100 TROPICAL MEDICINE AND HYGIENE 



The worms are often numerous, and unless they cause 

 haemorrhage or suppuration cannot be located. The 

 lymphatic obstruction has been produced by the time the 

 patient comes for advice. 



In chyluria violent exertion must be avoided, and if 

 blood appears absolute rest insisted on. 



A person known to be suffering from filariasis should 

 live in a country where auto-infection is impossible. Such 

 a country must be one in which Culex fatigans does not 

 occur or is not numerous, otherwise he will infect the 

 mosquitoes that feed on him, and they in turn will re- 

 infect him, so that the number of adult filariae will be 

 increased continuously. 



If circumstances do not permit of a patient living in a 

 country with so temperate a climate, he must be warned 

 as to the necessity of guarding himself against mosquitoes, 

 and of killing such .mosquitoes as feed on him, both for 

 his own sake and that of others living in the house. 



Diagnosis. Filariasis is diagnosed by finding the em- 

 bryos in the peripheral blood, but in some cases even 

 when the adult filariae are in the lymphatic glands and 

 alive, no embryos are present in the blood. Eosmophilia 

 of a moderate degree and enlarged glands may be of some 

 value. In the infections with F. bancrofti the blood must 

 be examined at night, as the embryos are most numerous 

 at night and in many cases are not found in the daytime. 

 The films should be made as thick as possible, and the 

 blood can either be examined fresh or the thick films 

 when dry can be dehaemoglobinized by placing them in 

 water. In most countries the blood must be taken at 

 night, but in the Philippines, Fiji, and other Pacific 

 Islands the embryos are as numerous by day as by night. 

 The worms, which have no definite periodicity, are called 

 F. philippinense, but Leiper has shown that the adults are 

 indistinguishable from F. bancrofti. 



The clinical manifestations, if any, are those of 

 lymphatic obstruction. In chyluria, lymph scrotum, 

 and in many cases of lymph varix the embryos of the 



