Loa loa was first described in 1770 by a French surgeon, Mongin, when he unsuccessfully tried to excise a worm from the eye of a women in Santa Domingo. Later accounts came from Francois Guyot, a French ship's surgeon, who in 1778 observed the eye worm in slaves being taken from Africa to the West Indies.
Dr. Patrick Mason was the first to identify the microfilariae of Loa loa when in 1890 ophthalmologist Dr. Stephan Mackenzie invited him to examine blood smears of one of his patients who he thought had "sleeping sickness of the Congo." In 1895, Dr. Argyll Robertson was the first to connect the presence of "Calabar swellings," or raised bumps on the forearms and wrist, with Loa loa infection. His account of one woman from "Old Calabar," Nigeria reads as follows:
"My patient has several times directed my attention to ill-defined swellings under the skin of the forearms a little above the wrists...The surface of the swellings was not quite uniform, but did not give on the idea of being produced by coiled-up worm...My patient informs me that natives of Calabar...are subject to such swellings in the forearms and wrists, to which the natives apply the term, 'Ndi tot,' or swelling." Ref 9
Finally, it was R. T. Leiper, a helminthologist, who identified Chrysops as the insect vector of the eye worm, experimentally ruling out infection by the tsetse fly, mosquitoes, and other biting flies.
It was initially thought that Loa loa was first depicted in a 1598 engraving by J. T. de Bry. In the foreground a man is seen extracting a worm from his calf while in the background a man appears to be undergoing the surgical removal of a worm from his eye. However upon closer inspection the man is probably being purposefully blinded as a punishment. Furthermore, the man in the foreground most probably suffers from Guinea worm or Dracunculus medinesis.
Engraving depicting Dracunculus on left and an enlargement on right of a man being blinded that is often misinterpreted as the first account of a Loa loa eye worm extraction.
