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Therapeutic effect of praziquantel against taeniasis asiatica
International Journal of Infectious Diseases 17 (2013) e656–e657
Contents lists available at SciVerse ScienceDirect
International Journal of Infectious Diseases journal homepage: www.elsevier.com/locate/ijid
Short Communication
Therapeutic effect of praziquantel against taeniasis asiatica Kenji Ohnishi a,*, Naoya Sakamoto a, Ken-ichiro Kobayashi a, Sentaro Iwabuchi a, Fukumi Nakamura-Uchiyama a,b a b
Department of Infectious Diseases, Tokyo Metropolitan Bokutoh General Hospital, Tokyo, Japan Department of Pathogen, Infection and Immunity, Nara Medical University, Nara, Japan
A R T I C L E I N F O
S U M M A R Y
Article history: Received 18 January 2013 Received in revised form 25 January 2013 Accepted 27 February 2013
Eight Japanese adult patients infected with Taenia asiatica were treated with a single 600 mg dose of praziquantel. The patients’ body weights ranged from 47 to 87 kg (mean 67.1 12.7 kg). All patients expelled the strobila after taking praziquantel, and all of them were free from proglottids the day after praziquantel administration, hence all patients were considered to be cured. No side effects due to praziquantel were noted. Although the number of patients is small, our results indicate that praziquantel is a drug of choice for the treatment of taeniasis asiatica and that a single dose of 7–13 mg/kg (9.3 1.9 mg/kg) is effective. ß 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Corresponding Editor: Eskild Petersen, Aarhus, Denmark Keywords: Taenia asiatica Praziquantel Taeniasis
1. Introduction Human taeniasis asiatica is caused by an adult Taenia asiatica tapeworm infection in the small intestine. The infection occurs as a result of eating raw or undercooked pig liver harboring the larval stage. T. asiatica has not traditionally been common in Japan, however human cases of taeniasis asiatica have recently been reported in the Kanto area (Tokyo, Chiba Pref., Ibaraki Pref., Tochigi Pref., Gunma Pref., and Saitama Pref.).1 The treatment of children aged 8–14 years infected with Taiwan Taenia with a single dose of 150 mg of praziquantel has been reported, and good therapeutic effects were obtained.2 Taiwan Taenia is presently thought to be T. asiatica. Praziquantel is widely used against certain types of tapeworm infection, however data concerning the clinical effect of this agent against taeniasis asiatica are limited. We treated adult patients infected with T. asiatica with praziquantel, and good therapeutic effects were observed. 2. Patients and methods Eight Japanese patients (six males and two females) infected with T. asiatica were treated between June 2010 and May 2012. Their mean age was 46.8 14.7 years (range 25–69 years) and their
* Corresponding author. E-mail address: [email protected] (K. Ohnishi).
mean body weight was 67.1 12.7 kg (range 47–87 kg). All of the patients were thought to be contracted the disease in the Kanto area, because they ate raw pig liver in the Kanto area only. The therapeutic method was as follows: On the day before the administration of praziquantel, the patients ate a low fiber dinner and were then given 50 g of magnesium citrate dissolved in 150 ml of water at 8:00 p.m. and 24 mg of sennoside calcium with 500 ml of water at 9:00 p.m. The next morning, on an empty stomach, they were given 600 mg of praziquantel orally at 7:00 a.m., then 2 h later, 50 g of magnesium citrate dissolved in 300 ml of water. Patients were considered to be cured if the strobila was expelled after the administration of the praziquantel and if they were free from proglottids for more than 6 months after the day of praziquantel administration. 3. Results All patients expelled the strobila after taking the praziquantel and magnesium citrate, and all of them were free from proglottids for more than 6 months after the day of praziquantel administration, hence all patients were considered to be cured. Praziquantel was tolerated by all of the patients and no side effects due to praziquantel were noted. Proglottids expelled by all of the patients were confirmed as T. asiatica based on mitochondrial DNA analysis and nucleic allele analysis at the Department of Parasitology, National Institute of Infectious Diseases of Japan.
