Animal Parasitism in Connecticut and Adjoining States *

The variation in clinical manifestations is one of the most deceptive features of parasitic infections. Heavy infections cause a definite syndrome, are responsible for much invalidism, and may entail a high mortality. Many are notorious for retarding the mental and physical development of children. In milder infections, though no specific signs may indicate their presence, they are a complicating factor in association with chronic disorders such as tuberculosis, gastro-enteritis, rickets, syphilis, etc. Finally, even mild infections may play a role in protracting convalescence after such acute conditions as pneumonia and typhoid fever. From the earliest Colonial days and until the latter part of the last century parasitic diseases were a serious cause of invalidism and death in these states. In conjunction with other so-called tropical diseases, notably yellow fever, cholera, and bacillary dysentery, they were responsible for heavy mortality. Burrows tells us that remittent and intermittent fevers, now known as malaria, were recognized soon after the settlement of the Colony and thereafter caused much sickness in the State. With the drainage of the land necessarily associated with agricultural development the three malarial diseases, which from records we know existed, became less prevalent. With extensive commercial developments in the middle of the last century malaria again appeared and for nearly two decades following 1870 was more widespread than in the early days of its endemicity. This return of the infection is attributable to the extensive road making, railroad building, factory construction, and especially to the impounding of waters for the production of power. Thus were created numerous pools, ponds, and swampy places admirably adapted to the breeding of the mosquito vector of malaria. Since Webster's time there are abundant records of severe and frequent epidemics of dysentery in this State. While the majority of these were probably due to bacteria, some outbreaks were con-