First Record of Paramphistomes Fischoederius cobboldi and Paramphistomum epiclitum Detected in Bovine Rumen from a Local Market of Savannakhet Province, Lao PDR

In the present study, we report on the occurrence of paramphistomes, Fischoederius cobboldi and Paramphistomum epiclitum, in Lao PDR with the basis of molecular data. Parasite materials were collected from bovines bred in Ban Lahanam area, Savannakhet Province, Lao PDR at Lahanam public market. Morphological observations indicated 2 different species of paramphistomes. The mitochondrial gene cox1 of the specimens was successfully amplified by PCR and DNA sequencing was carried out for diagnosis of 11 specimens. Pairwise alignment of cox1 sequences were performed and confirmed F. cobboldi and P. epiclitum infecting bovines in Laos. Although there were many limiting points, as the small number of worm samples, and the restricted access of the animal host materials, we confirmed for the first time that 2 species of paramphistomes, F. cobboldi and P. epiclitum, are distributed in Lao PDR. More studies are needed to confirm the paramphistome species present in Savannakhet and its hosts to clear the natural history of these parasites of ruminants in the region and measure the impact of this parasite infection in the life and health of the local people.

Haplorchis taichui as a Possible Etiologic Agent of Irritable Bowel Syndrome-Like Symptoms

The aim of this study is to clarify the clinical features of Haplorchis taichui infection in humans in Nan Province, Thailand, and to correlate the clinical features with irritable bowel syndrome (IBS)-like symptoms. In this study area, only H. taichui, but neither other minute intestinal flukes nor small liver flukes were endemic. The degree of infection was determined by fecal egg counts and also by collecting adult worms after deworming. The signs and symptoms of individual patients together with their hematological and biochemical laboratory data were gathered to evaluate the relationship between the clinical features and the severity of infection. Special emphasis was made to elucidate the possible similarities of the clinical features of H. taichui infection and IBS-like symptoms. The results showed useful clinical information and the significant (> 50%) proportion of haplorchiasis patients complained of abdominal pain, lassitude, and flatulence, which were the important diagnostic symptoms of IBS. This study has reported a possible link between H. taichui and IBS, and H. taichui might probably play a role in the etiology of these IBS-like symptoms.

Two Plenosominoides Metacercariae from Mountain Crabs in Central and Eastern Thailand

Mountain or waterfall crabs from Nakhon Nayok, Saraburi, Kanchanaburi, and Chantaburiprovinces, were collected and examined for trematode metacercariae. Among the metacercariaerecovered, two species of the family Microphallidae were found−Plenosominoides yangshanensis andP. vajrasthirae n comb. The cysts were oval with a thick wall; the metacercariae inside the cyst wallwere fully developed−all organs were visible, but no eggs. Their common features were as follows:vitellaria formed into two groups anterior-lateral to each caecum, cirrus pouch incompletely circular,not enclosing a ventral sucker. Little information was known of these trematodes and there has beenno report of their public-health importance.

Opisthorchis viverrini Metacercariae in Cyprinoid Fish from Three Rivers in Khammouane Province, Lao PDR

This study aimed to determine the prevalence, intensity and distribution of Opisthorchis viverrinimetacercarial infection in cyprinoid fish collected from three rivers in Khammouane Province,central Lao PDR, between April 2007 and February 2008. A total of 1,356 freshwater fish were collected; of these, 1,246 cyprinoid fish of 18 species were examined for O. viverrini metacercariae–only 8 species of cyprinoid fish were infected with O. viverrini metacercariae. Infection rates were as follows: Cyclocheilichthys repasson (58.5%), C. armatus (43.1%), C. enoplos (10.0%), Dangila lineata (69.6%), Henicorhynchus lineatus (42.9%), Hampala dispar (44.4%), Puntioplites proctzysron (26.8%), Osteochilus waandersii (30.5%); and the mean ± SD intensities of infection were 2.63 ± 1.11, 1.05 ± 0.53, 0.90 ± 0.43, 2.60 ± 0.98, 2.4 ± 0.98, 0.92 ± 0.53, 0.93 ± 0.48, and 1.90 ± 0.45, respectively. The prevalence of O. viverrini metacercarial infection among cyprinoid fish from Namdone and Napakane increased markedly during the dry season. O. viverrini metacercariae were found scattered throughout the entire body; however, the body muscles harbored the highest density of metacercariae, followed by the fins, head, and visceral organs, respectively.

Egg Laying Capacity of Haplorchis taichui (Digenea: Heterophyidae) in Humans

Quantitative fecal egg counts represented as the number of eggs per gram of feces (EPG) are generally a reliable parameter to estimate the worm burden of intestinal and hepatic parasitoses. Although Haplorchis taichui (Digenea: Heterophyidae) is one of the most common minute human intestinal flukes, little is known about the relationship between EPG and the actual worm burden in patients or the severity of the disease. In the present study, fecal samples were collected from 25 villagers in northern Thailand before and after praziquantel treatment. The EPG values of each participant were determined by the modified cellophane thick smear method, and adult worms were collected from the whole stool after the treatment. Eggs per day per worm (EPDPW) of H. taichui were estimated 82 from egg counts and expelled worms. The EPG was not well correlated with the worm burden, and a reverse correlation was observed between the EPDPW and the worm burden.

Anchitrema sanguineum (Digenea: Anchitrematidae) Accidentally Found during Colonoscopy of a Patient with Chronic Abdominal Pain: A Case Report

In November 2007, a 46-year-old male Thai patient presented with chronic abdominal pain for over 3 years. Colonoscopy revealed a small parasite of about 2 x 1 mm in size attached to the cecum mucosa. The worm was removed endoscopically, fixed, and stained for morphological observations. The specimen was identified as Anchitrema sanguineum (Digenea: Anchitrematidae), a trematode first reported in a reptile, Chamaeleo vulgaris, from Egypt, and then sporadically found in the intestines of insectivorous bats and other mammals. The patient was treated with praziquantel but no more worms were found in his stool. His symptoms improved slightly but not cured completely. It remains unclear whether the chronic abdominal pain of the patient was caused by this trematode infection. Whatever is the pathogenicity of this trematode, this is the first human case of A. sanguineum infection in the literature.