控制急性血吸虫病在推进我国消除血吸虫病 进程中的作用

急性血吸虫病是一种临床病情较重的血吸虫病。急性血吸虫病发病人数是评估一个地区血吸虫病疫情态势和防治效果的敏感指标,也是判定“突发疫情”、评价是否达到疫情控制或传播控制标准的重要指标。因此,做好急性血吸虫病防控工作,对我国既定血防目标的实现具有重要意义。本文分析了当前我国急性血吸虫病的发病特征及其发生原因,并就今后做好急性血吸虫病防控工作的策略和措施提出了建议。     

江滩型疫区人群日本血吸虫感染与再感染的前瞻性研究

目的 :研究江滩型日本血吸虫病中度流行区化疗后人群血吸虫感染、再感染及其危险因素。方法 :在观察试区 ,以 1 2 9例感染者经吡喹酮治疗后虫卵转为阴性的 1 2 6人为“再感染”研究对象 ;2 4 7例粪检阴性人群作为“感染”研究对象。追踪观察两组人群在一个感染季节后的再感染情况 ,并调查其接触疫水情况以及当地螺情和疫水变化情况等因素 ;再对其进行单因素分析和多因素非条件 logistic回归分析。结果 :基线感染率为 1 3 .3 7% ,经过一个感染季节后 ,标准化感染率为 4 .1 1 % ,标准化再感染率高达 1 3 .76% ,再感染率已恢复到化疗前人群感染水平 ,其中年龄≤ 1 2岁组再感染率 ( 2 2 .50 % )高于 >1 2岁组感染率 ( 9.3 0 % )。接触疫水处水体尾蚴密度、年龄、6～ 9月疫水接触指数、居住地距阳性螺点距离是再感染发生的主要危险因素。接触疫水处水体尾蚴密度、职业和 6～ 9月疫水接触指数是血吸虫病感染的主要危险因素 ,结论 :在日本血吸虫病中度流行区也存在较快感染和再感染趋势 ,初步揭示了感染和再感染的主要危险因素     

三峡大坝工程对长江安徽段滩地开发利用及其对血吸虫病流行的影响

为阐明三峡建坝后水位变化对长江安徽段滩地开发利用及其对血吸虫病流行的影响,对长江安徽段江湖洲滩血吸虫病流行区人文、滩貌结构与植被分布、滩地开发利用以及钉螺分布等进行现况调查,结合三峡大坝工程对长江安徽段水位变化影响进行综合分析。结果长江安徽段江湖洲滩16.28%的滩地面积被农业开发利用,7.88%的滩地面积被开发为水产养殖,有10%左右的滩地被翻耕植树,已被农业开发的江洲湖滩,主要农作物有水稻、棉花、油菜、小麦。三峡建坝后长江中下游秋季水位将有所下降,使滩地露滩时间提前。表明三峡工程将有利于滩地农作物的播种,使滩地可开发耕种的面积扩大而有利于消灭滩地钉螺。     

Endoscopic, Ultrasonographic, and US-Doppler Parameters as Indicators of Variceal Bleeding in Patients with Schistosomiasis

Bleeding from esophagogastric varices is a potentially deadly complication in patients with hepatosplenic schistosomiasis. The aim of this study is to establish indicators of variceal bleeding. We studied 40 patients with compensated hepatosplenic schistosomiasis and varices, analyzing four endoscopic (variceal size, red color signs, fundic varices, and congestive gastropathy), nine ultrasonographic (right and left hepatic lobe size, periportal and gallbladder wall thickness, portal and splenic veins diameter, spleen longitudinal axis and volume, and presence of collateral circulation), and five US-Doppler parameters (portal and splenic veins velocity and flow and portal vein congestion index). Patients were divided in two groups according to previous history of variceal bleeding. The group with bleeding episodes was again divided in two groups: with and without treatment, namely endoscopic sclerotherapy. All endoscopic parameters and two ultrasonographic (periportal thickness and portal vein diameter) were statistically different between the groups with and without previous bleeding. The likelihood index, adopted to determine the best parameters related to previous bleeding showed that the most important combinations are: gastropathy and red signs followed by portal vein diameter and variceal size. In conclusion, although aware of the limits of the statistical analysis due to the small number of patients, our results demonstrated that endoscopic and US parameters (isolated or combined) can identify patients with a high risk of variceal bleeding, allowing physicians to optimize prophylactic therapy.     

