Clinical characteristics and epidemiology of intestinal tapeworm infections over the last decade in Tokyo, Japan: A retrospective review.

BACKGROUND: Tapeworm (cestode) infections occur worldwide even in developed countries and globalization has further complicated the epidemiology of such infections. Nonetheless, recent epidemiological data on cestode infections are limited. Our objectives were to elucidate the clinical characteristics and epidemiology of diphyllobothriosis and taeniosis in Tokyo, Japan. METHODOLOGY/PRINCIPAL FINDINGS: We retrospectively reviewed 24 cases of human intestinal cestode infection from January 2006 to December 2015 at a tertiary referral hospital in Tokyo, Japan. The patients included were diagnosed with cestode infection based on morphological and/or molecular identification of expelled proglottids and/or eggs and treated in our hospital. Fifteen and 9 patients were diagnosed with diphyllobothriosis and taeniosis, respectively. The median patient age was 31 years (interquartile range [IQR]: 26-42 years), and 13 (54%) were male. Most of the patients (91.7%) were Japanese. All patients were successfully treated with praziquantel without recurrence. Diphyllobothriosis was caused by Diphyllobothrium nihonkaiense in all patients. Taeniosis was due to infection of Taenia saginata in 8 [88.9%] patients and T. asiatica in 1 [11.1%] patient. All patients with taeniosis were infected outside Japan, as opposed to those with diphyllobothriosis, which were domestic. The source locations of taeniosis were mostly in developing regions. The median duration of the stay of the patients with taeniosis at the respective source location was 1 month (IQR: 1-8). CONCLUSIONS/SIGNIFICANCE: The cestode infection, especially with D. nihonkaiense, has frequently occurred, even in Japanese cities, thereby implicating the probable increase in the prevalence of diphyllobothriosis among travelers, as the number of travelers is expected to increase owing to the Tokyo Olympics/Paralympics in 2020. In addition, medical practitioners should be aware of the importance of providing advice to travelers to endemic countries of taeniosis, including the potential risks of infection and preventive methods for these infections.

Historic of therapeutic efficacy of albendazol sulphoxide administered in different routes, dosages and treatment schemes, against Taenia saginata cysticercus in cattle experimentally infected.

The present study aimed to notify the history of albendazole sulphoxide (ALB-SO) and albendazole (ALBZ) efficacy against Taenia saginata cysticercus (Cysticercus bovis) parasitizing experimentally infected bovines. A total of 11 efficacy trials were performed between the years of 2002 and 2010. In order to perform these trials, animals were individually inoculated with 2×10(4) eggs of T. saginata in each study's day zero (D0). For every trial, a positive control group (untreated infected animals) and a negative control group (animals that were neither infected nor treated) were used. ALB-SO or ALB were administered in the different dosages, in different days of treatments. In a last study with this formulation, this active principle was administered orally, mixed with the mineral supplement, on the 60th DPI, in a dosage of 30mg/kg. In all trials, on the 100th DPI, all animals were euthanized and submitted to the sequenced slicing of 26 anatomical segments (fragments of approximately five millimeters) for the survey of T. saginata cysticercus. With the obtained results it is possible to verify that in the first trials, conducted in 2002, ALB-SO reached, independently of dosage and treatment scheme, efficacies superior to 98% (arithmetic means). The trials conducted in 2005 (2.5mg/kg on the 30th, 60th, and 90th DPI) obtained values of efficacy all inferior to 60%. In 2008, the trials with 2.5 and 7.7mg/kg demonstrated efficacy values inferior to 40%, for both dosages and treatment schemes (30th/60th/90th DPI and 60th DPI). When this formulation was administered orally on the dosage of 30mg/kg on the 60th DPI, the efficacy against T. saginata cysticercus reached 88.28%. ALB administered orally showed efficacy values of 0.0%, 29.88% and 28.64% in the dosages of 5, 10 and 15mg/kg, respectively, using the treatment schemes described above for each dosage. Based on the results of these trials, conducted in an eight year period (2002-2010) using the sequenced slicing method for evaluating the efficacy of the aforementioned formulations against T. saginata cysticercus, it is possible to observe that, amongst the few molecules used in the chemotherapic treatment against T. saginata larvae, ALB-SO, administered in varied routes, dosages and treatment schemes, the studies conducted in 2008, 2009, and 2010, have a low therapeutic efficacy against C. bovis in Brazil, while ALBZ had insignificant efficacy values against T. saginata larvae parasitizing experimentally infected bovines. However, future studies using molecular biology will be necessary to assess whether the difference on the efficacy of the ALB-SO can be related to strain or another specific factor.

