Role of synaptic input remodeling of corticospinal motor neurons after spinal cord injury / 中国组织工程研究

BACKGROUND:The recovery of function after spinal cord injury depends on the functional remodeling of the motor cortex.However,the anatomical evidence underlying the functional remodeling of the motor cortex is still illusive.Analyzing the anatomical changes in the motor cortex after spinal cord injury can provide new ideas and research directions for regulating functional recovery and rehabilitation after spinal cord injury. OBJECTIVE:To analyze the neural circuit structural basis of functional remodeling of the primary motor cortex after spinal cord injury. METHODS:C57BL/6J mice were randomly divided into a sham operation group and a spinal cord injury group.The adeno-associated virus vectors expressing the fusion protein of Cre recombinase were injected into C4 of mice of both groups.The adeno-associated virus vectors with Cre recombinase-inducible expression of avian sarcoma/leukosis envelope glycoprotein receptor TVA and rabies glycoprotein were injected into the primary motor cortex.Fourteen days later,a C6 dorsal hemisection mice model was established in the spinal cord injury group.The pseudotyped rabies virus was injected into the primary motor cortex of mice of both groups.After 7 days,brain samples were collected and frozen sections were made.The distribution of input neurons innervating corticospinal motor neurons in the brain was observed and analyzed quantitatively. RESULTS AND CONCLUSION:Fluorescence microscopy observation and quantitative analysis found that input neurons innervating corticospinal motor neurons of the primary motor cortex in mice of both groups were distributed in the cerebral cortex,thalamus and midbrain.Among them,in the sham operation group,the number of input neurons in the mouse cerebral cortex accounted for(84.0±3.6)%of total brain input neurons;that in the thalamus accounted for(10.6±2.3)%,and that in the midbrain accounted for(0.7±0.4)%.Direct synaptic input neurons in the spinal cord injury group accounted for(81.7±1.0)%,(13.1±0.5)%,and(1.6±0.8)%in the cerebral cortex,thalamus and midbrain,respectively.The proportion and number of primary motor cortex input neurons in the three regions of the spinal cord injury group did not differ significantly from that of the sham operation group.After spinal cord injury,the number of input neurons innervating corticospinal pyramidal motor neurons in various brain regions did not change significantly,suggesting that functional remodeling of the motor cortex after spinal cord injury may not only depend on changes in synaptic input related to injured corticospinal motor neurons,but also on transcriptional regulation changes within the injured neurons themselves.

Effect of bioreactor scale-up culture of micro-carrier Vero cells after extra-tank trypsinization on virus-producing ability of rabies virus CTN-1Ⅴ strain / 中国生物制品学杂志

@#Objective To investigate the effect of amplification culture of micro-carrier Vero cells from 30 L bioreactor to 300 L bioreactor after extra-tank trypsinization on the virus-producing ability of rabies virus(RABV)CTN-1Ⅴ strain.Methods The 140-passage of Vero cells were cultured at 37 ℃ for 72-120 h,then amplified by passaging at a cell density ratio of 1∶4 into the 10 × cell factory. After incubation at 37 ℃ for 72-120 h,the monolayer cells were detached and inoculated into the 30 L bioreactor with micro-carriers 7-10 g/L,culture temperature 37 ℃,pH 7. 0-7. 4,dissolved oxygen 30%-80%,stirring speed 10-50 r/min,and continuous perfusion culture 72-120 h. Total three batches of microcarrier Vero cells were cultured,which were amplified to the 300 L bioreactor after extra-tank trypsinization,with microcarrier5-8 g/L,culture temperature 37 ℃,pH 7. 0-7. 4,dissolved oxygen 30%-80%,stirring speed 30-80 r/min,and perfusion culture 72-120 h. RABV CTN-1Ⅴ was inoculated at the MOI of 0. 05,and the virus solution was harvested every 24 h and detected for the virus titer and antigen content. Results The cell density was about 1 × 10~7 cells/mL after culture for 96 h in the 30 L bioreactor,and was about 7. 4 × 10~6 cells/mL after culture for 96 h in the 300 L bioreactor. At 96 h after virus inoculation,the virus harvest solution reached the peak potency,with the average virus titer of 6. 8 lgLD_(50)/mL and the average antigen content of 2. 58 IU/mL. Conclusion The scale-up culture process of micro-carrier Vero cells after extra-tank trypsinization from 30 L bioreactor to 300 L bioreactor is stable and feasible,with no significant effect on the virus-producing ability of RABV CTN-1Ⅴ strain,which provides a reference for the large-scale production of inactivated RABV vaccine

