title: Molecular diagnosis and species identification of imported malaria in returning travellers in Italy.
abstract: A new seminested polymerase chain reaction (sn-PCR)-based protocol was developed and used to detect and identify Plasmodium species in 1226 whole-blood samples from patients (872 Italians and 354 foreigners) with at least 1 symptom compatible with clinical malaria. The results were compared with those obtained by microscopy: 187 samples were positive by microscopy for malaria parasites and 196 were positive by sn-PCR. When compared to microscopy, the sn-PCR detected different malaria parasite species in 11 cases. In 4 of 11 cases, the sn-PCR identified 1 additional malaria parasite species not observed microscopically, suggesting increased sensitivity. In 4 samples with levels of parasitemia too low for accurate identification of species by microscopy, the sn-PCR detected 2 P. falciparum, 1 P. ovale, and 1 P. falciparum plus P. ovale. Moreover, 9 negative samples by microscopy were positive by sn-PCR. Follow-up analysis demonstrated a parasite clearance of P. falciparum DNA up to 3 days after the disappearance of parasitemia at microscopy. In conclusion, sn-PCR-based diagnosis of malaria appears to be a useful tool when the results of conventional techniques are negative in the presence of a syndrome consistent with malaria, yielding accurate species identification and consequential correct treatment.
authors.affiliation: National Institute for Infectious Diseases IRCCS Lazzaro Spallanzani, Via Portuense 292, 00149 Rome, Italy. pagliamicromol@inmi.it
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Paglia
authors.forename: Francesco
authors.initials: F
authors.lastname: Vairo
authors.forename: Nazario
authors.initials: N
authors.lastname: Bevilacqua
authors.forename: Piero
authors.initials: P
authors.lastname: Ghirga
authors.forename: Pasquale
authors.initials: P
authors.lastname: Narciso
authors.forename: Carlo
authors.initials: C
authors.lastname: Severini
authors.forename: Emanuele
authors.initials: E
authors.lastname: Nicastri
mesh_terms: D000328:Adult; D000349:Africa / Q000453:epidemiology; D001208:Asia / Q000453:epidemiology; D016054:DNA, Protozoan / Q000145:classification / Q000235:genetics; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007843:Latin America / Q000453:epidemiology; D008288:Malaria / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology*; D008297:Male; D008875:Middle Aged; D010961:Plasmodium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013997:Time Factors; D014195:Travel
chemical_list: D016054:DNA, Protozoan