LATENT INFECTIONS WITH PLASMODIUM OVALE MALARIA.

Two cases of Plasmodium ovale malaria acquired in West Africa appeared as primary delayed attacks after one year's continuous residence in Canada. Both patients took full prophylactic doses of chloroquine before, during, and for several weeks after exposure. The inadequacy of the 4-aminoquinolines for protection against latent benign tertian malaria is noted, and the use of primaquine is recommended. Paroxysms occurred in the evening and were accompanied by severe muscle pain, features considered typical of ovale malaria. One patient showed electrocardiographic changes and clinical signs of cardiac malfunction; these disappeared following specific treatment for malaria. In this age of accelerated travel and international movements of people it is important that physicians in temperate regions be aware of the exotic infections of the tropics, as well as of the need for protective measures for travellers to areas where these diseases are endemic.