Fundación Ciencias y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente (CEADES), Cochabamba, Bolivia.
Laboratorio de Biología Molecular de La Enfermedad de Chagas, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI), Buenos Aires, Argentina.
Lancet Microbe. 2024 Sep;5(9):100887. doi: 10.1016/S2666-5247(24)00110-1. Epub 2024 Jul 3.
Vertical transmission of Trypanosoma cruzi represents approximately 20% of new Chagas disease cases. Early detection and treatment for women of childbearing age and newborns is a public health priority, but the lack of a simple and reliable diagnostic test remains a major barrier. We aimed to evaluate the performance of a point-of-care loop-mediated isothermal amplification (LAMP) assay for the detection of T cruzi.
In this proof-of-concept study, we coupled a low-cost 3D printer repurposed for sample preparation and amplification (PrintrLab) to the Eiken T cruzi-LAMP prototype to detect vertically transmitted T cruzi, which we compared with standardised PCR and with the gold-standard algorithm (microscopy at birth and 2 months and serological study several months later). We screened pregnant women from two hospitals in the Bolivian Gran Chaco province, and those who were seropositive for T cruzi were offered the opportunity for their newborns to be enrolled in the study. Newborns were tested by microscopy, LAMP, and PCR at birth and 2 months, and by serology at 8 months.
Between April 23 and Nov 17, 2018, 986 mothers were screened, among whom 276 were seropositive for T cruzi (28·0% prevalence, 95% CI 25·6-31·2). In total, 224 infants born to 221 seropositive mothers completed 8 months of follow-up. Congenital transmission was detected in nine of the 224 newborns (4·0% prevalence, 1·9-7·5) by direct microscopy observation, and 14 more cases were diagnosed serologically (6·3%, 3·6-10·3), accounting for an overall vertical transmission rate of 10·3% (6·6-15·0; 23 of 224). All microscopy-positive newborns were positive by PrintrLab-LAMP and by PCR, while these techniques respectively detected four and five extra positive cases among the remaining 215 microscopy-negative newborns.
The PrintrLab-LAMP yielded a higher sensitivity than microscopy-based analysis. Considering the simpler use and expected lower cost of LAMP compared with PCR, our findings encourage its evaluation in a larger study over a wider geographical area.
Inter-American Development Bank.
克氏锥虫的垂直传播约占新出现的恰加斯病病例的 20%。对育龄妇女和新生儿进行早期检测和治疗是公共卫生的当务之急，但缺乏简单可靠的诊断检测方法仍是一个主要障碍。我们旨在评估一种即时检测环介导等温扩增（LAMP）检测克氏锥虫的性能。
在这项概念验证研究中，我们将低成本的 3D 打印机重新用于样品制备和扩增（PrintrLab），并将其与 Eiken T 锥虫-LAMP 原型结合，以检测垂直传播的 T 锥虫，我们将其与标准化 PCR 和金标准算法（出生时和 2 个月时进行显微镜检查，几个月后进行血清学研究）进行比较。我们对玻利维亚大查科省两家医院的孕妇进行了筛查，对 T 锥虫血清阳性的孕妇提供了让其新生儿参加研究的机会。新生儿在出生时和 2 个月时通过显微镜检查、LAMP 和 PCR 进行检测，并在 8 个月时进行血清学检测。
2018 年 4 月 23 日至 11 月 17 日，共筛查了 986 名母亲，其中 276 名母亲 T 锥虫血清阳性（28.0%的患病率，95%CI 25.6-31.2）。共有 221 名血清阳性母亲所生的 224 名婴儿完成了 8 个月的随访。通过直接显微镜观察，在 224 名新生儿中发现 9 例先天性传播（4.0%的患病率，1.9-7.5），另有 14 例通过血清学诊断（6.3%，3.6-10.3），总垂直传播率为 10.3%（6.6-15.0；23/224）。所有显微镜阳性的新生儿的 PrintrLab-LAMP 和 PCR 检测结果均为阳性，而这两种技术分别在其余 215 例显微镜阴性的新生儿中检测到 4 例和 5 例额外的阳性病例。
PrintrLab-LAMP 的灵敏度高于基于显微镜的分析。考虑到与 PCR 相比，LAMP 的使用更简单，预期成本更低，我们的发现鼓励在更广泛的地理区域进行更大规模的研究来评估 LAMP。
泛美开发银行。
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