Echinostoma ilocanum Infection in Two Residents of Savannakhet Province, Lao PDR

Adult specimens of Echinostoma ilocanum (Garrison, 1908) Odhner, 1911 (Trematoda: Echinostomatidae) were recovered from 2 riparian people who resided along the Mekong River in Savannakhet Province, Lao PDR. In fecal examinations done by the Kato-Katz technique, they revealed echinostome eggs together with eggs of Opisthorchis viverrini (and minute intestinal fluke eggs) and hookworms. To recover the adult flukes, they were treated with praziquantel 30–40 mg/kg in a single dose and purged with magnesium salts. A total of 658 adult fluke specimens were recovered from the 2 people; 456 from case 1 and 202 from case 2. Specimens from case 1 consisted of 335 echinostomes (301 E. ilocanum and 34 species undetermined), 120 O. viverrini, and 1 Haplorchis taichui, and those from case 2 consisted of 36 E. ilocanum, 134 O. viverrini, and 32 H. taichui. Thus, the number of E. ilocanum specimens was 337 in total (average per person, 168.5). From this study, it is suggested that foodborne intestinal flukes and liver flukes are highly prevalent along the Mekong River in Savannakhet Province. The present report describes for the first time human infections with E. ilocanum in Lao PDR.

Animal Models for Echinostoma malayanum Infection: Worm Recovery and Some Pathology

Echinostomes are intestinal trematodes that infect a wide range of vertebrate hosts, including humans, in their adult stage and also parasitize numerous invertebrate and cold-blooded vertebrate hosts in their larval stages. The purpose of this study was to compare Echinostoma malayanum parasite growth, including worm recovery, body size of adult worms, eggs per worm, eggs per gram of feces, and pathological changes in the small intestine of experimental animals. In this study, 6-8-week-old male hamsters, rats, mice, and gerbils were infected with echinostome metacercariae and then sacrificed at day 60 post-infection. The small intestine and feces of each infected animal were collected and then processed for analysis. The results showed that worm recovery, eggs per worm, and eggs per gram of feces from all infected hamsters were higher compared with infected rats and mice. However, in infected gerbils, no parasites were observed in the small intestine, and there were no parasite eggs in the feces. The volume of eggs per gram of feces and eggs per worm were related to parasite size. The results of histopathological changes in the small intestine of infected groups showed abnormal villi and goblet cells, as evidenced by short villi and an increase in the number and size of goblet cells compared with the normal control group.

A Case of Echinostoma cinetorchis (Trematoda: Echinostomatidae) Infection Diagnosed by Colonoscopy

Human cases of echinostomiasis have been sporadically diagnosed by extracting worms in the endoscopy in Korea and Japan. Most of these were caused by Echinostoma hortense infection. However, in the present study, we detected 2 live worms of Echinostoma cinetorchis in the ascending colon of a Korean man (68-year old) admitted to the Gyeongsang National University Hospital with complaint of intermittent right lower quadrant abdominal pain for 5 days. Under colonoscopy, 1 worm was found attached on the edematous and hyperemic mucosal surface of the proximal ascending colon and the other was detected on the mid-ascending colon. Both worms were removed from the mucosal surface with a grasping forceps, and morphologically identified as E. cinetorchis by the characteristic head crown with total 37 collar spines including 5 end-group ones on both sides, disappearance of testes, and eggs of 108x60 microm with abopercular wrinkles. The infection source of this case seems to be the raw frogs eaten 2 months ago. This is the first case of endoscopy-diagnosed E. cinetorchis infection in Korea.

