Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Adv Parasitol. 2011;75:19-47. doi: 10.1016/B978-0-12-385863-4.00002-2.
The acute phase of Chagas disease lasts 4-8 weeks and is characterized by microscopically detectable parasitaemia. Symptoms are usually mild with severe acute disease occurring in less than 1% of patients. Orally transmitted Trypanosoma cruzi outbreaks can have more severe acute morbidity and higher mortality than vector-borne infection. Congenital T. cruzi infection occurs in 1-10% of infants of infected mothers. Most congenital infections are asymptomatic or cause non-specific signs, requiring laboratory screening for detection. A small proportion of congenital infections cause severe morbidity with hepatosplenomegaly, anaemia, meningoencephalitis and/or respiratory insufficiency, with an associated high mortality. Infected infants are presumed to carry the same 20-30% lifetime risk of cardiac or gastrointestinal disease as other infected individuals. Most control programs in Latin America employ prenatal serological screening followed by microscopic examination of cord blood from infants of seropositive mothers. Recent data confirm that polymerase chain reaction (PCR) is more sensitive and detects congenital infections earlier than conventional techniques. For infants not diagnosed at birth, conventional serology is recommended at at 6 to 9 months of age. In programs that have been evaluated, less than 20% of at risk infants completed all steps of the screening algorithm. A sensitive, specific and practical screening test for newborns is needed to enable Chagas disease to be added to newborn screening programs.
恰加斯病的急性期持续 4-8 周，其特征是显微镜下可检测到寄生虫血症。症状通常较轻，不到 1%的患者发生严重急性疾病。经口传播的克氏锥虫暴发可能比媒介传播感染具有更严重的急性发病率和更高的死亡率。先天性克氏锥虫感染发生在 1-10%的受感染母亲的婴儿中。大多数先天性感染无症状或引起非特异性体征，需要实验室筛查来发现。一小部分先天性感染导致严重发病率，伴有肝脾肿大、贫血、脑膜脑炎和/或呼吸功能不全，死亡率较高。感染的婴儿被认为与其他感染者一样，终生患心脏病或胃肠道疾病的风险为 20-30%。拉丁美洲的大多数控制项目采用产前血清学筛查，然后对血清阳性母亲的婴儿脐带血进行显微镜检查。最近的数据证实，聚合酶链反应 (PCR) 比传统技术更敏感，可更早检测到先天性感染。对于出生时未确诊的婴儿，建议在 6 至 9 个月大时进行常规血清学检查。在已评估的项目中，不到 20%的高危婴儿完成了筛查算法的所有步骤。需要一种敏感、特异和实用的新生儿筛查试验，以便将恰加斯病纳入新生儿筛查计划。
