Schistosomal myeloradiculopathy in a non-endemic area / Mielorradiculopatia esquistossomótica em região não endêmica

ABSTRACT Objective: To report a schistosomal myeloradiculopathy case in a non-endemic area. Case description: A previously healthy 11-year-old boy, stricken by an acute loss of strength on his lower limbs, followed by a loss of strength on his upper limbs and upper body, associated with altered sensitivity of the vesical globe formation. The patient's cerebrospinal fluid analysis showed eosinophilic meningitis, in addition to peripheral eosinophilia. The investigation resulted in a positive serology for Schistosoma mansoni. The treatment included steroids and praziquantel 60mg/kg, with a new dose after a month, as well as physical therapy for rehabilitation. The patient evolved with clinical improvement in the neurological exam, with a medullary section initially at C6, but now at T6. The patient is kept at prednisolone use (30mg/day) and longterm urinary catheter dependence. Comments: The schistosomiasis is endemic in many regions of Brazil; however, it has low incidence in the south of the country. Among its main manifestations, the schistosomal myeloradiculopathy is the most severe ectopic form of the disease, and should be suspected in patients with low back pain, strength and/or sensibility disorder of the lower limbs or urinary tract's disturbance. Early diagnosis and treatment should be done in order to reduce severe neurological sequelae. Treatment includes schistosomiasis drugs, corticosteroids and/or surgery.

RESUMO Objetivo: Relatar um caso de mielorradiculopatia esquistossomótica em área não endêmica. Descrição do caso: Paciente do sexo masculino, 11 anos, previamente hígido, com história aguda de paresia de membros inferiores, que evoluiu para membros superiores e tronco, associada à alteração de sensibilidade e formação de globo vesical. O exame do líquor demonstrava meningite eosinofílica, além de eosinofilia periférica. A investigação resultou em sorologia positiva para Schistosoma mansoni. O tratamento foi realizado com corticoterapia e praziquantel 60 mg/kg, com nova dose após um mês, além de fisioterapia para reabilitação. Evoluiu com melhora clínica no exame neurológico, com nível de secção medular que inicialmente correspondia a C6, encontrando-se atualmente em T6. Mantém uso de prednisolona 30 mg/dia e dependência de sonda vesical de demora. Comentários: A esquistossomose é uma doença endêmica em muitas regiões do Brasil, porém com pouca incidência no Sul do país. Dentre as principais manifestações, a mielorradiculopatia esquistossomótica é a forma ectópica mais grave e deve ser suspeitada na vigência de dor lombar, alteração de força e/ ou sensibilidade de membros inferiores e distúrbio urinário. O diagnóstico e o tratamento devem ser instituídos precocemente para diminuir o risco de sequelas neurológicas graves. O tratamento pode ser realizado com esquistossomicidas, corticosteroides e/ ou cirurgia.

Neobenedenia melleni (Monogenea: Capsalidae) in ornamental reef fish imported to Brazil / Neobenedenia melleni (Monogenea: Capsalidae) em peixes ornamentais de recife importados para o Brasil

Abstract The capsalid monogenean Neobenedenia melleni is known as a lethal pathogen for captured marine teleost ornamental fish, if left untreated. This study reports the occurrence of N. melleni parasitizing four species of ornamental reef fish imported into Brazil and maintained in quarantine: Arabian angelfish (Pomacanthus asfur ), yellowbar angelfish (Pomacanthus maculosus), regal angelfish (Pygoplites diacanthus), and bluecheek butterflyfish (Chaetodon semilarvatus). Ten days after the beginning of quarantine, some fish showed behavioral alterations, such as irritability, and corneal opacity, which were rapidly diagnosed to be caused by monogenean parasites by body surface scraping. The fish from the same batch were treated with two applications of 2 mg L-1 praziquantel each at an interval of four days. Seven days after the first treatment, the mucus surface of the fish was re-examined, which did not reveal the parasites presence being delivered for commercialization.

