Application Of Laboratory Diagnosis For Rabies Diagnosis

Objective: Rabies is an acute zoonosis infection disease which is charactered with infection the nervous system caused by rabies virus . It is the acute infection disease with highest mortality in the world by now,nearly 100%. The World Health Organization estimates that nearly forty to fifty thousand people die of rabies every year in the world ,more than 99% of these deaths occure in developing countries . Asia ,Africa and Latin America are epidemic focus of rabies, India is the country where rabies most prevailed in the world, China is the secondary country of rabies cases following India . rabies virus is a kind of nervous virus,the clinical is different, diagnosis of rabies based on epidemiology and clinical ground is difficult and unreliable.Difinite diagnosis of rabies can only be obtained by laboratory investigations.The laboratory techniques include antigen detection,antibody titration,molecular techniques and genetic detection.We study the application value of laboratory diagnosis in rabies diagnosis by analysis the rabies laboratory results,in order to offer evidence in the application of rabies laboratory techniques.Methods :The laboratory examination results which include rabies virus antigen,neutralizing antibody against rabies virus and brain tissue histopathologic examination of 45 cases rabiators and 1350 dogs saliva were analysised by examing brain tissue,cerebrospinal fluid (csf),serum and dog saliva.All rabies virus antigen samples are used Rapid Rabies Enzyme Immuno-Diagnosis method with the diagnosis kit produced by the institution of Pasteur in France,neutralizing antibody against rabies virus samples are used Platelia kit produced by the institution of Pasteur in France,Operations were strictly according to specification and all reagent were used within expiration date.The brain tissue were taken at different sites in six hours after patient dead and do microanatomy examination ,especially examine the Negri'S body in nervous cell used seller's staining.Numeration data was analysed by chi-square test used statistic package SPSS14.0 for windows.when T<1, Numeration data was analysed by Fisher's exact probabilities in 2Χ2 tables.when P<0.5we think difference have statistic significance,P>0.5 have no statistic significance.Results:It was demonstrated that the positive rate of rabies virus antigen in the brain tissue,csf and dogs saliva were 100%,50% and5.11%,the total serum positive rate of neutralizing antibody was 97.62%,while only 40.48% in prodromal period and exciting period, 94.44% in paralysis period. The positive rate of neutralizing antibody between exciting period and paralysis period has statistically significant to the same patient.The different distribution of neutralizing antibody in csf and serum has no statistically significant to the same patient.Negri bodies were found in 4 of 7 patients′brain tissue (57.14%).Conclusions:It is concluded that there have some limitation for the application of rabies virus antigen test because of the specimen.It is hard to diagnosis rabies before death.The neutralizing antibody against rabies virus was an immune-response in the late course of rabies and had a course from low to high level.So the neutralizing antibody against rabies virus could be used as one of the diagnostic measures.There is no difference of neutralizing antibody distribution in csf and serum,we can diagnosis the post-exposure prophylaxis patient by detect the neutralizing antibody in the csf.The negri body was significance in retrospective rabies diagnosis ,but false positive and false negative should be depleted. The diagnosis rate will be elevated if connect more than one method.