Objective To investigate the therapeutic effect of VSD combined with external fixator in the treatment of open tibial and fibular fractures in Tibet plateau. Methods From August 2014 to August 2015, totally 16 cases of open tibial and fibular fractures were treated in our department, including 12 males and 4 females with an average 39. 4 years-old. There were 4 cases of proximal and mid tibial fractures while 12 cases were distal fractures. Debridement, vacuum sealing drainage combined with external fixator for stabilization of fractures was performed in all patients after general condition was improved. A vacuum sealing drainage change or second stage wound closure or soft tissue coverage was undergone after 7 days. Bone union time by X-ray and complications were recorded. Results All wounds were healed by second stage. Twelve patients months were followed up ( by calling back to the hospital ) for an average 18 months ( 12 to 24 months ) , 4 cases were lost to follow-up. X-ray demonstrated that bone union was obtained at a mean 5. 5th month (3 to 7 months). There were 9 cases (75%) obtained a first phase of fracture healing, while 3 cases ( 25%) of delayed healing. Pin-track infection was occurred in two patients and was cured by conservative treatment. No complications of deep infection, graft skin or flap necrosis, malunion, nonunion or osteomyelitis was seen during follow-up. Conclusions Vacuum sealing drainage combined with external fixator for treatment of open tibial and fibular fracture in Tibet can rapidly and effectively stabilize the fracture, and simultaneously safely and effectively seal the wound, reduce the wound healing time, promote fracture healing and lower the complication rates.

Objective:To evaluate the effectiveness of hepatitis B prevention and control in Tibet Autonomous Region by comparative analysis of the results of seroepidemiological surveys of hepatitis B in 2014 and 2020.Methods:The required sample size was calculated based on the estimated HBsAg positivity rates of permanent residents aged 1-4, 5-14, 15-29, and 30-69 years. A total of 7 163 people and 4 802 people were required in 2014 and 2020, respectively. The subjects were selected by stratified multistage cluster random sampling method, using questionnaires to obtain basic information, and 5 ml of venous blood was collected from each subject to detect HBsAg, anti-HBs, and anti-HBc, and rechecked the HBsAg positive samples. SPSS 22.0 software was used to analyze the survey results, calculate the positive rate and 95% confidence interval.Results:A total of 7 069 people were investigated in 2014 and 4 913 people in 2020. In 2020, the positive rate of HBsAg, anti-HBs, and anti-HBc was 9.20% (452/4 913), 37.11% (1 823/4 913), and 32.75% (1 609/4 913), respectively, and decreased by 22.95%, 15.54%, and 1.92% as compared with the rate in 2014. The positive rate of HBsAg of people aged 1-, 5-, 15- and 30-69 years in 2020 was 2.23% (8/358), 2.85% (20/701), 6.86% (69/1 006) and 12.46%(355/2 848), respectively, decreased by 61.82%, 62.75%, 54.81% and 24.21% as compared with the rate in 2014. The positive rate of anti-HBs of people aged 1-4 years was 52.79% (189/358), 10.30% increased compared with 2014; for people aged 5-, 15-, and 30-69 years was 32.67% (229/701), 37.67% (379/1 006) and 36.03%(1 026/2 848), respectively, decreased by 20.84%, 14.13% and 16.52% as compared with the rate in 2014. The positive rate of anti-HBc of people aged 1-, 5-, 15-, 30-69 years was 4.19% (15/358), 6.42%(45/701), 21.07% (212/1 006), and 46.95% (1 337/2 848), respectively, decreased by 59.63%, 58.93%, 50.49%, and 12.10% as compared with the rate in 2014.Conclusions:The prevention and control of hepatitis B in Tibet have made partial achievements. The prevalence of HBsAg among people aged 1-69 years in 2020 had declined compared with 2014, but it is still at a high epidemic level. People have a high risk of HBV infection for a low level of anti-HBs. It is necessary to strengthen the vaccination of hepatitis B further and effectively implement the strategy of blocking mothers and children of the hepatitis B virus.

