United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Building 1001, BARC-East, Beltsville, MD 20705-2350, USA.
Parasitology. 2012 Sep;139(11):1375-424. doi: 10.1017/S0031182012000765. Epub 2012 Jul 10.
Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Brazil. The burden of clinical toxoplasmosis in humans is considered to be very high. The high prevalence and encouragement of the Brazilian Government provides a unique opportunity for international groups to study the epidemiology and control of toxoplasmosis in Brazil. Many early papers on toxoplasmosis in Brazil were published in Portuguese and often not available to scientists in English-speaking countries. In the present paper we review prevalence, clinical spectrum, molecular epidemiology, and control of T. gondii in humans and animals in Brazil. This knowledge should be useful to biologists, public health workers, veterinarians, and physicians. Brazil has a very high rate of T. gondii infection in humans. Up to 50% of elementary school children and 50-80% of women of child-bearing age have antibodies to T. gondii. The risks for uninfected women to acquire toxoplasmosis during pregnancy and fetal transmission are high because the environment is highly contaminated with oocysts. The burden of toxoplasmosis in congenitally infected children is also very high. From limited data on screening of infants for T. gondii IgM at birth, 5-23 children are born infected per 10 000 live births in Brazil. Based on an estimate of 1 infected child per 1000 births, 2649 children with congenital toxoplasmosis are likely to be born annually in Brazil. Most of these infected children are likely to develop symptoms or signs of clinical toxoplasmosis. Among the congenitally infected children whose clinical data are described in this review, several died soon after birth, 35% had neurological disease including hydrocephalus, microcephaly and mental retardation, 80% had ocular lesions, and in one report 40% of children had hearing loss. The severity of clinical toxoplasmosis in Brazilian children may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil.
在巴西，人体和动物中普遍存在原虫寄生虫弓形虫感染。人体临床弓形虫病的负担被认为非常高。巴西政府的高流行率和鼓励为国际团体提供了一个独特的机会，可以研究巴西的弓形虫病流行病学和控制。许多关于巴西弓形虫病的早期论文都是用葡萄牙语发表的，英语国家的科学家往往无法获得。在本文中，我们回顾了巴西人体和动物中弓形虫的流行率、临床谱、分子流行病学和控制。这些知识对生物学家、公共卫生工作者、兽医和医生应该是有用的。巴西人体弓形虫感染率非常高。多达 50%的小学生和 50-80%的育龄妇女有抗弓形虫抗体。由于环境高度污染卵囊，未感染的妇女在怀孕期间感染弓形虫病和胎儿传播的风险很高。先天性感染儿童的弓形虫病负担也非常高。根据对出生时婴儿进行 T. gondii IgM 筛查的有限数据，巴西每 10 000 例活产儿中就有 5-23 例感染。根据每 1000 例出生感染 1 例的估计，巴西每年可能有 2649 例先天性弓形虫病患儿出生。这些感染的儿童中大多数可能会出现临床弓形虫病的症状或体征。在本综述中描述了临床数据的先天性感染儿童中，有几个在出生后不久就死亡，35%有神经疾病，包括脑积水、小头畸形和智力迟钝，80%有眼部病变，在一份报告中，40%的儿童有听力损失。巴西儿童临床弓形虫病的严重程度可能与巴西动物和人体中流行的弓形虫分离株的遗传特征有关。
