Why are tapeworm carriers so difficult to find? A methodological proposal for their search and recovery.

Neurocysticercosis, caused by the larval stage of Taenia solium, is a life-threatening condition and the most severe form of the disease. Yet, despite being a required link in the parasite life cycle, tapeworm carriers are rarely reported. This study is aimed to find and evaluate T. solium carriers, describing some characteristics of these patients and the treatment. Taeniasis cases were searched for in various Mexican states from 1983 to 2016. Previous informed consent, tapeworm-carrier patients were administered with niclosamide and a saline purge. Parasite specimens were recovered and identified, both morphologically and by PCR. From 117 treated patients, Taenia sp. specimens were obtained from 46 subjects (47.8%). From these, complete parasites were recovered from 42 (90.5%), and only detached proglottids from 4 patients. Cases were more frequent in Morelos, Chiapas, and Guerrero. More than one adult cestode was recovered from 4 patients (9.5%). To improve treatment efficacy and adherence, the drug was administered in late afternoon, resulting a high recovery yield of complete parasites (90.5%). The success rate of deworming campaigns in areas of Mexico and the world that are endemic for Taenia sp. could be improved by administering the treatment at times that do not interfere with the patients' daily activities, and national health authorities could apply this simple strategy to help eradication efforts in endemic areas. The detection of carriers will only be possible through the coordinated efforts of public and private health services, a better education of the general population to improve self-detection, and adequate, personalized diagnostic procedures for suspect cases.

Taenia solium Cysticercosis and Its Impact in Neurological Disease.

Taenia solium neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in developed countries because of immigration and travel, NCC is one of few diseases targeted for eradication. This paper reviews all aspects of its life cycle (taeniasis, porcine cysticercosis, human cysticercosis), with a focus on recent advances in its diagnosis, management, and control. Diagnosis of taeniasis is limited by poor availability of immunological or molecular assays. Diagnosis of NCC rests on neuroimaging findings, supported by serological assays. The treatment of NCC should be approached in the context of the particular type of infection (intra- or extraparenchymal; number, location, and stage of lesions) and has evolved toward combined symptomatic and antiparasitic management, with particular attention to modulating inflammation. Research on NCC and particularly the use of recently available genome data and animal models of infection should help to elucidate mechanisms of brain inflammation, damage, and epileptogenesis.

A co-infection case report of Taenia saginata in a patient with subclinical clonorchiasis confirmed by the combination of diagnostic tools.

BACKGROUND: Clonorchiasis is the common parasitic infection in the general population of the Republic of Korea, however, taeniasis is scarcely reported recently. Here, we describe a case of co-infection with the cestode T. saginata in a patient with subclinical clonorchiasis diagnosed by a combination of diagnostic tools in Korea. CASE PRESENTATION: A 56-year-old man visited the hospital having passed proglottids in his stool for the past two months and brought a stool sample with segments to our hospital. He had no abdominal symptoms, such as nausea, vomiting, abdominal pain, diarrhea, or constipation. He used to consume raw beef and fish frequently. We could not find evidence of gravid proglottids which contain fully developed uteri filled with ova or branched uterine structures, within the submitted sample. To identify the tapeworm species, we carried out molecular analyses on the proglottids. The cox1 and ef1a sequences had a 100% match with those of T. saginata and differed from the sequences of the other Taenia species. Upon examination of stool samples fixed by formalin-ether concentration method, no Taenia species ova were observed in 10 slides. Instead, C. sinensis ova were observed, despite the level of IgG specific to C. sinensis being within the normal range. The patient was treated with praziquantel (25 mg/kg, three times a day) for 3 days, and subsequently C. sinensis ova were not found in his stool. CONCLUSION: Our case indicates that a combination of morphological, serological, and molecular diagnostic tools should be used for the accurate diagnosis of subclinical parasitic infections.

Short communication: Four cases of Taenia saginata taeniasis in urban Venezuelan communities.

We report four cases of Taenia saginata taeniasis in different urban communities of Aragua state, Venezuela. After subsequent treatment with praziquantel and a saline purge, adult tapeworms were collected from all four patients and demonstrated to be T. saginata by morphological and molecular characterization. The finding of T. saginata in four distinct and separate urban municipalities of the Aragua state indicates the pertinence of rigorous meat inspection, and the importance of establishing parasite prevalence in human and bovine Venezuelan populations.

