Mefloquine as a single agent has also been used in the successful treatment of a Swedish traveller returning from Sarawak, Malaysia with PCR confirmed uncomplicated P. knowlesi infection in 2009 [24]. The long half life of mefloquine of around 14 days also means when used as the partner drug in an ACT for uncomplicated malaria caused by other Plasmodium species such as P. vivax, there is a significant reduction compared to A-L in the day 42 treatment failure rate [42].