Effect of different strains of mice immunized with rabies vaccine on detection of titer / 中国生物制品学杂志

@#Objective To study the effect of different strains of mice(KM and ICR)immunized with rabies vaccine on thedetection of titer.Methods The rabies vaccine and the national standard for the efficacy verification of rabies vaccine forhuman use(referred to as national standard)were diluted with PBS at the ratios of 1∶25,1∶125,1∶625 and 1∶3 125,and KM and ICR mice with half male and half female were immunized intraperitoneally respectively.Sixteen mice of each strain wereimmunized with 0.5 m L/mouse at each dilution.The immunization was strengthened once every one week at the same dose androute.The mice in each group were weighed 0,7 and 14 d after the initial immunization.After 14 d of the initial immunization,the mice were subjected to intracranial attack with rabies virus(RABV)CVS2(5-100 LD_(50)),0.03 m L/mouse.The numberof mice with death and typical rabies brain symptoms 5 d after the attack was counted.According to the national standard ED_(50),the relative efficacy was calculated by Reed-Muench method.Results The body mass of the two strains of miceshowed an increasing trend during the immunization stage,and the body mass of KM mice increased faster than that of ICRmice.The lgED_(50) values of the national standard in KM mice were all within the expected range of 2.10-2.75,while thevalues in ICR mice were higher than the range.The titers of rabies vaccine in KM mice were all significantly lower than thosein ICR mice(t = 2.887-6.619,each P < 0.05).Conclusion Mouse strains can significantly affect the results of rabies vaccine titer determination,and different standards should be adopted for different strains of mice to ensure the accuracy of vaccine detection results.

Development of large-scale amplification process of rabies virus in 150 L bioreactor / 中国生物制品学杂志

@#Objective To develop a large-scale culture process for rabies virus(RABV)in 150 L bioreactor,and lay a foundation for the further development of a larger-scale and high-density microcarrier reactor process.Methods Vero cells and RABV strain CTN-1V were cultured in 30 L(model:C30-2)and 150 L(model:VESSEL FERMENTER 300L)bioreactors by perfused culture with 20 g/L Cytodex-1 microcarrier and DO 20%-60%,at culture temperature 36-38 ℃ and pH 7.0-7.4.During the culture process,the cell density and virus titer were measured.The virus culture media was harvested for consecutive 13 d and detected for the sterility,mycoplasma,and the residues of antigen,host cell protein(HCP),bovine serum albumin(BSA)and DNA.Results The density of cultured cells in 30 L and 150 L bioreactors all reached above 1.2 ×10~7cell/mL.There was no significant difference in cell density at different time points during the culture(t = 0.225-2.173,P = 0.096-0.833).The highest virus titer(8.5 lgLD_(50)/mL)was found in the both bioreactors 6 d after infection with no significant difference(t = 1.000,P = 0.374).The residues of antigen,HCP,BSA and DNA in the virus suspension from the two bioreactors were basically the same.Conclusion 150 L bioreactor can be used for the large-scale culture of RABV,and the harvested virus conformed to the relevant standards in Chinese Pharmacopoeia(Volume Ⅲ,2020 edition).

Preparation,identification and comparison of murine and rabbit polyclonal antibodies against matrix protein of rabies virus strain CVS-11 / 中国生物制品学杂志

