Abstract：
BACKGROUND: There are close similarities between the life-cycles of Echinococcus granulosus sensu lato (E. granulosus s.l.) that causes cystic echinococcosis (CE) in humans and Taenia multiceps/Coenurus cerebralis that causes cerebral coenurosis in small ruminants. Recent evidence highlights that livestock in Maasai communities of northern Tanzania are suffering from increases in the prevalence of cerebral coenurosis, leading to concerns about a possible concurrent increased risk of human CE. The aim of this study was to estimate the prevalence of human abdominal CE and the prevalence and species/genotypes of E. granulosus s.l. in livestock in Maasai communities.
METHODS: Human CE was diagnosed by abdominal ultrasound on volunteers aged ≥ 7 years in five villages in the Longido and Ngorongoro Districts in northern Tanzania. Infection in ruminants was evaluated through inspection in local abattoirs, followed by molecular identification of one cyst per animal, with a priority for hepatic cysts, using PCR targeting of the cytochrome c oxidase I gene (COX1), followed by restriction fragment length polymorphism and multiplex PCR, and sequencing of non-E. granulosus s.l. samples.
RESULTS: Ultrasound was performed on 823 volunteers (n = 352 in two villages in Longido District, and n = 471 in three villages of Ngorongoro). Hepatic CE cases were diagnosed only in Ngorongoro (n = 6; 1.3%), of which three had active cysts. Village-level prevalence of CE ranged between 0 and 2.4%. Of the 697 ruminants inspected, 34.4% had parasitic cysts. Molecular identification was achieved for 140 of the 219 (63.9%) cysts sampled. E. granulosus s.l. and T. hydatigena/Cysticercus tenuicollis were identified in 51.4% and 48.6%, respectively, of livestock cysts. E. granulosus s.l. was identified in livestock from both Longido (35.3% of 116 genotyped cysts) and Ngorongoro (91.2% of 34 genotyped cysts). Of the total of 72 E. granuslosus s.l. cysts identified in livestock, 87.5% were E. granulosus sensu stricto (G1-G3 genotypes), 9.7% were E. ortleppi (G5) and one cyst was E. canadensis (G6-10). The three active human cysts, which were removed surgically, were G1-G3 genotypes.
CONCLUSIONS: Multiple species/genotypes of E. granulosus s.l. are circulating in Maasai communities of northern Tanzania. Human CE was detected in villages of Ngorongoro District and a high prevalence of echinococcal cysts was observed in livestock in both districts. More precise estimation of the prevalence in this area and a better understanding of the specific risk factors for CE among Maasai communities in northern Tanzania is needed. Interventions targeting transmission routes common to both E. granulosus s.l. and T. multiceps would have dual benefits for preventing both human and livestock disease.
METHODS: Human CE was diagnosed by abdominal ultrasound on volunteers aged ≥ 7 years in five villages in the Longido and Ngorongoro Districts in northern Tanzania. Infection in ruminants was evaluated through inspection in local abattoirs, followed by molecular identification of one cyst per animal, with a priority for hepatic cysts, using PCR targeting of the cytochrome c oxidase I gene (COX1), followed by restriction fragment length polymorphism and multiplex PCR, and sequencing of non-E. granulosus s.l. samples.
RESULTS: Ultrasound was performed on 823 volunteers (n = 352 in two villages in Longido District, and n = 471 in three villages of Ngorongoro). Hepatic CE cases were diagnosed only in Ngorongoro (n = 6; 1.3%), of which three had active cysts. Village-level prevalence of CE ranged between 0 and 2.4%. Of the 697 ruminants inspected, 34.4% had parasitic cysts. Molecular identification was achieved for 140 of the 219 (63.9%) cysts sampled. E. granulosus s.l. and T. hydatigena/Cysticercus tenuicollis were identified in 51.4% and 48.6%, respectively, of livestock cysts. E. granulosus s.l. was identified in livestock from both Longido (35.3% of 116 genotyped cysts) and Ngorongoro (91.2% of 34 genotyped cysts). Of the total of 72 E. granuslosus s.l. cysts identified in livestock, 87.5% were E. granulosus sensu stricto (G1-G3 genotypes), 9.7% were E. ortleppi (G5) and one cyst was E. canadensis (G6-10). The three active human cysts, which were removed surgically, were G1-G3 genotypes.
CONCLUSIONS: Multiple species/genotypes of E. granulosus s.l. are circulating in Maasai communities of northern Tanzania. Human CE was detected in villages of Ngorongoro District and a high prevalence of echinococcal cysts was observed in livestock in both districts. More precise estimation of the prevalence in this area and a better understanding of the specific risk factors for CE among Maasai communities in northern Tanzania is needed. Interventions targeting transmission routes common to both E. granulosus s.l. and T. multiceps would have dual benefits for preventing both human and livestock disease.
