Antimalarial prophylaxis - Use and adverse events in visitors to the Kruger National Park

Objectives. To determine the use of antimalarial prophylaxis and the relati ve frequency of adverse events with different regimens in visitors to the K ruger National Park. Design. Retrospective postal survey of a cohort of 7 397 visitors during Ap ril 1996. Telephonic interviews were conducted with all respondents who rep orted neuropsychiatric adverse events necessitating medical attention, and their medical caregivers. Results. The most commonly used regimens were chloroquine and proguanil in combination (C&P) (35.6%) and mefloquine (18.4%). However, non-recommended regimens were also used by travellers to this chloroquine-resistant area, i ncluding chloroquine alone (15.7%). Adverse events were reported by 23.8% o f travellers and were more common in the C&P group than the mefloquine grou p (28.9% v. 25.0%, P = 0.0100). Gastro-intestinal side-effects were signifi cantly more common in the C&P group (nausea (P = 0.0170), diarrhoea (P = 0. 0008), mouth ulcers(P = 0.0000)), while neuropsychiatric side-effects were more:common in the mefloquine group (depression (P = 0.0000), light-headedn ess (P = 0.0009), anxiety (P = 0.0060)). Only 30% of travellers reported us ing antimalarial drugs both regularly as prescribed and for 4 weeks after l eaving the malaria area. The most commonly reported reason for changing pro phylaxis;was advice from a physician or pharmacist (41.9%). Conclusions. Health professionals providing medical advice to prospective t ravellers to malarious areas must tailor recommendations based on the balan ce between malaria risk in aspecific geographical area and the benefits and tolerance of protective measures. Mosquito-avoidance measures should alway s be advocated, but counselling on antimalarial prophylaxis will be guided by the malaria/prophylaxis (serious adverse events) risk ratio. Where drug measures are indicated, the importance of their correct use should be empha sised.