@#Objective To prepare murine and rabbit polyclonal antibodies against rabies virus(RV) matrix(M) protein and compare their reactivity.Methods The prokaryotic expression vector pET-28a-M was constructed by using the cDNA of cells infected with RV CVS-11 strain as template,then transformed into E.coli BL21(DE3),and the induced by IPTG to express M protein.After nickel column affinity chromatography and dialysis renaturation,female BALB/c mice and New Zealand white rabbits were immunized with the M protein,and the whole blood was taken to separate the serum.The titers of the murine and rabbit polyclonal antibodies were detected by ELISA,and the reactivity was measured by Western blot,indirect immunofluorescence assay(IFA) and immunoprecipitation(IP).Results The plasmid pET-28a-M was constructed correctly as identified by sequencing.The titers of murine and rabbit polyclonal antibodies were 1:100 and 1:256 000respectively,and the polyclonal antibodies had reactivity with different RV strains.Conclusion The murine and rabbit polyclonal antibodies against M protein were successfully prepared,which provides important biological tools for exploring the interaction between M protein and host protein as well as studying the pathogenesis of RV.

Epidemiology and exposure management of rabies in Shanxi Province， 2011‒2022 / 上海预防医学

ObjectiveTo analyze the epidemiological features and influencing factors of rabies in Shanxi Province，and to provide evidence to further promote the elimination of rabies in Shanxi Province. MethodsThe incidence data of rabies in Shanxi from 2011 to 2022 were collected and subjected to descriptive analysis. ResultsFrom 2011 to 2022， a total of 348 rabies cases were reported in Shanxi Province， with an average annual incidence of 0.080 3/105. The incidence of rabies showed a downward trend overall. The highest incidence was in August. The cases were mainly farmers， mostly males， and most cases were reported between 50 and 69 years old. The data of cases showed that dogs were the main animals attacking human （93.96%）. The incubation period of most cases was 1‒3 months （37.37%）.The main exposure site was hand（51.33%）. Only 2.66% cases with grade Ⅲ exposure were injected with passive immune agents. ConclusionThe incidence of rabies in Shanxi Province continues to decrease， but there are still loopholes in prevention and control measures. It is necessary to strengthen the management and immunization of dogs，health education， and standardized procedures after exposure to maintain the achievements in the prevention and control of rabies.

Identification of peak 2 protein on right side of main peak of SEC-HPLC in lyophilized human rabies vaccine (Vero cells) stock solution(without human blood albumin) / 中国生物制品学杂志

@#Objective To identify the peak 2 protein on the right side of the main peak of size exclusion chromatograghy-high performance liquid chromatography(SEC-HPLC)in freeze-dried human rabies vaccine(Vero cell)stock solution(without human blood albumin),so as to determine the protein composition of the peak and ensure the vaccine quality.Methods The lyophilized human rabies vaccine(Vero cells)stock solution(without human blood albumin)was analyzed by SECHPLC,of which the peak 2 on the right side of the main peak was collected and concentrated by ultrafiltration,then reduced by dithiothreitol(DTT),alkylated by iodoacetamide (IAM) and hydrolyzed by Trypsin. The products were analyzed by nano LC-MS/MS.Results Four proteins were successfully identified in the right peak 2 of SEC-HPLC main peak in lyophilized human rabies vaccine(Vero cell)stock solution(without human blood albumin),and the number of matching peptides for a single protein ranged from 59 to 79. The number of single protein-matching characteristic peptides ranged from 6 to 12. The detection times of single protein-matching characteristic peptide segments ranged from 20 to 36 times. The sequence coverage of the identified proteins ranged from 37. 40% to 64. 31%. A total of 280 peptides participated in the statistics,and the mass spectrum deviation was less than 0. 15 Da.Conclusion The peak 2 on the right side of SEC-HPLC main peak of lyophilized human rabies vaccine(Vero cell)stock solution(without human blood albumin)is derived from rabies strain 4a GV,which is the vaccine particle dissociation.

Comparison of two methods for content analysis of vaccine particles in freeze-dried human rabies vaccine (Vero cells) bulk and final bulk / 中国生物制品学杂志

