Lymphatic filariasis is a neglected tropical disease caused by infection with the
mosquito-borne, thread-like, parasitic filarial worms Wuchereria bancrofti, Brugia malayi and B. timori.
In Egypt, nocturnally periodic bancroftian filariasis has been endemic
since Pharaonic times. The first written documents of filariasis come
from the ancient Greek and Roman writers who could differentiate between
the similar symptoms of leprosy and filariasis.
Jan Huygen Linschoten during his trip to Goa between 1588 and 1592 first
documented the disease symptoms and wrote that inhabitants ‘‘all born
with one of their legs and one foot from the knee downwards as thick as
an elephant’s leg.’’
Filariasis was the first human disease described in which transmission
through the skin was cause by the bites of arthropods. Doctor O.
Wucherer (1868) found the embryonic filarial worms in the urine of a
patient in Bahia, Brazil. T. R. Lewis (1872), working in India, observed
the embryos in the urine and also in the blood, and Joseph Bancroft
(1878) in Brisbane, Australia first described the adult worm. The
parasite has been designated Wuchereria bancrofti.
The momentous discovery of the role of the mosquito in transmitting the
disease was made by the Scotsman Patrick Mansion (1877) while he was
practicing medicine in the Far East with the Chinese Imperial Maritime
Customs. He became interested in the disease that confronted him,
including filariasis. In that disease he recognized the parasites in
peripheral blood films and also in postmortems material.
Patrick Mansion noted the nocturnal appearance of the parasites in the
peripheral blood and postulated that a blood sucking insect might be
responsible for transmitting the infection. Manson proved the presence
of the microfilaria in the mosquito Culex fatigans, thus supplying the missing link in the life cycle of the disease.
Filariasis in history
