洞庭湖渔民血吸虫感染情况及化疗效果分析

目的　调查洞庭湖渔民感染血吸虫的严重程度,评估其化疗防治效果。　方法　 2 0 0 1年11月选择湖南省岳阳县麓角镇洞庭湖水上作业渔民,询问血吸虫感染与化疗史。用改良加藤法检查虫卵和毛蚴孵化法检查毛蚴,酶联免疫吸附测定(ELISA)和间接血凝试验(IHA)检测抗可溶性虫卵抗原(SjSEA)的抗体,B超检查肝/脾病变程度。人群顿服吡喹酮40mg/kg,一个感染季节过后复查。用SPSS软件进行分析。 　结果　①询问调查渔民268人,“经常”或“间常”接触疫水的人数占907%;近5年每年平均化疗人数占240%,从未化疗者占394%;②粪检阳性率为681%(111/163),克粪虫卵数(EPG)为4877,男性均显著高于女性。 11～20岁阳性率最高(83 3 %),“经常”或“间常”接触疫水与从未化疗的两种人群阳性率分别为 763 %(106/139)和797%(51/64);③IHA检测阳性率为880%,ELISA检测阳性率为787%,均明显高于粪检阳性率;④肝/脾受损率为774%(82/10 6),其中,肝实质呈Ⅱ～Ⅲ级纤维化病变者占377%,肝肿率为585%,脾肿率为198%;⑤多次化疗人群感染率和EPG显著低于从未化疗人群;⑥复查结果表明,化疗人群粪检阳性率(354%)和EPG(3613)较未化疗人群(565%和684

Analysis on Morbidity and Chemotherapy Effects of Schistosoma japonicum Infection in Fishermen on Dongting Lake

OBJECTIVE: To clarify and evaluate the morbidity of schistosome infection and the effectiveness of chemotherapy among fishermen on East Dongting Lake. METHODS: Information on water-contact, history of infection and of praziquantel (PZQ) treatment among fishermen was collected. Kato-Katz method and miracidium hatching test were applied to detect the pathogens in stool specimen. Serum antibodies against soluble egg antigen (SEA) were detected with ELISA and IHA. B-ultrasonic examination was used to determine the pathological changes of liver and spleen. Chemotherapy PZQ 40 mg/(kg x d)] was given to the fishermen followed by a re-examination after a transmission season. RESULTS: The first investigation (six months before chemotherapy) showed that among 268 people inquired, 90.7% were frequently or intermittently contacting water, 24.0% were treated with PZQ each year, 39.4% had never been treated in the recent five years. Stool positive rate was 68.1% (111/163) and the geometric mean eggs per gram feces (EPG) were 48.77. Males had a higher infection rate (76.0%) and intensity (62.97 EPG) compared with that of females (58.7% infection rate and 30.42 EPG). The highest positive rate (83.3%) was in the age group of 11 to 20 years old. The prevalence of those who frequently or intermittently contacted water and were never treated before was 76.3% (106/139) and 79.7% (51/64), respectively. Serological positive rate was 88.0% (IHA) or 78.7% (ELISA). B-ultrasound revealed 77.4% (82/106) of the fishermen showing pathological changes in liver and/or spleen due to schistosomiasis. 37.7% of the patients showed II-III stage liver fibrosis (male: 53.0%, female: 15%), 58.5% hepatomegaly and 19.8% splenomegaly. The second investigation (six months after chemotherapy with PZQ) showed a stool positive rate of 35.4% and an average EPG 36.13 in the treatment group which were considerably lower than 56.5% infection rate and 68.47 EPG in the group without treatment. In 39 patients treated, the reversion rate from egg positive to negative was 48.7%, pathological change in liver and spleen declined by 40.6%. CONCLUSION: The prevalence and morbidity of schistosomiasis in fishermen on Dongting Lake were high due to frequent exposure to the affected water, and chemotherapy can effectively reduce the prevalence, the intensity of infection and morbidity of the fishermen.