The development of flagellates in Chinese sandflies (phlebotomus) fed on hamsters infected with Leishmania donovani.

Abstract

Sandflies (Phlebotomus) have assumed a particularly important position in the study of the leishmaniases since Knowles, Napier and Smith 1 reported the appearance of herpetomonad flagellates in a large proportion of Phlebotomus argentipes fed on kala azar patients in Calcutta.

The present paper is a report of certain phases of studies undertaken on the sandflies of North China as possible transmitting agents of kala azar. Three species of Phlebotomus are known to us, namely, Phlebotomus major var. chinensis Newstead, and two unidentified species which we have designated Phlebotomus “B” and “C”. Phlebotomus “B” is apparently the unnamed species mentioned by Newstead. 2 These three species occur in markedly variable proportions in several regions near Peking and Hsüchowfu, Kiangsu.

In these studies (1) sandflies captured in houses of kala azar patients and elsewhere have been examined for flagellates. (2) Sandflies reared in the laboratory have been fed on kala azar patients and on hamsters heavily infected with Leishmania donovani. In the attempt to transmit kala azar these sandflies have been refed upon tested negative hamsters, and a certain number have been inoculated into other hamsters. As many as possible of such sandflies were examined for the presence of flagellates. A total of over 250 hamsters used in these transmission studies were all negative by liver puncture from 81 to 137 days after the experiments, but final results will be reported from autopsy findings. It is desired to report at this itme (1) a technique of rearing sandflies and of feeding them on hamsters, with particular reference to the feeding of these insects a second time, a feature hitherto little studied, and (2) the results of examination for herpetomonad flagellates.

Technique. The method of rearing sandflies, which will be reported in detail in a separate paper, is a modification of the methods of Waterston 3 and Srnithb 4 The breeding vessels are porous earthen pots with a thin lining of plaster of Paris.