The Bridgeport evening farmer., 1912-11-22
INFANT|LE
 PARALYSIS
Conviction of Stable Fly by
 Massachusetts Scientists
How the Insect That Spreads Infanfi1e Paralysis Was Dis covered Told by the Harvard Alumni Bulletin

covered Told by the Harvard
 Alumni Bulletin
 There will be much local interest in
 an article in the Harvard Alumni Bull
 letin of this week on "An insect car- | rier Of infantile paralysis" The news ble fly is probably the instrument in the spread of antafior poliomyeIitis, 1 heavily. has already been printed. Within the last few months the offic- CTS of the Buseey institution of Har-
 vard siao, university and the Harvard collaboration with the State board of
 Health. and they have discovered how
 close scientific reasoning they have shown that the disease can be carried by the stable fly (etomoxys ealcitransl throughout the world
 The article traces briefly the dis
 covsries that insects serve as inter the tick for the Texas fever of cattle, mosquitoes for malaria and yellow fever and the tsetse fly for the sleep
 study of poliomyelitis by the state board of health. through c. T. Brues
 Pnifin 9 fhs ufsey hsnna snstitgtion ta and pr r. SpF1ngneld and made a thorough tn- l vestigation. It then says:
 |
 occurred during the summer and early autumn. growing more frequent after the middle of summer. and lasting un- til well on toward cold weather. There
 were so many isolated cases that con- tact was soon seen to be an improb- able mode of transmission. The in-
 some confidence to the theory of an insect carrier. Starting from a com plete list of the biting. bloodsucking and household insects which by their habits seemed suited to carry infec- ton, their first step was to eliminate
 all those winch did not satisfy these Such insects as fIeas and bedbugs
 were ruled out because many eases
 of infantile paralysis occurred in unknown, and the scattering occurr- efce of the disease did not agree with
 the non-traveIing habits of these in-
 were ruled out. since histories of such bites were not obtained in the ma
 jority Of cases. By such reasoning it was possible tentatively to eliminate all insects except one, the common sta ble fly. This insect seemed to satis- fy. all the conditions made by the dis probability was established that the stable fly is the means by which in-
 fantiie paralysis is carried from one person to another.
 EXPERIMENTS WITH MONKEYS The next step was to see by experi- ment whether the disease could be transmitted by this insect, under con- ditions which could be absolutely con l. i.trolied. It had long been known that nndnkeys were subject to the disease. Accordingly the investigation was i transferred to the medical school and 1 put under the charge of Prof. M- J. Rc5enau. He working with Mir. Brues I undertook to determine by experiment can actually serve as a carrier for infantile paralysis The results have shown that it can.
 l Mo,lSevs were fi-sf infested with the disease by injection and then allowed I to be bitten by stable flies. After the
 lowed to bite other monkeys. The first results were negative. Then it
 was suggested that the monkeys
 tat bene Re ana ea caught and ats all the flies that were
 brought into their cage. In the next
 paws Of the monkeys were tied This
 time, afer they were bitten by flies
 which had bitten other monkeys al
 ready. infected, they exhibited all the symptoms of the disease in 6 cases out Of F This established the fact that
 the disease could be carried by these
 No principle, however. is regarded as
 scientifically. established until 1t has been confirmed through repetition of
 e experiments by other observers. [ Accordingly at the request of Dr. Ro- senau. Drs. Anderson and Frost Of i the public health and marine hospital |
  the basis of the facts attained at the medical school, repeated the expert which developed in monkeys bitten by infected stable flies was fnfantlle paralysis by injecting another set of monkeys with a culture from the monkeys bitten by the flies. Thus, the proof is complete
 DIFFERS FROM HOUSE FLY
 The stable fly which has thus been proved such dangerous e1sIny 1s1l 10 ordinary house fly, to which 1t is closely related and for which it is ffe- auently mistaken on account of its size, somewhat similar co1oratic1. and common occurrence near human hab-l itations. It differs, however. in a nun Der of important respects, both in habits. structure and distribution.
 The adult stable fly feeds exclusive ly on blood, biting various animals, The domestic animals that they usual ly infest are cattle and horses, which are particularly pestered i5y them dur ing the latter part of the summer On this account the flies are more com mon in the country, where the mum Der of such animals is large, or III the neighborhood of staD or 5a zll arlls incities or towns It is difficult. how ever, to find any place of any size where under ordinary conditions this
 Although the flies are found near human hapitations. they do not enter houses so commonly as does the ordl- nary house fly puI IdlHSd ASAiioIAt l open and sunny places, except When attracted elsewhere to feed. Their normal food consist of the blood of and during it's lifetime each fly feeds every two or three days oftener, upon some warm blooded animal. The habit of this i'm sect Of staying out of doors in good weather has given rise to the popu- far tradition that house flies bite be- fore a rain, which is based upon the fact that at such times the stable fly is more apt to come indoors It bites more commonly. however out Of doors and in bright, sunny wea ther- It has