Taenia solium taeniasis and cysticercosis:extinction or outbreak

Taenia solium taeniasis and cysticercosis are neglected zoonotic diseases that affect human health and economies of developing countries.In this work,we formulate and analyze deterministic and continuous time Markov chain(CTMC)stochastic models to determine parameters that drive Taenia solium taeniasis and cysticercosis and the likelihood of their extinction.The basic reproduction number R0 is computed by the next generation matrix approach,sensitivity index of each parameter in R0 is derived by the normalized forward sensitivity index and the likelihood of diseases’extinction is computed by the multitype branching process.The analysis shows that humans with Taenia solium taeniasis,infectious pork and Taenia solium eggs in the environment play an important role in the transmission of Taenia solium taeniasis and cysticercosis,and the model exhibits forward bifurcation at R0=1.This implies that R0<1 is a sufficient condition to eliminate Taenia solium taeniasis and cysticercosis.For CTMC model,analysis shows that the probability of Taenia solium taeniasis and cysticercosis extinction is high if the diseases emerge from humans with Taenia solium cysticercosis and there is an outbreak if the diseases emerge from either humans with Taenia solium taeniasis or infectious pork or Taenia solium eggs in the environment.To control Taenia solium taeniasis and cysticercosis,the intervention strategies should focus on improving hygiene and sanitation for reducing shedding rate of Taenia solium eggs in the environment,inspection of pork for reducing the rate of acquiring Taenia solium taeniasis and spraying of insecticides for killing Taenia solium eggs in the environment.

Taeniasis vs cysticercosis infection routes

Although cysticercosis caused by Taenia solium(T. solium) is considered a neglected disease, its life cycle has been well known for more than two centuries. T. solium not only causes cysticercosis but also taeniasis in humans. These two diseases have totally different infection routes. To acquire taeniasis(the presence of the adult stage of T. solium in the intestine), humans have to ingest the larval stage(cysticercus) that infects a variety of organs and viscera in pigs, its intermediate hosts. Therefore, taeniasis is acquired when eating raw or undercooked infected pork. The adult stage in the human intestine release eggs that contain a hexacanth embryo, the oncosphere. If humans accidentally ingest the eggs of T. solium, the released oncospheres penetrate the intestine and become cysticerci. Therefore, cysticercosis is acquired by the ingestion of eggs that contaminate water, vegetables, hands etc. These facts should not be forgotten to avoid misinformation in scientific publications.

Effects of Arecoline Hydrobromide on Taeniasis and Cysticercosis in Domestic Animals

Taeniasis and cysticercosis in domestic animals belong to zoonosis and seriously threaten the public health security. Especially the cysticercosis and echinococcosis caused by the tapeworm eggs have great harms to bodies because they can attack many organs of body. According to the combination of experimental results and literature materials, the morphology and transmission mode of taenia and cysticercus, the prevalence status and monitoring of taeniasis and cysticercosis as well as the antitapeworm mechanism, comparative analysis to other drugs, expelling tapeworm tests in vitro, dose determining tests and usage notes of arecoline hydrobromide were expounded in detail. It provides a theoretical basis for prevention of taeniasis and cysticarcosis and more scientific usage of arecoline hydrobromide and thus relieves the harms of taeniasis and cysticercosis and ensuring the public health security.

The Serological Survey for Human Cysticercosis Prevalence in Mbulu District, Tanzania

Human cysticercosis, a zoonotic disease due to Taeniasolium, is of the highly debilitating and stigmatizing neglected tropical diseases due to epilepsy, ophthalmia and dermatological disorders in endemic developing countries. Tanzania is among the sub-Saharan African countries with an average prevalence of porcine cysticercosis 17.2% [1], which increases the risk of human cysticercosis infection. Studies on people with epilepsy in northern zone of Tanzania show a 16.2% [2] to be suffering from neurocysticercosis. While this was the case, there were no single report on the prevalence of human cysticercosis neither to regular hospital visitors, admissions, and nor general public that result to insufficient deployment of intervention strategies. Study was performed to assess the prevalence of human cysticercosis in general public in Mbulu district. The cephalic venous blood was collected from assorted community members. Serum was extracted and then subjected to Cysticercus IgG Western Blot Assay for human cysticercosis sero-screening. It was found that about 16.3% of the community members had antibodies signifying infection by human cysticercosis. This is the first ever study to assess the prevalence of human cysticercosis in the country and it has revealed the problem to be very high. This study can be valuable for deployment of appropriate intervention measures on human cysticercosis in the study area and extend to the entire country.