Three Echinostome Species from Wild Birds in the Republic of Korea

Three echinostome species, i.e., Patagifer bilobus, Petasiger neocomense, and Saakotrema metatestis, are newly recorded in the trematode fauna of the Republic of Korea. They were recovered from 3 species of migratory birds (Platalea minor, Podiceps cristatus, and Egretta garzetta), which were donated by the Wildlife Center of Chungbuk (WCC) and the Conservation Genome Resource Bank for Korean Wildlife (CGRB). Only 1 P. bilobus specimen was recovered from the intestine of a black-faced spoonbill (P. minor), and characterized by the bilobed head crown with a deep dorsal incision and 54 collar spines. Twenty P. neocomense were recovered from the intestine of a great crested grebe (P. cristatus), and they had a well-developed head crown with 19 spines and 2 testes obliquely located at the posterior middle of the body. Total 70 S. metatestis were collected from the bursa of Fabricius of 1 little egret (E. garzetta). It is characterized by stout tegumental spines covered in the entire leaf-shaped body, posterior extension of the uterus, presence of the uroproct and a well-developed head crown with 12 pairs of collar spines on each side. By the present study, these 3 echinostome species are newly added to the trematode fauna in Korea.

Epidemiology and molecular genotyping of echinostome metacercariae in Filopaludina snails in Lamphun Province, Thailand

OBJECTIVE@#To analyze the prevalence of echinostome metacercariae in Filopaludina dorliaris (F. dorliaris) and Filopaludina martensi martensi (F. martensi martensi) and genotype variation of echinostome metacercariae by using random amplified polymorphic DNA (RAPD) analysis.@*METHODS@#Filopaludina sp. snails were collected from eight localities of Lamphun Province, Northern Thailand and examined for echinostome metacercariae. RAPD-PCR was used to analyze genotype variation of echinostome metacercariae.@*RESULTS@#A total of 3 226 F. dorliaris and F. martensi martensi snails were collected from eight localities. The overall prevalences of echinostome metacercariae in F. dorliaris and F. martensi martensi were 40.89% and 36.27%, while the intensity of infection was 20.37 and 12.04, respectively. The dendrogram constructed base on RAPD profiles, 4 well supported domains were generated; (i) group of metacercariae from Ban Hong, Mae Ta, Meaung, Pa Sang, Toong Hua Chang, and Weang Nong that were clustered in the group of E. revolutum, (ii) Ban Thi, (iii) Lee, and (iv) 3 adults of an out group.@*CONCLUSIONS@#This research demonstrated RAPD profiling has been a useful tool to detect DNA polymorphisms to determine genetic relationship between echinostome metacercariae in Lamphun Province, Northern Thailand.

Praziquantel Treatment in Trematode and Cestode Infections: An Update

Status and emerging issues in the use of praziquantel for treatment of human trematode and cestode infections are briefly reviewed. Since praziquantel was first introduced as a broadspectrum anthelmintic in 1975, innumerable articles describing its successful use in the treatment of the majority of human-infecting trematodes and cestodes have been published. The target trematode and cestode diseases include schistosomiasis, clonorchiasis and opisthorchiasis, paragonimiasis, heterophyidiasis, echinostomiasis, fasciolopsiasis, neodiplostomiasis, gymnophalloidiasis, taeniases, diphyllobothriasis, hymenolepiasis, and cysticercosis. However, Fasciola hepatica and Fasciola gigantica infections are refractory to praziquantel, for which triclabendazole, an alternative drug, is necessary. In addition, larval cestode infections, particularly hydatid disease and sparganosis, are not successfully treated by praziquantel. The precise mechanism of action of praziquantel is still poorly understood. There are also emerging problems with praziquantel treatment, which include the appearance of drug resistance in the treatment of Schistosoma mansoni and possibly Schistosoma japonicum, along with allergic or hypersensitivity reactions against praziquantel treatment. To cope with and overcome these problems, combined use of drugs, i.e., praziquantel and other newly introduced compounds such as triclabendazole, artemisinins, and tribendimidine, is being tried.

Review of food-borne trematodiases in the Philippines

Food-borne trematodes (FBTs) are emerging infections and of substantial public health importance but are among the most ignored of the neglected tropical diseases (NTDs) in terms of attention, research and funding. A review of the status of FBTs in the Philippines based on the best available local and national information may provide a basis for the formulation of appropriate prevention and control measures most suitable for its setting. This review presents a summary of the key features of FBTs and the epidemiologic pattern of FBTs in the Philippines and on the current measures being done for infection control and prevention in other countries. Paragonimiasis, echinostomiasis, and heterophyidiasis are still prevalent in the Philippines with food preparation and hygiene practices and presence of infected intermediate hosts as major determinants of epidemiology and disease burden. Control and prevention of food-borne trematodes may be best achieved with political will, coordinated efforts among responsible public sectors, and involvement of relevant communities.

