Failure of atovaquone-proguanil malaria chemoprophylaxis in a traveler to Ghana Andrea K. Boggild a,b,c, *, Rachel Lau c , Denis Reynaud d , Kevin C. Kain a,b,e , Marvin Gerson f a Tropical Disease Unit, Division of Infectious Diseases, University Health Network-Toronto General Hospital, Toronto, Canada b Department of Medicine, University of Toronto, Toronto, Canada c Public Health Ontario Laboratories, Public Health Ontario, Toronto, Canada d The Centre for the Study of Complex Childhood Diseases, Hospital for Sick Children, Toronto, Ontario, Canada e Sandra A. Rotman Laboratories, Sandra Rotman Centre for Global Health, University of Toronto, Canada f Humber River Hospital, North York, Canada Received 14 December 2014; received in revised form 18 December 2014; accepted 23 December 2014 KEYWORDS Drug resistance; Malabsorption; Malaria; Malarone; Plasmodium falciparum Summary Clinical failure of Malaroneä chemoprophylaxis is extremely rare. We report a case of Plasmodium falciparum malaria in a returned traveler to Ghana who fully adhered to atovaquone-proguanil (Malaroneä) chemoprophylaxis daily dosing, yet took the pills on an empty stomach. Screening of the P. falciparum isolate revealed triple codon mutation of Dhfr at positions 51, 59, and 108. Plasma drug levels of both atovaquone and proguanil re- vealed sub-therapeutic concentrations. ª 2014 Elsevier Ltd. All rights reserved. 1. Case report A 28-year-old woman returned from a one-month trip to urban Ghana for the purpose of visiting friends and relatives (VFR), and was well until 5-days post-travel, at which time she developed fever. Prior to travel, she sought pre-travel medical advice, and was prescribed Malaroneä for malaria chemoprophylaxis. She filled her prescription locally in Canada, and took her Malaroneä everyday until her pre- sentation to the emergency room, starting 1-day prior to travel, continuing each day during travel, and then taking her last dose within 24 h of admission to hospital. The pa- tient took her Malaroneä each morning approximately 60 min before breakfast with water. She was born in Ghana * Corresponding author. 200 Elizabeth Street, 13EN-218, Toronto, ON M5G 2C4, Canada. Tel.: þ1 (416) 340 4800x4681; fax: þ1 (416) 340 3260. E-mail address: andrea.boggild@utoronto.ca (A.K. Boggild). + MODEL Please cite this article in press as: Boggild AK, et al., Failure of atovaquone-proguanil malaria chemoprophylaxis in a traveler to Ghana, Travel Medicine and Infectious Disease (2015), http://dx.doi.org/10.1016/j.tmaid.2014.12.010 http://dx.doi.org/10.1016/j.tmaid.2014.12.010 1477-8939/ª 2014 Elsevier Ltd. All rights reserved. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevierhealth.com/journals/tmid Travel Medicine and Infectious Disease (2015) xx,1e5