| 【Objective】To understand the situations of echinococcosis and echinococcus in southeast ofQinghai province, we checked human, yaks, sheep, pikas, Tibetan dogs and wild foxes. First, mainspecies of echinocossus which have found to be infectious in human and animals were confirmedby analyzing mitochondria gene polymorphism of echinocossus collected from Tibetan dogs andwild foxes of Qinghai province. Second, distribution, behavior and feeding habits of wild foxeswere investigated by analyzing feces at Heka district in summer and gastric content at somecounties such as Guinan,Gangcha, Haiyan and Chenduo in winter which provide importantdatas about how to prevent wild animals to transmit echinococcosis. Third, to establishingtreatments by drugs treatment and then using praziquantal into Chengduo county and Heka sheepfarm of Qinghai province to find an effective way to prevent and cure echinococcsis of Tibetan dogsin pastoral areas of Qinghai province.【Methods】The main research methods used in this paper were as follows:(1) A rapid sero-diagnosis kit for detecting specific antibodies against echinococcus was usedto screen villagers as the primary survey, then B ultrasound and X-ray were used furtherconfirmation check among these sero-positive objectives; Yaks and sheep were inspected by visualand palpation at slaughterhouses and those cysts which confirmed were taken to laboratory forfurther study like numbers， size,location and statistics of infection rates of yaks and sheep; Pikaswere trapped and dissected for checking lungs and livers and other abdominal organs to recordingnumbers, size, location and statistics of infection rates.(2) Detect dohemg feces gold standard reagent strips and arecoline purge were used to detectEchinococcus in Tibetan dogs in southeast of Qinghai province. Wild foxes were trapped and theintestines were checked by necropsy.(3) The genetic diversity of Echinococcus were assessed by two mitochondrial target genes, i.e.coxI and nadI, in which the genetic polymorphism of Echinococcus of isolated strain of differentdistricts and hosts was analyzed.(4)Searchlight and infrared camera were used to count numbers of wild foxes and indentify thespecies of wild foxes in Heka district of Qinghai province. Further more, we used detect dog fecesgold standard reagent strips to detect the infection rate of Echinococcus in wild foxes. And feedinghabits of wild foxes was carried out by detecting feces in summer and gastric content in winter.(5)To screen medicine for prevention and cue echinococcosis, we choose two sites(Hekadistrict and Chengduo county)to do research. In addition, we gave medicine to Tibetan dogs every45days in Heka district and twice a year (April and October) in Chengduo county for two years. 【Results】The results was obtained in the paper as follows:(1)752residents(male:387,female:365) were serologically screened and of them50arepositive,thus the positive of rate is6.6%(50/752). And21sero-positive villagers(male:10,female:11) were confirmed positive by physical image techniques, so the positive rate of allresidents were2.8%（21∕752）the male is2.6%and the female is3.0%.57.4%(570/993) of sheepwere infected with cystic echinococcosis(liver,331;lung,239) and34.5%(205/594）of yaks wereinfected with cystic echinococcosis(liver,128;lung,91).Besides,4.9%(17/374)of Ochotonacurzoniaes were found hydatid cysts (liver:13, lung:4), but we found hydatid cysts in lungs only atChengduo county.(2)Arecoline purge was used to detect the prevalence of Echioncoccus at Tibetan dogs in manyarea in Qinghai Province like Yushu county, Chengduo county, Guinan county, Xinghai county, etc.And175of Tibetan dogs were investigated,9.1%(16/175) of them were infected Echinococcus, theinfection intensities are different from1to10195. The infection rate of Tibetan dogs of Chengduocounty（13.8%） and Xinghai county（9.1%）were much higher. With the detect dog feces goldstandard reagent strips, we surveyed611Tibetan dogs in Chengduo county, Gangca county, etc. inQinghai Province. And21.0%（128/611）of Tibetan dogs were positive. In addition,28foxes werearrested and collected in Chengduo county, Guinan county,Haiyan county, etc., and5of foxes(Chengduo conty:4,Haiyan county:1)were infected, the infection rate reach to17.9%, the infectionintensities were different from116to1670.