My first attempts to transmit typhus to laboratory animals, including the smaller species of monkeys, had failed, as had those of my predecessors, for reasons which I can easily supply today.
Charles Jules Henry Nicole

Just as the only reservoir for the typhus virus in nature is provided by man, so the only vector of infection is the louse. The bite of the louse is not virulent immediately after the infecting meal. It becomes so only towards the 7th day following infection.
Charles Jules Henry Nicole

I demonstrated the characteristics of experimental fever. It appears after an incubation period which is never less than five days. It follows the same pattern as natural fever in man, but is of shorter duration and less pronounced.
Charles Jules Henry Nicole

Even if it had not been possible to reproduce the disease in animals and consequently to verify the hypothesis, this simple observation would have been sufficient to demonstrate the way in which the disease was propagated.
Charles Jules Henry Nicole

From the practical point of view, the susceptibility to infection of the guinea pig proved to be the most useful step forward. Today, all laboratories use this animal for preserving the virus.
Charles Jules Henry Nicole

At the time when I was conducting my research there was no known method for taking the guinea pig's temperature. I demonstrated a technique which is now widely used.
Charles Jules Henry Nicole

Most of the doctors in the Tunisian administration, especially those in country districts, contracted typhus and approximately one third of them died of it.
Charles Jules Henry Nicole