Only 8.4% of 1,286 Chinese boys and girls from the ages of 5-12 years in Pulau Ketam were infected with soil-transmitted helminths. The majority of these children had single infections with Trichuris or Ascaris alone. Mixed infections made up less than 5% of all infected cases. The worm burdens of infected children were very low. There was no definite pattern of distribution of infection among children of different ages and no differences in the distribution of infection between boys and girls. The main factors for the low prevalence and intensity of infection were the absence of suitable soil for the development and survival of infective helminth stages and the lack of contact with contaminated soil on this island. These two factors acted as very effective barriers to the transmission of soiltransmitted helminths on Pulau Ketam.
A study was conducted to determine the helminthes in dog's feces and soil samples from urban and rural areas. Six species of nematodes (Toxocara sp, an undetermined nematode larvae, Strongyloides sp larvae, Ascaris sp ova, hookworm ova, Trichuris sp ova) and one species of Cestode (Taenia sp) were found in 175 stool samples. Seventy-eight point nine percent of stool samples were positive for helminthes. Mixed infection with at least one parasite was found in 32.6% of the samples. The prevalence of helminth infection ranged from 1.1% to 45.1%. The prevalence of hookworm sp was the highest with 45.1%. The highest prevalence in urban dogs was hookworm sp in 76.7% and in rural areas was Ascaris sp in 48.7%. Soil samples were also examined to determine contamination of the environment, especially due to Toxocara canis, as a potential source of infection. Urban soil samples showed a higher contamination rate with 26.7% compared to rural areas with 4.9%. Toxocara ova were the most prevalent helminthes contaminating the soil with 12.1%. This study showed that humans from both urban and rural areas are at risk of acquiring helminth infection from contaminated soil.
The principal etiologic agent of human eosinophilic meningitis, Angiostrongylus cantonensis, was first detected in rats in Canton, China in 1933. The first human case was detected on Taiwan in 1944. Epidemic outbreaks were noted on Ponape (E. Caroline Is.) from 1944 to 1948. The disease may present as transient meningitis or a more severe disease involving the brain, spinal cord and nerve roots, with a characteristic eosinophilia of the peripheral blood and CSF. Since 1961 it has been known that human infections are usually acquired by purposeful or accidental ingestion of infective larvae in terrestrial mollusks, planaria and fresh-water crustacea. There is no effective specific treatment. The African land snail, Achatina fulica played an important role in the panpacific dispersal of the organism: it will be important in Africa in the future as well. Rats were, and will continue to be the principal agents of expansion of the parasite beyond the Indopacific area. During and just after WWII the parasite was introduced, and/or spread passively from South and Southeast Asia into the Western Pacific islands and eastward and southward through Micronesia, Melanesia, Australia and into Polynesia, sequestered in shipments of war material and facilitated by post-war commerce. In the 1950s numerous cases were identified for the first time on Sumatra, the Philippines, Taiwan, Saipan, New Caledonia, and as far east as Rarotonga and Tahiti. Then cases were detected in Vietnam, Thailand, Cambodia, Java, Sarawak, the New Hebrides, Guam and Hawaii during the 1960s. Subsequently in the Pacific Basin the disease has appeared on Okinawa, other Ryukyu islands, Honshu, Kyushu, New Britain, American Samoa and Western Samoa, Australia, Hong Kong, Bombay, India, Fiji and most recently in mainland China. The parasite in rats now occurs throughout the Indopacific Basin and littoral. Beyond the Indopacific region, the worm has been found in rodents in Madagascar (ca 1963), Cuba (1973), Egypt (1977), Puerto Rico (1984), New Orleans, Louisiana (1985) and Port Harcourt, Nigeria (1989). Human infections have now been detected in Cuba (1973), Réunion Island (1974) and Côte d'Ivoire (1979) and should be anticipated wherever infected rats of mollusks have been introduced. Caged primates became infected in zoos in Hong Kong (1978) and New Orleans and Nassau, Bahamas (1987). The use of mollusks and crustacea as famine foods, favored delicacies and medicines has resulted in numerous outbreaks and isolated infections. Economic and political instability, illicit trade, unsanitary peridomestic conditions and lack of health education promote the local occurrence and insidious global expansion of parasitic eosinophilic meningitis.(ABSTRACT TRUNCATED AT 400 WORDS)