Control de parásitos gastrointestinales en caballos pura sangre de carrera (Equus Caballus) en el Hipódromo "La Rinconada" Caracas, Venezuela / Control of gastrointestinal parasites in thoroughbred horses (Eqqus Caballus) the Racetrack

Se realizo un estudio coprológico por la técnica de flotación Mc Master (Willis-Molloy), realizando contaje de Huevos por gramo de Heces (HPG), a 100 equinos Pura Sangre de Carreras, durante el periodo de cuarentena Hipodromo “La Rinconada” Caracas Venezuela. Se procedió a la desparasitacióncon una terapéutica a base de Febantel, dosis 6mg/kg, presentación en pasta, vía oral (CALOXBANTEL) Febantel 88.7 mg; Excipientes c.s.p. 1g. A los 7 días post-desparasitación se realizo un estudio coprológico por la técnica de flotación Mc Master (Willis-Molloy), realizando contaje de Huevos por gramo de Heces (HPG). El estudio coprológico evidencio un 60% de infestación (60/100) en los caballos estudiados. El 40% (40/100) fue negativo al examen coprológico. Los resultados post-tratamientos fueron 1% de infestación persistente (01/100) y un 99% (99/100) negativos al examen coprológico. En todos los casos la infestación parasitaria fue por Strongylus sp. La presencia de Strongylus sp. se mantuvo por equino infestado entre un rango de 400-1200 HPG

We study 100 Thoroughbred horses, in the Racetrack “La Rinconada” Caracas, Venezuela, by McMaster flotation technique (Willis-Molloy), making counting of eggs per gram of feces (EPG) before deworming, each of the copies, then proceeded to the parasite with a Febantel based therapy, dose 6mg/kg, pasta presentation, oral (CALOXBANTEL) Febantel 88.7 mg, Excipients 1g. At 7 days post-parasite stool study was conducted by the McMaster flotation technique (Willis- Molloy), by counting eggs per gram of faeces (EPG). The coprology study showed 60% infestation (60/100) in horses studied. The 40% (40/100) was negative. The post-treatment were 1% infestation (01/100) and 99% (99/100) was negative. In all cases, parasite infestation was by Strongylus sp. within the range of 400-1200 HPG

Echinostoma revolutum: Metacercariae in Filopaludina Snails from Nam Dinh Province, Vietnam, and Adults from Experimental Hamsters

We detected metacercariae of Echinostoma revolutum in Filopaludina sp. snails purchased from a local market in Nam Dinh Province for the first time in Vietnam. Adult flukes were harvested from experimentally infected hamsters at days 14 and 17 post-infection. The metacercariae were round, 170-190 microm (n=15) in diameter, with a cyst wall thickness of about 12 microm. A total of 37 collar spines were arranged around the head collar, and large excretory granules were seen in 2 canals of the excretory bladder. The 14-day old adult flukes were elongated, ventrally curved, and 5.0-7.2x0.8-1.3 mm (n=20). The head collar had a total of 37 collar spines arranged in 2 alternating rows, including 5 corner spines on each side. The cirrus sac contained a saccular seminal vesicle, a prostatic gland, and an unarmed cirrus. Two tandem testes were smooth or slightly lobed. Eggs were ovoid to elliptical, 110-118x70-75 microm. These morphological characters were similar to those of E. revolutum and E. jurini. We tentatively identified it as E. revolutum because the validity of E. jurini remains to be elucidated. The taxonomic relationship of E. revolutum and E. jurini is discussed.