1201-9712/$36.00 – see front matter ß 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijid.2013.02.028
K. Ohnishi et al. / International Journal of Infectious Diseases 17 (2013) e656–e657
4. Discussion It is very difficult to differentiate T. asiatica from Taenia saginata, both macroscopically and microscopically, so identification of this parasite was made using a PCR method for finding specific genes by investigating a proglottid of the parasite.3 In this study, all expelled worms were confirmed to be T. asiatica through PCR. Symptoms of taeniasis asiatica are mild in general, but patients infected with this tapeworm suffer emotionally for a long period while passing the proglottids. Hence it is important to cure patients of this worm in order to free them from the anxiety. We were able to treat our adult patients infected with taeniasis asiatica with a single oral administration of 600 mg of praziquantel; the body weights of our patients ranged between 47 and 87 kg (67.1 12.7 kg) and the dose of praziquantel was between 7 and 13 mg/kg (9.3 1.9 mg/kg). It has been reported that praziquantel induces vacuolization of the tegument of proglottids of the neck region of Hymenolepis nana in vitro.4 T. asiatica and H. nana are both tapeworms, so praziquantel may destroy the tegument of proglottids of the neck region of T. asiatica via vacuolization. However, the pathological changes in expelled proglottids of the neck region after praziquantel administration were not investigated in our study, and the exact mechanism of action of praziquantel against T. asiatica is not known. Although the number of patients is small, our results show a 100% cure rate, with no side effects experienced by patients with
e657
taeniasis asiatica following a single oral administration of praziquantel. This indicates that praziquantel is the drug of choice for treatment, and that a dose of between 7 and 13 mg/kg (9.3 1.9 mg/kg) is effective against taeniasis asiatica. Acknowledgements We are grateful to Dr Hiroshi Yamasaki, Department of Parasitology, National Institute of Infectious Diseases of Japan, for confirming the tapeworms as Taenia asiatica via findings through a mitochondrial DNA analysis and nucleic allele analysis. Conflict of interest: No conflict of interest to declare. References 1. Yamasaki H, Morishima Y, Sugiyama H, Mutou M. Cases of Taenia asiatica, possible emerging parasitic infestation reported from Kanto area of Japan since June 2010 (in Japanese). Infect Agents Surveil Rep 2011;32:106–7, http:// www.nih.go.jp/niid/ja/jasr.html. 2. Fan PC, Chung WC, Chan CH, Chen YA, Cheng FY, Hsu MC. Studies on taeniasis in Taiwan. V. Field trial on evaluation of therapeutic efficacy of mebendazole and praziquantel against taeniasis. Southeast Asian J Trop Med Public Health 1986;17:82–90. 3. Yamasaki H, Allan JC, Sato MO, Nakao M, Sako Y, Nakaya K, et al. DNA differential diagnosis of taeniasis and cysticercosis by multiplex PCR. J Clin Microbiol 2004;42:548–54. 4. Becker B, Mehlhorn H, Andrews P, Thomas H. Scanning and transmission electron microscope studies on the efficacy of praziquantel on Hymenolepis nana (cestoda) in vitro. Z Parasitenkd 1980;61:121–33.
Contents lists available at SciVerse ScienceDirect
International Journal of Infectious Diseases journal homepage: www.elsevier.com/locate/ijid
Short Communication
Therapeutic effect of praziquantel against taeniasis asiatica Kenji Ohnishi a,*, Naoya Sakamoto a, Ken-ichiro Kobayashi a, Sentaro Iwabuchi a, Fukumi Nakamura-Uchiyama a,b a b
Department of Infectious Diseases, Tokyo Metropolitan Bokutoh General Hospital, Tokyo, Japan Department of Pathogen, Infection and Immunity, Nara Medical University, Nara, Japan
A R T I C L E I N F O
S U M M A R Y
Article history: Received 18 January 2013 Received in revised form 25 January 2013 Accepted 27 February 2013
Eight Japanese adult patients infected with Taenia asiatica were treated with a single 600 mg dose of praziquantel. The patients’ body weights ranged from 47 to 87 kg (mean 67.1 12.7 kg). All patients expelled the strobila after taking praziquantel, and all of them were free from proglottids the day after praziquantel administration, hence all patients were considered to be cured. No side effects due to praziquantel were noted. Although the number of patients is small, our results indicate that praziquantel is a drug of choice for the treatment of taeniasis asiatica and that a single dose of 7–13 mg/kg (9.3 1.9 mg/kg) is effective. ß 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Corresponding Editor: Eskild Petersen, Aarhus, Denmark Keywords: Taenia asiatica Praziquantel Taeniasis
1. Introduction Human taeniasis asiatica is caused by an adult Taenia asiatica tapeworm infection in the small intestine. The infection occurs as a result of eating raw or undercooked pig liver harboring the larval stage. T. asiatica has not traditionally been common in Japan, however human cases of taeniasis asiatica have recently been reported in the Kanto area (Tokyo, Chiba Pref., Ibaraki Pref., Tochigi Pref., Gunma Pref., and Saitama Pref.).1 The treatment of children aged 8–14 years infected with Taiwan Taenia with a single dose of 150 mg of praziquantel has been reported, and good therapeutic effects were obtained.2 Taiwan Taenia is presently thought to be T. asiatica. Praziquantel is widely used against certain types of tapeworm infection, however data concerning the clinical effect of this agent against taeniasis asiatica are limited. We treated adult patients infected with T. asiatica with praziquantel, and good therapeutic effects were observed. 2. Patients and methods Eight Japanese patients (six males and two females) infected with T. asiatica were treated between June 2010 and May 2012. Their mean age was 46.8 14.7 years (range 25–69 years) and their
* Corresponding author. E-mail address: [email protected] (K. Ohnishi).
