis caused by B. microti.