Genetic Evidence of Drug-Resistant Malarial Strain from the Democratic Republic of the Congo Imported to Guatemala - Volume 20, Number 6—June 2014 - Emerging Infectious Disease journal - CDC
Volume 20, Number 6—June 2014
Genetic Evidence of Drug-Resistant Malarial Strain from the Democratic Republic of the Congo Imported to Guatemala
Jaymin C. Patel , Steve M. Taylor, Patricia C. Juliao, Christian M. Parobek, Mark Janko, Luis Demetrio Gonzalez, Lucia Ortiz, Norma Padilla, Antoinette K. Tshefu, Michael Emch, Venkatachalam Udhayakumar, Kim Lindblade, and Steven R. Meshnick
Author affiliations: University of North Carolina, Chapel Hill, North Carolina, USA (J.C. Patel, S.M. Taylor, C.M. Parobek, M. Janko, M. Emch, S.R. Meshnick); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (P.C. Juliao, V. Udhayakumar, K. Lindblade); Military Medical Center, Guatemala City, Guatemala (L.D. Gonzalez); Universidad de Valle de Guatemala, Guatemala City (L. Ortiz, N. Padilla); University of Kinshasa, Kinshasa, Democratic Republic of the Congo (A.K. Tshefu)
Imported malaria threatens control and elimination efforts in countries that report low malaria transmission rates (1–3). In Central America, malaria transmission decreased by >50% during 2000–2010 (4); in 2010, the Guatemala Ministerio de Salud Pública y Asistencia Social reported 31 confirmed cases of malaria, all caused by the species Plasmodium falciparum (5). Central America is unusual compared with other areas in which malaria is endemic because chloroquine remains an effective treatment option for P. falciparum infection there, but not in other parts of the world (6–8); the introduction of parasites harboring chloroquine-resistant genotypes could fuel a resurgence of clinical illness and transmission.
In 2010, an outbreak of malaria was reported among 12 soldiers from Guatemala shortly after they returned from a United Nations (UN) peacekeeping mission in the Democratic Republic of the Congo (DRC). Of the 12, 8 also reported visiting >1 area in Guatemala in which malaria is endemic when they returned but before the outbreak was identified. An outbreak investigation was undertaken after 1 of the infected soldiers died; laboratory tests of blood from this patient identified choroquine-resistant and -sensitive strains of P. falciparum.
The epidemiologic evidence suggested that the soldiers were infected while stationed in the DRC (9). Because the local acquisition of chloroquine-resistant parasites in Guatemala could necessitate a change in local treatment practices, it was vital to determine the origin of the soldiers’ infections.
Molecular markers have been used to assess the genetic relatedness of malarial parasites from different geographic regions (10,11). Accordingly, if the soldiers acquired P. falciparum in the DRC during their stay, the genotypes of the parasites isolated from the soldiers’ samples would be more closely related to parasites from the DRC than to parasites from Guatemala. To test this hypothesis, we used molecular methods from the field of population genetics to determine the source of the malaria outbreak among the soldiers who returned to Guatemala after being stationed in the DRC.
We thank Silvia Sosa for help in obtaining samples from Guatemala. We also thank Fabiola Enriquez, Mario Roberto Perez Franco, Harold Garcia Sergio Fernando, Nitsch Montiel, and Mario Luis Ovalle Figuero for their help in obtaining samples from the soldiers.
This work was supported by a Gillings Innovation Laboratory award from the UNC Gillings School of Global Public Health and by grants from the National Institutes of Health (NIH) (NIAID 1R56AI097609-01) and National Science Foundation (NSF) (BSC-13339949).
- Figure 1. Location of the major cities, rivers, and the 7 Demographic Health Survey clusters (203, 81, 88, 183, 211, 164, and 29) within the Democratic Republic of the Congo (DRC)...
- Figure 2. Genetic relatedness (pairwise RST comparisons) among Plasmodium falciparumidentified in samples from the soldiers from Guatemala, persons in the Democratic Republic of the Congo, and persons in Guatemala.
- Figure 3. Neighbor-joining tree of 3 Plasmodium falciparum populationsPrefixes of genomes indicate parasite origins: Green text indicates parasite populations from the Democratic Republic of the Congo (DRC); orange indicates parasite populations...
- Figure 4. Phylogenetic tree showing predicted clustering between Plasmodium falciparumpopulations from the Democratic Republic of Congo (DRC), soldiers returning to Guatemala from the DRC, and GuatemalaThe predicted split between parasites...
- Table. Neutral microsatellite loci and primer sequences used for PCR amplification of Plasmodiumfalciparum malaria genes to identify origin of drug-resistant genotype, Guatemala
Suggested citation for this article: Patel JC, Taylor SM, Juliao PC, Parobek CM, Janko M, Gonzalez LD, et al. Genetic evidence of drug-resistant malarial strain from the Democratic Republic of the Congo imported to Guatemala. Emerg Infect Dis. 2014 Jun [date cited].http://dx.doi.org/10.3201/eid2006.131204