Resumo Neobenedenia melleni é conhecido como um parasito letal para peixes teleósteos ornamentais marinhos capturados se não tratado. Este estudo relata a ocorrência de N. melleni parasitando quatro espécies de peixes ornamentais importados para o Brazil: Arabian angelfish (Pomacanthus asfur), yellowbar angelfish (Pomacanthus maculosus), regal angelfish (Pygoplites diacanthus) e bluecheek butterflyfish ( Chaetodon semilarvatus). Dez dias depois do início da quarentena, foram observados irritabilidade e opacidade na córnea dos peixes que, foram diagnosticadas com N. melleni na superfície corporal. Todos os peixes foram tratados com duas aplicações de praziquantel 2 mg L-1 em intervalo de quatro dias. Sete dias após o início do tratamento, um novo exame parasitológico foi realizado o qual não revelou a presença dos parasitos, sendo liberados para comercialização.

Evaluation of the efficacy of pediatric suspension of praziquantel against schistosoma mansoni in experimental animals

Background: Schistosomiasis is one of the neglected tropical diseases with recent evidences about the high prevalence among preschool-age children. The pediatric formulation of Praziquantel [PZQ] has to be assessed for the efficacy as it gave controversial results in several countries

Objective[s]: The current study aimed at evaluating the efficacy of the pediatric suspension of PZQ against Schistosoma mansoni Egyptian strain in the experimental animals

Methods: 150 Swiss albino mice infected with Schistosoma mansoni were divided into three groups, the first group was treated with 600 mg/kg body weight of PZQ pediatric suspension, the second group was treated with 600 mg/kg PZQ tablets and the third one received no treatment as a control. The efficacy of the pediatric formulation was experimentally evaluated in comparison with the tablet formulation as a benchmark on the basis of the following specific parasitological parameters [worm burden, tissue egg load, and oogram pattern i.e. percentage of dead, live or immature eggs shown in the stool sample]

Results: The comparison between the mean egg count per gram stool in the two groups pediatric suspension of PZQ [Epiquantel] and adult tablets of PZQ [Distocide], and the control group by applying one way ANOVA revealed a statistically significant difference [p<0.05] between the mean egg count in both treated groups [Epiquantel and Distocide] and their control group. The reduction of the total worm burden caused by Epiquantel[registered] was 96.9%, while that of Distocide[registered] was 86.7%, they were found to be statistically significant[p<0.05] in comparison with the control group. Epiquantel[registered] reduced the male worms by 100% and the females were reduced by 94.1%. Distocide showed a similar effect, it reduced the worms by 88.4% and 85.1% for males and females respectively. The administration of a single oral dose of both Epiquantel[registered] and Distocide[registered] resulted in a statistically significant reduction [p<0.05] in the mean egg count per gram tissue either the liver or the wall of small intestine when compared to their infected untreated control group. Complete absence of immature egg stages, high reduction in the mature eggs, and the increase in the dead eggs were observed in both Epiquantel[registered] and Distocide[registered] groups when compared to the control group

Conclusion: The results prescribed that the pediatric suspension formula of PZQ is as efficient as the tablet formula against Schistosoma mansoni [Egyptian CD strain] in the mouse model. It could be recommended for pediatric treatment

Four Human Cases of Acanthotrema felis (Digenea: Heterophyidae) Infection in Korea

Acanthotrema felis is an intestinal trematode of cats originally reported from the Republic of Korea. Only 1 human case infected with a single adult worm has been previously recorded. In the present study, we report 4 human cases infected with a total of 10 worms recovered after anthelmintic treatment and purging. All 4 patients reside in coastal areas of Jeollanam-do, Korea, and have consumed brackish water fish including the gobies, Acanthogobius flavimanus. The worms averaged 0.47 mm in length and 0.27 mm in width, and had 3 sclerites on the ventrogenital sac; 1 was short and thumb-like, another was long and blunt-ended, and the 3rd was long and broad-tipped. They were identified as A. felis Sohn, Han, & Chai, 2003. Surveys on coastal areas to detect further human cases infected with A. felis are required.

