[Zooprophylaxis: old and new problems].

In the present note the authors report on the most important works which have examined the application of zooprophylaxis as a means for malaria control from the onset of this century to the present day. The method of zooprophylaxis has evolved throughout the years in close connection with other problems, undoubtedly more important in the history of malaria, which in the present paper are amply discussed. From the very beginning this subject was the object of heated debates by those who retained it a valid method of malaria control and those who denied its validity, among whom some of the most important Italian and foreign malariologists. The experiments of zooprophylaxis received most attention in the twenties, but, following the works of Missiroli and co-workers in the early thirties by which the varieties of the "complex maculipennis" were identified, the interest on zooprophylaxis was less heightened. It should be noted, however, that the increase of cattle, and especially land reclamation, reduced considerably malaria endemicity in northern Italy where zoophilic varieties were most prevalent. Recently, renewed interest on zooprophylaxis has been shown in Pakistan, where some experiments on the use of cattle have led to an unexpected increase of malaria transmission.