Relapsing malaria: two cases of malaria presenting 8 months after return from Africa despite adherence to antimalarial chemoprophylaxis

It has become increasingly common for UK patients to travel to malarial regions: in 2004 over 2.5 million visits were made by UK individuals to countries in which malaria is endemic, representing a 300% increase since 1987.1 Malaria prophylaxis routinely provided in general practice comprises atovaquone–proguanil, mefloquine, doxycycline, or chloroquine plus proguanil. This article describes two cases of malaria that presented 8 months after foreign travel, despite adherence to antimalarial prophylaxis. Two 16-year-old boys presented to the same UK hospital during the same week. Both had a 2-week history of unexplained fever and myalgia. They had travelled together to a malarious area of Kenya for a fortnight 8 months previously on a school trip, and had shared a tent. Both pupils reported adherence to a complete course of atovaquone–proguanil (Malarone®, GSK) on this trip, and had not been to any other malarious regions subsequently. Neither patient reported symptoms at the time of the trip or on initial return to the UK; nor were any other pupils or staff member on the …