Congenital Transmission of Lineages I and II of Trypanasoma cruzi

描述（由研究者提供）：T. cruzi分为两个主要谱系：T. cruzi I（TcI）和T. cruzi II（TcII）。TcI主要分布在墨西哥和中美洲，而TcII主要分布在南美洲的大部分地区，包括阿根廷。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。有人认为T. cruzi与菌株有关，迫切需要知道TcI是否与TcII不同地传递。我们的主要假设是TcI与TcII的先天性传播率不同。我们的次要假设是T.克氏病感染的母亲（例如，年龄、产次、前一次怀孕的传播）以及对病媒的接触情况，在TcI占主导地位的地区和TcII占主导地位的地区是不同的。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、洪都拉斯和阿根廷分别招募10,000名、5,000名和5,000名分娩妇女。我们将测量通过母体传播的T。如果结果呈阳性，我们将通过对脐带血进行寄生虫学检查和在4-8周时进行检查，并在10个月时进行血清学随访，确定婴儿是否先天感染。我们还将进行标准PCR、实时定量PCR和T。母血cruzi基因分型，标准PCR和T.对先天性感染新生儿的脐带血进行cruzi基因分型，并对兄弟姐妹进行血清学检查。我们将估计家庭中的病媒暴露量。此外，我们将测量血清阳性母亲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。本研究的具体目的是：1）确定TcI与TcII相比的先天性传播率;描述TcI和TcII血清阳性妇女所生的受感染和未受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.