Congenital Transmission of Lineages I and II of Trypanasoma cruzi

描述(由调查人员提供)：克鲁氏锥虫分为两个主要谱系：克鲁氏锥虫I(Tci)和克鲁氏锥虫II(TcII)。TCI在墨西哥和中美洲占主导地位，而TcII在包括阿根廷在内的南美洲大部分地区占主导地位。在阿根廷最近的研究中，先天性传播的风险估计在2.6%到7.9%之间。相比之下，我们对TCI的先天性传播知之甚少。有研究表明，克氏毛滴虫的先天传播与菌株有关，迫切需要了解TCI是否与TcII传播不同。我们的主要假设是TCI和TcII的先天性传播率不同。我们的第二个假设是，在TCI占主导地位的地区和TcII占主导地位的地区，感染弓形虫的母亲的特征(例如，年龄、产次、以前怀孕时的传播)及其对媒介的暴露是不同的。为了验证这些假设，我们建议进行一项前瞻性研究，在墨西哥招募10,000名妇女，在洪都拉斯招募5,000名妇女，在阿根廷招募5,000名妇女。我们将检测脐带血中传播的母体旋毛虫抗体，如果结果呈阳性，我们将通过对脐带血和4-8周进行寄生虫学检查来识别先天感染的婴儿，并在10个月时进行血清学随访。我们还将对母血进行标准PCR、实时荧光定量PCR和克氏锥虫基因分型，对先天感染的新生儿脐带血进行标准PCR和克氏支原体基因分型，并对兄弟姐妹进行血清学检查。我们将估计在家庭中接触病媒的情况。此外，我们还将测量母亲血清阳性的感染和未感染婴儿的产前结局，以及他们兄弟姐妹的出生体重。这项研究的具体目的是：1)确定TCI和TcII的先天性传播率；2)比较TCI和TcII感染地区克氏锥虫母亲的特征和接触媒介的情况；3)描述TCI和TcII血清阳性母亲所生感染和未感染婴儿的出生结局。

DESCRIPTION (provided by investigator): T. cruzi has been divided into two main lineages: T. cruzi I (TcI) and T. cruzi II (TcII). TcI is predominant in Mexico and Central America, while TcII is predominant in most of South America, including Argentina. In recent studies from Argentina, the risk of congenital transmission has been estimated to vary between 2.6 percent and 7.9 percent. By contrast, we know very little about the congenital transmission of TcI. It has been suggested that congenital transmission of T. cruzi is strain related, and there is an urgent need to know if TcI transmits differently than TcII. Our primary hypothesis is that congenital transmission rates are different for TcI versus TcII. Our secondary hypothesis is that the characteristics of T. cruzi infected mothers (e.g., age, parity, transmission in previous pregnancies) and their exposure to vectors are different in regions where TcI is predominant versus regions where TcII is predominant. To test these hypotheses, we propose to conduct a prospective study to enroll at delivery 10,000 women in Mexico, 5,000 women in Honduras, and 5,000 women in Argentina. We will measure transmitted maternal T. cruzi antibodies in cord blood, and, if the results are positive, we will identify infants who are congenitally infected by performing parasitological examinations on cord blood and at 4-8 weeks, and serological follow-up at 10 months. We will also perform standard PCR, real-time quantitative PCR, and T. cruzi genotyping on maternal blood, standard PCR and T. cruzi genotyping on the cord blood of congenitally infected newborns, and serological examinations on siblings. We will estimate the exposure to vectors in the household. In addition, we will measure prenatal outcomes among infected and uninfected infants with seropositive mothers, and the birth weight of their siblings. The specific aims of this study are: 1) To determine the rate of congenital transmission of TcI compared to TcII; 2) To compare the T. cruzi infected mothers' characteristics and exposure to vectors in regions where TcI is predominant and regions where TcII is predominant; and 3) To describe the birth outcomes of infected and uninfected infants born to TcI and TcII seropositive women.