Figure 1. Rabies virions are bullet-shaped and measure approximately 180 nm in length and 75 nm in diameter. The outer surface is covered by 10-nm spike-like glycoprotein peplomers. The basic structure and composition is depicted in the longitudinal diagram. The internal construction of the virion is portrayed in the cross-sectional diagram.

Figure 2. The cycle of replication and infection in lyssaviruses involves: (1) adsorption; (2) penetration; (3) uncoating; (4) transcription; (5) translation; (6) processing; (7) replication; (8) assembly; and (9) budding.

Figure 3. The rabies virus genome is single-stranded, antisense, nonsegmented RNA of approximately 12 kb. There is a leader (LDR) of 50 nucleotides followed by N, NS, M, G and L genes, which code for the five structural proteins. The intergenic nontranslated regions (NC) are considered variable, especially between G and L genes. The numbers below each gene are the length, in nucleotides, of the mRNA transcripts for each gene.

Figure 4. The distribution of the predominate terrestrial maintenance hosts for rabies in the USA are indicated on this map (Arctic/Red Fox, Arizona (AZ) Grey Fox, North–Central (NC) Skunk, Texas (TX) Coyote, Texas Grey Fox, South–Central Skunk, Raccoon). Epidemiologically separate variants can be defined by limited nucleotide (nt) sequence analysis of 200 nt of the rabies N gene, and are indicated by different shading patterns. The relationships between the rabies virus variants are demonstrated in the phylogram on the right. The genetic distance is proportional to horizontal branch lengths. The percent homology is given at the major branch nodes.