Efficacy of low doses of praziquantel in taeniasis

Early experimental studies suggested that doses of 1 to 5 mg of praziquantel (PZQ) per kg are effective against several intestinal cestodiases. The usually recommended single dose of PZQ in human taeniasis is 5 or 10 mg/kg. A study in T. saginata taeniasis showed a full efficacy at a dose of 2.5 mg/kg. A field study confirmed that a dose between 3.4 and 7.5 mg/kg was effective in expulsion T. solium tapeworms in man. A dose of 2.5 mg of PZQ per kg would be safer and more economical in population-oriented interventions aiming at control of T. solium taeniasis in man.     

Determination of the minmum effective dosages of praziquantel, albendazole, and mebendazole against Clonorchis sinensis infection in rats

In order to determine the minimum effective dosages of praziquantel, albendazole, and mebendazole against Clonorchis sinensis infection in Sprague-Dawley rats, each rat was infected with 30 metacercariae and treated with one of three drugs. The rats were killed and examined 25 days after praziquantel treatment or 11 days after albendazole or mebendazole treatment. The minimum effective dosages were a single dose of praziquantel 375 mg/kg, albendazole 150 mg/kg, and mebendazole 150 mg/kg. Trials are required to determine whether these dosages are useful in the treatment of human clonorchiasis.     

Taeniasis unresponsive to a single dose of niclosamide: case report of persistent infection with Taenia saginata and a review of therapy

A patient infected in Ethiopia with the beef tapeworm Taenia saginata was unsuccessfully treated with 2 g of niclosamide on four separate occasions over four months. clinical and parasitologic cures were effected by a regimen of 2 g of niclosamide given on three consecutive days. Niclosamide is the drug of choice for treatment of T. saginata and Taenia solium (pork tapeworm) infection; cure rates are approximately 90%. It is not absorbable and thus is nontoxic. Alternative treatments of taeniasis vary in the degree of safety; tin compounds and Aspidium extracts often are toxic. Paromomycin sulfate, which is also nonabsorbable, is effective, although adverse gastrointestinal effects are common with multiple-dose regimens. A relatively safe therapy is with mebendazole, a broad-spectrum anthelmintic agent, although efficacy has varied in different trials. A number of benzimidazoles, as well as nitazoxamide, have been effective against tapeworms. Praziquantel is the best alternative to niclosamide in terms of cost, efficacy, availability, and safety.     

Usefulness of pumpkin seeds combined with areca nut extract in community-based treatment of human taeniasis in northwest Sichuan Province, China

Taeniasis refers to the infection with adult tapeworms of Taenia spp. in the upper small intestine of humans, which is also a cause of cysticercosis infection in either both humans and/or animals. Currently the most commonly applied anthelminthics for treatment of taeniasis are praziquantel and niclosamide. Praziquantel is very effective, but has the risk of induction of epileptic seizures or convulsions in carriers with asymptomatic concurrent neurocysticercosis. In contrast, niclosamide is safe and effective, but is not readily available in many endemic countries including China. In the current community-based study, we assessed the curative effect of either pumpkin seeds or areca nut extract alone in taeniasis, and also looked at synergistic effects of these two herb drugs on tapeworms. In the study group with the pumpkin seed/areca nut extract treatment, 91 (79.1%) of 115 suspected taeniasis cases (with a history of expulsion of proglottids within the previous one year) released whole tapeworms, four (3.5%) expelled incomplete strobila, and no tapeworms or proglottids were recovered in the remaining 20 cases. In these 115 persons, 45 were confirmed as taeniasis before treatment by microscopy and/or coproPCR. Forty (88.9%) of 45 confirmed cases eliminated intact worms following treatment. The mean time period for complete elimination of tapeworms in 91 taeniasis cases was 2h (range 20min to 8h 30min), and 89.0% (81) of 91 patients discharged intact worms within 3h after drug administration. In Control Group A with treatment of pumpkin seeds alone, 75.0% (9/12) of confirmed taeniasis cases expelled whole tapeworms, but the mean time period for complete elimination was about 14h 10min (range 3h 20min to 21h 20min), which was much longer than that (2h) for the study group, whereas in Control Group B treated with areca nut extract alone, only 63.6% (7/11) of taeniasis cases discharged whole tapeworms, and the mean time period was 6h 27min (range 1-22h). Mild side effects included nausea and dizziness in about 46.3% of patients with the pumpkin seeds/areca nut extract treatment, but all discomforts were transient and well tolerated. In conclusion, a synergistic effect of pumpkin seed and areca nut extract on Taenia spp. tapeworms was confirmed in the current study, primarily in producing an increased rate of effect on tapeworm expulsion (average time 2h for combination vs 6-21h for individual extracts). The pumpkin seed/areca combined treatment was indicated to be safe and highly effective (89%) for human taeniasis.     