Avaliação do papel das células estreladas hepáticas, células endoteliais sinusoidais e macrófagos tipo II, no remodelamento pós-quimioterápico das lesões hepáticas na esquistossomose mansônica experimental / Assessing the role of hepatic stellate cells, sinusoidal endothelial cells and macrophages type II, post-chemotherapy remodeling of liver lesions in experimental schistosomiasis

Na esquistossomose mansônica o fígado é o órgão alvo das agressões patogênicas, onde as lesões hepáticas caracterizam-se principalmente pela presença de granulomas periovulares e formação de fibrose periportal, além de alterações vasculares responsáveis pela hipertensão dentro do sistema venoso portal. A angiogênese precede a maioria dos casos de fibrose, onde se verifica participação direta das células estreladas hepáticas (CEH) e das células endoteliais sinusoidais (CES) que são estimuladas, principalmente por macrófagos do tipo II (M2) – ativados alternativamente. O tratamento para esquistossomose é feito pelo uso do praziquantel (PZQ)...

The liver is a target for pathogenic attacks during schistosomiasis, showing periovular granulomas and the formation of periportal fibrosis, besides vascular changes responsible for hypertension within portal venous system. Angiogenesis precedes most cases of fibrosis, which can be verified the presence of hepatic stellate cells (HSC) and liver sinusoidal endothelial cells (LSEC) stimulated mostly by macrophages type II (M2) – alternatively activated. Schistosomiasis treatment is based on praziquantel (PZQ)...

Avaliação do polimorfismo genético de TLR9 em pacientes com lúpus eritematoso sistêmico / Evaluation of genetic polymorphism of TLR9 in systemic lupus erythematosus

Lúpus Eritematoso Sistêmico (LES) é uma doença autoimune sistêmica na qual a principal alteração está relacionada à ativação policlonal de linfócitos B com a produção de uma ampla variedade de autoanticorpos dirigidos contra componentes nucleares, citoplasmáticos, de superfície celular e moléculas solúveis do plasma. Fatores genéticos têm sido implicados na patogênese dessa patologia. TolI-like receptor 9 (TLR9) é um importante componente do sistema imune inato que reconhece sequências não metiladas CpG de DNA...

Echinostome Flukes Receovered from Humans in Khammouane Province, Lao PDR

Echinostome eggs were detected in 22 (1.1%) of 2,074 people residing in riparian villages along the Mekong River in Khammouane Province, Lao PDR. In order to recover the adult flukes, 9 persons were treated with praziquantel and purged with magnesium salts. A total of 55 echinostome specimens (4 species) were recovered from the 9 persons. Echinostoma revolutum (8 specimens) was recovered from 3 persons, Artyfechinostomum malayanum (8 specimens) was from 2 persons, Echinochasmus japonicus (33 specimens) was from 7 persons, and Euparyphium sp. (6 specimens) was from 1 person. In Lao PDR, only human infections with E. japonicus were previously known. Therefore, the present study describes human infections with E. revolutum, A. malayanum, and Euparyphium sp. for the first time in Lao PDR. These results indicate that the surveyed villages of Khammouane Province, Lao PDR are low-grade endemic foci of echinostomiasis.

Four Human Cases of Diphyllobothrium latum Infection

Diphyllobothrium latum infections in 4 young Korean men detected from 2008 to 2012 are presented. Three were diagnosed based on spontaneously discharged strobila of the adult worm in their feces, and 1 case was diagnosed by finding the worm at colonoscopy examination in a local clinic. The morphologic characteristics of the gravid proglottid and eggs were consistent with D. latum. All patients were treated with praziquantel 15 mg/kg, and follow-up stool examinations were done at 2 months after the medication. The main clinical complaints were intermittent gastrointestinal troubles such as indigestion, abdominal distension, and spontaneous discharge of tapeworm's segments in their feces. The most probable source of infection was the flesh of salmon or trout according to a patient's past history. These are the 45th to 48th recorded cases diagnosed by the adult worm in the Republic of Korea since 1971.

