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ABSTRACT:Strongyloides stercoralis is an opportunistic parasitic nematode ,whose larvae can invade the lung ,brain ,liv‐er ,kidney and other organs of hosts and cause strongyloidiasis .The infection opportunity of strongyloidiasis increased with raised living standard ,changed lifestyle and family pets .So far ,the relevant domestic researches of strongyloidiasis are limited in case reports and epidemiological investigation ,but researches involving biological characteristics ,immune phenomenon and protective immune response in humans are still very little .Based on the references ,this review summarizes recent findings in morphology ,life cycle ,pathogenicity ,epidemiology ,immunology ,diagnosis and prevention of S .stercoralis for raising the awareness of strongyloidiasis .
ABSTRACT
The potamon that were sold by Mengla market were examined positive for two species of paragonimus metacercariae andexcyted metac ercariae, this is the first report in Yunnan Province． The potamon that were sold by cities market from other suburbs may cause epdemic or outbreak of paragonimiasis, there is of momentous significance in epidemiology．
ABSTRACT
69 crabs were collected from Daxing, Gekui and Niukong townships of Lvchun county, Yunnan Province in 2006 and excysted metacercariae were only obtained from crabs of Niukong. The infection rate was 27.6% (8/29) with an average metacercaria number of 2.25 each crab. No encysted metacercariae were found. The excysted metacercariae were morphologically identified as Paragonimus proliferus.
ABSTRACT
The second intermediate hosts of lung fluke in the jinghong region are Potamon chinghungense and P.hispidum.Their natural infection rates are 68.3% and 55.6% respectively and on the average,each crab contains 11.3 and 2.6 metacerc- ariae.There is no difference between male and female in the natural infection rate, but the infectiosity is different in different places.5.8% of the crabs are infected by three sp(?)cies of metacercariae simultaneously.About 70% metacercariae of Par- ogonimus microrchis or P.proliferus are parasitized in the cephalothorax of P.chinghungense or P.hispidum.
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Objective To study the life span of Trichinella spiralis male adult and its effect on female fertility.Methods 22 Kunming mice were divided into three groups.Group A was orally inoculated by encysted larvae,dissected at day 5,10,20,and 30 post infection,adult worms were then collected and counted.Group B was fed with 5-day adults(70 females + 30 males/mouse).Group C was fed with 5-day females(70/mouse) only.Groups B and C were sacrificed 30 days post inoculation,larvae were collected to calculate reproductive capacity index(RCI).Male worms of day 5,10,20 and 30 were fixed in glutaraldehyde for scanning electron microscopy(SEM) and transmission electron microscopy(TEM).Results 20 days after infection,there were more males than females in the intestines of group A mice(female :male =1 :1.3),but much more males than females on the 30th day after infection(female :male =1 :8.5).Mice of groups B and C were infected by 5-day adults successfully with a RCI of 154.90?2.62 and 13.77?1.67 respectively(t=111.26,P
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Objective To make identification between Paragonimus menglaensis and Paragonimus proliferus. Methods Crabs were collected from same area where P. proliferus and P. menglaensi were reported, metacercariae and excysted metacercariae were separated. Adult worms were collected from experimental infection and identified. Results The metacercaria is large, with an average size of (1.23?0.087)mm?(1.10?0.073)mm, covered with a thin and fragile cyst wall; the size of excysted metacercariae is (2.01?0.71) mm ?((0.62)?0.12) mm, with irregular bough-like wrinkles excretory bladder resembling in front of ventral sucker, two pointed and slim distal ends of gut locate at 1/6 of the body from the tail end; the adult worm has large uterine mass, with an average length of 1/(4.2) of the whole body. The natural definitive host for P. proliferus is not monkeys, dogs, and cats, but rats. The metacercaria of the reported P. menglaensis has been mixed up with that of P. microrchis from the same crab, excysted metacercaria has been same to that of P. proliferus, and an immature worm has been mistakenly identified as its adult worm. Conclusion P. proliferus is a valid independent species, while P. menglaensis is a mis-identified, invalid one.
ABSTRACT
This paper gives the natural hosts and experimental hosts of Paragonimus microrchis a pri- mary investigation and an experimental research.The results confirm the first intermediate hosts are several species of Tricula,and the second intermediate hosts are Potamon chinghungense and P.hispidum.The suitable final hosts are dogs and cats.Both Paguma larvata and rats can be in- fected,but they are unfavorable final hosts.A rhesus monkey hasn't been successfully infected by the metaceraria of Paragonimus microrchis.