Assays for parasite detection in insect vectors provide important information for disease control. American Trypanosomiasis (Chagas disease) is the most devastating vector-borne illness and the fourth most common in Central America behind HIV/AIDS and acute respiratory and diarrheal infections (Peterson et al., 2019). Under-detection of parasites is a general problem which may be influenced by parasite genetic variation; however, little is known about the genetic variation of the Chagas parasite, especially in this region. In this study we compared six assays for detecting the Chagas parasite, Trypanosoma cruzi: genomic reduced representation sequencing (here referred to as genotype-by-sequencing or GBS), two with conventional PCR (i.e., agarose gel detection), two with qPCR, and microscopy. Our results show that, compared to GBS genomic analysis, microscopy and PCR under-detected T. cruzi in vectors from Central America. Of 94 samples, 44% (50/94) were positive based on genomic analysis. The lowest detection, 9% (3/32) was in a subset assayed with microscopy. Four PCR assays, two with conventional PCR and two with qPCR showed intermediate levels of detection. Both qPCR tests and one conventional PCR test targeted the 195 bp repeat of satellite DNA while the fourth test targeted the 18S gene. Statistical analyses of the genomic and PCR results indicate that the PCR assays significantly under detect infections of Central American T. cruzi genotypes.

昆虫载体中寄生虫检测的测定为疾病控制提供了重要信息。美国锥虫病（恰加斯病）是最具破坏性的病媒传播疾病，在中美洲排名第四，仅次于艾滋病毒/艾滋病和急性呼吸道和腹泻感染（Peterson 等，2019）。寄生虫检测不足是一个普遍的问题，可能受寄生虫遗传变异的影响；然而，人们对恰加斯寄生虫的遗传变异知之甚少，尤其是在该地区。在这项研究中，我们比较了六种检测南美锥虫寄生虫的方法，克氏锥虫：基因组减少代表性测序（这里称为基因型测序或 GBS），两个使用常规 PCR（即琼脂糖凝胶检测），两个使用 qPCR 和显微镜检查。我们的结果表明，与 GBS 基因组分析相比，显微镜和 PCR 检测不到T. cruzi在来自中美洲的载体中。根据基因组分析，在 94 个样本中，44% (50/94) 呈阳性。最低检测率 9% (3/32) 是在用显微镜检测的一个子集中。四种 PCR 检测，两种使用常规 PCR，两种使用 qPCR，显示出中等水平的检测。qPCR 测试和一项常规 PCR 测试均针对卫星 DNA 的 195 bp 重复，而第四项测试针对 18S 基因。基因组和 PCR 结果的统计分析表明 PCR 检测显着低于检测中美洲T. cruzi基因型的感染。