@#Objective To compare and analyze two methods for determination of vaccine particle content in freeze-dried human rabies vaccine(Vero cells)bulk and final bulk,and to provide experimental basis for establishing standard detection method for particle content and purity of rabies vaccine products.Methods The samples were subjected to vaccine particle cracking,BCA quantification,and size exclusion chromatograghy-high performance liquid chromatography(SEC-HPLC)analysis. BCA-SEC relative area method and BCA-SEC vaccine particle standard curve method were used to detect the total protein concentration of the bulk and final bulk,separately,and the content of vaccine particles was quantitatively analy-zed. Finally,the detection results of the two methods were compared and analyzed.Results The content of vaccine particles in freeze-dried human rabies vaccine bulk was determined to be within 256-305 μg/mL by the two methods,with an average value of 267-285 μg/mL,and the relative standard deviations(RSDs)ranged from 5. 8% to 10. 2%,with good consistency between two methods. The content of vaccine particles in freeze-dried human rabies vaccine final bulk was determined to be in the range of 149-169 μg/mL by the two methods,with an average value of 152-164 μg/mL,and the two methods showed the RSDs between 0. 9%-4. 7% with good consistency.Conclusion The measured value by BCA-SEC standard curve method deviates less from the expected value and is closer to the actual situation of samples,so it is recommended to use this method as a reference for enterprises.

Human Rabies during the COVID-19 Pandemic: Insights into Rabies Worldwide and Brazil

ABSTRACT Human Rabies (HR) is a fatal zoonotic disease caused by lyssaviruses, with the rabies virus (RABV) identified as the causative agent. While the incidence of HR transmitted by dogs has decreased in Latin America, there has been a corresponding rise in transmission via wild animals. Given the lack of effective treatments and specific therapies, the management of HR relies on the availability of post-exposure prophylaxis and animal control measures. This review examines the dynamics and spread of HR during the global pandemic.

Detection of rabies virus in Callithrix penicillata (Geoffroy, 1812) in Montes Claros, Minas Gerais State, Brazil

ABSTRACT This report describes the occurrence of the rabies virus in two species of wild animals in the urban area of Montes Claros (MOC), Minas Gerais State, Brazil, in May 2023. The virus has been detected in frugivorous chiropterans (Artibeus sp) and marmosets (Callithrix penicillata). This is the first notified case of the rabies virus in the species C. penicillata in the urban area of MOC. Our findings show that the rabies virus is circulating in the urban area of MOC; therefore, permanent preventive measures must be adopted to avoid infection of other animals and humans.

Lesiones ocasionadas por mordeduras de perros en niños atendidos en un hospital de tercer nivel de Bolivia / Dog bite injuries in children seen at a tertiary care hospital in Bolivia

Introducción. Este estudio pretende caracterizar las lesiones provocadas por perros en niños de un hospital pediátrico de Bolivia. Población y métodos. Se realizó un estudio observacional, retrospectivo, en pacientes atendidos del 2017 al 2021. Resultados. Se estudiaron 769 pacientes. Las lesiones representaron el 5,6 % de las emergencias y el 0,8 % de las internaciones. Fueron más frecuentes en niños de hasta 5 años (55,1 %), en quienes se observó mayor gravedad de las lesiones (p = 0,008), antecedente de provocación al animal (p = 0,048), un animal agresor conocido (p <0,036), el contexto doméstico del accidente (p = 0,021), mayor frecuencia de profilaxis con suero luego de la exposición (p = 0,005) y regiones afectadas principalmente maxilofaciales (p <0,001). Observamos 3 casos de mortalidad por rabia humana y 1 por shock hipovolémico. Conclusión. Las lesiones producidas por perros son causas frecuentes de visita a emergencia y hospitalización en pediatría, y tienen características particulares en niños de hasta 5 años de edad.

Introduction. The objective of this study is to describe the characteristics of dog bite injuries in children seen at a children's hospital in Bolivia. Population and methods. This was an observational, retrospective study in patients seen between 2017 and 2021. Results. A total of 769 patients were studied. Dog bite injuries accounted for 5.6% of emergency visits and 0.8% of hospitalizations. They were more frequent in children younger than 5 years (55.1%), in whom the following were observed: greater injury severity (p = 0.008), history of animal provocation (p = 0.048), known attacking animal (p < 0.036), domestic accident (p = 0.021), greater frequency of post-exposure prophylaxis with anti-rabies serum (p = 0.005), and maxillofacial area as the main region involved (p < 0.001). There were 3 deaths due to human rabies and 1 due to hypovolemic shock. Conclusion. Dog bite injuries are a frequent cause of visit to the emergency department and hospitalization in pediatrics and have specific characteristics in children younger than 5 years.