A Review of Human Cysticercosis and Diagnostic Challenges in Endemic Resource Poor Countries

Human cysticercosis is a neglected tropical parasitic zoonotic disease with high public health concerns. Infection of Taenia solium cysticerci in the brain commonly known as neurocysticercosis is a cause to over 29% of all epileptic cases in endemic countries. Unfortunately, this infection can go unnoticed for over 10 years. The objective of this review was to characterize the diagnostic approaches accessible in endemic poor resource countries. The review sought literature from library catalogues and public databases for studies on epidemiology and diagnosis challenges of human cysticercosis. The search key words included “Taenia solium, T. solium cysticercosis, human cysticercosis, neurocysticercosis and diagnosis”. Most of the diagnostic procedures rely on serology. Neuroimaging tools which would confirm and thus enable the assessment of the burden of the disease in endemic countries are rarely used. Therefore assessing the estimate on prevalence and burden of the disease fallacious is owing to the low sensitivity of serological tools and the inhibition of humoral, cellular immune responses, inflammatory reaction and cytokines by the living cysticerci.

Disseminated cysticercosis incidentally diagnosed in a patient of low backache:A case report and concise review of literature

Disseminated cysticercosis is an uncommon presentation of a common disease.Asymptomatic disseminated cysticercosis is rarely reported in literature.Here,we are reporting a case of asymptomatic disseminated cysticercosis incidentally diagnosed in a patient of low backache. Magnetic resonance imaging of lumbosacral spine and neuroimaging done subsequently during the course of evaluation revealed diffuse cysticercosis involving abdominal,paraspinal,pelvic and gluteal muscles along with neurocysticercosis.Such a disseminated cysticercosis was diagnosed incidentally in this patient of low backache with right sciatica and radiculopathy at L5-S1 prolapsed intervertebral disc and was subsequently managed by L5-S1 interlaminar fenestration and discectomy.

A preliminary analysis of some epidemiological factors involved in porcine cysticercosis in Bafut and Santa subdivisions,North West Region of Cameroon

Objective:To examine the magnitude and some risk factors of porcine eysticercosis in Bafut and Santa,two sub-divisions noted for pig farming in the North West Region of Cameroon.Methods: A total of 499 pigs in 300 households were examined by tongue inspection and serologically by Ag-ELISA.Information was sought on the age and sex of the animals,prevailing husbandry systems,types of feed,the state of each pen and the state of toilets.Futhermore,a questionnaire was administered to the farmers to determine their awareness on taeniasis/cysticercosis and related factors.Results:The prevalence of the disease was significantly higher in Santa(10.2%) than in Bafut(4.2%),although there was a higher level of awareness in both localities(62.3%).Age of pigs,traditional rearing systems(roaming,tethered,earth floor pen,raised floor pen),faecal disposal in the environmenl and poor sanitation significantly influenced the seroprevalence of porcine cysticercosis in both localities.Most farmers(79.7%) used a combination of concentrate, grass and kitchen waste to feed pigs.Financial loss from porcine cysticercosis was estimated at 346 900 CFA representing 2%of total income.Conclusions:Control measures advanced here include sensitization campaigns,periodic examination and treatment of infected pigs by veterinarians,improved husbandry systems,proper use of standard latrines regularly inspected by sanitary officers,and sound hygienic and sanitary practices.

Intraventricular neurocysticercosis: Presentation, diagnosis and management

Neurocysticercosis is thought to be the most common helminthic infection of the central nervous system and its epidemiology is changing due to increasing travel and migration.Evidence to guide management of the intraventricular form is limited.We aimed to review the clinical presentation,diagnosis and treatment of intraventricular neurocysticercosis with reference to two recent cases seen at our institution.The intraventricular variant of neurocysticercosis is less common than parenchymal disease and usually presents with acutely raised intracranial pressure and untreated it progresses rapidly with high mortality.The diagnosis is based on imaging and serological tests but more invasive testing including histopathological examination of surgically acquired tissue specimens is sometimes required.Treatment is mainly surgical,using a neuroendoscopic approach if possible.Patients should also receive antihelmintic treatment with concomitant corticosteroids to reduce the incidence of shunt failure if a ventricular shunt is inserted and to treat viable lesions elsewhere.

A Brazilian Case of Tongue Cysticercosis

Human cysticercosis is a neglected tropical parasitic disease due to the tapeworm Taenia solium, common in endemic developing countries. Cysticerci are most commonly found within the central nervous system, but they may also localize in a variety of tissues, including the tongue. Here, we described a case of a 21-year-old woman with a painless, firm, smooth, mucosa-colored nodule located in the lateral region of the tongue was seen by a dentist. An excisional biopsy was performed, and the surgical specimen was examined histomorphologically. The analysis revealed the presence of a cystic lesion containing a serrated larva (Cysticercus cellulosae) as well as a cystic capsule with predominantly mononuclear inflammation. The morphological findings were consistent with the diagnosis of cysticercosis of the tongue. The patient was followed for 22 months and showed no signs of recurrence.

