Tropical Ulcer 



533 



tiple, as many as twenty sometimes occurring simultaneously. It 

 is thought that recovery is followed by immunity. 



Organism. In 1885 Cunningham* described a protozoan organ- 

 ism found in the tropical ulcer, the observation being confirmed 

 by Firth, f who called the bodies Sporozoa furunculosa. Later, 

 J. H. Wright t studied a case of tropical ulcer and found bodies pre- 

 cisely like the Leishmania donovani. He gave it the name Hel- 

 cosoma tropicum. The great similarity to the other organisms has 

 led more recent writers to identify it with Leishmania, but as it 

 induces a local and not a general infection like kala-azar, it is now 

 known as Leishmania furunculosa. 



Cultivation. The organism has been cultivated by Nicolle and 



Fig. 221. Oriental sore (Wellcome Research Laboratory) . 



Manceaux upon the same media and in the same manner as 

 Leishmania donovani and Leishmania infantum with which these 

 investigators believe it to be identical. Cultivation was also success- 

 fully achieved by Row. 



Pathogenesis. The virus is pathogenic for man, monkeys such 

 as Macacus simius, M. cynomolgus, M. rhesus and M. inuus, and for 

 dogs. The same effects are produced whether fresh virus from a 

 human ulcer, or from an artificial culture be employed. In dogs 

 the inoculations produce only nodular formations; in monkeys, 

 nodules like those in human beings that go on to ulceration. Intra- 

 peritoneal inoculations usually fail. The most successful inocula- 



' "Scientific Memoirs by Medical Officers of the Army in India," 1884, I. 

 t "British Med. Journal," Jan. 10, 1891, p. 60. 

 t 'Jour, of Med. Research," 1904, x, 472. 

 "Ann. de 1'Inst. Pasteur," 1910, xxrv, 683. 



