Objective

To evaluate the effectiveness and tolerability of secnidazole combined with high-dose mebendazole for treatment of 5-nitroimidazole-resistant giardiasis.

Method

Adults with microscopically verified Giardia intestinalis monoinfection attending a secondary level hospital in Matanzas City, Cuba were prospectively included in a cohort. A recently introduced treatment ladder consisting of metronidazole as first-line treatment, followed by secnidazole, tinidazole, secnidazole plus mebendazole and quinacrine as second-to fifth-line treatments, respectively, was used. Adverse events and treatment success were determined by questioning and microscopy on concentrated stool samples, respectively on days 3, 5 and 7 after the end of treatment. If G. intestinalis was detected on day 3, 5 or 7, then the infection was classified as refractory and no further microscopy was performed.

Results

A total of 456 individuals were included. Metronidazole, 500 mg three times daily for 5 days, cured 248/456 (54%) patients. A single 2-g secnidazole dose as second-line treatment cured 50/208 (24%) patients. A single 2-g tinidazole dose as third-line treatment cured 43/158 (27%) patients. Three rounds of 5-nitroimidazole therapy therefore cured 341/456 (75%) patients. Secnidazole plus mebendazole (200 mg every 8 hours for 3 days) cured 100/115 (87%) of nitroimidazole refractory infections. Quinacrine cured the remaining 15 patients. All treatments were well tolerated.

Conclusions

5-Nitroimidazole refractory giardiasis was common, indicating that an alternative first-line treatment may be needed. Retreatment of metronidazole refractory giardiasis with an alternative 5-nitroimidazole was suboptimal, indicating cross-resistance. Mebendazole plus secnidazole were well tolerated and effective for the treatment of 5-nitroimidazole refractory G. intestinalis infection in this setting.

中文翻译：

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5-硝基咪唑难治性贾第鞭毛虫病在古巴马坦萨斯很常见，并通过塞尼达唑加大剂量甲苯达唑或奎纳克林有效治疗：一项前瞻性观察性队列研究。

客观的

评价塞尼达唑联合大剂量甲苯达唑治疗5-硝基咪唑耐药贾第鞭毛虫病的有效性和耐受性。

方法

在古巴马坦萨斯市的二级医院接受显微镜检查的贾第鞭毛虫单感染的成年人可能包括在内。最近采用的治疗阶梯包括甲硝唑作为一线治疗，然后分别使用塞尼达唑，替硝唑，塞尼达唑加甲苯达唑和喹那林作为二线至五线治疗。分别在治疗结束后第3、5和7天通过浓缩粪便样品的质询和显微镜检查确定不良事件和治疗成功。如果G.肠在第3天，第5或7中检测到，则感染被列为耐火并且不进行进一步的显微术。

结果

总共包括456个人。甲硝唑500毫克，每天3次，连续5天，治愈248/456（54％）患者。单剂量2克塞克硝唑作为二线治疗可治愈50/208（24％）患者。一次2g替硝唑剂量作为三线治疗可治愈43/158（27％）患者。因此，三轮5-硝基咪唑治疗治愈了341/456（75％）患者。塞尼达唑加甲苯咪唑（每8小时200毫克，共3天）治愈了100/115（87％）的硝基咪唑难治性感染。奎纳克林治愈了其余15例患者。所有治疗均耐受良好。

结论

5-硝基咪唑难治性贾第鞭毛虫病很常见，表明可能需要另一种一线治疗。用替代的5-硝基咪唑对甲硝唑难治性贾第鞭毛虫病的再治疗效果欠佳，表明存在交叉耐药性。甲苯咪唑加塞克硝唑的耐受性良好，有效的治疗-5-硝基咪唑耐火材料G.肠在此设置感染。