[Human and animal leptospirosis in irrigated lands]

To study the influence of amelioration on the spread of leptospirosis, the survey of humans, agricultural animals and rodent was made on the territory where the irrigation system was under construction and during 2 years after the beginning of irrigation. This survey failed to establish the occurrence of significant changes in the number of rodents and their species composition, as well as in the number of agricultural animals showing the positive reaction to leptospirosis. No cases of leptospirosis were registered, and during the first years after the beginning of irrigation antibodies in low titers were detected only in 4 out of 536 subjects. The results obtained in this survey suggest that during the first years of artificial irrigation the conditions for a wider spread of leptospirosis do not appear, but the final solution of this problem can be made on the basis of observations lasting for many years.