Malaria eradication in Portugal.

Research on malaria, which was endemic in several parts of Portugal at the beginning of this century, was intensified in the 1940's and led to the development of better control methods, especially in the rice-growing areas of the country. In the 1950's residual DDT spraying was introduced and followed by extensive detection of cases of malaria and their treatment. Plans for eradication of the disease were made, and by 1958 the transmission of the infection was interrupted in nearly all areas of European Portugal. The country was placed in the maintenance phase of malaria eradication and the certification of malaria eradication was confirmed by the WHO in 1973. The political and military events of the past five years greatly increased the number of cases of malaria imported into Portugal from tropical Africa and indicated the need for much vigilance to prevent the resumption of transmission by the local vectors. It appears that the measures put into action have succeeded in this respect. This was due to the high degree of effective surveillance and also to the fact that Anopheles atroparvus does not readily transmit the exotic strains of Plasmodium falciparum and P. vivax. However, further vigilance must be maintained and intensified.