大理市市售福寿螺广州管圆线虫感染监测报告

从大理市泰兴农贸市场随机抽取在售的福寿螺,用肺检法检测广州管圆线虫幼虫。共采集福寿螺32次,62份样品,其中24份阳性,阳性率38.71%;检查福寿螺4 708只,其中68只感染广州管圆线虫,感染率1.44%。福寿螺主要来源于瑞丽和洱源。大理州存在着广州管圆线虫病流行的危险因素,应加强食品流通中的卫生监测及公众的健康教育;并进一步做好大理市广州管圆线虫自然疫源地调查。     

温州市一起广州管圆线虫病暴发流行的调查

[目的 ]调查 1997年 10月至 11月间温州市暴发流行的嗜酸细胞性脑脊髓膜神经根炎的病因和传播因素。[方法 ]对市区某饭店聚餐的 182人进行回顾性病史调查及血清抗体检测 ,并对福寿螺及鼠类进行病原学检查。[结果 ]聚餐人员中 ,有半生食福寿螺 (Ampullaria gigas,又称大瓶螺 ,苹果蜗螺 )螺肉的 10 5人 ,发病 47例 ,罹患率为 44 .8% ;未食这种螺肉的 77人 ,无 1人发病 ,两者有非常显著性差异 (P<0 .0 0 1)。吃螺肉 4块以上者罹患率为86 .2 % (2 5 /2 9) ,少于 4块者罹患率为 2 8.9% (2 2 /76 ) ,两者差异非常显著 (χ2 =2 7.83,P<0 .0 0 1,RR=2 .98)。在同一来源地的福寿螺中找到广州管圆线虫第三期幼虫 ,在当地鼠类中找到广州管圆线虫成虫。病人血清抗广州管圆线虫抗体阳性率为 84.0 %。 [结论 ]根据临床、流行病学、病原学和血清免疫学研究结果 ,证实为一起由半生吃福寿螺引起的广州管圆线虫病暴发流行。此在我国大陆尚属首次     

广州市番禺地区褐云玛瑙螺和福寿螺广州管圆线虫感染情况调查

目的了解广州市番禺地区褐云玛瑙螺和福寿螺广州管圆线虫感染情况。方法用人工胃液消化法对采集到的褐云玛瑙螺和福寿螺进行处理,镜下观察和计数广州管圆线虫第3期幼虫,比较不同地区、不同螺种的感染率和感染度;将螺体内检获的幼虫感染健康SD大鼠并解剖,以验证之前的检查结果。结果共检测褐云玛瑙螺367只,福寿螺357只,其中褐云玛瑙螺广州管圆线虫感染率为22.62%,阳性螺感染度为57.00条/螺;福寿螺感染率为3.08%,阳性螺感染度为1.64条/螺。大岗、石碁、化龙、榄核4镇和南沙区褐云玛瑙螺广州管圆线虫感染率分别为13.33%、15.00%、20.93%、73.68%和8.41%,福寿螺感染率分别为5.88%、2.88%、1.89%、0%和3.96%。结论番禺地区褐云玛瑙螺和福寿螺均存在广州管圆线虫感染,且以褐云玛瑙螺感染较为严重。不同调查区域间螺的感染情况亦存在一定差异。     

江西省首次发现广州管圆线虫病自然疫源地

广州管圆线虫是一种以鼠类为终宿主,福寿螺等软体动物为中间宿主的自然疫源性寄生虫病。近年的调查资料显示,我国广州管圆线虫病呈现上升的趋势,而江西省的地理环境和气候适宜于福寿螺等中间宿主的生长、繁殖。为了解江西省广州管圆线虫病的流行情况,我们于2006年10月对江西省兴国县和九江县广州管圆线虫终宿主和中问宿主的感染情况进行了调查,报告如下。     

