title: Use of an HRP2-based rapid diagnostic test to guide treatment of children admitted to hospital in a malaria-endemic area of north-east Tanzania.
abstract: OBJECTIVE
  To compare the performance of the Paracheck™ rapid diagnostic test (RDT) with microscopy for diagnosing malaria in hospitalised children.
  
  
  METHODS
  Children aged between 2 months and 13 years with fever were enrolled in the study over 1 year. A standard clinical history and examination were recorded and blood drawn for culture, complete blood count, Paracheck™ RDT and double-read blood slide.
  
  
  RESULTS
  Of 3639 children enrolled, 2195 (60.3%) were slide positive. The sensitivity and specificity of Paracheck were 97.5% (95% CI 96.9-98.0) and 65.3% (95% CI 63.8-66.9), respectively. There was an inverse relationship between age-specific prevalence of parasitaemia and Paracheck specificity. In logistic regression model, false-positive Paracheck results were significantly associated with pre-admission use of antimalarial drug (OR 1.44, 95% CI 1.16-1.78), absence of current fever (OR 0.64, 95% CI 0.52-0.79) and non-typhi Salmonella bacteraemia (OR 3.89. 95% CI 2.27-6.63). In spite of high sensitivity, 56/2195 (2.6%) of true infections were Paracheck negative and 8/56 (14.3%) were in patients with >50,000 parasites/μl.
  
  
  CONCLUSIONS
  Paracheck had poor specificity in diagnosing malaria in severely ill children; this was likely to be due to HRP2 persistence following recent parasite clearance. The combination of positive Paracheck and negative blood slide results identified a group of children at high risk of non-typhi Salmonella infection. While Paracheck was highly sensitive, some high-density infections were missed. For children with severe febrile illness, at least two reliable negative parasitological test results should be available to justify withholding antimalarial treatment; the optimal choice of these has yet to be identified.
authors.affiliation: National Institute for Medical Research, Amani Centre, Muheza, Tanzania. mtoveg2002@yahoo.co.uk
authors.forename: George
authors.initials: G
authors.lastname: Mtove
authors.forename: Behzad
authors.initials: B
authors.lastname: Nadjm
authors.forename: Ben
authors.initials: B
authors.lastname: Amos
authors.forename: Ilse C E
authors.initials: IC
authors.lastname: Hendriksen
authors.forename: Florida
authors.initials: F
authors.lastname: Muro
authors.forename: Hugh
authors.initials: H
authors.lastname: Reyburn
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D004812:Epidemiologic Methods; D005189:False Positive Reactions; D005260:Female; D005334:Fever / Q000469:parasitology; D006760:Hospitalization; D006767:Hospitals, District; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology / Q000302:isolation & purification; D015800:Protozoan Proteins / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D012423:Rural Health / Q000706:statistics & numerical data; D013636:Tanzania / Q000453:epidemiology
chemical_list: D000953:Antigens, Protozoan; C514457:HRP-2 antigen, Plasmodium falciparum; D015800:Protozoan Proteins; D011933:Reagent Kits, Diagnostic