Fish-borne Parasitic Diseases / 한양의대학술지

Parasites transmitted by fish (=fish-borne parasites) and the diseases caused by them are briefly reviewed. The fish-borne parasites known to occur in the Republic of Korea are taxonomically classified as 23 helminth species, which include 5 species of nematodes, 16 species of trematodes, and 2 species of cestodes. Among them, Anisakis simplex, Clonorchis sinensis, Metagonimus yokogawai, Heterophyes nocens, Echinostoma hortense, and Diphyllobothrium latum are the most important species in public health points of view. The kinds of fish responsible for human infections include various species of fresh water fish, brackish water fish, and marine fish. Pathogenicity and clinical manifestations are variable according to different parasite species and immune status of the host. For prevention of these infections, avoidance of consuming raw or improperly cooked fish is important.

Echinostoma hortense and Heterophyid Metacercariae Encysted in Yellowfin Goby, Acanthogobius flavimanus, from Shinan-gun and Muan-gun (Jeollanam-do), Korea

Fishborne trematode (FBT) metacercariae were investigated in yellowfin goby, Acanthogobius flavimanus, collected from Shinan-gun and Muan-gun, Jeollanam-do (province), Korea. All collected fishes were examined using the artificial digestion method. In all of 15 gobies from Aphae-myeon in Shinan-gun, metacercariae of Stictodora spp. (334 metacercariae/fish), Heterophyes nocens (153/fish), and Heterophyopsis continua (20/fish) were detected. In 2 of 14 gobies from Jido-myeon in Shinan-gun, 8 Echinostoma hortense metacercariae in total were detected. In 15 gobies from Haeje-myeon in Muan-gun, the metacercariae of H. continua were found in 100%, Stictodora spp. in 86.7%, and H. nocens in 6.7% of fish examined. The average numbers of metacercariae per infected fish were 23.3 (H. continua), 416.0 (Stictodora spp.), and 2.0 (H. nocens), respectively. The metacercariae of E. hortense found in gobies were elliptical, with 150 x 138 micrometer in average size, and had 27 collar spines on the head crown. The above results suggest that yellowfin gobies from 2 localities may be the potential infection sources of FBT. Moreover, it is proved for the first time that the yellowfin goby, A. flavimanus, acts as a second intermediate host for E. hortense.

Echinostome Infections in the Striped-Field Mouse, Apodemus agrarius, and the Ussuri White-Toothed Shrew, Crocidura lasiura, Caught Near the Demilitarized Zone, Gyeonggi-do (Province), Republic of Korea

A total of 1,498 small mammals (rodents and insectivores), including Apodemus agrarius (n = 1,366), Crocidura lasiura (54), Mus musculus (32), Micronytus fortis (28), Eothenomys regulus (9), Micronys minutes (6), and Cricetulus triton (3), were live-trapped in Gyeonggi-do (Province) (Paju-si, Pocheon-gun, and Yeoncheon-gun) near the demilitarized zone (DMZ) from December 2004 to September 2005. A. agrarius was found to be infected with 3 species of echinostomes (Echinostoma hortense, Echinostoma cinetorchis, and Euparyphium murinum), while C. lasiura was infected with 1 species (Echinochasmus japonicas) of echinostome. Other mammals were free from echinostome infections. Total 16 E. hortense were detected in 7 (0.5%) mice, 9 E. cinetorchis from 5 (0.4%), and 3 E. murinum from 2 (0.1%) out of 1.366 A. agrarius examined. E. japonicus was found only in 1 (1.9%; total 3 specimens) C. lasiura. These results demonstrate that A. agrarius and C. lasiura, inhabiting near the DMZ of Gyeonggi-do serve as the natural definitive hosts for several species of echinostomes, although their infection rates are low. This is the first record of natural infections of A. agrarius with E. cinetorchis and C. lasiura with E. japonicus in the Republic of Korea.

