Investigations on typhus
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Pediculus humanus |
Charles Nicolle decided to study Typhus when he began working in Tunisia, where a seasonal epidemic spread through the cities each winter. Nicolle saw that most doctors contracted Typhus, a third of them dying from the disease, he also noticed a connection between handling the dirty linen of patients and infection. He guessed quickly that the disease was spread by lice, and set about proving his hypothesis experimentally by developing animal models of the disease.
At first he worked on monkeys, which he inoculated with the blood of patients to produce a fever. Then he cultivated lice on the infected monkeys, and spread them to other monkeys, showing that lice were responsible for transmission. A major break-though came when, three years into his experiments, he found that guinea-pigs could contract typhus. This meant that he could keep the virus alive indefinitely in guinea-pigs and was no longer reliant on the seasonal epidemic as a source of the disease.
He discovered that in some guinea-pigs typhus was so mild they did not even develop a fever, but their blood could transmit the full disease to another animal. He called this inapparent infection, a concept which offered explanation for disease epidemic patterns.
Tags
Research Fields: Infection and Immunity, Disease characteristics(yes - 2 items)Date: 1928 (required)
Scientist(s): Charles Nicolle (required)
Countries: Middle East, France(yes - 2 items)
Animals Used: Rat, Mouse, Guinea pig, Other or unspecified mammals (non-rodent/non-primate), Primates, Other or unspecified birds(required - 6 items)
Description: Charles Nicolle discovers the route of infection of typhus (yes)
Medical Applications: Vaccine, Medicine, Basic research(yes - 3 items)
