The Bridgeport evening farmer., 1916-07-25

bright daylight and sunshine. It is
 readily destroyed by exposure to sum- light.
 Conveyance by Insects.-Since epi- denies of infantile paralysis always arise during the period of warm or summer weather, they have been | thought of as possibly being connect
 ed with or dependent on insect life.
 The blood-sucking insects have es- pecially come under suspicion. Ex- pertments have been made with biting 1 flies, bedbugs, mosquitoes, and with | lice. Neither mosquitoes nor lice seem able to take the virus from the
 the blood of infected monkeys or to
 retain 1t for a time in living state.
 In one instance. bedbugs have been
 made to take up. the virus from the
 blood of monkeys, but they did not convey it by biting to healthy mon- keys. Certain experiments did indi-
 cate that the biting stable fly could
 both withdraw the virus from the
 blood of the infected and reconvey it to the blood of healthy monkeys, which became paralyzed. But more recent studies have failed to confirm the earlier ones. Moreover, experi-
 mentally inoculated monkeys differ
 in one way from human beings suffer- ing from infcntile paralysis. for while the virus may appear in the blood of the former, it has never been detect
 ed in the blood the latter: The ordin- ary or domestic fly may become con- taminated with the vi1us contained in the secretions of the body and serve
 as the agent of it's transportation to persons and to food with which it comes into contact Domestic flies expertmentally contaminated with the virus remain infective for. forty eight hours or longer. While our present knowledge excludes insects from be- ing active agents in the disse imitation of infantile paralysis, they neverthe- less fall under suspicion as being po- tential mechanical carriers of the vii
 rus of that disease
 Conveyance by Domestic Animals. .-- The attention which the recent epi- demic of infantile paralysis has drawn to the diseases attended by paralysis has led to the discovery that domestic animals and pets are subject to para
 
 have especially come under suspicion as possibly distributing the germ of infantile paralysis are poultry, pigs, and dogs and cats. But in isolated
 instances. sheep, cattle and even horses have been suspected. All these kinds of animals are subject to dis eases in which paralysis of the legs and other parts of the body some T~ s,,- paralytfc diseases among poultry or pigs have been noted to coincide with the appearances of cases of infantile paralysis on farm or in commun- ity. Experimental studies have, how ever. excluded the aforementioned animals from being carriers of the vii rus of infantile paralysis. The para lytic diseases which they suffer have long been known and are quite differ ent from infantile paralysis. Their occurrence may be scoincidental; in no instance investigated has one been found to be responsible for the other 1 Routes of Travel Studies carried out in various countries in which in fantile paralysis has been epidemic Fall indicate that; in extending from place to place of point to point, the
 route taken isl that of ordinary travel.
 This is equally true whether the route Ia by water or land. along simple f highway or the line of railroad In other words, the evidence derived from this class of studies confirms the
 evidence obtained from other sources I in connecting the distributing agency i intimately with human beings and
 their activities
 | Z I tI. l Survival of the Virus in the Infect ed Body.-The virus of fnfantfle para lysis is destroyed in the interior Of the body more quickly and completely
 than in some ihstances, in the mucous
 membrane of the nose and throat, It has been found in monkeys, in. which accurate experiments can be carried
 out that the virus may disappear | from the brain and spinal cord witt, I in from a few days to three weeks
 after the appearance of the paralysis 4 while at the same time it is still pres- lent on the mucous membranes men, toned. The longest period after in oculation in which the virus has been detected in the mucous membrane -of the nose and throat of monkeys is six months. It is far more. difficult to detect the human than the monkey carriers of the virus since, as directly obtained from human beings, the vi. ] rus displays 8 low degree of infectiy. , ity. for monkeys; while once adapted 4 to monkeys. the virus becomes incred- libly active. so that minute quantities ] are capable of ready detection by in. } Oculation tests. Yet in an undoubted instance of the human disease, the vi. ! rus was detected in the mucous mem. brane of the throat five months after
 its acute onset Hence we, posses. conclusive evidence of the occurrence
 of occasional chronic Human carrier. of the virus of infantile paralysis.
 T Punctuation in Epidemics Not al ], epfdemics of infantile paralysis art equally severe. Indeed, great varia ftions of fluctuations are known te : occur not only in the number of cases but also In the death rate. The ex l, ttremes are represented by the occa lsional instances of infantiIe paralvsi, known in every considerable com , munity and from which no extensio, , takes place. and the instances i, which in few days or weeks tn, , humber rises by leaps and bounds in 7 to the hundreds, and the death rat reaches 20 per cent. or more of thos attacked. While all the factors whicl determine this discrepancy are no . known, certain of them have becom : apparent. A factor of high impor tance is the infective power of DO ] tency, or technically stated the ,viru 1ence, of the mfcro-organism or yiru