MALARIA AND ITS IMPLICATIONS FOR PUBLIC-HEALTH IN FAR NORTH QUEENSLAND - A PROSPECTIVE-STUDY

This prospective study's objectives were to describe the features of a ll episodes of malaria diagnosed in Far North Queensland (excluding th e Torres Strait) and to assess how much of a threat they posed to the area's public health. Over a three-year period, 216 episodes of malari a were diagnosed (158 Plasmodium vivax and 68 Fl falciparum infections ). Most (82%) of the infections were acquired in Papua New Guinea (PNG ). Approximately 70% of the episodes occurred in Australian citizens, about half of whom were in malaria-endemic countries for work; the rem ainder travelled abroad for recreation. Three-quarters of the Australi an citizens with malaria had taken either no or inadequate prophylaxis . Australian citizens who had taken adequate prophylaxis were much les s likely to develop Fl falciparum than other types of malaria compared to those who took either no or inadequate prophylaxis (p=0.01). Gamet ocytes were present in 121 (56%) of the episodes of malaria. Mosquito surveillance was carried out in response to 38 (31%) of these gametocy taemic episodes. Significant numbers of Anopheles farauti sensu late m osquitoes were found close to the residence of a patient in 4 (11%) of these episodes. Only two occasions when local transmission could have possibly occurred were recognised. We do not believe malaria poses an important threat to the health of the public in Far North Queensland. Nevertheless, it remains an important problem for those who travel ab road to malarious areas.