396 Acute Anterior Poliomyelitis 



In 191 2, Rosenau and Brues* reported that in 50 per cent, of their 

 experiments, the virus of acute anterior poliomyelitis was trans- 

 mitted from monkey to monkey by the bite of the stable fly Stomoxys 

 calcitrans, and expressed the belief that it was a biological and not a 

 mechanical transfer, and that the virus underwent some change and 

 development in the flies. These results were confirmed by Ander- 

 son and Forst,t but failed to be confirmed by other workers and 

 later could not be successfully repeated by the same investigators. 



Howard and Clarkf worked over the subject of transmission of 

 the disease by insects, and investigated the house-fly Musca domes- 

 tica; the bed-bug, Cimex lectularius; the Uce, Pediculus capitis and 

 Pediculus vestimenti; various mosquitoes, Culex pipiens, Culex 

 solicitans and Culex cantator, and found that only one of these 

 insects, the common house-fly, Musca domestica, can carry the virus 

 in an active state for several days both upon the surface of its 

 body and in its gastro-intestinal tract. None of the suctorial 

 insects withdrew the virus with the blood of the infected monkeys 

 to which they were appHed. 



Flexner and Noguchi§ made experiments upon the cultivation 

 of the micro-organism supposed to be the infective agent. The 

 technic employed was much like that employed for the cultivation 

 of Treponema palKdum (q.v.), and resulted in an undoubted quan- 

 titative increase in the infectiveness of the virus. Further, they 

 were now able, for the first time, to describe an organism that 

 might be the specific infectious agent. It is a globoid body meas- 

 uring from 0.15-0.3 fi, arranged in pairs, chains and indefinite masses. 

 Its smaU size makes it barely visible and able to penetrate the pores 

 of the Berkefeld filters. 



This organism they were able to stain both by the methods of 

 Giemsa and Gram. Having come to recognize it in the culture, 

 they were subsequently able to find it in sections of tissue from the 

 lesions of poliomyelitis, and conclude that "The micro-organism 

 exists in the infectious and diseased organs; it is not, so far as is 

 known, a common saprophyte, or associated with any other patho- 

 logical condition; it is capable of reproducing, on inoculation, the 

 experimental disease in monkeys, from which animals it can be re- 

 covered in pure culture. And besides these classical requirements, 

 the micro-organism withstands preservation and glycerination as 

 does the ordinary virus of pohomyelitis within the nervous organs. 

 Finally, the anaerobic nature of the micro-organism interposes no 

 obstacle to its acceptance as the causative agent, since the living 

 tissues are devoid of free oxygen and the virus of poliomyeUtis has 

 not yet been detected in the circulating blood or cerebro-spinal fluid 



* "Monthly Bull, of the State Board of Health of Massachusetts,"i9i2, vii, 

 314- 



t "Public Health Reports," 1913, xxvni, 833. 

 t "Jour. Exp. Med.," 1912, xvi, 850. 

 § "Jour. Exp. Med.," 1913, xviii, 461. 