Historia de la rabia en Chile: tres tesis médicas / History of rabies in Chile: three medical theses

En la antigüedad ya se describía la rabia como una enfermedad zoonótica fatal cuyo pronóstico inexorable superaba todas las alter-nativas terapéuticas de los más célebres médicos. La realidad chilena sobre esta enfermedad a fines del siglo XIX fue descrita certeramente por el médico mártir Pedro Videla Órdenes en su tesis "La rabia" de 1879, destacando la descripción clínica de la rabia, su pronóstico fatal y la ausencia de tratamientos eficaces. Tan sólo seis años después, en 1885, el aclamado químico y microbiólogo Louis Pasteur desarrolló la vacuna antirrábica, logrando por primera vez en la historia de la humanidad prevenir esta terrible enfermedad. En Chile, se inició rápidamente la implementación de la vacuna Pasteur, vacunando al primer chileno el 7 de julio de 1896. Los doctores Milcíades Espinosa y Arturo Atria, en sus tesis "Generalidades sobre la rabia" (1898) y "Sobre la rabia y su profilaxia en Chile" (1905), respectivamente, abordaron esta primera etapa del desarrollo de la vacuna antirrábica en el país.

In antiquity, rabies was already described as a fatal zoonotic disease whose inexorable prognosis exceeded all the therapeutic alternatives of the most famous doctors. The Chilean reality about this disease at the end of the 19th century was accurately described by the martyred doctor Pedro Videla Ordenes in his thesis "La rabia" of 1879, highlighting in it his description about the unknown etiological agent, the fatal prognosis of the disease and the absence of effective treatments. Just six years later, in 1885, the acclaimed chemist and microbiologist Louis Pasteur developed the rabies vaccine, managing to prevent this terrible disease for the first time in human history. In Chile, the implementation of the Pasteur vaccine began rapidly, vaccinating the first Chilean on July 7, 1896. Doctors Milcíades Espinosa and Arturo Atria, in their theses "Generalidades sobre la rabia" (1898) and "Sobre la rabia y su profilaxia en Chile" (1905), respectively, addressed this first stage of the development of the rabies vaccine in the country.

Virología molecular de la rabia: un enfoque clínico / Rabies molecular virology: a clinical approach

Introducción: La rabia es una enfermedad zoonótica asociada al virus RABV, el cual tiene características neurotrópicas. El virus se transmite por el contacto con saliva de animales infectados; la mordedura de un perro es la causa más común. Es un virus que causa la muerte de miles de personas cada año. Objetivo: Describir a profundidad los principios moleculares de la infección por rabia, así como su patogenia, diagnóstico y tratamiento. Métodos: Se realizó una búsqueda de bibliografía en PubMed, SciELO, Scopus, Researchgate; se consultaron 163 referencias y se seleccionaron 51 fuentes que contenían la información más relevante para cumplir con el objetivo del trabajo. Conclusión: Actualmente es posible entender de mejor manera los mecanismos de transmisión y propagación del virus en el organismo; existe nuevo conocimiento sobre los receptores involucrados, así como la función de estos en la replicación viral. Sin embargo, el objetivo de la erradicación de la rabia a corto plazo es complejo. La invasión de territorios selváticos vuelve a la rabia un posible patógeno reemergente; la vacunación de especies transmisoras es el medio ideal para conseguir el control de la enfermedad.

Introduction: Rabies is a zoonotic disease associated with the RABV virus, which has neurotropic characteristics. The virus is transmitted by contact with saliva from infected animals; a dog's bite is the most common cause. This virus causes the death of thousands of people every year. Objective: To describe in depth the molecular principles of rabies infection, as well as its pathogenesis, diagnosis and treatment. Methods: A literature search was conducted in PubMed, SciELO, Scopus, and Researchgate. A total of 163 references were consulted, and 51 sources containing the most relevant information were selected to fulfill the objective of the work. Conclusions: It is currently possible to better understand the mechanisms of transmission and spread of the virus in the organism; there is new knowledge about the receptors involved, as well as their function in viral replication. However, the goal of eradicating rabies in the short term is complex. The invasion of wild territories makes rabies a possible re-emerging pathogen; vaccination of transmitting species is the ideal means to achieve disease control.