河南省带绦虫病与囊尾蚴病流行趋势及防治历程

河南省原是绦虫病、囊尾蚴病高发省份之一,主要流行绦虫种类为猪带绦虫。自20世纪70年代以来,经过多年积极有效防治,河南省人群带绦虫、囊尾蚴感染率已处于极低流行水平,推动了全国“驱绦灭囊”工作。“驱绦灭囊”和分类指导并重的工作方针在全省范围内取得较好防治效果。随着我国对外开放及“一带一路”倡议的持续推进,带绦虫病、囊尾蚴病防控工作仍存在着一些问题与挑战。本文主要回顾河南省带绦虫病和囊尾蚴病防治历程,并对目前带绦虫病和囊尾蚴病防治工作面临的挑战进行分析。     

吡喹酮与槟榔-南瓜子治疗带绦虫病的疗效比较

目的 比较吡喹酮与槟榔-南瓜子治疗带绦虫病的疗效,总结治疗经验,提高治疗水平.方法 回顾性分析2014-2019年收治的250例患者资料,分吡喹酮治疗组142例,槟榔-南瓜子治疗组108例,进行疗效比较.结果 吡喹酮组治愈率为93.66％,槟榔-南瓜子组为91.67％,差异无统计学意义(P>0.05).治疗后24 h粪...     

Population-based survey of taeniasis along the United States-Mexico border

Taenia solium and T. saginata are zoonotic tapeworms of substantial medical and economic importance. Although human taeniasis is widely recognised as an endemic problem in Mexico, its presence in the United States is poorly understood. The first population-based study to estimate the prevalence of human infection with Taenia tapeworms along the Texas-Mexico border has recently been conducted. Households were interviewed in the Texan city of El Paso and in the neighbouring Ciudad Juárez, in Mexico. Faecal samples from household members were then checked for Taenia eggs by flotation and/or for Taenia copro-antigens in an ELISA. The overall prevalence of taeniasis in this border region was found to be 3% but, compared with the residents of Juárez, El Paso residents were 8.6-fold more likely to be tapeworm carriers. The interviews revealed some important differences between the two study sites, particularly the more frequent use of anthelminthic drugs on the Mexican side of the border. These findings have implications in terms of the planning of effective health-education campaigns to decrease the prevalence of taeniasis in the human populations along the Texas-Mexico border.     

The use of mebendazole in the treatment of Taenia saginata taeniasis in an endemic area in the Philippines.

The successful treatment of Taenia saginata taeniasis with mebendazole is herein reported. 41 subjects ascertained to have taeniasis based on the history of passage of gravid segments and positivity for Taenia egg were treated with 300 mg mebendazole b.i.d. for 3 days without need for fasting. No side-effects were observed. The drug acts as a taeniacide. The worms were expelled either as degenerated boluses or fragmented segments on the 2nd to the 4th day (Mean: 2.4 days) after the initial dose. 33 (84.6%) of the 41 subjects expelled the worm. A follow-up of all the subjects 2--3 months after treatment revealed that all those who expelled the worm following treatment and 6 of those who did not were negative for both Taenia egg and gravid segment, or a cure rate of 95%.     

