632 THE ANIMAL PARASITES OF MAN 



B. Yaws or Framboesia tropica. 



Yaws is essentially a tropical disease, though it is found in the 

 tropical and subtropical zones in all parts of the world, except in the 

 mountains and cold districts. In 1905, Castellani found the causal 

 organism, Treponema pertenue (sometimes called Spirochaia pertennis) 

 (see p. 127). The disease shows three periods : (i) The primary stage, 

 consisting of the development of the primary lesion or papule, which 

 is usually extragenital. The papule dries into a crust beneath which 

 an ulcer lies. (2) The secondary or granulomatous stage, which com- 

 mences from one to three months after the primary lesion is first seen. 

 It consists of a general eruption of small papules, some of which enlarge 

 and become granulomatous nodules covered with a yellowish crust. 

 They are common on the limbs and face. (3) The tertiary stage, in 

 which deep ulcerations and gummatous nodules appear. Any of the 

 tissues may be involved. Osseous lesions may occur. The disease 

 does not appear to be hereditary ; it is usually spread by contact. 



The best treatment appears to be by salvarsan or neo-salvarsan. 

 Castellani and Chalmers recommend intramuscular and intravenous 

 injections. For intramuscular injection an alkaline or neutral solu- 

 tion of the drug is preferable, or a suspension of the drug in oil 

 may be used. The dose varies from 0^3 to 0*5 grm., according to 

 the age and sex of the patient. For use intravenously, a slightly 

 smaller dose is required. Galyl is also being used. 



In countries where frambcesia is endemic, slight skin abrasions 

 should be carefully treated with antiseptics. Yaws patients should be 

 isolated till cured, and their dwellings and personal possessions 

 disinfected. 



C. Syphilis. 



Syphilis, due to Treponema pdllidum (sometimes called Spirochaia 

 pallida), is prevalent throughout the tropics as well as in temperate 

 zones. The disease is amenable to treatment by salvarsan and neo- 

 salvarsan, for administration of which see relapsing fever and yaws. 

 Galyl is also being used with favourable results. Lambkin's mercury 

 cream has been found useful in treating numerous cases in Uganda. 

 The life-history of the parasite is given on p. 124, and further medical 

 details hardly come within the purview of this book. 



D. Bronchial Spirochaetosis. 



Bronchial spirochastosis, due to Spirochceta bronchialis (see 

 pp. 122, 739) is probably of wide distribution in the tropics. The 

 spirochaetes have been found in cases of chest complaints, especially 

 those with bronchitic symptoms. The disease may be suspected in 

 atypical cases of pneumonia and bronchitis, and may be mistaken for 

 incipient phthisis. 