Objective:To understand the positive rate of 2019 novel coronavirus (2019-nCoV) specific IgG antibody induced by Coronavirus Disease 2019 (COVID-19) inactivated vaccine in healthy population in Xizang Autonomous Region, and evaluate the immune effect of the vaccine.Methods:Serum samples were collected from COIVD-19 vaccine immunized health population without history of 2019-nCoV infection from six prefecture-level cities in Xizang Autonomous Region. The IgG antibody against 2019-nCoV were tested by chemiluminescence method. Then, the positive rate of IgG antibody was analyzed for different immunization histories and age groups.Results:A total of 22 255 participants were enrolled in this survey. After full-access (two doses of vaccine) and booster immunization, the overall positive rate of specific IgG antibody against 2019-nCoV was 96.38%. The positive rate of IgG antibody in the booster immunized population was 97.12%, which was much higher than the 88.38% in the full-access immunization population, the difference is statistically significant ( χ2=381.11, P<0.001). There was a significant differences in the positive rates of specific IgG antibodies in different age groups ( χ2=138.28, P<0.001). Especially in the younger age groups, including less than 10 years old and the 11-20 years age group, the positive rate of specific IgG antibody were 93.44% and 89.03% respectively, which were lower than those in other age groups. Except for Naqu city and the age group ≤ 10 years old, the differences in antibody positivity rates were statistically significant between different age groups in the same region and between the different regions in the same age group for the two populations with different immunization histories ( P<0.05). Conclusions:The COVID-19 inactivated vaccine showed a good immune effect in the healthy population in Xizang Autonomous Region, and the booster immunization helps to increase the positive rate of specific IgG antibody in healthy population.

This study was aimed at identifying species of ticks and investigating infections with tick-borne pathogens a-mong people in Yadong,Tibet.The total of 23 ticks(Ixodes and Haemaphysalis)collected from livestock in Yadong,Tibet in July 2021,the gene sequences of cytochrome oxidase subunitⅠ(COX Ⅰ),mitochondrial 16S ribosomal DNA(16S rDNA)and mitochondrial 12S ribosomal DNA(12S rDNA)were identi-fied on the basis of molecular biology classification.The gene sequences of spotted fever group rickettsia(SFGR),Borrelia burgdorferi,Francisella tularensis and Coxiella burnetii in ticks were amplified by PCR and sequenced,and phylogenetic ana-lyses were performed.In addition,184 serum samples collected from Yadong in 2021 were screened for antibodies to Lyme dis-ease,Q fever,spotted fever,and tularemia by ELISA,and infections with tick-borne pathogens in Yadong were comprehen-sively analyzed.The ticks(Ixodes)collected in Yadong,Tibet,were grouped into two categories.The COX Ⅰ,16S rDNA,and 12S rDNA gene sequences of the ticks had 99.5％,97.57％,and 99.12％ similarity,respectively,to those of Ixodes nuttallia-nus in GenBank.The similarities between the COX Ⅰ and 16S rDNA gene sequences of another Ixodes tick species and the COXⅠ and 16S rDNA gene sequences of Ixodes ovatus in GenBank were 88.29％ and 95.75％,respectively.The similarity between the COX Ⅰ,16S rDNA,and 12S rDNA gene sequences of Haemaphysalis ticks and those of Haemaphysalis Tibet in GenBank were 96.04％,96.17％,and 97.47％,respectively.The sequence amplification results for Borrelia burgdorferi,Francisella tularensis,and Coxsiella burnetii in 23 ticks were negative,whereas gltA gene amplification of spotted fever group Rickettsia in 23 ticks was positive.The similarity of gltA gene sequences with respect to those of Candidatus Rickettsia tarasevichiae,Rickettsia raoultii,Rickettsia canadensis,and a Rickettsia endosymbiont of Eucalyptus brunneri in GenBank was 96.77％,96.76％,95.35％,and 95.35％,respectively.Among 184 serum samples from Yadong,the positivity rates of Lyme disease,Q fever,spotted fever,and tularemia were 6.52％,12.50％,8.70％,and 10.87％,respectively.These results indicated that the 23 parasitic ticks collected in Yadong,Tibet,in July 2021 were Ixodes nuttallianus,Ixodes ovatus and Haemaphysalis ti-betensis,and 23 ticks were infected with SFGR.Lyme disease,Q fever,spotted fever,and tularemia infection were prevalent in the population of Yadong.Therefore,efforts to control tick-borne diseases must be strengthened.