大理州洱源县西湖地区广州管圆线虫自然疫源地调查

目的了解大理州广州管圆线虫疫源地的分布、宿主种类及感染情况,为预防控制广州管圆线虫病提供科学依据。方法以市售福寿螺主要来源地洱源县西湖为调查点,对广州管圆线虫中间宿主、转续宿主和保虫宿主感染情况进行调查。结果在调查点内发现广州管圆线虫中间宿主螺类3种(福寿螺、中国圆田螺、铜锈环棱螺),剖检未查见广州管线虫感染。捕获的保虫宿主(鼠)和转续宿主(鱼、虾、蟾蜍)经检查均无广州管圆线虫感染。结论大理州目前尚无广州管圆线虫自然疫源地存在,但具备了广州管圆线虫病流行的基本条件,是潜在的疫源地,一旦有广州管圆线虫传入则可引起传播,故应加强健康教育和疫情监测。     

大理洱海周边福寿螺感染广州管圆线虫调查

广州管圆线虫成虫寄生于鼠类肺部血管,幼虫侵染人体引起嗜酸性粒细胞增多性脑膜脑炎和脑膜炎。人主要是食用含有广州管圆线虫第Ⅲ期幼虫的中间宿主或转续宿主而受到感染。福寿螺是广州管圆线虫重要的中间宿主,也是引起广州管圆线虫病暴发流行的重要生物因素之一。     

三明市广州管圆线虫病疫源地调查

在三明市广州管圆线虫病疫源地,共采集水生螺962只,鼠粪18份,蛞蝓1只,其中福寿螺312只,感染率18.27%,鼠粪感染率22.22%,蛞蝓和其他水生螺未检出广州管圆线虫。调查表明,三明市属于广州管圆线虫病疫源地分布地区,福寿螺是主要的中间宿主。     

中国不同品系福寿螺对广州管圆线虫易感性的分析

福寿螺作为广州管圆线虫的中间宿主在广州管圆线虫病的流行中扮演了重要的角色。根据福寿螺外壳及软组织特点将其分为三类：黑色福寿螺、黄色福寿螺、灰色福寿螺。将三类福寿螺用低剂量和高剂量的广州管圆线虫感染以观察其易感性,结果发现高剂量感染组中,黄色福寿螺感染率低于灰色福寿螺,这可能是黄色福寿螺在中国多个省份占优势的一个原因。通过对三类福寿螺对广州管圆线虫易感性的分析,期望为广州管圆线虫病的防治提供证据。     

福建省广州管圆线虫病流行病学调查

目的调查福建省广州管圆线虫的分布情况,分析福建广州管圆线虫病流行病学特征。方法调查全省各地的鼠类和各种软体动物广州管圆线虫的感染情况,并调查全省广州管圆线虫病人的发病情况和过程。结果福建省的沿海和山区均有广州管圆线虫的分布,终宿主主要为褐家鼠;中间宿主为福寿螺、褐云玛瑙螺和蛞蝓。人因食用或接触螺类而受感染患嗜酸性粒细胞增多性脑膜炎和脑膜脑炎,已有2起集体爆发和多例散发病例。该病用阿苯哒唑和甲苯咪唑治疗,效果良好。结论福建为广州管圆线虫病的流行区,动物感染严重,人易受感染而造成爆发流行,应引起重视,加强预防。     

间接荧光抗体试验检测广州管圆线虫病

目的 研究温州流行性嗜酸粒细胞增多性脑膜炎病是否为广州管圆线虫。方法 间接荧光标记抗体技术检验广州管圆线虫抗体,间接证实广州管圆线虫感染。结果 发现此批病人血清存在广州管圆线虫抗体,阳性检出率为８３％,且阳性滴度大于１：１０。结论 此批因食不熟福寿螺肉而患流行性嗜酸粒细胞增多性脑膜炎病人为广州管圆线虫感染引起。     

