Asymptomatic Human Paragonimiasis among the Karen People in Tak Province, Thailand: A Case Report

During the mobile clinic activities in Tak Province, Thailand, Paragonimus sp. eggs were found in a fecal sample of a 72-year-old Karen resident. Paragonimus DNA was amplified from the stool sample and identified to P. heterotremus. The patient did not have any symptoms. Apparent pulmonary lesion was not found on the chest X-ray. The patient admitted habitual consumption of semi-cooked or roasted waterfall crabs for several years. The waterfall crabs collected from stream near the village were found negative for Paragonimus metacercariae. In northern Thailand, paragonimiasis remains as one of the public health concerns and should be ruled out for asymptomatic pulmonary patients.

House Flies: Potential Transmitters of Soil-Transmitted-Helminth Infections in an Unsanitary Community

This study aimed to determine an appropriate technique for isolating helminthic objects from the exteriors of the bodies of lies, and to investigate helminth transmission rates among lies in an unsanitary community. The study area was Ban Nam Khem Village, Takua Pa District, Phang-nga Province, Thailand. In 2006, the prevalence of soil-transmitted-helminth (STH) infections in the community was 34.9%. Soil contamination in the swamp areas, where human feces were observed, ranged between 41.2-100% in the period February 2005-May 2006. Flies were abundant in defecation areas and around houses. One year after treatment and health education, the prevalence decreased to 22.5%. While the infection rate among the schoolchildren decreased, the rate among the villagers increased to 50.0%. In June 2007, the soil contamination rate was 13.3%. The 567 houselies in the study were all Chrysomya megacephala. Hookworm and Trichuris trichiura eggs on the body surfaces of the lies were isolated using an ultrasonic cleaner. The helminth transmission rate for lies in the defecation area was 25.9%, and in the household surroundings 11.8%. The average number of eggs on the body surfaces of lies in the defecation area was 0.4. After feeding on human excreta, 508 resting lies left 0.5 g of feces with pathogens in the surroundings. Anthelminthic treatment and health education were repeated to improve the helminth infection situation in the community. Manual shaking and ultrasonic-cleaner techniques provided equal detection rates (80%), but ultrasonic cleaning retrieved more eggs.

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.

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.

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.