He then spent some time in laboratory work, examining bacteriological and pathological specimens at the Royal Victoria Hospital.

The two men left Liverpool on 21 August 1902,[5] and established themselves at Cape St. Mary, near Bathurst, where they treated patients and conducted research, working long hours.

[3] In 1903 Todd and Dutton accepted an invitation by King Leopold II of Belgium to research the connection between trypanosoma and sleeping sickness in the Congo Free State.

[3] The twelfth expedition of the Liverpool School of Tropical Medicine left for the Congo Free State on 13 September 1903.

Christy went back to England in June 1904, while Todd and Dutton went upstream to Stanley Falls, which they reached late in 1904.

[8] Todd and two other scientists from the LSTM, Rupert Boyce and Ronald Ross, were invited to meet King Leopold II in August 1906.

Todd said of this visit,[9] "After we'd finished telling the old man how to make the Congo healthy and promised to administer a lovely coat of whitewash to his character in the eyes of the English, he created Boyce, Ross and myself officers of his Order of Leopold II..."[10] In 1907 Todd accepted the position of Associate Professor of Parasitology at McGill.

After the war he led an expedition for the American Red Cross to find a way to contain a violent outbreak of typhus in eastern Europe.

John Lancelot Todd died on 27 August 1949 in a car accident in Sainte Anne de Bellevue, a few miles from home.