A Study of Clinico-social Profile of Animal Bite Patients Attending the Antirabies Clinic of BRD Medical College, Gorakhpur

Background: Rabies is one of zoonotic viral disease, estimated to cause 59000 human deaths annually in over 150 countries, of which 20,000 are from India alone; about 40% of which are in children under the age of 15. Rabies though 100% fatal is preventable with post-exposure prophylaxis which includes wound washing, anti-rabies vaccination and rabies immunoglobulin. Objective: To describe the clinico-social profile of animal bite patients attending the anti-rabies clinic of BRD Medical College, Gorakhpur. Methodology: A cross-sectional study was conducted in the anti-rabies clinic of Nehru hospital, BRD Medical College, Gorakhpur from January 2022 to May 2022. Study participants were interviewed by using a pre-phrased, pre-designed and pre-tested questionnaire. Data regarding socio-demographic and clinical profile of the study participants following animal bite exposure was collected. Results: The total number of animal bite victims were 250, in which majority of them were males (76.77%) and highest percentage was of adult population (20-59 years). Maximum number of victims were from rural area (78.70%). 19.35% were working and 39.35% were students. 77.43% were category III bites and in 50.96% cases lower limb was the site of bite and dogs were responsible for 89.67% of the bites. 60.64% victims did not wash the wound properly before reaching the anti-rabies clinic. Conclusion: This study concludes that as majority of the animal bite victims were students and majority of victims were unaware about the importance of wound care, therefore a step can be taken to create awareness in various schools.

Development and validation of size exclusion column-high performance liquid chromatography for purity determination of bulk material of freeze-dried rabies vaccine for human use / 中国生物制品学杂志

@#Objective To develop and validate size exclusion column-high performance liquid chromatography(SEC-HPLC)for determination of the purity of bulk material of freeze-dried rabies vaccine for human use.Methods Chromatography column TSK-gel G6000PW_(XL)(7.8 mm × 30 cm,13 μm)was used for the determination(column temperature 30 ℃)with mobile phase of 0.1 mol/L PB buffer(pH 7.8)at a flow rate of 0.5 mL/min.The detection wavelength was 280 nm and injection volume was 20 μL.The method was validated for system suitability,specificity,precision and durability and determined for detection limit and quantitation limit,which was applied to analyze bulk material purity of freeze-dried rabies vaccine for human use of 3 batches of Vero cells and 1 batch of human diploid cells.Results The resolution of target protein spectrum peak of bulk material of reference sample and freeze-dried rabies vaccine for human use prepared with two substrates was more than 1.5 with a tailing factor less than 1.5;The blank solvent showed no absorption peak at the position of target protein peak with no interference in the determination;The RSDs of retention time and peak area in precision verification were both less than 2.0%;The quantitative limit was 10 μg/mL,and the detection limit was 4 μg/mL;The reference sample was injected three times continuously at three different detection wavelengths of 278,280 and 282 nm,and the RSDs of retention time and peak area were also less than 2.0%.The purity of 4 batches of freeze-dried rabies vaccine bulk material for human use was all more than 97%.Conclusion The developed SEC-HPLC for determination of the purity of freeze-dried rabies vaccine bulk material for human use showed good specificity,precision and durability,which provided a reliable method for the quality control of human rabies vaccine.

Epidemiological characteristics of rabies and post-exposure immunization failure cases in Hubei Province in 2015-2021 / 公共卫生与预防医学

