title: Investigating portable fluorescent microscopy (CyScope) as an alternative rapid diagnostic test for malaria in children and women of child-bearing age.
abstract: BACKGROUND
  Prompt and correct diagnosis of malaria is crucial for accurate epidemiological assessment and better case management, and while the gold standard of light microscopy is often available, it requires both expertise and time. Portable fluorescent microscopy using the CyScope offers a potentially quicker, easier and more field-applicable alternative. This article reports on the strengths, limitations of this methodology and its diagnostic performance in cross-sectional surveys on young children and women of child-bearing age.
  
  
  METHODS
  552 adults (99% women of child-bearing age) and 980 children (99% ≤ 5 years of age) from rural and peri-urban regions of Ugandan were examined for malaria using light microscopy (Giemsa-stain), a lateral-flow test (Paracheck-Pf) and the CyScope. Results from the surveys were used to calculate diagnostic performance (sensitivity and specificity) as well as to perform a receiver operating characteristics (ROC) analyses, using light microscopy as the gold-standard.
  
  
  RESULTS
  Fluorescent microscopy (qualitative reads) showed reduced specificity (<40%), resulting in higher community prevalence levels than those reported by light microscopy, particularly in adults (+180% in adults and +20% in children). Diagnostic sensitivity was 92.1% in adults and 86.7% in children, with an area under the ROC curve of 0.63. Importantly, optimum performance was achieved for higher parasitaemia (>400 parasites/μL blood): sensitivity of 64.2% and specificity of 86.0%. Overall, the diagnostic performance of the CyScope was found inferior to that of Paracheck-Pf.
  
  
  CONCLUSIONS
  Fluorescent microscopy using the CyScope is certainly a field-applicable and relatively affordable solution for malaria diagnoses especially in areas where electrical supplies may be lacking. While it is unlikely to miss higher parasitaemia, its application in cross-sectional community-based studies leads to many false positives (i.e. small fluorescent bodies of presently unknown origin mistaken as malaria parasites). Without recourse to other technologies, arbitration of these false positives is presently equivocal, which could ultimately lead to over-treatment; something that should be further explored in future investigations if the CyScope is to be more widely implemented.
authors.affiliation: WHO Collaborating Centre Schistosomiasis, Wolfson Wellcome Biomedical Laboratories, Department of Zoology, Natural History Museum, London SW7 5BD, UK. j.figueiredo@nhm.ac.uk
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Sousa-Figueiredo
authors.forename: David
authors.initials: D
authors.lastname: Oguttu
authors.forename: Moses
authors.initials: M
authors.lastname: Adriko
authors.forename: Fred
authors.initials: F
authors.lastname: Besigye
authors.forename: Andrina
authors.initials: A
authors.lastname: Nankasi
authors.forename: Moses
authors.initials: M
authors.lastname: Arinaitwe
authors.forename: Annet
authors.initials: A
authors.lastname: Namukuta
authors.forename: Martha
authors.initials: M
authors.lastname: Betson
authors.forename: Narcis B
authors.initials: NB
authors.lastname: Kabatereine
authors.forename: J Russell
authors.initials: JR
authors.lastname: Stothard
mesh_terms: D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008288:Malaria / Q000175:diagnosis*; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods*; D008875:Middle Aged; D010274:Parasitology / Q000379:methods*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012424:Rural Population; D013997:Time Factors; D014454:Uganda; D055815:Young Adult
references.citation: Lancet. 1986 Feb 8;1(8476):307-10
references.pmid: 2868172
references.citation: Bull World Health Organ. 1967;37(2):330-1
references.pmid: 4866450
references.citation: Scand J Clin Lab Invest. 2008;68(1):77-80
references.pmid: 18224558
references.citation: Am J Trop Med Hyg. 2006 Aug;75(2):219-25
references.pmid: 16896122
references.citation: BMJ. 1999 May 15;318(7194):1322-3
references.pmid: 10323817
references.citation: Trans R Soc Trop Med Hyg. 2008 Nov;102(11):1064-6
references.pmid: 18586290
references.citation: Lancet. 2004 Nov 20-26;364(9448):1896-8
references.pmid: 15555670
references.citation: Trop Med Int Health. 2001 Jul;6(7):505-10
references.pmid: 11469942
references.citation: Am J Trop Med Hyg. 1963 May;12:296-7
references.pmid: 14044737
references.citation: Biometrics. 1988 Sep;44(3):837-45
references.pmid: 3203132
references.citation: Bull World Health Organ. 1967;37(4):665-8
references.pmid: 5301742
references.citation: J Infect Dis. 2006 Apr 1;193(7):978-86
references.pmid: 16518760
references.citation: Clin Chem. 1993 Apr;39(4):561-77
references.pmid: 8472349
references.citation: Malar J. 2010 Mar 31;9:88
references.pmid: 20356369
references.citation: Malar J. 2007 Jul 06;6:89
references.pmid: 17617912