Enzootic angiostrongyliasis in Guangzhou, China, 2008-2010

This study was conducted to gain an understanding of the Angiostrongylus cantonensis infection status of rodent definitive host, snail intermediate host, and local residents in Guangzhou, China. A total of 430 rats were captured and 23 rats, from two species, were infected, with an average infection rate of 5.35%. A total of 795 Achatina fulica snails and 734 Pomacea canaliculata snails were collected. The average infection rates of these two species were 13.96% (111 of 795) and 1.50% (11 of 734), respectively. As for the seroprevalence of different occupations, the rate among the "general group" was significantly lower than the "occupational group." From this survey, Guangzhou is implicated to be the natural focus of Angiostrongylus cantonensis. Rattus norvegicus and Achatina fulica play important roles in spreading this nematode in Guangzhou. Residents who live in Guangzhou, especially those working in certain industries such as agriculture, food-making, and aquaculture, face a higher risk of infection.     

我国南方部分地区螺类感染广州管圆线虫的调查分析

目的 了解目前我国南方部分地区螺类中广州管圆线虫的感染情况和特点。方法 2017年4-10月在我国南方8个省份采集鲜活螺1 517只,用消化法检验广州管圆线虫3期幼虫。结果 螺类中广州管圆线虫的平均感染率为9.62%(146/1 517),其中褐云玛瑙螺的感染率最高,达16.78%(24/143),其次为福寿螺13.91%(79/568),环棱螺和圆田螺中的感染率在6%左右,其他螺类未检出。在6-9月采集的螺中,广州管圆线虫的感染率在10.11%~14.02%,显著高于其他月份的检测结果(4.24%~6.22%),不同月份的感染率差异有统计学意义(χ²=19.031,P<0.05)。直接从自然环境采集的螺类,其广州管圆线虫的感染率为22.28%(43/193),而采自流通环节和餐饮环节的感染率分别为8.11%(97/1196)和6.19%(6/97)。结论 我国南方部分地区螺类中存在广州管圆线虫的感染,生食螺肉类食品存在潜在感染的风险,建议在这类有螺地区开展灭鼠工作、加大螺类食品的监督管理、规范食品操作、加强食品安全教育。     

Eosinophilic meningitis risk associated with raw Ampullarium canaliculatus snails consumption

In Taiwan, Angiostrongylus cantonensis infection has been reported in foreign laborers who had consumed raw Ampullarium canaliculatus snails. This study analyzed three foreign laborers who had contracted enzyme-linked immunosorbent assay-confirmed A cantonensis infection while working in Taiwan. All three workers had consumed either roasted snails or raw snails flavored with seasoning while drinking wine. This study investigated possible risk factors for A cantonensis, including naturally occurring A cantonensis in A canaliculatus snails, viability of third-stage A cantonensis larvae in raw seasoned snails and in roasted snails, infectivity of larvae, and effects of alcohol while consuming snails. Positive infection rates in snails from five different irrigation canals in south Taiwan ranged from 12.3% to 29.4% and the average number of motile larvae per infected snail ranged from 36 to 65. The number of motile and coiled larvae in snail meat after 120 minutes seasoning was 93 (27.7%) and 233 (69.3%), respectively. After 20 minutes of roasting, most larvae in the snail meat were dead. The infectivities of motile and coiled larvae from snail meat after 60 minutes seasoning were 53.2% and 33.2%, respectively, and those from snail meat after 5 minutes roasting were 33.2% and 7.0%, respectively. Eating Taiwan A canaliculatus snails raw is extremely risky given their high infection rates and infection intensities. Even after 120 minutes seasoning or after 20 minutes roasting, snail meat should be considered unsafe for human consumption. Finally, experimental rodent studies indicated that consuming alcohol while ingesting larvae does not significantly reduced infectivity.     

