CHAPTER XI 
SOME POSSIBLE, BUT IMPERFECTLY ESTABLISHED CASES OF 
ARTHROPOD TRANSMISSION OF DISEASE 
Infantile Paralysis or Acute Anterior Poliomyelitis 
The disease usually known in this country as infantile paralysis 
or, more technically, as acute anterior poliomyelitis, is one which 
has aroused much attention in recent years. 
The causative organism of infantile paralysis is unknown, but 
it has been demonstrated that it belongs to the group of filterable 
viruses. It gives rise to a general infection, producing characteristic 
lesions in the central nervous system. The result of the injury to 
the motor nerves is a more or less complete paralysis of the corres¬ 
ponding muscle. This usually manifests itself in the legs and arms. 
The fatal cases are usually the result of paralysis of the muscles 
of respiration. Of the non-fatal cases about 60 per cent remain 
permanently crippled in varying degrees. 
Though long known, it was not until about 1890 that it was 
emphasized that the disease occurs in epidemic form. At this time 
Medin reported his observations on an epidemic of forty-three cases 
which occurred in and around Stockholm in 1887. Since then, 
according to Frost (1911), epidemics have been observed with increas¬ 
ing frequency in various parts of the world. The largest recorded 
epidemics have been those in Vermont, 1894, 126 cases; Norway and 
Sweden, 1905, about 1,500 cases; New York City, 1907, about 
2,500 cases. Since 1907 many epidemics have been reported in the 
United States, and especially in the Northern States east of the 
Dakotas. In 1912 there were over 300 cases of the disease in Buffalo, 
N. Y., with a mortality of somewhat over 11 per cent. 
In view of the sudden prominence and the alarming spread of 
infantile paralysis, there have been many attempts to determine 
the cause, and the manner in which the disease spreads and develops 
in epidemic form. In the course of these studies, the question of 
possible transmission by insects was naturally suggested. 
C. W. Howard and Clark (1912) presented the results of studies 
in this phase of the subject. They dealt especially with the house¬ 
fly, bedbug, head, and body lice, and mosquitoes. It was found 
that the house-fly {Musea domestica) can carry the virus of poliomye¬ 
litis in an active state for several days upon the surface of the body 
241 