Pharmacodynamics of mefloquine and praziquantel combination therapy in mice harbouring juvenile and adult Schistosoma mansoni

Praziquantel (PZQ) is currently the only drug widely used for the treatment of schistosomiasis, but the antimalarial drug mefloquine (Mef) possesses interesting antischistosomal properties. Combination therapy with these two drugs has been suggested as a strategy for transmission control, as PZQ is active against adult worms and Mef is active against schistosomula. To examine the efficacy of combination therapy, Schistosoma mansoni-reinfected mice were separated into seven groups: untreated (I), treated with PZQ in doses of 200 mg/kg (II) or 1,000 mg/kg (III), treated with Mef in doses of 200 mg/kg (IV) or 400 mg/kg (V); each dose was divided equally and given on two consecutive days. Group VI was treated with doses of PZQ + Mef as in groups II and IV, respectively, while group VII was treated with PZQ + Mef as in groups III and V, respectively. PZQ + Mef at the reduced doses of 200 mg/kg each enhanced the therapeutic efficacy over the reduced PZQ dose alone as shown by a very high reduction in the total numbers of mature worms (95 percent vs. 49 percent), immature worms (96 percent vs. 29 percent) and the complete eradication of immature females, mature females and immature eggs. The reduction in worm burden was associated with the healing of hepatic granulomatous lesions and the normalisation of all liver enzymes. Therefore, the use of Mef with PZQ is more effective than PZQ alone and should be considered for clinical trials in humans as a potential treatment regimen to prevent treatment failures in areas with high rates of schistosomiasis.

Echinostoma ilocanum Infection in Oddar Meanchey Province, Cambodia

Fecal examinations using the Kato Katz technique were performed on a total of 1,287 villagers (945 students and 342 general inhabitants) of Oddar Meanchey Province, Cambodia in May 2007 and November 2009. The overall intestinal helminth egg positive rate was 23.9%, and the most prevalent helminth species was hookworms (21.6%). Other helminth eggs detected included echinostomes (1.0%), Enterobius vermicularis (0.8%), small trematode eggs (0.7%), which may include Opisthorchis viverrini and Haplorchis spp., and Hymenolepis nana (0.4%). In order to recover adult echinostomes, we treated 2 patients with 10-15 mg/kg praziquantel and purged. Total 14 adult echinostomes, 1 and 13 worms from each patient, were collected. The echinostomes characteristically had 49-51 collar spines and 2 round or slightly lobated testes. They were identified as Echinostoma ilocanum (Garrison, 1908) Odhner, 1911. So far as literature are concerned, this is the first record on the discovery of human E. ilocanum infection in Cambodia.

Hypersensitive Reaction to Praziquantel in a Clonorchiasis Patient

Praziquantel is the drug of choice for clonorchiasis. Since clonorchiasis is endemic in most river basins, praziquantel has been widely used for 30 years in Korea. A 54-year-old Korean woman suffered from hypersensitive reactions, such as nausea, dyspnea, rash, and urticaria after taking the first dose of praziquantel to treat clonorchiasis. She ingested one dose again and the same symptoms appeared, and she was treated at a clinic with anti-histamines. She tried one more dose with anti-histamines but found the same symptoms. Later, she was found to pass eggs of Clonorchis sinensis and medicated with flubendazole. The hypersensitive reaction to praziquantel is rare but occurs. This is the 5th case report in the world.

