190 OTHER SPOROZOA 



Kedani or Japanese Flood Fever. In certain parts of Japan 

 there occurs a disease usually called kedani, or tsutsugamushi, 

 which is reminiscent of American spotted fever. It begins after 

 an incubation of five or six days or longer with a fever and break- 

 ing out of the skin, the fever reaching its height between the 

 third and seventh days. It lasts from one to three weeks and 

 is accompanied by a swelling of the lymph glands, especially in 

 the vicinity of the point of infection. This is usually the armpit, 

 neck or groin region, where a small ulcerous wound can be found 

 resulting from the bite of a mite. 



The disease is transmitted by the bite of a very small reddish 

 mite, probably an immature mite of the genus Trombidium, 

 or harvest bug. These mites live in great numbers on a very 

 abundant local field-mouse, Microtus montebelli. The mice are 

 not only the hosts of the mites but are also subject to the disease 

 and undoubtedly are an important factor in its distribution and 

 control. Kedani is apparently most common in laborers working 

 in hemp fields in July and August, on the plains which are an- 

 nually flooded by the overflow of certain rivers. 



In Sumatra a similar disease, which is either identical or closely 

 related to kedani, occurs commonly among Chinese and Japanese 

 laborers in the tobacco fields. The disease as it occurs in Su- 

 matra, where it is called pseudo-typhus, 

 differs in some slight respects from the 

 typical Japanese disease and has a very 

 much lower fatality. In its incubation 

 period, eruption, and general course it re- 

 sembles spotted fever more closely than 

 does the Japanese disease, and Schueffner, 

 who has worked most with it, thinks it 

 , 5 . 8 * " Gran V lar may be transmitted by ticks as well as 



bodies in mono nuclear 



leucocyte, supposed to be mites. The disease has also been reported 

 parasites of Kedani f th Philippines, and about 150 cases 



(Theilena tsutsugamushi). ' 



(After Hayashi.) have been reported in the Malay States. 



It is not improbable that it will be found 



to be widely distributed in southeastern Asia, having been in- 

 correctly diagnosed as other diseases. 



A number of organisms thought to be the cause of Kedani have 

 been described. Hayashi has recently found granular bodies of 

 several morphological types in both the plasma and cells of the 