Cluster of eosinophilic meningitis attributable to Angiostrongylus cantonensis infection in French policemen troop returning from the Pacific Islands

BACKGROUND: Outbreaks of eosinophilic meningitis are reported rarely, even in regions of endemic infestation with the roundworm Angiostrongylus cantonensis, such as the Pacific Basin. We report a cluster of eosinophilic meningitis presumably attributable to A. cantonensis among French policemen returning from French Polynesia. METHODS: A retrospective cohort study among French policemen who had stayed in Tahiti was conducted using a clinical definition of eosinophilic meningitis that included severe headache within 30 days after return and eosinophilia, and who consumed locally exotic ethnic dishes with uncooked freshwater prawns. RESULTS: Five persons met the case definition for eosinophilic meningitis. Corticosteroid therapy associated with antihelminthic regimen led to improvement of symptoms in one patient. Other patients were treated with albendazole alone. All patients recovered. CONCLUSION: Among travellers at risk, the presence of severe headache and eosinophilia combined with a consistent exposure history to exotic food should alert to the possibility of A. cantonensis infestation. Travellers should be aware of the risk of infection associated with eating exotic ethnic dishes.     

Epidemiologic studies of eosinophilic meningitis in southern Taiwan.

A study of the epidemiologic characteristics of 125 cases of eosinophilic meningitis or meningoencephalitis, probably caused by Angiostrongylus cantonensis, which occurred in southern Taiwan in 1968 and 1969 revealed a close association of the disease with the rainy season. In contrast to findings in other geographic areas, most such cases in this study occurred among children. A higher attack rate was observed among aborigines than among descendants of mainland Chinese. Most patients had eaten the giant African snail, Achatina fulica, prior to their illness and this mollusc was commonly found infected with third-stage larvae of A. cantonensis. However, in almost all instances the snail was eaten after it had been thoroughly cooked and examination of cooked snail meat revealed only dead larvae. It is suspected that patients became infected by inadvertently ingesting A. cantonensis larvae liberated when the snails were prepared for consumption.     

广西广州管圆线虫病疫源地调查

目的了解广西广州管圆线虫病疫源地的分布现状,为预防控制广州管圆线虫病提供科学依据。方法采用区域抽样法,由中国疾病预防控制中心统一抽取调查点。从每个点的野外、螺类养殖场、餐饮场所、自由市场等收集各类软体动物,采用酶消化法检查,阳性者计幼虫数。结果采集到的软体动物有福寿螺、褐云玛瑙螺、蜗牛和蛞蝓等4类。每个调查点都发现有阳性中间宿主,蛞蝓、福寿螺、玛瑙螺和蜗牛平均感染率分别为11.71%,10.82%,8.85%和2.67%,阳性者平均感染度分别为231条,224条,38条和2.5条幼虫。结论广西软体动物种类多、分布广,广州管圆线虫病疫源地广泛存在,中间宿主感染率和感染度高,发生疫情的可能性大,应该采取相应的防控工作。     

Angiostrongylus cantonensis infection in Ampullarius canaliculatus (Lamarck) in Kyushu, Japan

Ampullarius canaliculatus is a large fresh-water snail of which the original habitat is said to be Argentina. Recently, the snail which grew wild has propagated in various parts of Japan, and is causing damage to aquatic plants by feeding on them. The present study was performed to find out whether the snail can be a suitable intermediate host for Angiostrongylus cantonensis. Natural infection with A. cantonensis was confirmed in the snails collected from 5 different places in 4 hamlets in Okinawa and in those from Ishigaki Island. All snails experimentally infected with first-stage larvae of the parasite showed second-stage and third-stage larvae developing at the time of examination later on. Thus, A. canaliculatus is a suitable intermediate host for A. cantonensis, and, if eaten raw, it can be a potential source of human infection with eosinophilic meningoencephalitis in the endemic areas.     

宁波市广州管圆线虫病自然疫源地调查

在宁波市海曙区、慈溪市、鄞州区和奉化市进行广州管圆线虫中间宿主感染调查,在宁海县进行转续宿主调查。共采集福寿螺730只,发现15只有第Ⅲ期幼虫寄生,自然感染率为2.05%;捕捉解剖青蛙13只,发现感染青蛙5只,共检出广州管圆线虫幼虫164条,平均每蛙寄生32.8条。首次证实宁波市为广州管圆线虫病自然疫源地。