Prevalence of the Intestinal Flukes Haplorchis taichui and H. yokogawai in a Mountainous Area of Phongsaly Province, Lao PDR

Phongsaly Province, located in the northernmost area of Lao PDR, was previously suggested to be endemic for the liver fluke Opisthorchis viverrini infection. To confirm, or rule out, this suggestion, the Phonxay village in the Khoua District, Phongsaly Province, was selected for a survey. Ten volunteers (8 men and 2 women aged 31-57 years) who consumed raw freshwater fish and had gastrointestinal troubles were treated with a single dose of praziquantel (40 mg/kg) and pyrantel pamoate (10 mg/kg) and purged with magnesium sulfate to recover any worm parasites. Eight of the 10 volunteers expelled 1 or more species of trematodes, nematodes, or cestodes (worm positive rate; 80%). The worms were morphologically identified as H. taichui (861 worms from 8 people), H. yokogawai (59 from 6 people), Phaneropsolus bonnei (1 from 1 person), Trichostrongylus sp. (2 from 2 people), Ascaris lumbricoides (2 from 1 person), Enterobius vermicularis (11 from 3 people), and Taenia saginata (1 strobila with scolex from 1 person). The results indicate that the mountainous area of Phongsaly Province, Lao PDR, is not endemic for the liver fluke but endemic for intestinal flukes, in particular, Haplorchis taichui and H. yokogawai.

Association of oxamniquine praziquantel and clonazepam in experimental Schistosomiasis mansoni

The antischistosomal activity of clonazepam, when administered alone or in association with oxamniquine and praziquantel, was experimentally evaluated in mice infected with Schistosoma mansoni. The animals were treated 45 days post-infection with a single dose, by oral route, according to three treatment schedules: clonazepam 25 mg/kg and sacrificed 15 min, 1h or 4 h after treatment; clonazepam 1.0, 2.5 or 10.0 mg/kg and sacrificed 15 days post-treatment or with the dose of 10 mg/kg in association with oxamniquine 50 mg/kg or praziquantel 200 mg/kg, single dose, orally, every schedule with a control group. The efficacy of the drugs in vivo was assessed by means of worm counts and their distribution in mesentery and liver, mortality and oogram changes. In the chemotherapeutic schedules used, clonazepam did not present antischistosomal activity and the result of the association of this drug with oxamniquine or praziquantel was not significantly different from the one obtained when these two last drugs were administered alone. In the in vitro experiments, the worms exposed to 0.6 mg/mL clonazepam remained motionless throughout the 8-day-period of observation, without egg-laying, whereas the worms of the control group showed normal movements, egg-laying and hatching of miracidia on the last day of observation. The results obtained in the present study confirm the action of clonazepam on S. mansoni adult worm, in vitro, causing total paralysis of males and females. However, no additive or synergistic effects were observed when clonazepam were used in association with oxamniquine or praziquantel.

Guidelines for the diagnosis and treatment of schistosomal myeloradiculopathy

Schistosomal myeloradiculopathy is the most severe and disabling ectopic form of Schistosoma mansoni infection. The prevalence of SMR in centres in Brazil and Africa that specialise in attending patients with non traumatic myelopathy is around 5 percent. The initial signs and symptoms of the disease include lumbar and/or lower limb pain, paraparesis, urinary and intestinal dysfunctions, and impotence in men. The cerebrospinal fluid of SMR patients shows an increase in protein concentration and in the number of mononuclear cells in 90 percent of cases; eosinophils have been reported in 40 percent. The use of magnetic resonance imaging is particularly valuable in the diagnosis of Schistosomal myeloradiculopathy. The exclusion of other myelopathies and systemic diseases remains mandatory. Early diagnosis and treatment with steroids and schistosomicides provide a cure for most patients, whilst delayed treatment can result in irreversible physical disabilities or death. To improve awareness concerning Schistosomal myeloradiculopathy amongst public health professionals, and to facilitate the control of the disease, the Brazilian Ministry of Health has launched a program of education and control of this ectopic form of schistosomiasis. The present paper reviews current methods for the diagnosis of SMR and outlines protocols for treatment of the disease.

