ECONOMIC LOSS THROUGH INSECTS 



737 



probabilities are that it was endemic, and 

 it is supposed that the cause of the failure 

 of the early colonies in Virginia was due 

 to this disease. It is certain that malaria 

 retarded in a marked degree the advance 

 of civilization over the North American 

 Continent, and particularly was this the 

 case in the march of the pioneers 

 throughout the Middle West and 

 throughout the Gulf States west to the 

 Mississippi and beyond. In many large 

 regions once malarious the disease has 

 lessened greatly in frequency and viru- 

 lence owing to the reclamation of swamp 

 areas and the lessening of the number of 

 the possible breeding places of the ma- 

 larial mosquitoes, but the disease is still 

 enormously prevalent, particularly so in 

 the southern United States. 



There are many communities and many 

 regions in the North where malaria is 

 unknown, but in many of these localities 

 and throughout many of these regions 

 Anopheles mosquitoes breed, and the ab- 

 sence of malaria means simply that ma- 

 larial patients have not entered these re- 

 gions at the proper time of the year to 

 produce a spread of the malady. It has 

 happened again and again that in com- 

 munities where malaria was previously 

 unknown it has suddenly made its ap- 

 pearance and spread in a startling man- 

 ner. These cases are to be explained, 

 as happened in Brookline, Mass., by the 

 introduction of Italian laborers, some of 

 whom were malarious, to work upon the 

 reservoir ; or, as happened at a fashion- 

 able summer resort near New York City, 

 by the appearance of a coachman who 

 had had malaria elsewhere and had re- 

 lapsed at this place. In such ways, with 

 a rapidly increasing population, malaria 

 is still spreading in this country. 



MALARIA RESPONSIBLE FOR MORE DEATHS 

 THAN ANY PARASITIC DISEASE 



It is undoubtedly safe to assume that 

 the death rate for the whole population 

 of the United States due to malaria is in 

 the neighborhood of 15 per 100,000. 



But with malaria perhaps as with no 

 other disease does the death rate fail to 



indicate the real loss from the economic 

 point of view. A man may suffer from 

 malaria throughout the greater part of 

 his life, and his productive capacity may 

 be reduced from 50 to 75 per cent, and. 

 yet ultimately he may die from some en- 

 tirely different immediate cause. In fact, 

 the predisposition to death from other 

 causes brought about by malaria is so 

 marked that if, in the collection of vital 

 statistics, it were possible to ascribe the 

 real influence upon mortality that malaria 

 possesses, this disease would have a very 

 high rank in mortality tables. 



Writing of tropical countries, Sir Pal- 

 rick Manson declares that malaria causes 

 more deaths, and more predisposition to 

 death by inducing cachectic states pre- 

 disposing to other affections, than all the 

 other parasites affecting mankind to- 

 gether. Moreover, it has been shown 

 that the average life of the worker in 

 malarious places is shorter and the infant 

 mortality higher than in healthy places. 



But, aside from this vitally important 

 aspect of the subject, the effect of malaria 

 in lessening or destroying the productive 

 capacity of the individual is obviously of 

 the utmost importance, and upon the pop- 

 ulation of a malarious region is enor- 

 mous, even under modern conditions and 

 in the United States. It has been sug- 

 gested that the depopulation of the once 

 thickly settled Roman Campagna was due 

 to the sudden introduction of malaria by 

 the mercenaries of Scylla and Marius. 

 Celli, in 1900, states that owing to ma- 

 laria about 5,000,000 acres of land in 

 Italy remain — not uncultivated, but cer- 

 tainly very imperfectly cultivated. Then 

 also, in further example, in quite recent 

 years malaria entered and devastated the 

 islands of Mauritius and Reunion, prac- 

 tically destroying for a time the produc- 

 tiveness of these rich colonies of Great 

 Britain and France. 



Creighton, in his article on malaria in 

 the Encyclopaedia Britannica, states that 

 this disease "has been estimated to pro- 

 duce one-half of the entire mortality of 

 the human race ; and inasmuch as it is the 

 most frequent cause of sickness and 