Comparison of albendazole, mebendazole and praziquantel chemotherapy of Echinococcus multilocularis in a gerbil model.

The efficacy of albendazole (50 mg/kg/d), mebendazole (50 mg/kg/d) and praziquantel (500 mg/kg/d) against established intraperitoneal infections of Echinococcus multilocularis in gerbils was compared by monitoring parasite weight and making ultrastructural observations on treated and untreated material. Praziquantel was the most active protoscolicidal agent, reducing protoscolex viability to less than 2%, although it did not inhibit cyst growth. Albendazole was the most effective agent in reducing cyst growth and was, when compared with other regimes significantly more effective than mebendazole (p less than 0.05), praziquantel (p less than 0.01) or untreated controls (p less than 0.01).     

Species identification after treatment for human taeniasis

Identification of species of human tapeworms is crucial because the consequences of infection by Taenia solium and T saginata are very different. However, evacuation of species-identifiable tapeworms is uncommon and Taenia spp eggs are indistinguishable under the microscope. Treatment of taeniasis consists of niclosamide followed by a purgative. Recently, we adopted preniclosamide and postniclosamide electrolyte-polyethyleneglycol salt (EPS) purges to improve bowel cleaning. Retrospective comparison of traditional castor oil with EPS purge showed that recovery of the tapeworm scolex was significantly improved (20 of 68 vs none of 46, p=0.0001) in the EPS group. Furthermore, 42 of 68 (62%) individuals receiving EPS excreted identifiable gravid proglottids. EPS treatment helps the visual identification of Taenia spp.     

2016-2019年大理市带绦虫病疫情监测结果分析

目的 了解大理市带绦虫病流行现状和动态,掌握流行规律,预测流行趋势,为制订防治规划提供依据。 方法 2016-2019 年,在大理市开展带绦虫病病史调查和粪检查病,对自愿接受驱绦治疗的部分感染者和自述有排节片史而粪检阴性居民进行驱虫治疗,后者驱出带绦虫完整虫体或节片者判为阳性,计入查病结果。 结果  2016-2019 年,带绦虫感染率依次为 2. 94%、2. 26%、0. 93%和 0. 33%,呈逐年下降趋势。 年平均感染率男性(2. 13%) 高于女性(1. 18%);14~组(2. 44%)高于 3~组(0. 47%)和 60 ~ 组(1. 18%);农民组(1. 99%)高于在校学生组(0. 64%);文盲或半文盲组(3. 56%)高于学龄前儿童及小学组(1. 49%),也高于中学组(1. 25%);所有感染者均为白族。 教师、村干部及大学专科及以上居民 4 年均未查到阳性。 结论 当前大理市带绦虫病疫情处于历史最低水平,但市民喜食生肉、生猪肝等习惯依然存在,因此带绦虫病防治工作还面临诸多挑战,应进行综合治理。     

Prevalence and risk factors for Taenia solium taeniasis and cysticercosis in humans and pigs in a village in Morelos, Mexico.

In a Mexican village in which Taenia solium infection was known to be endemic, we selected a cluster sample of 368 households (21% of the total) for demographic, environmental, and diagnostic surveys, and medical histories for taeniasis and cysticercosis. Coproparasitologic studies of 1,531 participants revealed infection by Taenia sp. in four (0.3%) individuals; however, 5.8% of the respondents reported a history of having passed tapeworm proglottids in feces. Of 1,552 human serum specimens, 10.8% tested positive in the cysticercosis immunoblot assay. Seropositivity increased with age and reached a maximum in subjects ages 46-55 years. Risk factors associated with seropositivity included a history of passing tapeworm proglottids, frequent consumption of pork, and poor personal and household hygiene (P less than 0.05). A history of seizures was also significantly associated with seropositivity (P less than 0.05); approximately one-third of persons with such histories were seropositive. Of 571 pigs examined by tongue inspection, 23 (4.0%) had cysticerci; infection rates increased with the age of pigs, and were higher in pigs that habitually ran loose or were fed human feces (P less than 0.05). Goodness of fit analysis confirmed that seropositive persons (but not infected pigs) were significantly clustered within households, particularly, in households in which a member reported a history of having passed tapeworm proglottids. The results of this study have identified community behavioral and environmental practices that must be modified to prevent continued transmission of cysticercosis and taeniasis.     