A glance at Taenia saginata infection, diagnosis, vaccine, biological control and treatment.

The Taenia saginata taeniasis-cysticercosis complex is a cosmopolitan zoonosis of great medical, veterinary and economic importance where humans play an important role as the carrier of adult stage and cattle as carrier of the larval stage of the parasite. Here we reviewed aspects concerning diagnosis, vaccine development, biological control and treatment of the disease.

Taenia solium: antioxidant metabolism enzymes as targets for cestocidal drugs and vaccines.

This review focuses in the role that antioxidant enzymes play in protection and other important physiological functions such as signal transduction, cell differentiation, growth and apoptosis. Parasites use these enzymes to evade ROS produced by the host immune response and for development inside the host. In the cestoda Taenia solium, three antioxidant enzymes have been studied: a cystosolic Cu,Zn superoxide dismutase that is a target of cestocidal drugs (bencimidazoles); a 2-Cys peroxiredoxin that is a regulatory enzyme of H(2)O(2), molecule essential for several physiological functions; and two isoforms of glutathione transferases that are immunological targets, since they protect immunized mice against cysticercosis. Moreover, all these enzymes are present in all stages of the parasite. These findings suggest that antioxidant enzymes have an important role in T. solium physiology and infection, therefore they might represent the Achilles' heel of the parasite.

Successful treatment of niclosamide- and praziquantel-resistant beef tapeworm infection with nitazoxanide.

BACKGROUND: Beef tapeworm (Taenia saginata) infection is acquired by eating inadequately cooked beef that contains the larvae or cysticerci of T. saginata. Niclosamide and praziquantel have proved effective for its treatment but treatment failures are well known. We report herein the results of nitazoxanide therapy. METHODS: A prospective study was conducted in 18 children and 34 adults to assess the efficacy and safety of nitazoxanide in the treatment of niclosamide- and praziquantel-resistant T. saginata infection. Nitazoxanide was administered twice daily for 3 days in 500-mg doses for those aged over 14 years and at 20mg/kg body weight/day in children aged 5-14 years. Post-treatment follow-up was undertaken at 1, 2, 4, 8, and 12 weeks for fecal samples for proglottides, and to check the presence, number, and viability of Taenia eggs. RESULTS: Nitazoxanide cured 51 of 52 (98.1%) patients. Mild side effects occurred in seven patients, which resolved spontaneously. There were no abnormalities in laboratory parameters. CONCLUSIONS: Nitazoxanide is a safe, effective, inexpensive, and well-tolerated drug for the treatment of niclosamide- and praziquantel-resistant beef tapeworm infection.

[Effect of gamma-interferon on hepatic granuloma formation in mice infected by cysticerci of Taenia saginata asiatica].

Immunohistochemical streptavidin biotin-peroxidase complex method was used to investigate the effect of gamma-interferon (IFN-gamma) on the hepatic granuloma formation and liver fibrosis in mice infected with Taenia saginata in Duyun area of Guizhou Province. The results reveal contrary relation between the level of IFN-gamma in the liver and the degree of liver fibrosis (p<0.01). The injection of IFN-gamma considerably decreased (p<0.01) the area and size of granuloma (p<0.01).

Effect of some chemical agents on the viability of Cysticercus bovis.

The effect of eight chemicals; vinegar, Allium sativum (crude garlic), Acacia auriculiformis, lemon juice, praziquantel, pumpkin, perosan and yomesan on the viability of cysticerci of Taenia saginata in vitro was investigated. The minimum exposure time required for cysticerci to be non-evaginable for the eight chemicals were 5, 10, 25, 40, 55, 75, 90 and 105 minutes respectively. The best one was vinegar and the least effective was yomesan.