Evaluation of Mammalian and Intermediate Host Surveillance Methods for Detecting Schistosomiasis Reemergence in Southwest China
Evaluation of Mammalian and Intermediate Host Surveillance Methods for Detecting Schistosomiasis Reemergence in Southwest China
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DOI：
10.1371/journal.pntd.0000987
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发表时间：
2011-03-01
影响因子：
3.8
通讯作者：
Spear, Robert C.
中科院分区：
文献类型：
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作者：
Carlton, Elizabeth J.;Bates, Michael N.;Spear, Robert C.
背景：血吸虫病在中国重新出现，威胁着消除血吸虫病的努力。需要能够确定血吸虫病重新出现地点的监测方法，以防止感染进一步传播。方法和主要发现：我们对人类、牛、水牛和中间宿主钉螺进行了日本血吸虫感染检测，评估了钉螺密度并提取了四川省血吸虫病重新出现地区的区域监测记录。然后，我们评估了监测方法识别存在人类感染的村庄的能力。接受调查的 53 个村庄中有 35 个发现了人类感染（感染率：0 至 43%），其中 28 个村庄中有 17 个先前没有证据表明出现了复发。 23 个村庄发现牛感染（感染率：0 至 65%），1 个村庄发现蜗牛感染。两种常见的监测方法，即急性血吸虫病病例报告和感染日本血吸虫病的蜗牛调查，严重低估了存在人类感染的村庄数量（敏感性分别为 1% 和 3%）。对牛进行日本血吸虫筛查和湖北血吸虫存在调查具有适度的敏感性（分别为 59% 和 69%）和特异性（分别为 67% 和 44%）。老年人和牛主感染的风险较高。仅对这些高危人群进行检测，灵敏度分别为 77% 和 71%。 结论：在血吸虫病重新出现的地区，人血吸虫病和牛血吸虫病广泛存在，但急性血吸虫病和感染日本血吸虫的钉螺很少见，因此监测目标较差。在制定更有效、更敏感的监测策略之前，应考虑对高危人群进行直接、有针对性的寄生虫学检测，以监测血吸虫病的复发。
Background: Schistosomiasis has reemerged in China, threatening schistosomiasis elimination efforts. Surveillance methods that can identify locations where schistosomiasis has reemerged are needed to prevent the further spread of infections.Methods and Principal Findings: We tested humans, cows, water buffalo and the intermediate host snail, Oncomelania hupensis, for Schistosoma japonicum infection, assessed snail densities and extracted regional surveillance records in areas where schistosomiasis reemerged in Sichuan province. We then evaluated the ability of surveillance methods to identify villages where human infections were present. Human infections were detected in 35 of the 53 villages surveyed (infection prevalence: 0 to 43%), including 17 of 28 villages with no prior evidence of reemergence. Bovine infections were detected in 23 villages (infection prevalence: 0 to 65%) and snail infections in one village. Two common surveillance methods, acute schistosomiasis case reports and surveys for S. japonicum-infected snails, grossly underestimated the number of villages where human infections were present (sensitivity 1% and 3%, respectively). Screening bovines for S. japonicum and surveys for the presence of O. hupensis had modest sensitivity (59% and 69% respectively) and specificity (67% and 44%, respectively). Older adults and bovine owners were at elevated risk of infection. Testing only these high-risk human populations yielded sensitivities of 77% and 71%, respectively.Conclusions: Human and bovine schistosomiasis were widespread in regions where schistosomiasis had reemerged but acute schistosomiasis and S. japonicum-infected snails were rare and, therefore, poor surveillance targets. Until more efficient, sensitive surveillance strategies are developed, direct, targeted parasitological testing of high-risk human populations should be considered to monitor for schistosomiasis reemergence.