title: Accurate identification of the six human Plasmodium spp. causing imported malaria, including Plasmodium ovale wallikeri and Plasmodium knowlesi.
abstract: BACKGROUND
  Accurate identification of Plasmodium infections in non-endemic countries is of critical importance with regard to the administration of a targeted therapy having a positive impact on patient health and management and allowing the prevention of the risk of re-introduction of endemic malaria in such countries. Malaria is no longer endemic in Italy where it is the most commonly imported disease, with one of the highest rates of imported malaria among European non-endemic countries including France, the UK and Germany, and with a prevalence of 24.3% at the University Hospital of Parma. Molecular methods showed high sensitivity and specificity and changed the epidemiology of imported malaria in several non-endemic countries, highlighted a higher prevalence of Plasmodium ovale, Plasmodium vivax and Plasmodium malariae underestimated by microscopy and, not least, brought to light both the existence of two species of P. ovale (Plasmodium ovale curtisi and Plasmodium ovale wallikeri) and the infection in humans by Plasmodium knowlesi, otherwise not detectable by microscopy.
  
  
  METHODS
  In this retrospective study an evaluation of two real-time PCR assays able to identify P. ovale wallikeri, distinguishing it from P. ovale curtisi, and to detect P. knowlesi, respectively, was performed applying them on a subset of 398 blood samples belonging to patients with the clinical suspicion of malaria.
  
  
  RESULTS
  These assays revealed an excellent analytical sensitivity and no cross-reactivity versus other Plasmodium spp. infecting humans, suggesting their usefulness for an accurate and complete diagnosis of imported malaria. Among the 128 patients with malaria, eight P. ovale curtisi and four P. ovale wallikeri infections were detected, while no cases of P. knowlesi infection were observed.
  
  
  CONCLUSIONS
  Real-time PCR assays specific for P. ovale wallikeri and P. knowlesi were included in the panel currently used in the University Hospital of Parma for the diagnosis of imported malaria, accomplishing the goal of adhering to the recommendations of the World Health Organization to countries that are malaria-free to include the improvement of the early diagnosis of all cases of imported malaria.
authors.affiliation: Unit of Microbiology and Virology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Surgery, University of Parma, Viale A, Gramsci 14, Parma, Italy. adriana.calderaro@unipr.it.
authors.forename: Adriana
authors.initials: A
authors.lastname: Calderaro
authors.forename: Giovanna
authors.initials: G
authors.lastname: Piccolo
authors.forename: Chiara
authors.initials: C
authors.lastname: Gorrini
authors.forename: Sabina
authors.initials: S
authors.lastname: Rossi
authors.forename: Sara
authors.initials: S
authors.lastname: Montecchini
authors.forename: Maria Loretana
authors.initials: ML
authors.lastname: Dell'Anna
authors.forename: Flora
authors.initials: F
authors.lastname: De Conto
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Medici
authors.forename: Carlo
authors.initials: C
authors.lastname: Chezzi
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Arcangeletti
mesh_terms: D000328:Adult; D006801:Humans; D007558:Italy; D008288:Malaria / Q000175:diagnosis* / Q000469:parasitology*; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D010961:Plasmodium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012189:Retrospective Studies; D014195:Travel
references.citation: Duodecim. 2010;126(4):427-34
references.pmid: 20486493
references.citation: Lancet. 2004 Mar 27;363(9414):1017-24
references.pmid: 15051281
references.citation: Clin Microbiol Rev. 2013 Apr;26(2):165-84
references.pmid: 23554413
references.citation: Emerg Infect Dis. 2001 Nov-Dec;7(6):915-9
references.pmid: 11747716
references.citation: J Clin Microbiol. 2002 Nov;40(11):4343-5
references.pmid: 12409427
references.citation: Malar J. 2009 Jan 16;8:15
references.pmid: 19146706
references.citation: Malar J. 2013 Mar 27;12:113
references.pmid: 23537145
references.citation: Braz J Infect Dis. 2010 May-Jun;14(3):299-309
references.pmid: 20835518
references.citation: Int J Parasitol. 2009 Aug;39(10):1125-8
references.pmid: 19358848
references.citation: Methods Mol Med. 2002;72:189-203
references.pmid: 12125116
references.citation: Emerg Infect Dis. 2010 Jun;16(6):1033-4
references.pmid: 20507769
references.citation: Diagn Microbiol Infect Dis. 2008 Aug;61(4):434-9
references.pmid: 18501548
references.citation: PLoS One. 2012;7(10):e48033
references.pmid: 23110165
references.citation: J Clin Microbiol. 2007 May;45(5):1624-7
references.pmid: 17360843
references.citation: Emerg Infect Dis. 2008 May;14(5):811-3
references.pmid: 18439369
references.citation: Trends Parasitol. 2008 Sep;24(9):406-10
references.pmid: 18678527
references.citation: Malar J. 2010 Jul 27;9:219
references.pmid: 20663184
references.citation: Acta Trop. 2013 Feb;125(2):191-201
references.pmid: 23088834
references.citation: Malar J. 2010 Jan 11;9:10
references.pmid: 20064229
references.citation: Malar J. 2012 Sep 17;11:328
references.pmid: 22985344
references.citation: J Clin Microbiol. 2009 Dec;47(12):4173-5
references.pmid: 19812279
references.citation: J Infect Dis. 1992 Jul;166(1):145-8
references.pmid: 1607686
references.citation: J Clin Microbiol. 2004 Mar;42(3):1214-9
references.pmid: 15004078
references.citation: Emerg Infect Dis. 2009 Sep;15(9):1478-80
references.pmid: 19788819
references.citation: J Infect Dis. 2010 May 15;201(10):1544-50
references.pmid: 20380562
references.citation: Eur J Clin Microbiol Infect Dis. 2011 Apr;30(4):597-601
references.pmid: 21161559
references.citation: Malar J. 2013 May 24;12:169
references.pmid: 23706132
references.citation: Malar J. 2013 Jul 31;12:264
references.pmid: 23902626
references.citation: Emerg Infect Dis. 2011 Jul;17(7):1248-55
references.pmid: 21762579
references.citation: Malar J. 2010 Nov 30;9:344
references.pmid: 21114872
references.citation: Acta Biomed. 2006 Aug;77(2):75-80
references.pmid: 17172185