A mielorradiculopatia esquistossomótica é a forma ectópica mais grave da infecção pelo Schistosoma mansoni. A prevalência da mielorradiculopatia esquistossomótica em centros médicos no Brasil e em África, especializados no atendimento de pacientes com mielopatia, encontra-se em torno de 5 por cento. Os sintomas e sinais iniciais da doença incluem: dor lombar e/ou dor em membros inferiores, paraparesia, disfunções urinária e intestinal, e impotência no homem. A análise do líqüor destes pacientes revela aumento na concentração de proteínas e no número de células mononucleares em 90 por cento dos casos; a presença de eosinófilos foi documentada em 40 por cento. O uso rotineiro da ressonância magnética tornou-se obrigatório na definição diagnóstica. A exclusão de outras mielopatias e doenças sistêmicas é mandatória. O diagnóstico precoce e o tratamento com corticoesteróides e esquistossomicidas curam a maioria dos pacientes, enquanto o atraso em iniciar o tratamento resulta em seqüelas irreversíveis ou morte. Para melhorar a percepção da importância da mielorradiculopatia associada à esquistossomose, o Ministério da Saúde do Brasil lançou programa de controle dessa forma ectópica da esquistossomose. Nesta revisão, descrevem-se os métodos diagnósticos atuais para o diagnóstico e os protocolos para o tratamento da doença.

Utilização de fenbendazole e da associação febantel, pamoato de pirantel e praziquantel no controle de oxiurídeos em gerbis / Use of fenbendazole and the febantel, pamoato of pirantel and praziquantel association in the control of oxiurids in jirds

Eighteen jirds were equally distributed in two treated and one control groups. The commercial products to the fenbendazole base (10mg) and the association of febantel (1.5mg), pirantel (1.44mg) and praziquantel (0.5mg) were orally administred in the concentration of 0.1ml in each group. The effectiveness of febendazole against oxiurids was 81.8 percent, 65.0 and 38.7 percent and for the association of febantel, pirantel and praziquantel was 72.7 percent, 73.8 percent and 51.0 percent on days 7, 14 and 21, respectively. Three applications of that dose of the tested medications, within intervals of 10 days, associated to hygiene, are recommended.

High prevalence of liver and intestinal fluke infections among residents of Savannakhet Province in Laos

The prevalence of liver and intestinal fluke infections was surveyed on residents of Savannakhet Province, Laos. Fecal specimens were collected from a total of 981 residents in 4 Mekong riverside villages and examined by the Kato-Katz thick smear technique. The results revealed that the overall helminth egg positive rate was 84.2%, and the positive rate for small trematode eggs, including Opisthorchis viverrini, heterophyids, or lecithodendriids, was 67.1%. To obtain adult flukes, 38 small trematode egg positive cases were treated with a 20-30 mg/kg single dose of praziquantel and purged. Diarrheic stools were then collected from 29 people and searched for helminth parasites using stereomicroscopes. Mixed infections with O. viverrini and 6 kinds of intestinal flukes were found, namely, Haplorchis taichui, Haplorchis pumilio, Haplorchis yokogawai, Prosthodendrium molenkampi, Phaneropsolus bonnei, and echinostomes. The total number of flukes collected was 7,693 specimens (av. no. per treated person; 265.3). The most common species was O. viverrini, followed by H. taichui, P. molenkampi, echinostomes, H. pumilio, P. bonnei, and H. yokogawai. The results indicate that foodborne liver and intestinal fluke infections are prevalent among residents of Savannakhet Province, Laos.

Inermicapsifer madagascarensis: a propósito de 17 casos / Inermicapsifer madagascarensis: based on 17 cases

