血吸虫病对公共卫生的影响——疾病与死亡率

五种血吸虫可引起血吸虫病.每种血吸虫均可导致急性或慢性疾病,其症状和体征差异很大.1 患病率慢性血吸虫病患病率的最新研究已证实在儿童中感染度与高患病率间存在普遍联系.在高流行率和高感染度的社区,临床表现多种多样.迄今,体检和实验室检查仍是标准的诊断技术.手提式超声显像仪不久前用于现场,使诊断更为精确灵敏.     

鄱阳湖区血吸虫病患者感染状态的超声显像变化

B超影像是一种快速、简便、无损伤性诊断血吸虫病的影像学检查方法,广泛应用于日本血吸虫病的临床诊断、流行病学调查,以及血吸虫病疫区疾病监测等。本文报道了血吸虫病疫区居民感染血吸虫病后肝脾损害状况及病程不同时期血吸虫感染程度对脏器的影响。     

日本血吸虫病重疫区531例肝脾超声检查结果分析

1990年10月开罗WHO召开的“用超声显像法评价血吸虫病患病率”专题讨论会,制订了“血吸虫感染所致损伤的B超检查标准化暂行草案”。1992年公布了“超声诊断在血吸虫病应用中试行标准化方法”。此后,国内一些学者对我国血吸虫病不同流行区进行了B超用于血吸虫病诊断和评价及其在流行病学调查中价值的研究。蔡卫民等还对正常人群肝脾大小及门脉内径进行了测定。     

日本血吸虫病重疫区人群B超流行病学调查

按照世界卫生组织1990年开罗会议制定的”超声诊断在血吸虫病应用中的试行标准化方法”，在日本血吸虫所致肝脏病理损害超声图上可显示明确特征性的基础上，作者于1992年在血吸虫病重疫区的两个自然村，整群抽样1004例村民进行腹部B超检查。结果显示肝实质有不同程度改变者639人（63．6％），其中肝实质改变为I级者454人（45．2％）、Ⅱ级131人（13．0％）、Ⅲ级54人（5．4％）。肝实质超声图显示异常者中粪检、免疫学检查、直检阳性者与各项检测阴性者进行比较，两组超声异常率分别为74．1％及9．8％（P＜0．01），而非流行村200例配对对照组未发现1例超声异常。另通过对成人和儿童肝、脾、门静脉内径的超声测量结果表明，判断异常的标准值尚有待进一步探讨。本研究再次证实了B超在现场应用中，对人群血吸虫病患病率的评估和防治效果的判断具有实用价值，可作为该病流行病学调查的一种较好的方法。     

西昌邛海周边地区超声检测日本血吸虫所致肝纤维化结果分析

目的了解日本血吸虫对西昌邛海周边地区人群肝脏损害的情况.方法随机选择该地区4个乡20个村民小组5～60岁村民1060例进行腹部超声检查.结果经超声检查肝纤维化异常率为26.89%,日本血吸虫感染率与肝纤维化异常率存在正相关(P<0.002), 虫卵负荷量与肝脏的损害有直接的关系(P<0.001);不同性别感染血吸虫者II级以上肝损害与未感染者差异有显著性(P<0.025);肝纤维化随年龄增长明显呈上升趋势;有血吸虫病诊断依据者肝纤维化异常率明显高于无依据者(P<0.005);未接受治疗的患者肝纤维化异常率与接受治疗者差异有显著性(P<0.025).结论人群肝纤维化与血吸虫病流行地区的感染率、感染度、接触疫水及治疗等因素有关,超声检测能直接评价人群血吸虫病病情.     