Objective To analyze the epidemic characteristics and causes of post-exposure immunization failure of rabies in Hubei Province from 2015 to 2021, and to provide evidence for the prevention and control of rabies in Hubei Province. Methods The investigation data of rabies cases in Hubei Province from 2015 to 2021 were collected, and descriptive epidemiological methods were used for data analysis. Results A total of 127 cases of rabies were reported in Hubei Province from 2015 to 2021, with an average annual incidence of 0.31/million, showing a downward trend. The male to female ratio was 1.70:1. Farmers accounted for 82.67% of the total cases, and the 50-79 years old group accounted for 75.59%. The incidence was mainly concentrated in Xiangyang, Shiyan, Yichang and Jingmen, accounting for 77.17%. Most of the cases were concentrated in summer and autumn. Exposure of grade Ⅱand Ⅲ accounted for 24.79% and 75.21%, respectively. Hands, lower limbs below knee, head, arms and lower limbs above knee accounted for 46.15%, 25.21%, 9.40%, 8.55% and 7.69% of the exposed parts, respectively. Dogs, cats and wild animals accounted for 95.73%, 3.42% and 0.85% of the exposed animals, respectively. Stray animals, domesticated animals, neighbors' animals and wild animals accounted for 41.88%, 37.61%, 19.66% and 0.85% of animal sources, respectively. Neither the neighbors’ animals nor domesticated animals were vaccinated against veterinary rabies virus. After exposure, 8.55% of patients went to medical institutions for standard treatment of wounds, 9.40% were vaccinated with human rabies vaccine, and 4.55% of patients with grade III exposure were injected with rabies virus immunoglobulin. The incubation period within 6 months, from 6 months to 1 year, and over 1 year accounted for 72.22%, 14.74%, and 12.04%, respectively. The exposure degree (Z=-1.98, P 2=10.91, P 2=15.73, P < 0.05) had statistically significant effects on the incubation period. Among the 11 cases of post-exposure immunization failure, all were grade Ⅲ exposure, 63.63% were exposed to the head and face, 81.81% were not fully vaccinated with human rabies virus vaccine, 63.63% were not immunized with immunoglobulin, and 27.27% were inappropriate wound treatment. Conclusion The key to rabies prevention and control is to standardize dog management, strengthen rabies education, standardize post-exposure wound treatment, timely vaccinate against rabies virus, and inject rabies virus immunoglobulin when necessary.

Characteristics of populations exposed to rabies in Anji County / 预防医学

Objective@#To investigate the epidemiological characteristics of rabies-exposed populations in Anji County, Zhejiang Province from 2017 to 2021, so as to provide insights into rabies control in the county.@*Methods@#All data pertaining to rabies were captured from Monthly Report of Rabies-exposed Populations in Huzhou City and Investigation Form of Multiple Dog Injuries reported by dog injury clinics in Anji County from 2017 to 2021, and the species of animals causing dog injuries, duration, degree and site of exposure, and post-exposure treatment of rabies-exposed populations were descriptively analyzed. @*Results@#Totally 46 186 cases with rabies exposure were reported in dog injury clinics in Anji County from 2017 to 2021, and the rate of exposure appeared a tendency towards a decline year by year (Z=-23.249, P<0.001), with an annual mean exposure rate of 1 739.59/105. The number of cases with exposure to rabies peaked in July and August (10 066 cases, 21.79%). Dogs were predominant animals causing injuries (31 732 cases, 68.70%), and the rate of exposure to dog bites appeared a tendency towards a decline year by year (Z=-35.541, P<0.001). There were 11 350 cases with cat-causing injuries (24.57%), and the rate of exposure to cat bites appeared a tendency towards a rise (Z=14.834, P<0.001). Lower extremity was the main site of exposure (22 364 cases, 48.42%), and the proportions of grade Ⅱ and Ⅲ exposure to rabies were 72.85% and 25.23%, the rates of exposure both appeared a tendency towards a decline (Z=-14.522, P<0.001; Z=-21.820, P<0.001). The proportion of using human rabies immune globulin was 25.72% among populations with grade Ⅲ exposure, which appeared a tendency towards a rise (Z=6.636, P<0.001). @*Conclusions@#The rate of exposure to rabies appeared a tendency towards a decline in Anji County from 2017 to 2021. Dogs were predominant animals causing injuries, and the rate of cat bites appeared a tendency towards a rise from 2017 to 2021; however, the proportion of using human rabies immune globulin remains to be improved among populations with grade Ⅲ exposure.