Impact of Echinoparyphium recurvatum against schistosoma haematobium, on some physiological parameters of bulinus truncatus snails

The effects of single and double infection of Bulinus. truncatus with Schistosoma haematobium and/or Echinostorna recurvatum on free amino acid and some enzymes activity were hereby studied. The results indicated a disruption in the snail metabolism due to exposure to S. haematobium and E. recurvatuin miracidia and this effect was more pronounced in case of double exposure to the two parasites. The results obtained also revealed results showed that the infection rate of B. truncatus snails with E. recurvatum was higher than that by S. haematobium. Moreover, E recurvatum exerted a negative that free amino acids showed variation in their concentrations and percentages of TFAA in tissue of infected snails with two parasites as compared to control snails. Aspartic, Glutamic, Glyc ine, Threonine, Alanine, Methio-nine, Cystine, Tyrosine, Phenylalanine, Lysine and Luecine were increased in the tissue, but Serine, Histidine, Arginine, Proline, Valine and Isolucecine were decreased. The glucose, lipid and cholesterol level in the haemolymph of infected snails was increased, while the protein and glycogen content decreased in soft tissues. A significant elevation in the levels of Aspartate aminotransferase [ASAT] and alanine aminotransferase [ALAT] enzymes was recorded in heamolymph and tissues of exposed snail than unexposed. There were significant increases in the levels of acid and alkaline phosphatases enzymes in exposed snails

Endoscopic and Clinical Characteristics of Gastrointestinal Parasite Infections / 대한소화기내시경학회지

BACKGROUND/AIMS: Although the overall infection rate of infection with parasites has decreased, the rate of food-mediated infection with parasites has not declined. This study was conducted to define the various endoscopic and clinical characteristics of gastrointestinal (GI) parasite infections diagnosed endoscopically. METHODS: We reviewed retrospectively the medical records including the endoscopic reports of 27 patients with GI parasite infections diagnosed endoscopically at University Hospital from January 1993 through September 2006. RESULTS: Among 27 patients with a GI parasite infection, 66.7% were female and food-mediated parasite infections including anisakiasis accounted for 77.8% of all of the infections. Soil-mediated parasites were still detected. Extremely rare cases of echinostomiasis and diphyllobothriasis were also identified. Abdominal pain was most frequent symptom (48.1%) and even intestinal or biliary obstructions were seen. The most common endoscopic finding was a visible worm, and various findings including the presence of a pseudotumor were observed. The median period from symptom onset to endoscopy was 15 days for anisakiasis with a pseudotumor compared to 1 day for anisakiasis without a pseudotumor. CONCLUSIONS: Endoscopy revealed the presence of various GI parasite infections as well as the presence of anisakiasis, a food-mediated parasitic disease. Various clinical and endoscopic features were seen, including GI bleeding, obstruction, and a pseudotumor. Therefore, a thorough endoscopic examination is required promptly together with detailed history taking concerning the consumption of raw fish.

Transition of Parasitic Diseases in Korea

The transition of important parasitic diseases in Korea is briefly reviewed in this article. Soiltransmitted helminthiases, such as ascariasis, trichuriasis, and hookworm infections, which had been prevalent all over the country, decreased remarkably, largely owing to the national control activities by means of mass examination-mass treatment schemes for school students. Paragonimiasis has shown significant reduction in its incidence, but clonorchiasis still remains as an important health-threatening trematode infection. Intestinal trematodiases, including metagonimiasis, heterophyidiases, and echinostomiases are prevalent, and new species, such as Gymonphalloides seoi and Neodiplostomum seoulense, have been documented as new human parasitic diseases. Tapeworm infections including larval cestodiases are also decreasing. Among the protozoan infections, amebiasis and malaria showed an apparent decreasing trend, but in recent years, vivax malaria has become a re-emerging disease. Brugian filariasis, which was prevalent in southern parts of the Korean peninsula, has been completely eliminated nowadays. In terms of the prevalence and distribution, clonorchiasis, enterobiasis, and vivax malaria are currently the major parasitoses of public health importance in Korea.