巴布亚新几内亚马丹地区不同脾肿率的两组妇女对疟疾免疫应答的差异

作者过去在巴布亚新几内亚北部沿海村落对疟疾进行流行病学调查时发现,血统和语言不同的两组妇女,其脾肿率差异有显著意义,但平均疟原虫阳性率差别无显著意义。为了探讨当地高脾肿率组脾脏肿大是否由超敏性疟疾脾肿大(HMS)造成,作者又在马丹镇以北25公里处的17个村庄中进行研究。将594名妇女按所讲语言的不同分成两组:非南岛语组,也就是高脾肿率组(HS组),和南岛语组,即低脾肿率组(LS组)。两组妇女均不包括孕妇。进行疟原虫阳性率、脾     

猪日本血吸虫感染和血清及组织中维生素A和锌的浓度

近年来,一些对曼氏血吸虫感染患者的研究提出,曼氏血吸虫的感染与患者血清中低水平的维生素A和锌之间可能存在某种关系。本文作者对感染日本血吸虫的猪肝组织及血清中维生素A以及肝、脾、肌肉及血清中锌的浓度进行了调查,以了解日本血吸虫感染对机体内维生素A和锌浓度的影响。     

洲岛型血吸虫病重疫区选择性化疗效果分析

在洲岛型血吸虫病毒疫区，连续4年采用选择性化疗措施，以改良Kato法和超产检查考核其防治效果，结果显示，居民感染率从39．26％下降至28．60％，感染度（人群EPG算术均数）从59．70降至37．00；肝肿率、巨大肝肿率和脾肿率分别下降40．06％、93．94％和95．56％，肝纤维化患病率从31．16％下降至16．12％。提示在重疫区进行选择性化疗能有效地降低血吸虫病的患病率，但难以控制疾病的流行与传播。     

洞庭湖渔民血吸虫病感染程度与免疫状态关系的研究

目的了解洞庭湖频繁接触疫水渔民的免疫状态及其与感染度和肝病变程度间的关系。 方法 采用询检、粪检、肝B超、流式细胞术（FCM）、免疫比浊法和ELISA法，检测血吸虫感染度、肝脾病变程度和血中CD4+和CD8+T细胞百分率及抗体水平等指标，用SPSS 10.0统计软件分析数据。 结果 与非疫区人群比较，疫区渔民人群外周血中的CD4+T细胞百分比和CD4＋/CD8＋细胞比值显著降低，而且粪检阳性患者均随血吸虫感染度增高和肝脾病变加重而更为突出。相反，疫区渔民血清总IgM抗体和特异性IgG水平增高，并随感染度增加或肝脾病变加重而更为明显。血清总IgA水平在肝脾病变严重的人群中有显著增高。总IgG水平仅粪检阳性者有增高现象。 结论 长期作业于洞庭湖的血吸虫感染渔民表现为细胞免疫功能降低而体液免疫亢进，这种免疫失调程度与其感染度和肝脾损害程度相关。     

日本血吸虫先天性传播的研究进展

通常认为 ,日本血吸虫尾蚴只能在宿主接触疫水时经皮肤感染 ,但近期的研究表明 ,日本血吸虫还存在先天性传播途径。先天性感染日本血吸虫病已为许多动物实验所证实。尽管目前的人群流行病学调查尚未发现先天性感染的病例 ,但不能排除人群存在先天性感染的可能性。本文从实验寄生虫学、实验免疫学及流行病学等方面全面地综述了日本血吸虫先天性传播这一现象。     

Morbidity control of schistosomiasis in China

After reviewing the schistosomiasis control program in China with focusing on the socio-economic impact on schistosomiasis endemicity, we introduce the promotion process of morbidity control strategy undertaken before and during the World Bank Loan Project (WBLP) on Schistosomiasis Control. We analyzed the data derived from case study of morbidity control for schistosomiasis, and evaluated the efficacy of chemotherapy. It is suggested that appropriate drug treatment declines worm burden and the intensity of infection as well as prevalence, but chemotherapy alone can hardly reduce the transmission because zoonotic Schistosoma japonicum infection has a great impact on the transmission of the disease. Therefore, the strategies in different (high, medium, and low) transmission areas during the maintenance stage were put forward in consideration of challenges in national control program in the future.     

Factors associated with Schistosoma mansoni infection 5 years after selective treatment in a low endemic area in Brazil.