Development of a health education intervention strategy using an implementation research method to control taeniasis and cysticercosis in Burkina Faso

Background:Taeniasis and cysticercosis are two diseases caused by Taenia solium,a parasite transmitted between humans and pigs,leading to considerable economic loss and disabilities.Transmission of the parasite is linked to environmental and behavioural factors such as inadequate sanitation and hygiene,poor pig management,and consumption of infected pork.This study used implementation research method to design a health education intervention strategy for reducing T.solium infections in Burkina Faso,a country endemic for the parasite.Methods:Eighteen group discussions were conducted with 8-18 participants each in three villages.In addition,structured interviews were conducted among 4777 participants and 2244 pig owners,who were selected through cluster random sampling in 60 villages of three provinces of Burkina Faso.Both approaches assessed knowledge and practices related to T.solium.The information obtained was used to develop a community-adapted health education intervention strategy to control taeniasis and cysticercosis in Burkina Faso.Results:The group discussions revealed that participants had a poor quality of life due to the diseases as well as inadequate access to latrines,safe water,and healthcare services.In addition,it was found that pig production was an important economic activity,especially for women.Furthermore,financial and knowledge constraints were important limitations to improved pig management and latrine construction.The survey data also showed that open defecation and drinking unboiled water were common behaviours,enhanced by a lack of knowledge regarding the transmission of the parasite,perceived financial barriers to the implementation of control measures,lack of public sensitization,as well as a lack of self-efficacy towards control of the parasite.Nevertheless,the perceived financial benefits of controlling porcine cysticercosis could be emphasized by an education program that discourages open defecation and encourages drinking safe water.The final intervention strategy included a Participatory Hygiene and Sanitation Transformation(PHAST)approach,as well as a 52-min film and an accompanying comic booklet.Conclusions:The main problem in the study communities regarding the transmission of T.solium cysticercosis is the random disposal of human faeces,which can be contaminated with parasite eggs.Prevention of open defecation requires the building of latrines,which can be quite problematic in economically challenged settings.Providing the community with the skills to construct durable latrines using low-cost locally available materials would likely help to resolve this problem.Further studies are required to implement and evaluate the T.solium control strategy developed in this study.

3956例绦、囊虫病门诊病例分析

对3956例1973～1990年来就诊的绦、囊虫病例进行了分析,结果发现绦、囊虫病有逐年增多的趋势。病人分布广,来自山东15个地市、91个县区。发病年龄以青壮年占多数,男性多于女性,农民发病率最高。囊虫病者自体感染占51.86％、异体感染为48.14％.脑囊虫病约占80％,合并皮下囊虫者约占60％,癫痫型最多。目前囊虫病的误诊率仍较高,免疫诊断和脑CT的应用提高了单纯型脑囊虫病的诊断率。襄虫病的临床分型对于选择治疗方案和预后具有重要意义。

猪带绦虫/囊虫病的流行现状及防制策略

猪带绦虫/囊虫病呈世界性分布,尤其在拉丁美洲、非洲和亚洲等发展中国家广泛流行,而且正在成为发达国家新的健康问题。猪囊虫病不仅造成养猪业巨大的经济损失,而且严重危害人体健康。因此,在建立灵敏、特异诊断方法的基础上,对绦虫、脑囊虫病人进行药物治疗和对易感猪的免疫保护以及加强健康教育、市场检疫的综合措施,将是预防和控制猪囊虫病的有效途径。

青海省东部农村人体猪带绦/囊虫病调查分析

目的调查青海省东部农村人体猪带绦/囊虫病的流行情况。方法使用问卷进行流行因素调查;粪抗原ELISA法用于绦虫病检测;生理盐水直接涂片法和醛醚法镜检绦虫卵用于绦虫病人的确诊;囊虫病ELISA法用于囊虫病检测。结果调查4个自然村,共766人。镜检598人,确诊绦虫病病人2例,患病率为0.33%;绦虫病粪抗原ELISA检查512人份,阳性率为9.18%;囊虫病ELISA检查652人,阳性率为4.14%。结论该地区绦/囊虫病流行仍然很严重。

