ABSTRACT
A nationwide survey of human parasites in China was conducted during 1988-1992, with a coverage of 30 provinces/autonomous regions/municipalities (P/A/M). A total of 2,848 pilot sites in 726 counties were selected by random sampling, and 1,477,742 individuals residing on were surveyed by fecal examination. The status of paragonimiasis, hydatid diseases, cysticercosis and trichinellosis were summarized through data review. The overall infection rate of intestinal parasites was 62.6% whereas at provincial level, the highest infection rate (94.7%) was recovered in Hainan, and the lowest (17.5%) in Heilong-jiang. A high proportion (43.3%) of polyparasitism among the infected population (882,080) was revealed. Altogether 56 species of parasites comprising protozoa (19), trematode (16), cestodes (8), nematodes (12) and thorny-headed worm (1) were discovered. During the survey a new species and several new records were documented. The number of the population infected with common intestinal parasites was estimated. The diversities of parasite distribution were noted in different nationalities as well as in varied occupations.
Subject(s)
Adolescent , Adult , Aged , Child , Child, Preschool , China/epidemiology , Feces/parasitology , Female , Health Surveys , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Occupations , Parasitic Diseases/epidemiology , Pilot Projects , Population Surveillance/methods , Prevalence , Residence Characteristics , Sampling StudiesABSTRACT
In order to explore the possible occurrence of inducing resistance of Schistosoma japonicum to praziquantel (PZQ), a set of animal experiments were carried out. Outbred mice (NIH strain), Anhui isolates of S. japonicum and Oncomelania hupensis were used. In one protocol five weeks after being infected with 48-52 cercariae, mice were orally dosed with PZQ 300 mg/kg, and killed 82 days later to isolate eggs from the liver. Snails were exposed to miracidia released from egg-hatching. F1 progeny were thus obtained through cercarial inoculation. The same scheme was applied for the establishment of the F2 generation. In another protocol two weeks after infection, PZQ 50 mg/kg/day was given to mice for 5 days. Eggs were collected 26-27 days post treatment and the identical procedures were adopted for F1 and F2 generations successively. Analysis of total worm and female worm reduction rates indicated that there was no significant difference between the sensitivity to PZQ of F1 and F2 progenies of S. japonicum and the parent worms.