Army Malaria Institute - its Evolution and Achievements Third Decade (1st Half): 1985-1990

The first half of the third decade (1985-1990) after the establishment of the Malaria Research Unit was characterised by a substantial increase in laboratory and field activities. Various new procedures were developed to discover and counter the increasing problem of parasite resistance to established antimalarial drug regimens. After early findings that the currently-used pyrimethamine/dapsone (Maloprim) prophylaxis was no longer effective against Plasmodium falciparum malaria, in vitro, ex vivo and pharmacological investigations were undertaken with proguanil and a low dose of dapsone. This led to a field study in Papua New Guinea (PNG) which indicated that such a drug combination might be more effective than Maloprim. Before the effectiveness of this combination could be determined further, it became obvious that Maloprim/ chloroquine had become inadequate for the protection of ADF soldiers on exercises in PNG. During one of these exercises, the landmark discovery that P. vivax had developed resistance to chloroquine was the first documented evidence that this previously successful standard medication had lost its efficacy against vivax malaria. These findings in 1988/1989 led to the evaluation of mefloquine and doxycycline as alternative prophylactic regimens for ADF personnel serving in malarious areas. In efforts to identify and assess other potential antimalarial drugs, in vitro studies were continued with various strains of P. falciparum. These studies were supplemented by investigations with P. falciparum and P. vivax in non-human primates and by malaria transmission studies with Anopheles farauti mosquitoes. The survey of anopheline mosquitoes in northern Australia indicated the widespread presence of three isomorphic species of An. farauti and the ever-present possibility of re-introducing malaria into northern Australia. Investigations relating to the biological control of mosquitoes were gradually phased out and emphasis was given to the assessment of novel mosquito repellent measures for improved personal protection against malaria.