mean body weight was 67.1 12.7 kg (range 47–87 kg). All of the patients were thought to be contracted the disease in the Kanto area, because they ate raw pig liver in the Kanto area only. The therapeutic method was as follows: On the day before the administration of praziquantel, the patients ate a low fiber dinner and were then given 50 g of magnesium citrate dissolved in 150 ml of water at 8:00 p.m. and 24 mg of sennoside calcium with 500 ml of water at 9:00 p.m. The next morning, on an empty stomach, they were given 600 mg of praziquantel orally at 7:00 a.m., then 2 h later, 50 g of magnesium citrate dissolved in 300 ml of water. Patients were considered to be cured if the strobila was expelled after the administration of the praziquantel and if they were free from proglottids for more than 6 months after the day of praziquantel administration. 3. Results All patients expelled the strobila after taking the praziquantel and magnesium citrate, and all of them were free from proglottids for more than 6 months after the day of praziquantel administration, hence all patients were considered to be cured. Praziquantel was tolerated by all of the patients and no side effects due to praziquantel were noted. Proglottids expelled by all of the patients were confirmed as T. asiatica based on mitochondrial DNA analysis and nucleic allele analysis at the Department of Parasitology, National Institute of Infectious Diseases of Japan.
1201-9712/$36.00 – see front matter ß 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ijid.2013.02.028
K. Ohnishi et al. / International Journal of Infectious Diseases 17 (2013) e656–e657
4. Discussion It is very difficult to differentiate T. asiatica from Taenia saginata, both macroscopically and microscopically, so identification of this parasite was made using a PCR method for finding specific genes by investigating a proglottid of the parasite.3 In this study, all expelled worms were confirmed to be T. asiatica through PCR. Symptoms of taeniasis asiatica are mild in general, but patients infected with this tapeworm suffer emotionally for a long period while passing the proglottids. Hence it is important to cure patients of this worm in order to free them from the anxiety. We were able to treat our adult patients infected with taeniasis asiatica with a single oral administration of 600 mg of praziquantel; the body weights of our patients ranged between 47 and 87 kg (67.1 12.7 kg) and the dose of praziquantel was between 7 and 13 mg/kg (9.3 1.9 mg/kg). It has been reported that praziquantel induces vacuolization of the tegument of proglottids of the neck region of Hymenolepis nana in vitro.4 T. asiatica and H. nana are both tapeworms, so praziquantel may destroy the tegument of proglottids of the neck region of T. asiatica via vacuolization. However, the pathological changes in expelled proglottids of the neck region after praziquantel administration were not investigated in our study, and the exact mechanism of action of praziquantel against T. asiatica is not known. Although the number of patients is small, our results show a 100% cure rate, with no side effects experienced by patients with
e657
taeniasis asiatica following a single oral administration of praziquantel. This indicates that praziquantel is the drug of choice for treatment, and that a dose of between 7 and 13 mg/kg (9.3 1.9 mg/kg) is effective against taeniasis asiatica. Acknowledgements We are grateful to Dr Hiroshi Yamasaki, Department of Parasitology, National Institute of Infectious Diseases of Japan, for confirming the tapeworms as Taenia asiatica via findings through a mitochondrial DNA analysis and nucleic allele analysis. Conflict of interest: No conflict of interest to declare. References 1. Yamasaki H, Morishima Y, Sugiyama H, Mutou M. Cases of Taenia asiatica, possible emerging parasitic infestation reported from Kanto area of Japan since June 2010 (in Japanese). Infect Agents Surveil Rep 2011;32:106–7, http:// www.nih.go.jp/niid/ja/jasr.html. 2. Fan PC, Chung WC, Chan CH, Chen YA, Cheng FY, Hsu MC. Studies on taeniasis in Taiwan. V. Field trial on evaluation of therapeutic efficacy of mebendazole and praziquantel against taeniasis. Southeast Asian J Trop Med Public Health 1986;17:82–90. 3. Yamasaki H, Allan JC, Sato MO, Nakao M, Sako Y, Nakaya K, et al. DNA differential diagnosis of taeniasis and cysticercosis by multiplex PCR. J Clin Microbiol 2004;42:548–54. 4. Becker B, Mehlhorn H, Andrews P, Thomas H. Scanning and transmission electron microscope studies on the efficacy of praziquantel on Hymenolepis nana (cestoda) in vitro. Z Parasitenkd 1980;61:121–33.