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.

Freshwater mollusks of medical importance in Kalasin Province, northeast Thailand.

A snail survey was performed in six districts around irrigation areas of Lampao Dam, in Kalasin Province. The survey caught a total of 5,479 live snails and classed them into five families, 12 genera and 15 species, of which 7 species are suspected of transmitting human parasitic diseases. The seven species were Pila polita, Pomacea canaliculata, Filopaludina (S.) m. martensi, Bithynia (Digoniostoma) siamensis goniomphalos, Melanoides tuberculata, Radix rubiginosa, and Indoplanorbis exustus. Of these, B. (D.) s. goniomphalos and I. exustus were found to harbor emergent cercariae. Only B. (D.) s. goniomphalos hosted several types of cercariae--Opisthorchis viverrini, unidentified species of intestinal flukes, echinostomes, xyphidio and furcocercous cercariae. Indoplanorbis exustus shed only echinostome cercariae. B. (D.) s. goniomphalos showed a rather high natural infection rate with O. viverrini, 1.3% in Yang Talat district, and 0.61% in Kamalasai district, in Kalasin Province.

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.

Changes on Schistosoma mansoni (Digenea: Schistosomatidae) worm load in Nectomys squamipes (Rodentia: Sigmodontinae) concurrently infected with Echinostoma paraensei (Digenea: Echinostomatidae)

The water rat, Nectomys squamipes, closely involved in schistosomiasis transmission in Brazil, has been found naturally infected simultaneously by Schistosoma mansoni and Echinostoma paraensei. Laboratory experiments were conducted to verify parasitic interaction in concurrent infection. It was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with E. paraensei. Rodents were divided into three groups in each replication. A wild strain recently isolated from Sumidouro, RJ, and a laboratory strain of S. mansoni from Belo Horizonte (BH) was used. Rats infected with E. paraensei were challenged 4 weeks later with S. mansoni and mice 2 or 6 weeks after the infection with S. mansoni. Necropsy took place 8 weeks following S. mansoni infection. The N. squamipes treatment groups challenged with S. mansoni RJ strain showed a significant decrease (80 and 65 percent) in the S. mansoni parasite load when compared with their respective control groups. There was a significant change or no change in the hosts challenged with the BH strain. The persistence time of E. paraensei within host was extended in relation to control groups, with a consequent enhancement of the number of recovered worm. An E. paraensei strain-specific influence on S. mansoni parasitism is reported. This paper presents some experimental data about this interaction in N. squamipes and Mus musculus

Studies on lymnaea snails and their trematode parasites in Abis village, Alexandria

Lymnaea snails in Abis II Village were studied as regard to their species, monthly distribution, density and infection rates in different water bodies. The trematode parasites in L. cailliaudi, the only species of Lymnaea in Abis II Village were Xiphidio in 40% of snails and Fasciola in 10%. Echinostome cercariae were detected from few snails outside Abis II Village. The morphological characters of the different larval stages of the detected parasites were described

Lymnaea (Bullastra) cumingiana Pfeiffer (Pulmonata: Lymnaeidae): second intermediate host of Echinostoma malayanum in the Philippines.

Adult flukes were obtained from laboratory rats and hamsters fed with metacercariae isolated from Lymnaea (Bullastra) cumingiana Pfeiffer and were identified as Echinostoma malayanum Leiper based on the presence of a circumoral collar of 43-45 spines and the highly lobed testes. This discovery is of public health significance because L. (Bullastra) cumingiana in eaten raw by certain local populations in northern Luzon. The proposed new species, Cathaemasia cabrerai (Jueco and Monzon, 1984), is probably invalid because it apparently was based on E. malayanum flukes that had lost their circumoral collar of spines after treatment with praziquantel and bithionol. This is the first case where L. (Bullastra) cumingiana has been proven to be of medical importance in the Philippines. i.e., as the natural second intermediate host of E. malayanum. The first intermediate host and reservoir host of this parasite in the country are still unknown. Previously, only E. ilocanum was reported to be present in the Philippines.