[Correlation between HLA-DB1 genes and susceptibility to echinococcosis in Tibetan population in Tibetan Plateau].

OBJECTIVE: To determine the susceptibility genes and resistance genes in HLA-DRB1 alleles in Tibetan patients with cystic and alveolar hydatid diseases, so as to provide the references for the research of the genetic characteristics and infection mechanism of Tibetan hydatid diseases. METHODS: The case control method was applied. The Tibetan patients with cystic and alveolar hydatid diseases (63 and 73 cases respectively) in Yushu and Guoluo Tibetan Autonomous Prefecture, and unrelated healthy people (60 cases) in this area were selected as the study subjects. The polymerase chain reaction-sequence based typing (PCR-SBT) technique was applied for genotyping of HLA-DRB1, and the comparison of the gene frequency. RESULTS: The frequency of HLA-DRB1*04 in the alveolar/cystic echinococcosis group was lower than that in the control group ( χ2 = 4.71, 4.31, both P < 0.05). CONCLUSIONS: HLA-DRB1*04 genotypes may be associated with the resistance of cystic and alveolar echinococcosis and its resistance genes.

[Epidemic status of alveolar echinococcosis in Tibetan children in south Qinghai Province].

OBJECTIVE: To understand the epidemic status of alveolar echinococcosis in Tibetan children in south Qinghai Province. METHODS: The imageology and serology methods were applied to investigate the epidemic status of alveolar echinococcosis of elementary school students in Yushu and Guoluo prefectures. RESULTS: Totally 19 629 children were investigated by the portable B ultrasound and 221 children were diagnosed as alveolar echinococcosis with the morbidity of 1.13%. Totally 9 888 were investigated by the indirect ELISA, and the positive rate of serum tests was 12.59% (190/9 888). The total morbidity of alveolar echinococcosis of children in Yushu Prefecture was 0.42% (31/7 454) and it was 1.57% (190/12 175) in Guoluo Prefecture and there was a significant difference between them (χ2 = 53.42, P＜0.005). The sero-positive rates of children in Yushu and Guoluo were 4.26% (302/7 081) and 18.56% (1 835/9 888), respectively (χ2 = 765.77, P＜0.005). The counties with the highest prevalence of alveolar echinococcosis in children were Dari County (4.31%, 106/2 461) and Banma County (1.92%, 26/1 351) of Guoluo Prefecture, and Chengduo County (1.11%, 18/1 612) of Yushu Prefecture. The total morbidity rates of alveolar echinococcosis of male and female children were 0.91% (91/9 954) and 1.34% (130/12 175) respectively (χ2 = 7.35, P＜0.005). The total sero-positive rates of alveolar echinococcosis of male and female children were 12.10% (1 037/8 568) and 13.09% (1 100/8 406) respectively (χ2 = 3.63, P＞0.05). The total morbidity of alveolar echinococcosis of children in different age groups was from 1.00% to 1.13%, and there was no significant difference among the age groups (χ2 = 2.73, P＞0.05). The P1a type, P1b type and P2 type accounted for 67.76% (145/214), 10.75% (23/214) and 16.36% (35/ 214) respectively among the alveolar echinococcosis patients. The diameters of nidus of 87.38% (187/214) patients were less than 5 cm, and 2.80% (6/214) were more than 10 cm. CONCLUSIONS: The epidemic status of alveolar echinococcosis of Tibetan children in south Qinghai Province is serious, but most of the patients were at early stage of the disease. The screening work of alveolar echinococcosis should be strengthened in Tibetan children, so as to perform the early diagnosis and treatment.

[Prevention and control knowledge of echinococcosis in students in Qinghai Province].

OBJECTIVE: To understand the situation of prevention and control knowledge of echinococcosis in students in Qinghai Province, so as to provide an evidence for effective prevention and control of echinococcosis. METHODS: The students of Grade Four or above were randomly selected with the multi-stage stratified cluster sampling method and investigated with the questionnaire about echinococcosis in Qinghai Province. RESULTS: Totally 23 600 students were selected and surveyed, with the pass rate of 66.0% (15 566 cases). The pass rates of the male and female students were 65.1% (7 947 cases) and 66.9% (7 619 cases) respectively, and the difference was significant (χ2 = 8.454, P < 0.01). The difference of pass rates among different districts of Qinghai Province was statistically significant (χ2 = 3 848.619, P < 0.01). CONCLUSIONS: The general aware rate of echinococcosis knowledge in students is not high in Qinghai Province, and therefore, it is necessary to enhance the health education, especially for students in pasturing areas.

Current situation of Echinococcus infection in different hosts in Qinghai plateau / 中国地方病学杂志

ObjectiveTo analyze Echinococcus infection in definitive and intermediate hosts in different zones of Qinghai plateau,Qinghai southern plateau,Qilian mountain-Hehuang valley and Chaidamu basin,and to provideascientificbasisfor developing controlstrategiesagainstEchinococcosisinfection. Methods Echinococcosis infection in definitive hosts,dogs and foxes,was identified by morphological observation; in domesticated and wild intermediate host animals was identified by anatomy and pathology; some of the suspected samples were further identified by molecular biological methods.ResultsStray dogs in different zones of Qinghai plateau were infected with Echinococcus granulosus,the infection rates were 38.71％(300/775),49.60％(124/250),and 9.76％(4/41 ) in Qinghai southem plateau,Qilian mountain-Hehuang valley and Chaidamu basin,respectively,and the difference was statistically significant(x2 =25.72,P ＜ 0.01 ).in addition,only Qinghai southern plateau dogs were infected with Echinococcus multiloularis,and the infection rate was 16.04％(98/611).The infection rates of fox with Echinococcus multilocularis were 22.89％(38/166) and 30.77％(12/39) in Qinghai southern plateau and Qilian mountain-Hehuang valley,respectively,and wolves were also found to be infected with Echinococcus granulosus in the same areas.The infection rates of domesticated sheep,yaks,goats and pigs with Echinococcosis were significantly different statistically in those different areas(x2 =82.70,41.82,212.63,194.58,all P ＜ 0.01 ).The infection rates of sheep and yaks were higher[43.43％(5664/13 042),49.47％(2917/5896),52.99％ (887/1674),42.18％ (779/1847),50.70％ (1049/2069),52.90％ (685/1295) ] in three areas.The infection rates of goats and pigs [3.26％ (7/215),0.00％ (0/108)] in Qinghai southern plateau were lower than that of other two areas[ 19.51％(119/610),26.91％(43/1598),47.91％(343/716),21.91％(71/324)].The infection rates of Ochotona curzoniae with Echinococcosis were 6.21％ (243/3910),1.80％ (3/167) and 0.00％ (0/199) in Qinghai southern plateau,Qilian mountain-Hehuang valley and Chaidamu basin,respectively,and the difference was statistically significant (x2 =18.50,P ＜ 0.01 ).Moreover,wild intermediate hosts of Echinococcosis,such as Microtus fuscus,Lepus oiostolus,Pseudois nayaur,Procapra picticaudata,and Prodorcas gutturosa were found to be infected only in Qinghai southern plateau.ConclusionsHuman is faced with a threat of Echinococcosis infection from various definitive hosts in different zones of Qinghai plateau.And stray dogs are the most crucial factor.The life-cycles of Echinococcus are very complicated in Qinghai plateau.Qinghai plateau is a key area in prevention and control of Echinococcosis infection in China.