At present, the problem of drug resistant malaria is basically that of treatment and control in South America and southeast Asia of strains of P. falciparum resistant to chloroquine. Some of these strains are resistant to quinine and many of them to the folic reductase inhibitors pyrimethamine and chlorguanide (proguanil).
Treatment, both prophylactic and curative, involves to an increasing extent the use of sulfones and sulfonamides, occasional failure of which may be attributable to host factors rather than extension of parasite resistance to these drugs. Pending the arrival of effective new antimalarial compounds still in various stages of testing, several prophylactic and curative regimens are available for use in the field or clinic, and these are described.
Fundamental to control are the observations, by no means conclusive, that the strains are no more virulent in man than are chloroquine sensitive ones, and that they are not preferentially carried by certain anophelines inaccessible or resistant to insecticidal attack.