Nacife Maria Beatriz Pena E Silva Leite, Siqueira Liliane Maria Vidal, Martins Rafael, Vianna Valeska Natiely, Barbosa Keila Furbino, Masioli Cássio Zumerle, Silva Jaime Costa da, Machado-Coelho George Luiz Lins
Laboratório de Epidemiologia, Escola de Medicina, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil.
Laboratório de Esquistossomose, Instituto de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil.
Rev Inst Med Trop Sao Paulo. 2018;60:e26. doi: 10.1590/s1678-9946201860026. Epub 2018 Jun 28.
Intestinal parasitic infections are a common health problem among Amerindian populations and schistosomiasis represents one of the most prevalent diseases in Maxakali people. The Kato-Katz is the diagnostic method recommended by WHO for epidemiological studies; however, one of the technique's limitations is the failure to detect parasites in individuals with low parasite load. The aim of this study was to establish the prevalence of Schistosoma mansoni in indigenous Maxakali villages, evaluating the TF-Test® performance for diagnosis compared to the Kato-Katz technique. Stool samples from 545 individuals were processed by the TF-Test® (1 sample) and Kato-Katz (1 slide). The positivity rate for S. mansoni by Kato-Katz was 45.7%. The rate by the TF-Test® was 33.2%, and 51.9% by the combined parasitological techniques. The amplitude of parasite load was 24 to 4,056 eggs per gram of feces (epg), with a geometric mean of 139 epg. The co-positivity, co-negativity, and accuracy values by TF-Test® in relation to Kato-Katz were 59.0%, 88.5%, and 75.0%, respectively. The agreement between these techniques was moderate (k=0.486) as determined by the kappa index. Thus, the results of this study demonstrated that the performance of Kato-Katz was superior (p <0.05) to that of TF-Test® in the detection of S. mansoni. The combination of TF-Test® and Kato-Katz resulted in an increased positivity rate of S. mansoni, demonstrating the high risk of infection to which indigenous populations are exposed and the importance of the implementation of control strategies in Maxakali villages.
肠道寄生虫感染是美洲印第安人群中常见的健康问题，血吸虫病是马克萨卡利人中最普遍的疾病之一。加藤厚涂片法是世界卫生组织推荐用于流行病学研究的诊断方法；然而，该技术的局限性之一是无法检测出寄生虫负荷低的个体中的寄生虫。本研究的目的是确定曼氏血吸虫在马克萨卡利土著村庄中的流行率，评估TF-Test®与加藤厚涂片法相比的诊断性能。对545名个体的粪便样本分别采用TF-Test®（1份样本）和加藤厚涂片法（1张玻片）进行处理。加藤厚涂片法检测曼氏血吸虫的阳性率为45.7%。TF-Test®的阳性率为33.2%，联合寄生虫学技术的阳性率为51.9%。寄生虫负荷范围为每克粪便24至4056个虫卵（epg），几何平均数为139 epg。TF-Test®相对于加藤厚涂片法的共同阳性、共同阴性和准确性值分别为59.0%、88.5%和75.0%。根据kappa指数确定，这两种技术之间的一致性为中等（k=0.486）。因此，本研究结果表明，在检测曼氏血吸虫方面，加藤厚涂片法的性能优于TF-Test®（p<0.05）。TF-Test®和加藤厚涂片法联合使用导致曼氏血吸虫阳性率增加，表明土著人群面临的高感染风险以及在马克萨卡利村庄实施控制策略的重要性。
