Abstract. A cross-sectional study was performed to determine the prevalence of giardiasis in hilltribe children of 2 different remote districts (Mae-chaem and Hod), Chiang Mai, Northern Thailand from November 2006-April 2007. The overall prevalence of giardiasis was 5.2%. Genetic characterization of Giardia duodenalis isolated from these children was performed using PCR methods specific for small subunit ribosomal rRNA (SSU-rRNA) and glutamate dehydrogenase (gdh) gene. This study shows that the distribution of Giardia assemblages varied in these 2 populations. Assemblage BIV was found predominantly in children from Hod District while assemblage AII was more common in children from Mae-Chaem District. Our result showed that assemblage A was significantly associated with loose/watery stool (p= 0.001). In addition, children harbouring assemblage B had shed a significantly higher number of cysts (p= 0.019) in stools than those infected with assemblage A. Further study on the epidemiology of giardiasis especially risk factors associated with genotyping would help to understand the nature of this disease in each population.

From July 2008 to June 2009, livers of the swamp eels (Monopterus alba) were investigated for advanced third-stage larvae (AL3) of Gnathostoma spinigerum. Results revealed that 10.2% (106/1,037) and 20.4% (78/383) of farmed eels from Aranyaprathet District, Sa Kaeo Province and those of wild-caught eels obtained from a market in Min Buri District of Bangkok, Thailand were infected, respectively. The prevalence was high during the rainy and winter seasons. The infection rate abruptly decreased in the beginning of summer. The highest infection rate (13.7%) was observed in September and absence of infection (0%) in March-April in the farmed eels. Whereas, in the wild-caught eels, the highest rate (30.7%) was observed in November, and the rate decreased to the lowest at 6.3% in March. The average no. (mean+/-SE) of AL3 per investigated liver in farmed eels (1.1+/-0.2) was significantly lower (P=0.040) than those in the caught eels (0.2+/-0.03). In addition, the intensity of AL3 recovered from each infected liver varied from 1 to 18 (2.3+/-0.3) in the farmed eels and from 1 to 47 (6.3+/-1.2) in the caught eels, respectively. The AL3 intensity showed significant difference (P=0.011) between these 2 different sources of eels. This is the first observation that farmed eels showed positive findings of G. spinigerum infective larvae. This may affect the standard farming of the culture farm and also present a risk of consuming undercooked eels from the wild-caught and farmed eels.
Animals ; Aquaculture ; Fish Diseases/*epidemiology/*parasitology ; Gnathostoma/*isolation & purification ; Gnathostomiasis/epidemiology/parasitology/*veterinary ; Larva ; Liver/parasitology ; Parasite Load ; Prevalence ; Seasons ; Smegmamorpha/*parasitology ; Thailand/epidemiology

A 22-year-old Thai man from the Northeast region presented with acute eye swelling, itching, and discharge on his left eye. He was suspected of having gnathostomiasis and treated with albendazole and prednisolone for 3 weeks. Nine months later, he was treated with high-dose oral prednisolone for the preliminary and differential diagnoses with thyroid-associated orbitopathy and lymphoma. He had been administered prednisolone intermittently over a few years. Then he developed a painless movable mass at the left upper eyelid and recurrent pseudotumor oculi was suspected. The surgical removal of the mass was performed. A white pseudosegmented worm revealed a definite diagnosis of ocular sparganosis by a plerocercoid larva. Molecular diagnosis of the causative species was made based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Proper technique of extraction and amplification of short fragments DNA from formalin-fixed paraffin-embedded tissue successfully identified parasite species. The result from the sequencing of the PCR-amplified cox1 fragments in this study showed 99.0% sequence homology to Spirometra ranarum. This is the first report of S. ranarum in Thailand.