Five years after a single dose treatment, prevalence, intensity and morbidity of schistosomiasis mansoni were evaluated in Agua Branca, a low endemic community in the South East Brazil (cure rate 94%). At community level, prevalence showed a decrease from 38.9 to 24.5% and the intensity of infection dropped from 119.5 to 38.9 eggs per g of faeces (epg). However, after the exclusion of immigrants, newborn children and individuals that had left the area after the first evaluation, the prevalence among the treated and followed population was not significantly affected. Multivariate analysis showed that the 10-29 age group and water contact for agricultural purposes were independently associated with the presence of infection on post treatment evaluation [OR 3.9 and 5.09, respectively]. A previous treatment among subjects older than 15 years was inversely associated [OR 0.58]. The authors wish to draw attention to the fact that mobility may lead to a serious bias in evaluating the impact of the control programme.     

全民化疗控制血吸虫病病情效果纵向观察

本文报道了在一血吸虫病中度流行区,通过连续3年的全民化疗,居民血吸虫感染率、感染度及肝脾肿大的变化趋势.结果表明,试区居民的血吸虫感染率从1992年的15.6%下降到1994年的4.7%;感染度明显下降.受检居民的肝脾肿大及肝纤维化程度显著改善,提示在中度流行区全民化疗可显著降低感染,控制病情.     

Achievement of the World Bank loan project on schistosomiasis control (1992-2000) in Hubei province and the challenge in the future

Since the World Bank provided a loan for control of schistosomiasis in China, started from 1992, with the objective of a reduction of prevalence and intensity of the infection both in humans and animals by 40%, through mass chemotherapy in areas of high prevalence, and selective chemotherapy in areas with medium and low endemicity together with focal mollusciciding, the objective of morbidity control of the project has been reached in Hubei Province.     

Liver ultrasound findings in a low prevalence area of S. japonicum in China: comparison with history, physical examination, parasitological and serological results.

The paper describes a study carried out in a community in Dongdian township, Anhui Province, People's Republic of China. Medical history and the results of a physical examination, ultrasound investigation, parasitological and serological tests for Schistosoma japonicum infection were compared in 661 persons of 169 households. A lack of correlation between parasitological and serological indicators of infection and morbidity was observed in this area of low (6.4%) prevalence and intensity of infection. The prevalence of abnormal ultrasound findings in the liver in this population was high (56%), and was significantly higher than the prevalence of S. japonicum infection. The abnormal ultrasound findings correlated with a history of schistosomiasis, and the correlation increased significantly according to the number of times treated and the time since the last treatment, which suggested that past parenteral treatment has a role in the high rate of abnormal liver ultrasound findings. The significant correlation between the qualitative and quantitative serological results and abnormal ultrasound parenchymal patterns suggests that cross-reactivity between the etiology of the parenchymal disease and these tests is occurring. The presence of HBsAg correlated with the composite presence of ultrasound abnormalities of the liver parenchyma: increased echogenicity, periportal fibrosis and/or nodules and irregular fibrosis, whereas a normal ultrasound pattern was associated with the absence of HBV antigenemia.     

鄱阳湖区血吸虫病防治试点研究

目的：纵向观察鄱阳湖区血吸虫病重疫区血吸虫病防治效果。方法：采取每年全民化疗结合健康教育的防治策略。此外,在 １９９６ 年血吸虫病易感季节,成年男性加服血吸虫病预防药物青蒿琥酯。结果：居民血吸虫感染率和感染度分别从 １９９２ 年的 ２６．０％ 和 １．９２ 下降到 １９９４ 年的 １０．７％ 和 ０．５５;居民肝、脾肿大,肝实质状况得到显著改善;１９９５ 年夏季试区遭受洪水灾害,居民血吸虫感染率和感染度又上升至１８．４％和 １．０４;１９９６ 年由于上述防治策略的继续实施及易感季节高危人群口服血吸虫病预防药物青蒿琥酯,居民血吸虫病感染率和感染度又下降至５．０％ 和０．２５。结论：每年全民化疗结合健康教育与高危人群口服血吸虫病预防药物是控制湖区血吸虫病的一项有效策略。     

Intensity of Schistosoma mansoni, hepatitis B, age, and sex predict levels of hepatic periportal thickening/fibrosis (PPT/F): a large-scale community-based study in Ethiopia

