1638 THE MYIASES AND ALLIED CONDITIONS 



the whole subject in 1908 to the Journal of the Royal Army 

 Medical Corps : while Smith described the symptoms of the disease 

 in the same journal. 



In 1913 Rodhain, Pons, Vandenbranden, and Bequaert, demon- 

 strated by experiment the method of infection; and Heckenroth and 

 Blanchard recorded four cases due to Cordylobia rodhainim French 

 Equatorial Africa. 



Climatology. — Tumbu seems to be widespread throughout tropical 

 Africa, extending from Senegal in the north to Natal in the south, 

 and from the west to the east coasts. 



iEtiology.— The cause of the disease is the invasion of the sub- 

 cutaneous tissues by the larva of Cordylobia anthropophaga and allied 

 species. The method of infection, thanks to the labours of Smith 

 in 1908, and Rodhain, Pons, Vandenbranden, and Bequaert in 1913, 

 is fairty well known. 



The eggs are apparently sometimes laid on the clothing, the fiy, 

 perhaps, being attracted by the odour, or perhaps at other times the 

 egg is laid in dirt or fsecal matter on the floor, from which the larva 

 wanders on to the human being, especially/ when using the latrine. 



Having arrived on the skin of man or animals, it penetrates this 

 by means of its buccal hooks, but seems to require a long time to do 

 so, as one experiment took six hours. If this is reall}^ so, then there 

 must be some ancillary process, as this is not natural. 



Monkeys, goats, rabbits, dogs, and cats are also attacked. 



Symptomatology. — During the attack slight pricking sensations 

 may be noted. The parts most affected are the scrotum, thigh, 

 and buttocks in Europeans, but the forearm, axilla (especially 

 in natives), and the head also may be invaded. The infected area 

 presents the appearance of a boil, in the central portion of which 

 there is an opening, more or less clearly defined, which is marked 

 by black matter (the excrement of the larva). In this hole the 

 posterior end of the larva may be noted, and on pressing on it con- 

 siderable pain is produced, probably due to the movements of the 

 larva. Surrounding the central opening is an inflamed area about 

 I inch in diameter. The opening may, however, be obscured by 

 dried-up discharge. Strong pressure easily expels the maggot, 

 so that it is seldom allowed to grow old. In children and helpless 

 persons it may attain its full size, and is then usually associated 

 with suppuration, and when full grown is about 12 miUimetres in 

 length, of a yellowish-white colour, and bluntly pointed anteriorly, 

 while it possesses twelve segments, on the posterior aspect of the 

 last of which are the two posterior stigmatic plates, which are visible 

 in the orifice of the swelling, appearing and disappearing after the 

 manner of a jack-in-the-box. 



Treatment. — The larva is easily expressed by strong pressure, 

 and then the resulting hole can be cleansed with antiseptic solutions 

 and the wound dressed aseptically. 



