Division of primary care medicine, Department of community medicine, primary care and emergency medicine, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.
BMC Infect Dis. 2013 Feb 13;13:85. doi: 10.1186/1471-2334-13-85.
With declining vectorial transmission, Chagas disease predominantly affects adults nowadays. The efficacy of nifurtimox in the chronic phase in adult patients is poorly known, particularly in regions where there is no risk of reinfection. Recommendations for treatment outcome assessment rely on serological follow-up. We evaluated the serological and parasitological response to nifurtimox in a cohort of adult patients three years post-treatment in Switzerland.
Patients treated with nifurtimox in 2008 during a cross-sectional study in Geneva, Switzerland, were contacted for follow-up in 2011. Two ELISAs and a rapid immunochromatographic test were used to test 2008 and 2011 serum samples simultaneously. In addition, conventional and real-time PCR were performed on 2011 samples.
Thirty-seven (84.1%) of 44 eligible patients, predominantly female, middle-aged, Bolivians at the indeterminate stage, were enrolled. All 2011 ELISA and immunochromatographic tests were positive. Twenty-eight (75.7%) patients presented a lower optical density (OD) in 2011 compared to 2008. This OD difference was significant in both commercial (P < 0.001) and in-house (P = 0.002) ELISAs. Agreement between the two ELISAs was low (Kappa = 0.469). All patients had negative conventional PCR results but one (2.7%) was positive with real-time PCR.
Our results highlight the inadequacy of serology for assessing response in adults, three years after treatment. In our cohort, 97.3% had results that could either indicate treatment failure or persistant humoral response despite treatment. The lack of accurate early post-treatment tests of cure prevents appropriate patients information and councelling. New follow-up tests are needed to assess treatments efficacy given the large adult population in need of antiparasitic therapy.
随着病媒传播的减少，如今恰加斯病主要影响成年人。在慢性期，硝呋替莫治疗成人患者的疗效知之甚少，特别是在没有再次感染风险的地区。治疗效果评估的建议依赖于血清学随访。我们评估了瑞士一个成年患者队列在治疗后三年的血清学和寄生虫学对硝呋替莫的反应。
2008 年，在瑞士日内瓦进行的一项横断面研究中，用硝呋替莫治疗的患者在 2011 年接受了随访。同时使用两种 ELISA 和一种快速免疫层析试验检测 2008 年和 2011 年的血清样本。此外，对 2011 年的样本进行了常规和实时 PCR。
44 名符合条件的患者中有 37 名（84.1%），主要为女性，年龄中位数为 47 岁，均为玻利维亚人，处于不确定期。所有 2011 年的 ELISA 和免疫层析试验均为阳性。与 2008 年相比，28 名（75.7%）患者在 2011 年的光密度（OD）较低。两种商业 ELISA（P < 0.001）和内部 ELISA（P = 0.002）的 OD 差异均有统计学意义。两种 ELISA 之间的一致性较低（Kappa = 0.469）。所有患者的常规 PCR 结果均为阴性，但有 1 名（2.7%）患者的实时 PCR 结果为阳性。
我们的结果强调了在治疗后三年，血清学对评估成年人的反应是不充分的。在我们的队列中，97.3%的患者的结果可能表明治疗失败或治疗后持续的体液反应，尽管已经进行了治疗。缺乏准确的早期治疗后治愈测试，阻碍了对合适患者的信息和咨询。需要新的随访测试来评估治疗效果，因为有大量的成年人口需要抗寄生虫治疗。