Human Tapeworm from Simalungun, Indonesia.

A 46-years-old man from Indonesia, resides in Nagori Dolok Village, Silau Kahaean Subdistrict, Simalungun District, Sumatra Utara Province, had of spontaneous discharge of tapeworm segments (proglottids) from anus almost every day for ten years. There were 1-5 segments which can move actively discharge per day. Although he feels embarrassed about the condition, no significant symptoms were found, and physical examination was within normal limits. Clinical diagnosis of Taeniasis was made on October 20, 2017, and subsequently received oral Praziquantel 600 mg tablet single dose and 5 mg of oral Bisacodyl. Four hours later, the patient was defecated. The stool was collected in plastic and filtered with a filter device to collect any tapeworm segments.A full segment of tapeworm as long as 2.86 meters were found. Microscopic examination was done to identify the egg worms, proglottids, and scolex. Dye substance was injected into a mature gravid proglottid through the genital pore and pressed in two object-glasses to identify the reproductive organs. Microscopic examination (400x magnification) of this sample revealed that the number of uterine branches and testes in a proglottid were 16 pairs. The number of uterine branches in T. solium are 8-12 pairs and T. saginata are 18-32 pairs.The filtered stool was moved into a container and carefully observed. A soft yellowish-white material of 1.5 mm in diameter was found, which turned out to be the head of the tapeworm called Scolex. Microscopic examination of scolex revealed that the rostellum was absent. A segment called 'snout' was found at the apex. The functions were probably as a sense of smell and vacuum organ.The patient was lived in Simalungun, North Sumatera, some tribe in that area has a long tradition of culinary called 'Hinasumba', consist of raw pork liver and meat, and 'Naiholat' consist of poorly cooked pork.Even though pig was determined as an intermediate host, the type of tapeworm was not consistent with T.solium. The patient had the long history of infection but never had sign or symptoms of neurocystecercosis. Based on etno-geographical condition, the patient was infected by T.asiatica. Microscopic examination of the uterus and scolex indicate that the tapeworm had most similarity to T.asiatica.Amin et al.8 from Bangladesh in 2009 reported a case of T. asiatica in human with total strobila length was 1.5 meters. Macroscopic morphology (length:width) of gravid proglottid segment of T.saginata is 3:1, T. solium 1.5:1. The tapeworm that we discovered had 1-1.5:1 ratio (2.5 cm length and 2 cm width).Some features of the tapeworm (no rostellum, present of the snout, and fix number of theuterus in every proglottid) were not found in three existing type of Taenia species. Further microscopic and molecular study should be done to determined type or subtype of the tapeworm. A case of taeniasis asiatica who had completed treatment was reported. Macroscopic and microscopic was done to support the clinical diagnosis.

Mathematical model of the life cycle of taenia-cysticercosis: transmission dynamics and chemotherapy (Part 1).

BACKGROUND: Taenia solium is the aetiological agent of human taeniasis, pig cysticercosis and human neurocysticercosis, which are serious public health problems, especially in developing countries. METHODS: A mathematical model of the transmission dynamics of taeniasis-cysticercosis is formulated. The model consists of a coupled system of differential equations, which are density-dependent equations for describing the flow of the parasite through the life cycle. The model is hybrid since it comprises deterministic equations with stochastic elements which describe changes in the mean parasite burden and incorporates the overall pattern of the parasites' distribution. RESULTS: Sensitivity and bifurcation analyses were carried out to determine the range of values of the model. The model can reproduce the observed epidemiological patterns of human taeniasis, pig and human cysticercosis. For example, for a wide range of parameter values, the mean intensity of adult worms tends to rapidly stabilize in one parasite per individual host. From this model, we also derived a Susceptible-Infected model to describe the prevalence of infection in humans and pigs. Chemotherapeutic interventions against pig cysticercosis or human taeniasis may reduce rapidly and effectively the mean intensity of human taeniasis, pig cysticercosis and human cysticercosis. This effect can be achieved even if the protective efficacy of the drug is of the order of 90% and the coverage rate is 90%. This means that health in humans infected either with adult worms or cysticerci may be achieved by the application of anthelmintic drugs against pig cysticercosis. However, treatment against human cysticercosis alone, does not influence neither human teniasis nor pig cysticercosis. This is because human cysticercosis infection does not influence the value of the basic reproductive number (Ro). CONCLUSIONS: Even coverage of 100% in the administration of anthelmintics did not eliminate the infection. Then elimination of the infection in all hosts does not seem a feasible goal to achieve by administering only chemotherapeutic interventions. Throughout the manuscript a discussion of our model in the context of other models of taeniasis-cysticercosis is presented.