Integrated community-directed treatment for the control of onchocerciasis, schistosomiasis and intestinal helminths infections in Uganda: advantages and disadvantages

Onchocerciasis is co-endemic with schistosomiasis and intestinal helminths infections, which are all diseases of the rural and the poorest communities in Africa. Community-directed treatment (ComDT) for the control of onchocerciasis is the only functional health approach in most of these communities and the strategy has proven to be effective for onchocerciasis control. This study was conducted to assess the feasibility of integrating ComDT with ivermectin for the control of onchocerciasis, and with praziquantel (PZQ) and mebendazole (MBD) for the control of schistosomiasis and intestinal helminths infections in children aged 5-14 years, and to assess advantages and disadvantages of the integrated ComDT over the routine ComDT and the school-based treatment approach. Integrated ComDT achieved higher treatment coverage (85%) for PZQ and MBD than the school-based treatment approach (79%) among children aged 5-14 years (P = 0.03). There were more reported adverse reactions after treatment with a combination of PZQ and MBD in the school-based treatment approach (33%) than for the combination of ivermectin and MBD on day 1 and PZQ on day 2 in the integrated ComDT (18%). However, all adverse reactions were mild (headache, nausea/vomiting and abdominal pain). The integrated ComDT also achieved higher ivermectin treatment coverage for all ages (81.3%) than routine ComDT (77.2%) (P = 0.0003). To achieve even better coverage for PZQ and MBD among the targeted high risk groups, integrated ComDT should treat all age groups in areas where the prevalence of schistosomiasis and intestinal helminths infections is >50%. This would minimize the shortage of the drugs targeted to treat the high risk groups, as the non-targeted groups, will inevitably demand and receive the treatment from the distributors. The results of this study show that PZQ and MBD treatment for the control of schistosomiasis and intestinal helminths, respectively, can be integrated with ivermectin treatment for the control of onchocerciasis without negatively affecting ivermectin treatment coverage.     

On the increase of portal pressure during the acute and chronic phases of murine schistosomiasis mansoni and its reversibility after treatment with oxamniquine

The purpose of the present study was to evaluate the effect of treatment with oxamniquine on the portal pressure of mice infected with Schistosoma mansoni. The animals were infected with 30 cercariae and portal pressure was measured with a polygraph at 70 (acute phase) and 160 (chronic phase) days after infection. On days 70 and 160 two other groups of infected mice were treated with 400 mg/kg of oxamniquine and portal pressure was measured 90 days later (160 and 250 days after infection). A group of uninfected mice was used as control. The measured portal pressures, in mmHg, were: matched uninfected control mice 8.7+/-2.1 and acute phase group, measured at day 70, 13.4+/-3.5. Matched uninfected control 7.5+/-0.6 and chronic phase group, measured at day 160 post-infection, 11.6+/-1.5. Matched uninfected mice 6.9+/-0.9 and chronic phase group, measured at day 250, 10.4+/-1.8. Oxamniquine-treated at day 70 and measured at day 160 7.9+/-0.4; oxamniquine-treated at day 160 and measured at day 250, 7.6+/-1.7. The infection of mice with 30 cercariae of S. mansoni induced portal hypertension, both during the acute and chronic phases and treatment with oxamniquine caused portal pressure to return to normal levels.     

Measuring morbidity in schistosomiasis mansoni: relationship between image pattern,portal vein diameter and portal branch thickness in large-scale surveys using new WHO coding guidelines for ultrasound in schistosomiasis

OBJECTIVE: World Health Organization consensus meetings on 'Ultrasound in Schistosomiasis' in 1996 and 1997 anticipated further challenges in the global implementation of a standardized protocol for morbidity assessment in schistosomiasis mansoni. We evaluated the performance of the qualitative and quantitative components of the new Niamey criteria. METHOD: Use of the Niamey protocol among 3954 subjects in two linked, cross-sectional ultrasound surveys of Schistosoma mansoni-endemic populations in Egypt and Kenya. RESULTS: There were significant differences between Egyptian and Kenyan sites in prevalence and age distribution of S. mansoni-related hepatic fibrosis (36%vs. 3%, P < 0.001). Protocol image pattern scoring could be performed quickly and was stable to interobserver variation. However, there were unintended but systematic differences between study sites in the measurement of portal vein diameter (PVD) and wall thickness. By Niamey criteria, a high prevalence of portal dilation was scored for normal Egyptian subjects, which reduced the predictive value of image pattern for portal hypertension. Using alternative height-indexing of PVD, image pattern plus PVD findings predicted 15% of Egyptians and 2.5% of Kenyans were at risk for variceal bleeding, whereas locally derived PVD norms estimated 25% of Egyptians and 12% of Kenyans to be at possible risk. CONCLUSION: Niamey scoring criteria performed acceptably as a relative grading system for disease in schistosomiasis mansoni, but failed to account fully for site-to-site variation in test performance and morbidity prevalence. Consequently, standardized image pattern scoring appears to provide the most useful tool for detection and comparison of S. mansoni-associated morbidity in large-scale surveys.     

