442 BACTERIA PATHOGENIC TO MAN 



The question is still undecided as to whether these bacilli are anything 

 more than very frequent causes of secondary infection. 



Pemphigus Neonatorum. Several micrococci have been described 

 as the cause of infection. 



Impetigo Contagiosa. The findings have been similar to those in 

 pemphigus. 



Scurvy. This disease is probably not due to micro-organisms. 



Mumps. Diplococci have been considered by several investigators 

 as possibly being the exciting organisms. 



Noma. It is as yet undecided whether this disease is due to one 

 or to several micro-organisms. A special predisposition of the tissues 

 is necessary. A streptothrix, pseudodiphtheria bacilli, and diphtheria 

 bacilli have been the organisms most frequently present. 



Articular Rheumatism. The specific organisms of this disease 

 have been sought in the synovial fluid, blood, vegetations on heart 

 valves, and in exudates on tonsils, etc. Streptococci have been, of all 

 bacteria, most frequently found. They grow in short chains or as 

 diplococci. Most bacteriologists believe the exciting factor has not 

 yet been identified and that the streptococci and other bacteria are 

 secondary infections. 



Beriberi. Micro-organisms, both of bacterial and protozoan 

 nature, have been considered as the exciting factor, but nothing definite 

 has been proven. 



Yellow Fever. The bacillus described by Sanarelli as the exciting 

 factor is now known to be at most a rather frequent secondary invader. 

 Reed, Carroll, and Agramonte have shown that the stegomyia fasciata 

 is the only carrier of the infecting agent. Twelve days after biting a 

 yellow-fever patient the mosquito is able to infect a non-immune by 

 biting. The insect continues for a number of weeks to be capable of 

 infecting man. The blood of yellow-fever patients is only capable of 

 infecting mosquitoes during the first few days. It has also been im- 

 possible to infect mosquitoes by letting them bite the body of a person 

 who has died of yellow fever. The blood of yellow-fever patients in- 

 jected into non-immunes produced the disease. The virus of yellow fever 

 is apparently capable of passing through a Berkefeld filter. At present 

 nothing is known about the micro-organism. The bite of the mos- 

 quito is the only known method of causing infection. The clothing 

 and the discharges from the mouth, kidney, and intestines are harm- 

 less. 



Dengue. The organism exciting this disease is unknown. An 

 influenza-like bacillus has been observed as frequently present. The 

 mosquito has also been suspected as the carrier of infection. 



Invisible Micro-organisms. There are a number of diseases from 

 which the infectious material passes through stone filters which are 

 known not to allow the passage of visible micro-organisms. The horse 

 sickness of South Africa, yellow fever, and the cattle plague, pleuro- 

 pneumonia of cattle, are of this nature. 