To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was undertaken involving 2,451 subjects (mean age, 18.8 +/- 15.3 [SD] years) from four endemic sites in Ethiopia. Overall prevalence of infection was 65.9%, reported blood in stools was 35.8%, and schistosomal periportal thickening/fibrosis (PPT/F) was 4.6%. Similarly, 43.2% were positive for at least one marker of hepatitis B virus (HBV), 5.3% were HBsAg positive, and 1.3% were anti-hepatitis C virus (HCV) positive. Prevalence of PPT/F increased significantly with increasing community prevalence and intensity of S. mansoni infection. In a multiple logistic regression analysis, intensity of egg excretion, markers of HBV infection, age, and male sex were significantly associated with PPT/F, whereas co-infection with other intestinal helminths was associated with lower odds for PPT/F. HCV was not associated with S. mansoni infection or with schistosomal PPT/F. In conclusion, integrated helminth control targeting school-aged children, who have the highest burden infection, should be used to substantially reduce the risk of periportal fibrosis.     

Schistosoma haematobium infection and morbidity before and after large-scale administration of praziquantel in Burkina Faso

BACKGROUND: In sub-Saharan Africa, 112 million people are infected with Schistosoma haematobium, with the most intense infections in children 5-15 years old. METHODS: We describe a longitudinal epidemiological study that evaluates the relationship between S. haematobium infection and associated morbidity in children before and after the large-scale administration of praziquantel for schistosomiasis and albendazole for soil-transmitted helminths. RESULTS: At baseline, higher intensities of S. haematobium infection were observed in children with anemia and/or severe microhematuria, but there was no apparent association between the risk of undernutrition and intensity of S. haematobium infection. Significant reductions in the prevalence and intensity of S. haematobium infection 1 year after treatment were, however, observed. Children who benefited the most from anthelmintic treatment in terms of increased hemoglobin concentrations were those who had anemia at baseline and those with highly positive microhematuria scores at baseline. CONCLUSIONS: This study suggests that even a single round of mass chemotherapy can have a substantial impact on S. haematobium infection and its associated morbidity in children.     

Intestinal schistosomiasis in mothers and young children in Uganda: investigation of field-applicable markers of bowel morbidity

To control intestinal schistosomiasis at a national level in sub-Saharan Africa, there is a need for field-applicable markers to measure morbidity associated with this disease. The purpose of this study was to determine whether fecal calprotectin or fecal occult blood assays could be used as morbidity indicators for intestinal schistosomiasis. The study was carried out in Uganda with a cohort of young children (n = 1,327) and their mothers (n = 726). The prevalence of egg-patent schistosomiasis was 27.2% in children and 47.6% in mothers. No association was found between schistosomiasis infection and fecal calprotectin in children (n = 83, odds ratio [OR] = 1.08, P = 0.881), although an inverse relationship (n = 58, OR = 0.17, P = 0.043) was found in mothers. Fecal occult blood was strongly associated with Schistosoma mansoni infection in children (n = 814, OR = 2.30, P < 0.0001) and mothers (n = 448, OR = 1.95, P = 0.004). Fecal occult blood appears to be useful for measuring morbidity associated with intestinal schistosomiasis and could be used in assessing the impact of control programs upon disease.     

Discrepancies in outcome of a control program for schistosomiasis haematobia in Fayoum governorate, Egypt

A large scale mollusciciding and chemotherapy program in the Fayoum area of Egypt was reported to have decreased prevalence of schistosomiasis haematobia from 46% to 7% in approximately 12 years. In order to assess the uniformity of results reported, we have studied the prevalence and intensity of urinary tract disease in a random sample of children aged 6 months-12 years in 3 areas selected on the basis of distance from the main canal supplying Fayoum and where mollusciciding was applied. Only 1 location near the main canal showed low prevalence (2.2%), while in the other 2 areas prevalence was 75.3% and 61.3%. Intensity of infection and disease were significantly more in the latter 2 locations. Following chemotherapy, a marked reduction in prevalence and intensity of infection and reversal of pathology was seen. Since the reported favorable results of the Fayoum project were used to implement a wider control program in southern Egypt, an independent assessment must be included in future plans.