Construction and verification of recombinant chimeric vesicular stomatitis virus expressing rabies virus G protein / 中国生物制品学杂志

@#Objective To construct recombinant chimeric vesicular stomatitis virus(VSV)expressing G protein of rabies virus(RV)using VSV as vector.MethodsTo rescue the recombinant virus,G gene of VSV antigenome was replaced with G gene of RV vaccine CTN-1 strain,and co-transfected into 293T cells with helper plasmids coding T7 RNA polymerase and proteins N,P and L of VSV. The expression of RV G gene and G protein was detected by RT-PCR,immunofluorescence assay and Western blot. The recombinant virus was subcultured in Vero cells,the virus titer of different generations was detected and the virus growth curve was drawn.ResultsThe recombinant virus VSV-RVG was successfully rescued. RTPCR results demonstrated that the RV G gene was successfully inserted into the genome of the recombinant virus,and the expression of RVG protein was detected by immunofluorescence assay and Western blot. The recombinant virus was continuously passaged for 5 generations,and the virus titer was stable within 7. 5 ～ 8. 5 lgTCID50/mL.ConclusionThe recombinant chimeric VSV expressing RV G protein was successfully constructed with good genetic stability,which lays a foundation of the construction of reverse genetics technology platform based on VSV vector.

Comparison of immunization strategies for human rabies pre-exposure prophylaxis in laboratory animals / 中华微生物学和免疫学杂志

Objective:To compare the differences in the safety, efficacy and protective effects of rabies vaccine using the current pre-exposure prophylaxis schedule in China (0-7-21 or 28) and the newly recommended immunization program of WHO (0-7), aiming to provide data support for modifying the related content of Technical Guideline for Human Rabies Prevention and Control. Methods:The mice were randomly divided into five groups, namely 0-7-21 group (3-injection regimen), 0-7 group (2-injection regimen), 0-14 group, 0-21 group and control group, according to the current 3-injection regimen (0-7-21) in China and the 2-injection regimen (0-7) recommended by WHO. The survival status of the mice was observed. The mice were weighed every five days to compare the safety of different immunization procedures. Rabies virus neutralizing antibodies (RVNA) were detected 7, 14, 21, 28 and 35 d after the initial immunization. On day 35, the mice in each group were challenged with lethal dose of CVS-11 rabies virus to evaluate the protective effects of different pre-exposure immunization procedures.Results:There was no significant difference in weight gain of mice after vaccination. The positive rate of RVNA was 100% in all immunized groups from day 14, which could provide complete protection to mice. There was a significant difference in RVNA levels between 0-7-21 and 0-7 groups at 35 d( P<0.05), but there was no statistical difference at other time points ( P>0.05). RVNA level had a significant difference between 0-7 and 0-21 groups at 21 d and 35 d ( P<0.05). There was no statistical difference in RVNA level between other groups at each time point ( P>0.05). In the protective test, the survival rates of mice in all immune groups were 100%. Conclusions:The current 3-injection pre-exposure immunization procedure for rabies vaccine (0-7-21) and the newly recommended 2-injection immunization procedure (0-7) had similar efficacy and protective effects in animal tests. In view of the cost saving and better compliance of the 2-injection immunization procedure, it was recommended that relevant departments should conduct clinical trials as soon as possible to promote the implementation of this program.

Rabies virus viability in vitro / 中华微生物学和免疫学杂志

Objective:To investigate the in vitro viability of rabies virus in tissues and body fluid samples. Methods:The viability of rabies virus in tissues and suspensions was analyzed by virus titer determination method, direct immunofluorescence, RT-PCR and laboratory techniques for virus isolation.Results:With the increase of temperature, the viability of rabies virus in brain tissues and suspensions decreased gradually. Rabies virus lost infectivity after 30 min at 56℃, but remained viable in tissues for 7 d at 37℃. The virus showed no viability after 1 h at pH9.6. The rabies virus in suspensions could be completely inactivated after the stimulation with ethanol at a final concentration above 30%, sodium hypochlorite above 500 mg/L or benzalkonium bromide above 100 mg/L for 3 min. It was found that 80% acetone had the strongest inactivation effect on rabies virus in tissues, and no virus could be isolated after soaking for 4 h.Conclusions:Rabies virus was not tolerant to high temperature and relatively stable in the environment with pH6.8-7.4. Common disinfectants could kill the virus. This study provided detailed data about the viability of rabies virus in vitro, which would be conducive to the prevention and control of rabies.