Longitudinal study for anthelmintic efficacy against intestinal helminths in naturally exposed Lithuanian village dogs: critical analysis of feasibility and limitations.

The efficacy of anthelmintic treatment at 1, 3, and 6 month intervals was evaluated in a prospective controlled field study with naturally exposed Lithuanian village dogs by monthly coproscopy during 1 year. A placebo-treated control group (C) (n = 202) and groups treated with two broad-spectrum anthelmintics, febantel/pyrantel-embonate/praziquantel (Drontal® Plus, Bayer) (D1, D3, D6; n = 113-117) and emodepside/praziquantel (Profender®, Bayer) (P1, P3, P6; n = 114-119), were included. At the beginning of the study, eggs of Toxocara canis (4.02%) and T. cati (0.44%) identified morphometrically and/or molecularly and eggs of taeniid- (0.78%) and Capillaria-like eggs (5.03%) were present in the feces without significant differences in prevalence between groups. Significant decreases in excretion of T. canis eggs was found 1 month after the treatment with Drontal® Plus in February (D1) and with Profender® in October (P1), November (P1), December (P3), February (P1), and March (P1, P3), as compared to controls in the same months. The incidence of egg excretion per dog at least once a year was significantly lower in group P1 for T. canis (4.24%; p < 0.01) and in groups D1, P1 for taeniid eggs (0%; p < 0.01 and p < 0.001), when compared to controls (16.96 and 6.70%, respectively). A critical analyses of factors possibly responsible for intestinal passage of canine helminth eggs revealed that chained dogs excreted T. canis eggs more frequently 1 month after treatment compared to dogs in pens, particularly from November to March (p = 0.01). The incidence of single detection of T. cati eggs was significantly increased in chained dogs (12.46%) as compared to fenced dogs (1.08%; p = 0.0001).

Monitoring the outcomes of interventions against Taenia solium: options and suggestions.

There is an increasing interest in reducing the incidence of human neurocysticercosis, caused by infection with the larval stage of Taenia solium. Several intervention trials are currently assessing various options for control of T. solium transmission. A critical aspect of these trials will be the evaluation of whether the interventions have been successful. However, there is no consensus about the most appropriate or valuable methods that should be used. Here, we undertake a critical assessment of the diagnostic tests which are currently available for human T. solium taeniasis and human and porcine cysticercosis, as well as their suitability for evaluation of intervention trial outcomes. Suggestions are made about which of the measures that are available for evaluation of T. solium interventions would be most suitable, and which methodologies are the most appropriate given currently available technologies. Suggestions are also made in relation to the most urgent research needs in order to address deficiencies in current diagnostic methods.

TAENIA SAGINATA INFECTION IN A 14-MONTH-OLD TODDLER.

A 14-month-old female toddler presented with a 3-day history of pass- ing gravid proglottids of Taenia saginata. Neither she nor her family members had a history of eating raw beef or other raw meat. Single doses of praziquantel and niclosamide were administered. To the best of our knowledge, this is the youngest described patient with T. saginata infection to date.

SCHISTOSOMICIDAL ACTIVITY OF THE CRUDE EXTRACT OF ARTOCARPUS LAKOOCHA.

Puag-Haad is a traditional anthelmintic drug used to treat taeniasis in Thailand and Lao PDR. It is derived from the aqueous extract of the plant Artocarpus lakoocha. We investigated the in vitro anthelmintic properties of Puag-Haad against Schistosoma mansoni. Adult worms were incubated in M-199 medium containing 250, 500 and 750 µg/ml of Puag-Haad or praziquantel (PZQ) at a concentration of 175 µg/ml for 3, 6, 12 and 24 hours. The relative motility (RM value), survival index (SI) and tegument alterations seen under scanning electron microscope were assessed at each incubation time. The results showed the crude extract of A. lakoocha at a concentration of 250 µg/ml was more effective in causing damage than PZQ at a concentration of 175 µg/ml using RM and SI values. The major target organ affected by Puag-Haad was the tegument. The damage was greater at higher concentrations of the crude extract. It is likely tetrahydroxystilbene (THS), the main compound in Puag-Haad, caused the damage. THS could be a future candidate as a schistosomal drug. Further studies are needed to explore its mechanism, efficiency and safety in vivo.

