Blood test generally can not detect rabies. Rabies is the body infected with rabies virus caused by a contagious disease, with zoonotic characteristics; from the body infected with rabies virus when the onset of this period, known as the incubation period, and the patient in the incubation period is no way to diagnose the disease; and once the patient onset of the disease, mainly through the clinical symptoms caused by the disease, medical history, and the virus test to confirm the diagnosis, purely through the blood test can not be found out the disease. The disease cannot be detected by blood test alone. Once rabies develops, the mortality rate is almost 100%. Being scratched or bitten by diseased animals or animals carrying the rabies virus is the main reason why human beings are endangered by rabies; therefore, in order to effectively prevent rabies, once an individual is scratched or bitten by a suspected animal, he or she should be vaccinated against rabies in a timely manner, and injected with immunoglobulin if necessary.