摘要：
背景：细粒棘球蚴的生命周期之间存在密切的相似之处（E.granulosuss.l.）在人类中引起囊性包虫病（CE）和在小反刍动物中引起脑coenurosusis的多头肌/脑尾带虫。最近的证据表明，坦桑尼亚北部马赛社区的牲畜正在遭受大脑多毛病患病率的增加，导致人们对人类CE风险可能同时增加的担忧。这项研究的目的是估计人类腹部CE的患病率以及E.granulosuss.l.在马赛社区的牲畜中的患病率和物种/基因型。
方法：在坦桑尼亚北部Longido和Ngorongoro地区的五个村庄，年龄≥7岁的志愿者通过腹部超声诊断出人类CE。通过在当地屠宰场的检查评估反刍动物的感染，然后分子鉴定每只动物一个囊肿，优先治疗肝囊肿，使用PCR靶向细胞色素c氧化酶I基因（COX1），其次是限制性片段长度多态性和多重PCR，和非E.Granulosuss.l.样品。
结果：对823名志愿者进行了超声检查（在Longido区的两个村庄中，n=352，在恩戈隆戈罗的三个村庄中，n=471）。仅在Ngorongoro诊断为肝CE病例（n=6;1.3％），其中三个有活动性囊肿。村一级的CE患病率在0到2.4%之间。在被检查的697只反刍动物中,34.4%有寄生虫囊肿。对取样的219个囊肿中的140个(63.9%)实现了分子鉴定。细粒E.s.l.和T.包虫病/囊尾蚴分别占51.4%和48.6%，分别,牲畜囊肿。在Longido（116个基因型囊肿中的35.3％）和Ngorongoro（34个基因型囊肿中的91.2％）的牲畜中都发现了E.granulosuss.l.。在牲畜中发现的72个E.granuslosuss.l.囊肿中，87.5%是E.grulosussensustricto（G1-G3基因型），9.7%为E.ortleppi(G5)，一个囊肿为E.canadensis(G6-10)。三个活跃的人类囊肿，通过手术切除，是G1-G3基因型。
结论：在坦桑尼亚北部的马赛社区中，有多种物种/基因型。在Ngorongoro区的村庄中发现了人类CE，并且在两个地区的牲畜中都观察到了高流行的棘球蚴。需要对该地区的患病率进行更精确的估计，并更好地了解坦桑尼亚北部马赛社区中CE的特定风险因素。针对S.granulosus和T.multiceps常见的传播途径的干预措施将对预防人类和牲畜疾病具有双重益处。
方法：在坦桑尼亚北部Longido和Ngorongoro地区的五个村庄，年龄≥7岁的志愿者通过腹部超声诊断出人类CE。通过在当地屠宰场的检查评估反刍动物的感染，然后分子鉴定每只动物一个囊肿，优先治疗肝囊肿，使用PCR靶向细胞色素c氧化酶I基因（COX1），其次是限制性片段长度多态性和多重PCR，和非E.Granulosuss.l.样品。
结果：对823名志愿者进行了超声检查（在Longido区的两个村庄中，n=352，在恩戈隆戈罗的三个村庄中，n=471）。仅在Ngorongoro诊断为肝CE病例（n=6;1.3％），其中三个有活动性囊肿。村一级的CE患病率在0到2.4%之间。在被检查的697只反刍动物中,34.4%有寄生虫囊肿。对取样的219个囊肿中的140个(63.9%)实现了分子鉴定。细粒E.s.l.和T.包虫病/囊尾蚴分别占51.4%和48.6%，分别,牲畜囊肿。在Longido（116个基因型囊肿中的35.3％）和Ngorongoro（34个基因型囊肿中的91.2％）的牲畜中都发现了E.granulosuss.l.。在牲畜中发现的72个E.granuslosuss.l.囊肿中，87.5%是E.grulosussensustricto（G1-G3基因型），9.7%为E.ortleppi(G5)，一个囊肿为E.canadensis(G6-10)。三个活跃的人类囊肿，通过手术切除，是G1-G3基因型。
结论：在坦桑尼亚北部的马赛社区中，有多种物种/基因型。在Ngorongoro区的村庄中发现了人类CE，并且在两个地区的牲畜中都观察到了高流行的棘球蚴。需要对该地区的患病率进行更精确的估计，并更好地了解坦桑尼亚北部马赛社区中CE的特定风险因素。针对S.granulosus和T.multiceps常见的传播途径的干预措施将对预防人类和牲畜疾病具有双重益处。