Taenia solium taeniasis and neurocysticercosis in a Mexican rural family.

A case of neurocysticercosis in a six-year-old Mexican boy and a case of Taenia solium taeniasis in his five-year-old brother are reported. Neurocysticercosis was suspected based on clinical findings and was confirmed by computed tomography scanning. A parasitologic examination with zinc-sulfate flotation and formalin-ether sedimentation techniques was carried out on the whole family, and revealed Taenia sp. eggs in three stool samples from the five-year-old boy. The entire family agreed to undergo chemotherapy with niclosamide, but only the child passing taeniid eggs eliminated T. solium. No additional taeniasis cases were found in an examination of 20% of the village population, using the same parasitologic techniques. The results of an ELISA using cysticercus antigens were negative for the boy with neurocysticercosis, for other family members, and for 24 village volunteers, but were positive for the T. solium tapeworm carrier. It was concluded that in this family, person-to-person transmission of the tapeworm occurred due to poor living conditions and hygiene.     

Development of a serologic assay to detect Taenia solium taeniasis

We developed a serologic assay to identify adult Taenia solium tapeworm carriers using excretory/secretory (TSES) antigens collected from in vitro cultured T. solium tapeworms. To identify taeniasis-specific antigens we used an immunoblot assay with serum samples from T. solium tapeworm carriers and cysticercosis patients. Antigens were identified that reacted with antibodies present in serum samples from taeniasis cases and not with those from cysticercosis patients. Using serum samples collected from persons with confirmed T. solium tapeworm infections, the test was determined to be 95% (69 of 73) sensitive. Serum samples (n = 193) from persons with other parasitic infections, including T. saginata tapeworm infections, do not contain cross-reacting antibodies to TSES, indicating that the assay is 100% specific. These data suggest that the immunoblot assay using TSES antigens can be used to identify persons with current or recent T. solium tapeworm infections and provides a new, important tool for epidemiologic purposes, including control and prevention strategies.     

Mebendazole.

The broad-spectrum of activity and safety of mebendazole remain, after 5 years of clinical experience, unique features of this anthelmintic. Through microtubular destruction, mebendazole kills helminths by inhibiting glucose uptake into susceptible parasites. The drug's poor absorption does not appear to affect clinical efficacy except, perhaps, in the treatment of systemic helminth infections. Mebendazole is generally considered the drug of choice for trichuriasis and has therapeutic advantages over other anthelmintics in the treatment of enterobiasis and hookworm infections. Although mebendazole is an effective agent against ascariasis, there are preferable alternatives. Among its nonapproved uses, mebendazole shows great promise in the treatment of capillariasis and hydatid disease. Further investigation is needed to establish its role in the treatment of taeniasis, Hymenolepsis nana, strongyloidiasis, trichinosis, and Dipetalonema perstans. Undoubtedly, mebendazole will find its greatest value in the treatment of patients with multiple helminth infections.     

