Re-emergence of Plasmodium malariae in Costa Rica

Abstract In this paper we report the diagnosis of four cases of Plasmodium malariae in humans in Costa Rica, using parasitological and molecular techniques. Real-time PCR detected P. malariae in all four samples and established absence of other spp., whereas PlasmodiumP. malariae was identified microscopically only in three samples. Sequence analysis of these three samples confirmed the results and identified them as P. malariae/P. brasilianum . This represents the first report of P. malariae in Central America since 1959. Future investigations are needed to elucidate if P. malariae is re-emerging in Costa Rica or if it has always been present but unreported due to lack of specificity and difficulties of P. malariae diagnosis by microscopic technique. The nucleotide sequences of samples 1, 2 and 4 were deposited in GenBank (http://www.ncbi.nlm.nih.gov/genbank/) and received the accession numbers KJ934251, KJ934252 and KJ934253, respectively. Keywords: Plasmodium malariae , humans, Costa Rica, real-time PCR, sequencing