A human case of Echinostoma hortense infection diagnosed by endoscopy in area of southwestern Korea / 대한내과학회지

Echinostomiasis is an endemic parasitic infection of humans in Korea, especially eastern areas. An Echinostoma infection was diagnosed by gastroduodenoscopy from a 75-year-old Korean female living in Hwasun-gun, Jeollanam-do. She complained of nausea, vomiting and epigastric pain that had persisted for 1 month. Two live worms were attached to the mucosal surface of the duodenal bulb area. After they were removed using an endoscopic forceps, the symptoms were gradually relieved. The worms were identified as Echinostoma hortense by egg morphology, visceral locations and tegumental ultrastructures. Microscopic examination of endoscopic biopsy specimens revealed infiltration by chronic inflammatory cells. In this case, the source of the infection was the loaches purchased from local fish markets located at Hwasun-gun. This is the 5th case of E. hortense infection diagnosed by endoscopy and the 1st case reported in area of southwestern Korea.

A human infection of Echinostoma hortense in duodenal bulb diagnosed by endoscopy

As gastroduodenoscopy performed more frequently, case reports of human echinostomiasis are increasing in Korea. A Korean woman presented at a local clinic with complaints of abdominal pain and discomfort that had persisted for 2 weeks. Under gastroduodenoscopy, two motile flukes were found attached on the duodenal bulb, and retrieved with endoscopic forceps. She had history of eating raw frog meat. The two flukes were identified as Echinostoma hortense by egg morphology, 27 collar spines with 4 end-group spines, and surface ultrastructural characters. This report may prove frogs to be a source of human echinostome infections.

Susceptibility of several strains of mice to Echinostoma hortense infection

Susceptibilities of 5 different mice strains, including C3H/HeN, BALB/c, C57BL6, FvB and ICR, to Echinostoma hortense infection, was evaluated. The worm expulsion rate, worm size and egg production were observed from 1 to 8 weeks after infection with 30 metacercariae. C3H/HeN and ICR mice showed the highest worm maturation rates. The worm recovery rate and the number of eggs per gram (EPG) of feces was also higher in C3H/HeN and ICR mice than in BALB/c, C57BL6, and FvB mice. It is suggested that E. hortense is highly infectious to ICR and C3H/HeN mice, but not to the other strains of mice. Based on the results obtained, we believe that the susceptibility of different mouse strains to E. hortense infection is dependent on the genetic and immunologic background of mice.

A human case of Echinostoma hortense (Trematoda: Echinostomatidae) infection diagnosed by gastroduodenal endoscopy in Korea

A human Echinostoma hortense infection was diagnosed by gastroduodenoscopy. An 81-year-old Korean male, living in Yeongcheon-shi, Gyeongsangbuk-do and with epigastric discomfort of several days duration, was subjected to upper gastrointestinal endoscopy. He was in the habit of eating fresh water fish. Two live worms were found in the duodenal bulb area and were removed using an endoscopic forcep. Based on their morphological characteristics, the worms were identified as E. hortense. The patient was treated with praziquantel 10 mg/kg as a single dose. The source of the infection in this case remains unclear, but the fresh water fish consumed, including the loach, may have been the source. This is the second case of E. hortense infection diagnosed by endoscopy in Korea.

Effects of double infection with Echinostoma liei and Schistosoma mansoni on hemoglobin content and circulating hemocytes in the hemolymph of the host snail Biomphalaria Alexandria

Three groups of hemocyte cells were identified in the hemolymph of B. alexandrina snails. These are granulocytes, hyalinocytes and undifferentiated [round] cells. Granulocytes are most common. Exposure of B. alexandrina to S. mansoni and E. Liei miracidia significantly increased the number of circulating hemocytes in one-week post miracidial exposure. Meanwhile, the increase in cell number counted at two and three weeks post exposure was not statistically significant. The percentage of hemocyte categories were changed in the exposed groups of snails one week and two-weeks post exposure. In one week post exposure group, snails had significantly higher percentages of undifferentiated cells than controls. While, in two weeks post miracidial exposure group, the percentage of granulocytes significantly increased. Infection of B. alexandrina with S. mansoni and E. liei significantly reduced the hemoglobin content in their hemolymph during first-, second and third weeks post miracidial exposure