Biliary Taeniasis: Case Series and Literature Review.

Biliary taeniasis is uncommon in clinical practice. We report two cases in our hospital. The first patient was diagnosed with acute biliary pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) showed a white, flat, segmented 1-cm-wide tapeworm drilling into the duodenal papilla that was identified as Taenia saginata. After tapeworm removal, bile duct sweeping, and anthelmintic therapy, the patient recovered uneventfully. The second patient was diagnosed with acute cholangitis and multiple stones in the common bile duct and gallbladder. Emergency ERCP showed no tapeworm in the duodenum. During a subsequent ERCP 6 days later, a flat tapeworm, also T. saginata, was identified drilling into the duodenal papilla. We review five patients cases with acute acalculous cholecystitis or cholangitis caused by T. saginata or Taenia solium, and 1 patient with T. saginata drilling into the T-tube. Taeniasis should be taken into consideration when dealing with biliary and pancreatic disease.

Treatment and management of coenurosis by Taenia multiceps: field data from outbreaks in endemic regions and literature review.

BACKGROUND: Taenia multiceps coenurosis is endemic in sheep from various regions worldwide. Dogs, the key hosts, shed T. multiceps eggs in their feces contaminating the pasture, and lambs are mostly infected during their first turnout into pastures. The disease is manifested in two forms: acute (due to the migrating oncospheres in the CNS) or chronic (due to the developing coenuri in the brain or spinal cord). Both forms are frequently accompanied by neurological symptoms. METHODS: Field trials conducted in an endemic region (Sardinia, Italy) to treat replacement lambs in six sheep flocks infected with acute coenurosis are summarized in this article. The article also reviews earlier reports on various approaches developed to treat and immunize sheep against coenurosis. RESULTS: Accurate detection of the time in which lambs become infected is crucial in deciding which treatment approach should be used. Acute disease can be successfully treated via chemotherapy. Results of field trials conducted in Sardinia revealed the efficacy of three (1-week apart) oxfendazole doses (14.15 mg/kg) in protecting apparently healthy lambs in the infected flocks from developing neurological symptoms. A single praziquantel dose (18.75 mg/kg) worked well for the same purpose and was also found significant in treating 5 of 16 clinically ill lambs in one flock. Earlier reports documented high rates of recovery (up to 100%) in clinically diseased lambs that received much higher doses (50-100 mg/kg) of praziquantel. However, chemotherapy is not preferred in chronic coenurosis since it can lead to rupture of the coenuri, giving rise to serious inflammation in the CNS. Surgical intervention is highly recommended in this case, and the pooled success rates for surgery in chronic-infected cases was estimated at 82.1% (95% CI 73.1-91.0%). However, various trials have been conducted to immunize sheep against T. multiceps coenurosis, and the 18k (Tm18) family of oncosphere antigens was found promising as a vaccine candidate. CONCLUSIONS: In acute coenurosis, selection of the proper anthelmintic should be done after consulting the owner for several reasons: (1) costs of the used anthelmintic: treating a small flock of 100 sheep costs around 1170 and 660 € for praziquantel and oxfendazole, respectively; (2) withdrawal time of the used anthelmintic: No time is required before consuming meat and milk from praziquantel-treated sheep, whereas meat and milk from oxfendazole-treated sheep should not be consumed for 44 and 9 days, respectively, causing additional costs for the farmers. Since no commercial vaccines have yet been developed against T. multiceps coenurosis in sheep, preventive measures remain the cornerstone of controlling this serious disease.

In vivo albendazole treatment of Taenia crassiceps cysticerci strain WFU: proliferation, damage, and recovery.

Taenia crassiceps has been widely experimented as a model for in vitro and in vivo studies on drug responses. The purpose of this study was to treat BALB/c mice infected with T. crassiceps strain WFU with commercially available albendazole and to analyze the reduction in parasite infrapopulations. Here, we describe the reduction and apparent damage of T. crassicceps WFU cysticerci in infected mice after antihelminthic drug treatment and subsequent inoculation of those treated parasites into a naïve host. We were able to reduce significantly the parasite counts to 33 and 48% after albendazole treatment for 20 or 25 days and compared with the untreated mice. We also observed morphological damage such as the partial blebbing in the tegument and parenchyma of treated parasites, as well as disorganized musculature and the loss of cell membranes in subtegumental tissue section. However, larvae from albendazole-treated mice inoculated into the next host were able to become re-established in the next murine host due, probably, to the survival of proliferative parasite cells.

