Seroprevalence of toxoplasmosis among migrant workers from different Asian countries working in Malaysia.

A serologic study of Toxoplasma antibodies among 501 foreign migrant workers in Malaysia was conducted in a plantation and detention camp. The highest prevalence rate of 46.2% was among Nepalese workers. Statistical analysis indicated the IgG positivity rate among local residents was significantly higher than the migrants studied (p < 0.05). The IgM positivity rate showed no significant difference between the two groups (p > 0.05). No significant difference in the prevalence rate was noted between the migrants and the local workers when grouped by agricultural and non-agricultural occupations (p > 0.05). The continuous introduction of these infections may influence the epidemiology and further compromise efforts in control and prevention. It is therefore important to monitor of non-notifiable diseases.

A brief survey of free-living amebae in Thailand and Hamamatsu District, Japan.

The aim of this study was to determine the presence of free-living amebae in aquatic habitats of human environments in Thailand and Hamamatsu district, Japan. Genus identification was based on the morphology of cyst and trophozoite forms and a flagellation test for genus Naegleria. The pathogenic potential was tested in mice by nasal instillation for genus Naegleria and Acanthameba. In 14 provinces of Thailand, amebae were isolated in 43 from 95 water samples and 67 from 120 soil swabs. Amebae of 49 isolates from waters were identified as Acanthameba (36.7%), Naegleria (28.6%), Hartmannella (20.4%), Vahlkampfia (12.2%) and Vannella (2%). Soil samples have significantly higher levels of Acanthameba and Hartmannella (p<0.05) but lower for Naegleria (p<0.05) and 7 unidentified amebae were found. In Hamamatsu district, Japan, 62 amebae of the same genera were isolated from 47 of 95 water samples. There were significantly higher levels of Acanthameba (22.6%) (p<0.05) but lower for Naegleria (4.8%) (p<0.05) than those of Thailand which each of them caused death in mice. Three unidentified amebae were isolated. This finding serves as additional evidence for the presence of free-living amebae under natural and the difference in distribution between tropic and subtropic areas.

Epidemiology, symptoms and treatment of paragonimiasis in Sin Ho district, Lai Chau province, Vietnam.

Sin Ho is a district of the northern mountainous province of Lai Chau, Vietnam, where the people have the habit of eating undercooked crabs. A study on paragoniamiasis carried out from 1994 to 1995 with 1,642 persons in this endemic area, showed that the rate of eating raw-crab was 72.5%. Crab examination (Ranguna kimboiensis) showed an infection rate of Paragonimus metacercaria of 98.1%. With 624 stool samples examined by Kato technique, the infection rate of Paragonimus in humans was 6.4%. With 338 sputum samples examined by direct and centrifuge methods, the infection rate of Paragonimus was 7.4%. Most of the patients were children (63.2%). The infection rate of Paragonimus in dogs was 18.2 - 33.3%. Adult worms, collected from the dogs in the field and from the cats in laboratory, were identified as Paragonimus heterotremus. The main symptoms of Paragonimus patients were cough and hemoptysis (92%), discontinuously developed (96%), without fever (94%), chest pain (70%), pleural effusion (26%), neurogical symptoms (8%), eosinophilia (88.9%), nodular ring shadows in the lungs, as shown by chest X-ray examination and more in lower lobe, (76.2%). Paragonimiasis patients were treated by (a) Praziquantel 25 mg/kg/day x 3 days; the cure rate was 68.8%. (b) Praziquantel 50 mg/kg/day x 3 days; the cure rate was 75%.

Epidemiology of clonorchiasis in Ninh Binh Province, Vietnam.

Clinical and stool examinations for clonorchiasis were carried out in an endemic area, Kim Son District, Ninh Binh Province, Vietnam. Stool examination with the Kato-Katz technic revealed that in 306 residents selected randomly, 42 people (13.7%) were infected with Clonorchis sinensis. The rate was biased towards men (23.4%) as opposed to women (1.5%) and increased with age. No children younger than 10 years old were infected, reflecting difference in a chance for acquisition of infection through a habit of eating raw fish. Few clinical abnormalities were found by blood and urine examinations of the patients. Treatment with praziquantel decreased the infection rate to 5.3% at 6 weeks later. Snails, Melanoides tuberculatus, collected from ponds around the settlements were infected with cercariae at a rate of 13.3%. Farmed fish (Hypophthalmichtys molitrix) in the ponds were infected with metacercariae at rates of 56.4% in small individuals and 100% in large ones. The life cycle of C. sinensis is exclusively completed in the ponds and the traditional habit of eating raw fish in summer was thought to be a major route of infection.