Primary infection and secondary reinfection in individual mice after airborne transmission across a 7.6-cm separation.

<p><i>In vivo</i> bioluminescence was measured in individual animals after airborne exposure to donor mice that had been directly inoculated with 70 or 7,000 PFU of rSeV-luc(M-F*). All mice were challenged on day 70 of the experiment with a lethal 3×10<sup>6</sup>-PFU dose of rSeV-luc(M-F*). Mice involved in the airborne transmission experiments were categorized based on the dynamics of the resultant infection: (<b>A</b>) no transmission (1–3), (<b>B</b>) non-productive infection (4), (<b>C</b>) tracheal dominant (5–12), (<b>D</b>) respiratory disseminated with nasopharyngeal first (13–16), and (<b>E</b>) respiratory disseminated with tracheal first (17–21). (<b>F</b>) Bioluminescence curves for two representative mice infected by contact transmission are also included. The bottom of the y-axis is 5.5×10<sup>5</sup> photons/s, the limit of detection of bioluminescence.</p>