(3)As a result of the amplification of partial sequence of mtDNA, we obtained fragments of285bp long CO1gene from21isolates. The results of alignment of our21mtDNA CO1genesequences show that the genotype of11isolates were E.g1(52.4%), of6isolates (28.6%) were E.m,and of4isolates (19.0%)were E.s. All the nucleotide sequences were found no insert mutation anddelete mutation, only base transition and transversion can be found and base transversion wasobviously more than base transition. The homology analysis showed that the similarity of E.g1strains were from98.9%to100%, while of the E.m strains’ were from97.9%to99.6%and of theE.s strains’were from98.9%to100%. It was shown90.2%～92.6%similarity with E.g1and E.m,and89.1%~90.2%similarity with E.g1and E. s strains, the homology similarity between E.s and E.m strains was88.8%~90.2%. There were7different sequences for E.g1genotype, which involved7different Nucleotide mutation points and made up2.5%of total gene. Haploid sequencedifference value are from0to1.1%. And there were6different sequences for E.m, which involved13different Nucleotide mutation points and made up4.6%of the total gene, and the haploidsequence are different from0.4to2.1%.And there were3different sequences for E.s, which waschecked involved7different Nucleotide mutation points and made up2.5%of the total gene, andthe haploid sequence are different from0to1.1%.By the alignment of sequences imported prior inGenBank,15of21isolates were can’t find the same variation strains, they are new genotype sequences never been found before in Qinghai Province.As a result of the amplification of partial sequence of mtDNA, we obtained fragments of507bp and510bp long ND1gene from21isolates. The results of alignment of our21mtDNA ND1gene sequences show that the genotype of11isolates were E.g1, reach to52.4%,6of isolates(28.6%) were E.m, and4of isolates (19.0%)were E.s. All the nucleotide sequences were found noinsert mutation and delete mutation, only base transition and transversion can be found and basetransversion was obviously more than base transition. The homology analysis showed that thesimilarity of E.g1strains were from99.0%to100%, while of the E.m strains’ were from99.2%to100%and of the E.s strains’ were from99.2%to100%. It was shown83.4%～84.2%similaritywith E.g1and E.m, and74.8%~75.3%similarity with E.g1and E. s strains, the homology similaritybetween E.s and E.m strains was75.9%~76.5%. There were6different sequences for E.g1genotype, and the Nucleotide mutation points were made up2.4%of the total gene, which involved12different Nucleotide mutation points, haploid sequence differences are from0to1.0%. E.m werechecked5different sequences, and the mutation points were made up1.8%of the total gene, whichinvolved9different Nucleotide mutation points, the Haploid sequences are different from0%to0.8%. While there were3different sequences for E.s, which involved10different Nucleotidemutation points were made up2.0%of the total gene involving the mutation of9amino acids, andthe difference value of Haploid sequence are from0%to0.8%. By the alignment of sequencesimported prior in GenBank,14of21isolates were can’t find the same variation strains, they arenew genotype sequences never been found before in Qinghai Province.(4)During our experiment at night, we surveyed five times and finally found five wild foxesand three rabbits. And in the whole Heka district if calculated in this way, there will be one wild foxeach10km2. And by our Infrared Automatic Induction Camera we shot wild fox, eagle and marmoteach for one time, and pikas for several times. Use detect dog feces gold standard reagent strips，Inthe area within1.76hm2of our experimental site, we selected6pieces of fox feces and all wereexamined negative, meanwhile,14pieces were collected beyond400m2and of13were examinednegative besides the positive one. We do trophic analysis for our17pieces collected in summerdays, it showed that in summer,19.5%food for fox were from mammals,58%were fromOrthoptera Acridoidea, and11.7%were from Coleoptera,0.05%were from larval worms,4.7%were from birds,6.1%were from plants. Also trophic analysis was conducted to our18piecescollected in winter days, and we finally found that in cold winter,36.3%food for fox were fromdomestic yak and sheep,53.7%were plateau pikas,3.5%were birds, and6.5%were plants.(5)We have selected Praziquantel tablet as the prior deworming pills for the canine, which wasused with excellent results. The drug should better be fed to the Tibetan dogs together with tsamba.For that Tibetan dogs usually like to eat with food other than to take it directly. Prevention andtreatment work of Echinococcosis for Tibetan dogs had conducted in Heka County Sheep Stud and Chengduo County area in Qinghai Province since two years’ prevention. The infection ratedecreased from25%and38.6%counted before prevention, down to4.9%and6.8%at present, sothe prevention effect is obvious. |
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