Taeniasis and cysticercosis in housemaids working in affluent neighborhoods in Lima, Peru

Taenia solium taeniasis/cysticercosis is endemic in most developing countries, where it is an important cause of epileptic seizures and other neurologic symptoms. In industrialized countries, cysticercosis results from travel or immigration of tapeworm carriers from endemic areas. In both endemic and nonendemic countries, housemaids commonly immigrate from cysticercosis-endemic areas and can transmit the infection if they carry the adult tapeworm. Between July 2001 and July 2002, 1,178 housemaids (961 of them work in the top five most affluent districts of Lima, a metropolis of 8 million inhabitants considered nonendemic for cysticercosis) were evaluated for serum antibodies to Taenia solium and stool microscopy for taeniasis and cysticercosis. The serosurvey revealed a prevalence of cysticercosis-specific antibodies of 14.6% (95% CI: 12.6-16.6%), and stool microscopy detected 12 T. solium tapeworm carriers, for a prevalence of taeniasis of 1.2% (95% CI: 0.6-1.8%). A nonrandom sample of 26 seropositive housemaids was examined by brain CT and 50% of them had brain lesions compatible with neurocysticercosis, mainly calcifications. From the families who used a tapeworm-carrier housemaid, cysticercosis antibodies were detected in 6 (23%) of 26 persons who agreed to participate. One seropositive member of the employer families was symptomatic for seizures and had brain calcifications. The prevalence of tapeworm infections in this housemaid group is similar to levels in endemic areas, constituting a source of neurocysticercosis infection.     

福建省绦、囊虫病流行现状调查

目的 了解福建省猪带绦虫病、囊虫病流行现状。方法 随机选择5个县（市、区）16个村（点）。检测受检者血清猪带绦、囊虫抗体，阳性者询问病史。结果共查16371人，人群抗体阳性率为2．28%（89／3899）；人体猪带绦虫感染率为0．02％（3／16371）。结论 福建省流行猪带绦、囊虫病，应引起重视。     

Substituted methyl benzimidazole carbamate: efficacy against experimental cysticercosis.

Methyl [5-([4-(2-pyridinyl)-1-piprazinyl] carbonyl)-1H benzimidazole-2-yl] carbamate, a broad spectrum anthelmintic, was tested against Cysticercus fasciolaris in rats and the cysticercoids of Hymenolepis nana in beetles. A dose of 50 mg kg-1, given intraperitoneally (i.p.) to infected rats on 10 alternate days, was found most effective, killing all mature cysticerci. The same dose, given on each of five days, either from the fifth day prior to infection or the sixth day following infection, fully arrested the establishment of cysticerci. A single prophylatic dose of 500 mg kg-1, given intramuscularly (i.m.), protected rats against challenge with Taenia taeniaeformis eggs for 10 days. The test compound, mebendazole and praziquantel were all totally ineffective against mature cysticercoids in grain beetles but, of the beetles fed the drugs in flour, 66.3%, 50% and 83.8%, respectively, failed to support the development of immature cysticercoids. The effective cysticidal action of the compound makes it a candidate medical anthelmintic.     

Economic implications of three strategies for the control of taeniasis

Objective To evaluate the cost‐effectiveness of three strategies for the control of taeniasis in a community, in terms of cost per case treated. Methods A study was conducted in South India to determine the prevalence of taeniasis by screening stool samples from 653 randomly chosen subjects, for coproantigens. The costs incurred in the project were used to estimate the cost per case screened and treated. A one‐way sensitivity analysis was carried out for varying rates of taeniasis, different screening strategies and mass therapy. Further sensitivity analysis was carried out with different manpower and test costs. Results The rate of taeniasis as detected by ELISA for coproantigen was 3 per 1000 (2 of 653 samples). Our study showed that mass therapy without screening for taeniasis would be the most economical strategy in terms of cost per case treated if field workers are employed exclusively for either mass therapy or screening. For each strategy, costs per case treated are higher at low prevalence of taeniasis, with a sharp rise below 15%. Conclusions In places that are endemic for taeniasis and neurocysticercosis, mass therapy or screening for taeniasis should be considered. Screening by stool microscopy is not cost‐effective in terms of cost per case of taeniasis treated owing to its low sensitivity. Although the cost per case of taeniasis treated is high at low prevalence of taeniasis for all options, incorporating mass therapy into existing mass drug distribution programmes might prove to be the most cost‐effective control strategy.     

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。