Malaria continues to be a common problem in the returning traveler. Six-doses of Coartem (artemether/lumefantrine) is highly efficacious and recommended by the CDC for treatment of uncomplicated P. falciparum malaria from areas with chloroquine resistance. While Coartem failure is documented in Sub-Saharan Africa, the extent of true Coartem resistance and the impact on treatment of returning travelers is not clear.
We report the first case in the US, of treatment failure with the six-dose regimen of Coartem in a traveler from Kenya with P. falciparum malaria.
21-year old Kenyan exchange student with no history of malaria presented to the ER with fevers, night sweats, headache and generalized malaise which began 3 days after returning from Kenya. She had been living in the US for 3 years but returned to Kenya during the summer months. Initial peripheral blood smears were positive for P. falciparum with 3% parasitemia. She received six doses of Coartem and showed remarkable improvement within 3 days but returned to the ER in one month’s time with same symptoms as before. Peripheral blood smear was again positive for P. falciparum with 0.1% parasitemia, confirmed by the CDC laboratory. She had not returned to a malaria area. Considered a Coartem failure she was treated with Malarone (atovaquone/proguanil). Follow-up after malarone treatment was uneventful with no return of symptoms. Coartem has a cure rate of 97%. Non adherence and poor absorption are common patient factors leading to treatment failure though there was no evidence of this in our patient. Literature review revealed treatment failures associated with sub-optimal lumefantrine concentrations and presence of mutations in P. falciparum multidrug resistance protein-1 (Pfmdr1) coding gene resulting in altered parasite sensitivity to anti-malarial drugs, especially lumefantrine.
While the exact reason is not clear, our returning traveler from Kenya with P. falciparum malaria failed to cure her malaria despite appropriate treatment with Coartem. Failure of Coartem, as with any antimalarial, has to be of concern when initiating treatment for malaria in the returning traveler
A. M. Sharma,
W. Syed, None
N. Gnanabakthan, None
C. Orellana, None
N. Sharma, None
M. Polhemus, None