Historical overview of Taenia asiatica in Taiwan.

An overview of the epidemiological, biological, and clinical studies of Taenia and taeniasis in Taiwan for the past century is presented. The phenomenal observations that led to the discovery of Taenia asiatica as a new species, which differ from Taenia solium and Taenia saginata, are described. Parasitological surveys of the aborigines in Taiwan revealed a high prevalence of taeniasis, which might be due to the culture of eating raw liver of hunted wild boars. Chemotherapeutic deworming trials involving many patients with taeniasis were discussed. Praziquantel was found to be very effective, but sometimes complete worms could not be recovered from the feces after treatment, probably due to the dissolution of the proglottids. Atabrine, despite some side effects, can still be used, in properly controlled dosages, as the drug of choice for human T. asiatica infection if we need to recover the expelled worms for morphological examinations. Research results on the infection of T. asiatica eggs from Taiwan aborigines in experimental animals were also noted. Since the pig serve as the natural intermediate host of T. asiatica and the predilection site is the liver, a differential comparison of other parasitic pathogens that might cause apparently similar lesions is also presented.

A review of the control of clonorchiasis sinensis and Taenia solium taeniasis/cysticercosis in China.

Clonorchiasis sinensis and Taenia solium taeniasis/cysticercosis are major foodborne parasitoses. Clonorchiasis sinensis is actively transmitted in some areas of China, Korea, Russia, Vietnam, etc. Currently, it is estimated that more than 200 million people are at risk of infection, 15-20 million people are infected, and 1.5-2 million show symptoms or complications. In China, it is relatively heavily transmitted in Zhujiang River Delta, including Hong Kong and Macao, and Northeast China, where many Korean people live. The transmission is related to the unhealthy habits of residents who like to have raw fish or half-raw fish. The infection of Clonorchis sinensis could result in serious liver and biliary system damages, and chronic cases may induce liver and bile duct cancers. T. solium taeniasis/cysticercosis is distributed around the world except the areas where the residents have a taboo against pork for religious reasons. Recent years, the urban inhabitants infected with T. solium/Cysticercus are increasing in China. T. solium results in intestinal diseases, and cysticercosis is a very serious disease, especially nervous system cysticercosis. Its symptoms include headache, epilepsy, sudden death, etc. Health education and health promotion, environmental reconstruction, and chemotherapy are the main control measures for these diseases. Through several decades of efforts in China, the achievements of control of clonorchiasis and T. solium taeniasis/cysticercosis are great. For example, in one of the main clonorchiasis-endemic provinces, Shandong Province, clonorchiasis has been controlled. In 31 T. solium taeniasis/cysticercosis-endemic counties of Henan Province, through a 6-year control program, the decline rates of T. solium taeniasis and cysticercosis were 90.8 and 96.8 %, respectively. This paper reviews the researches on the control of clonorchiasis and T. solium taeniasis/cysticercosis in China past decades so as to provide references for other countries where these diseases are endemic to improve the control or elimination of clonorchiasis and T. solium taeniasis/cysticercosis.

Oral expulsion of taenia worm by a pregnant lady.

The case of a pregnant lady who expelled a tapeworm orally is discussed and a brief review on Taeniasis is also presented.

Taenia saginata: failure treatment in a child with 5-year long-lasting infection.

The management of these infections requires protocols that allow the clinic and laboratory to reach a timely and accurate diagnosis through the differential identification of Taenia species and consequently determine appropriate treatment. On the other hand, the inadequate implementation of treatments and the lack of follow-up coupled with biological phenomena such as resistance to drugs contribute important risks of infection for the population. This case could be caused by a strain of T. saginata with a low sensitivity to albendazole. This case emphasizes the need of developing and implementing techniques that will help us differentiate the species of Taenia in laboratories as well as establish treatments with alternative drugs. It is important to report this kind of infection with the aim of giving laboratory personnel as well as healthcare providers a broader knowledge of these parasites in order to improve treatment with alternative drugs. In addition, improvements in the habits among individuals must be addressed to avoid the increased risk of infection.