Se presentan 17 casos de niños con edades que fluctuaron entre 4 meses y 4 años, parasitados por Inermicapsifer madagascariensis, en el período comprendido entre Enero del 2000 y Octubre del 2005, los cuales procedían de siete municipios de Camagüey (provincia de la región oriental de Cuba), todos pertenecientes a áreas urbanas, con ausencia de síntomas gastrointestinales y/o generales, que comenzaron a expulsar en el 100% de los casos en sus heces, partículas idénticas a “granos de arroz” (proglótides o fragmentos de estróbilos), cuyo diagnóstico y seguimiento se realizó en el Laboratorio de Parasitología del Centro Provincial de Higiene, Epidemiología y Microbiología de Camagüey. La edad promedio fue de 1,8 años, no hubo distinción en cuanto al sexo, siendo el 88,2% de raza blanca, el 58,82% tenia el pelo de color claro y el 70,6% los ojos pardos; la combinación de pelo y ojos de color claro se manifestó en un 64,7% de los pacientes. El 41,2% asistían a instituciones infantiles, teniendo el 58,8% como mascota un perro y el 5,8% la combinación perro-gato. Todos los casos fueron tratados con Praziquantel, taenicida de producción nacional, evolucionando satisfactoriamente.

The spatial distribution of Schistosoma mansoni infection before and after chemotherapy in the Jequitinhonha Valley in Brazil

Schistosomiasis prevalence and egg counts remained low one year after chemotherapy in most households in a hyperendemic rural area in northern Minas Gerais but several distinct spatial patterns could be observed in relation to IgE levels and to a lesser extent to exposure risk (TBM) and type of water supply. An inverse relationship between pre-treatment household prevalence and egg counts on the one hand and post-treatment IgE levels on the other were noted in two of the five communities. Low exposure risk was associated with the low pre-treatment infection rates in the central village but did not contribute to the decline of infection rates after chemotherapy in the study area, as indicated by the significant increase in water contact during the posttreatment period (p < 0.0001). Distance between households and the streams and socioeconomic factors were also unimportant in predicting the spatial distribution of infection. These results are consistent with the production and antiparasitic effect of high levels of IgE in Schistosoma mansoni infection.

Prevalence of Gymnophalloides seoi infection in coastal villages of Haenam-gun and Yeongam-gun, Republic of Korea

One coastal village in Haenam-gun and two in Yeongam-gun, Jeollanam-do were surveyed for intestinal parasite infections by fecal examination. The egg positive rates of Gymnophalloides seoi were high, 24.1% (14/58) in Haenam-gun and 9.3% (11/118) in Yeongam-gun. The egg positive rates of heterophyids, including Heterophyes nocens, and of Clonorchis sinensis were 10.3% and 6.9% in Haenam-gun, and 14.4% and 8.5% in Yeongam-gun, respectively. After praziquantel treatment and purgation, a total of 37,761 fluke specimens were recovered from 17 patients; 11 in Haenam-gun and 6 in Yeongam-gun. Gymnophalloides seoi was the most commonly recovered species, with 37,489 specimens in total (2,205 per person). Other recovered flukes included Heterophyes nocens, Stictodora fuscata, Heterophyopsis continua, Pygidiopsis summa, and undetermined species. These results indicate that the areas surveyed are new endemic foci of G. seoi.

Therapeutic effect of subcurative dose praziquantel on Schistosoma mansoni infected mice and resistance to challenge infection after treatment.

The therapeutic effect of a subcurative dosage of praziquantel (PZQ) on Schistosoma mansoni infected mice and resistance to challenged worm infection after treatment were assessed and compared with conventional treatment using a curative dosage of PZQ. S. mansoni infected mice were treated with PZQ at a curative dosage (600 mg kg(-1)) or a subcurative dosage (300 mg kg(-1)) at 9 weeks after infection. Untreated mice and non-infected mice were added as controls. The therapeutic effect of the drug was evaluated in terms of the mortality of mice after treatment, and the parasitological and pathological findings in mice sacrificed at 1 week, 1 month, or 3 months after treatment. Another sample of mice was not killed but challenged with S. mansoni cercariae at 1 week, 1 month, or 3 months after treatment. Resistance to re-infection was evaluated by the extent of challenged worm reduction. In conclusion, there was no significant difference in mortality, or parasitological and pathological findings between mice treated with PZQ at the two dosages. However, resistance to challenged worm infection was more sustained in the group treated with subcurative dose PZQ, especially at 3 months after treatment.