d (1). The problem of malaria
has been exacerbated in recent years by the development
and rapid spread of resistance in P. falciparum to
the more commonly used and affordable antimalarial
drugs. Chloroquine resistance, which first appeared in
East Africa in the late 1970s, has now spread
throughout most of the continent, and resistance to
pyrimethamine–sulfadoxine (Fansidar) has followed
rapidly.