TY - JOUR AU - Labbé, Annie-Claude AU - Patel, Samir AU - Crandall, Ian AU - Kain, Kevin C. T1 - A Molecular Surveillance System for Global Patterns of Drug Resistance in Imported Malaria T2 - Emerging Infectious Disease journal PY - 2003 VL - 9 IS - 1 SP - 33 SN - 1080-6059 AB - Analysis of imported malaria in travelers may represent a novel surveillance system for drug-resistant malaria. We analyzed consecutive falciparum malaria isolates from Canadian travelers from 1994 to 2000, for polymorphisms in pfcrt, dhfr, and dhps linked to chloroquine and pyrimethamine/sulfadoxine resistance. Forty percent of isolates possessed the K76 pfcrt allele, suggesting that many imported falciparum infections are still responsive to chloroquine. Travelers who had recently taken chloroquine had a significantly increased risk of harboring isolates with pfcrt resistance alleles (odds ratio = 4.47; p=0.03). The presence of two or more mutations in dhfr or dhps was found in 64.8% (95% confidence interval [CI] 54.6 to 73.9) and in 30.4% (95% CI 21.7 to 40.3) of isolates, respectively, and increased significantly over the course of the study. These molecular markers indicate that pyrimethamine/sulfadoxine resistance is increasing and is now too high to rely on this drug as a routine therapeutic agent to treat malaria in travelers. KW - Malaria KW - drug-resistance KW - molecular surveillance KW - Plasmodium falciparum KW - PCR KW - travelers KW - research KW - Canada DO - 10.3201/eid0901.020121 UR - https://wwwnc.cdc.gov/eid/article/9/1/02-0121_article ER - End of Reference