Etiological diagnosis and detection of the rabies virus neutralizing antibody in an event of one dog injured seven persons

Abstract

Objective To make etiological diagnosis and evaluate the protective effects of post-exposure prophylaxis(PEP) in an event of one dog injured seven persons. Methods Direct immunofluorescence assay (DFA) and nested polymerase chain reaction (PCR) were employed to detect nucleoprotein and nucleoprotein(N) gene of rabies virus in the brain tissues of the dog, the positive samples were sequenced for the full length of N gene of rabies virus, then the homology of the N gene of rabies virus was analyzed after the phylogenetic tree was constructed. Rapid fluorescent focus inhibition test (RFFIT) was applied to detect the rabies virus neutralizing antibodies(RVNA) on day 0, 14 and 40 after PEP. Results The cerebral, cerebellar and hippocampal tissues were positive by DFA and nested PCR. The phylogenetic tree indicated the rabies virus belonged to the rabies virus genotype I. The homology of the nucleotide and amino acid of the rabies virus N gene were over 86% with the vaccine strains. The titer of the RVNA increased significantly from the day 0 to day 14 after PEP, the lowest was 5.78 IU/ml and the highest was 26.15 IU/ml. On the day 40, the highest RVNA titer was 51.96 IU/ml. No rabies cases occurred in a one year follow-up visit. Conclusions Normative PEP can effectively prevent the occurrence of rabies cases. Key words: Rabies; Rabies virus; Post-exposure prophylaxis; Etiology; Neutralizing antibody