A new study indicates that there may be a difference in the protection provided by the three antimalarial treatments commonly prescribed to people visiting malaria-endemic areas.
For the period studied, there were just 3.0 cases of Plasmodium falciparum malaria per 100,000 prescriptions of Malarone (combination atovaquone plus proguanil), versus 16.8 cases for every 100,000 doxycycline prescriptions and 43.3 cases per 100 000 prescriptions of mefloquine.
Over the study period of seven years, for each case of P. falciparum malaria in travellers prescribed Malarone, there were 5.8 cases in those prescribed doxycycline and 14.5 among those prescribed mefloquine.
Despite being largely preventable, between 1,300 and 2,500 cases of malaria occur every year in travellers returning to the UK from malaria-endemic countries and, on average, nine of these cases result in death.
Globally, an estimated 30,000 travellers still fall ill with the disease every year. The study showed that the majority of cases of malaria occur in travellers not using antimalarials or for whom an antimalarial was not stated.
The paper's findings, recently published online in advance of print in the Journal of Travel Medicine and Infectious Disease, were taken from a real-life, retrospective analysis of the cases of malaria in returning UK travellers between 2001 and 2007 inclusive, which was designed to compare the effectiveness of Malarone, doxycycline and mefloquine.
Dr Jane Zuckerman, lead author and Director of the WHO Collaborating Centre for Reference, Research and Training in Travel Medicine, University College London Medical School, commented, "Existing clinical studies have reported similar rates of efficacy across the antimalarial options available.
"Our findings could suggest that the efficacy recorded in these clinical studies may not necessarily be replicated in a real life setting – certainly from this group of travellers there may be a difference in the protection offered by Malarone over other antimalarials.
"This trend should be considered alongside prospective trial data when healthcare professionals offer advice to people visiting at-risk areas."