畜禽绦/囊虫病及氢溴酸槟榔碱驱绦虫效能观察

畜禽绦/囊虫病是严重危害公共卫生安全的人畜共患病,尤其是绦虫虫卵引起的蚴虫病、囊虫病和肝、肺、脑包虫病等,因其侵蚀人的诸多实质器官而危害巨大。笔者将文献资料与试验结果相结合,从绦虫和囊虫的形态及传播途径、绦虫病和囊虫病的流行现状及监测、氢溴酸槟榔碱驱绦虫机理、氢溴酸槟榔碱与其它驱绦虫药物对比分析、氢溴酸槟榔碱的体外驱虫试验、氢溴酸槟榔碱剂量确认试验以及氢溴酸槟榔碱驱除畜禽绦虫注意事项这八个方面进行了详细阐述,以期为绦/囊虫病的控制和临床科学规范使用氢溴酸槟榔碱提供理论依据,减轻绦/囊虫病的危害,保障公共卫生安全。

山东省绦/囊虫病社区防治对策研究

在完成实验区内绦／囊虫病流行病学调查的基础上，采用控制传染源、培训基层卫生人员以及开展健康教育等措施，探讨社区防治绦／囊虫病的对策。结果显示，防治前当地猪带绦虫和囊虫患病率均为３．１，干预措施实施１年中，囊虫病仅发病１例，发病率为０．０５，未发现新发绦虫病病例，血清抗体阳性率由１．７３％降为０．５９％；防治前，猪体囊虫检出率为０．４％～０．８％，防治后调查未发现囊虫病猪；同时，健康教育的深入开展使居民的卫生防病知识有显著提高。

健康教育在绦、囊虫病防治中的价值研究

为了观察健康教育在绦、囊虫病防治中的效果，１９９４～１９９６年在河南夏邑县进行了健康教育干预及驱绦工作。两年干预后，结果为：关于绦囊虫病防治知识正确答卷率由干预前的２２．５％提高至１００％；绦虫感染率从０．０４％下降到０．００２％（Ｐ＜０．０１）；无新发囊虫病例。提示：抓好健康教育，提高居民的自我防病意识，在逐步消灭绦、囊虫病工作中具有重大的意义和价值。

鲁中地区猪带绦/囊虫病流行病学调查研究

为摸清鲁中地区猪带绦 /囊虫病流行情况 ,1997年对平阴等 5县 (区 ) 2 2处乡 (镇 ) 5 6个自然村的 35 5 12人进行了调查。人群绦虫病患病率为 0 .10 1% ,囊虫病患病率为 0 .10 7%。 5县 (区 )均有不同程度的流行。男女之间绦/囊虫病患病率无显著性差异 ,但患病率随年龄增加而升高 ,二者呈正相关。另外 ,发现其分布有明显的职业特征。人群抗囊尾蚴特异性 Ig G4抗体阳性率平均为 2 .2 4%。猪囊虫感染率在 0 .12 %～ 0 .48%之间 ;5县 (区 )共采集 2 0 4份猪血标本 ,血清学检测抗体阳性率为 4.41%。同时 ,对居民饮食、卫生习惯。

我国囊尾蚴病分布情况调查

囊尾蚴病的发生和流行是一个重要公共卫生问题，１９８８～１９９２年进行的全国人体寄生虫分布调查中，对囊尾蚴病作了回顾性调查，收集１６５０８例囊尾蚴病，分布在２９个省（区、市）的６７１个县（市）中。全国有５个集中分布区。年龄构成比是３０～３４岁组最高，性别构成比男性高于女性，职业构成比以农民最高，其次是工人和干部。当前我国囊尾蚴病流行病学的新特点是：①流行地域扩大，分布区域相对集中；②儿童患病人数有上升趋势；③城乡患病率差别正在缩小。

温州地区人群猪带绦虫/囊虫病流行病学调查

目的:了解温州地区猪带绦虫/囊虫病流行情况,为本地区猪带绦虫/囊虫病的防治工作提供参考依据。方法:运用流行病学方法、血清学和粪便检查对本地区猪带绦虫/囊虫病进行调查。结果:温州地区人群血清囊虫抗体阳性率为0.61％,猪带绦虫病现患率为0.02％,囊虫病现惠率为0.09％。结论:温州地区囊虫病呈零星散发状态,且较多为输入性感染,但仍须重视猪带绦虫病和囊虫病的防治工作。

山东省带绦虫病与囊虫病重点疫区流行现状调查研究

目的了解山东省带绦虫病与囊虫病在重点疫区的流行情况。方法 １９９９年对聊城等 ４市地的５县（区）１５个乡（镇）４３个行政村的 ３１１２４人进行了调查。结果人群带绦虫感染率３．２／万，囊虫感染率５．１／万，有较明显的职业分布特征。人群血清猪囊尾蚴特异性ＩｇＧ４，抗体阳性率１．３８％，商品猪血清囊尾蚴抗体阳性率０．３８％。结论初步搞清了山东省重点疫区带绦虫病与囊虫病的流行现状，并对该病的各流行环节做了分析，为该病的预防提供了参考信息。