血吸虫病流行区居民腹部超声显像指标典型相关及冗余度分析

目的　探讨日本血吸虫病肝、脾B超指标间以及与感染次数、感染时间和每克粪便平均虫卵数 (EPG )的相关性。　方法　采用典型相关方法分析肝、脾B超指标间及其与感染次数、感染时间和EPG的相关性 ,用冗余度分析方法分析肝、脾变异中有多少比例互为相关。　结果　男、女无既往感染组和既往感染组的第 1典型相关系数分别为0.7842、0.5483和 0.5800、0. 4220 (P值均 <0.01) ;男、女粪检阴性组和阳性组的第 1典型相关系数分别为 0.6063、0.5215和 0.6595、0.3849(P值均 <0. 01) ;男、女无既往感染组肝B超指标变异分别有 43.5 %和 17.5 %与脾B超指标变异有关 ,而既往感染组分别为 22.1%和 11.4%。而在男、女粪检阴性组分别为 26.8%和 16.8% ,粪检阳性组分别为 2 7.6%和 10.7% ;既往感染组 ,感染次数、调查时距首次感染时间和粪检阳性者的EPG与肝、脾B超指标的典型变量均无相关性 (P >0.05 )。　结论　日本血吸虫病肝、脾B超指标间具有典型相关关系 ,且男性的相关性大于女性 ;在既往感染者中感染次数、调查时距首次感染时间和粪检阳性者EPG与肝、脾B超指标的典型变量间均未发现相关性。     

新型定量集卵直检技术现场诊断血吸虫病的效果评价

目的　建立一种简便、经济、快速、准确、敏感性高于 Kato- Katz法的新型诊断血吸虫病的方法 ,以便在现场推广应用。　方法　对血吸虫病流行区的 15 9名居民的同一份粪便 ,用新型定量集卵直检法、Kato- Katz法和集卵孵化法同时进行检测。　结果　 3种方法血吸虫卵检出率依次为 2 5 .16 % (40 /15 9)、6 .2 9% (10 /15 9)和 2 5 .79% (41/15 9)。经配对计数资料的卡方检验 ,定量集卵直检法与集卵孵化法之间差异无显著性 (χ2 =0 ,P>0 .0 5 ) ;而定量集卵直检法与 Kato-Katz法之间差异有极显著性 (χ2 =2 8.0 3,P<0 .0 1)。定量集卵直检法镜下检出的虫卵形态不变 ,卵内毛蚴结构清晰 ,很容易辨认。　结论　定量集卵直检法不仅简便、快速、经济 ,而且诊断准确 ,敏感性高 ,明显优于 Kato- Katz法和集卵孵化法 ,值得进一步研究、推广。     

晚期日本血吸虫病与乙型肝炎关系的配对研究

目的　探讨晚期日本血吸虫病与肝炎的关系。　方法　采用 1∶ 1,1∶ 2配对病例 -对照研究的方法 ,两对照分别为慢性血吸虫病病人和正常人 ,共配 2 13对。调查被研究对象的一般情况、血吸虫病与肝炎患病情况、家属患肝炎情况 ,同时检测乙肝 5项指标。统计分析用 SAS6 .12版软件 ,方法为 χ2检验与条件 L ogistic回归分析。　结果　除 HBs Ab外晚期血吸虫病患者肝炎患病率、家属肝炎患病率、HBs Ag、HBc Ab、HBe Ag、HBe Ab、大三阳、小三阳的阳性率 (2 3.94 %、15 . 96 %、2 9.11%、37.0 9%、15 .0 2 %、38.5 0 %、4 .2 3%、19.72 % )均显著高于慢性血吸虫病患者 (9.39%、5 .6 3%、14 .0 8%、16 .90 %、7.5 1%、2 0 .19%、0、7.89% )和正常人 (7.5 1%、5 .16 %、15 .0 2 %、2 0 .19%、1.88%、19.2 5 %、0、9.86 % )(P均 <0 .0 5 ) ,经 L ogistic回归分析 ,晚期血吸虫病患者的大三阳和 HBe Ag阳性率的比值比 (OR)值分别达 2 0 .934和8.0 0 (晚血与正常人 1∶ 1配对 )。　结论　晚期血吸虫病与肝炎关系密切 ,可认为两者间存在相互促进的关系。