Diagnostic performance of rapid diagnostic tests versus blood smears for malaria in US clinical practice

William M. Stauffer, Charles P. Cartwright, Douglas A. Olson, Billie Anne Juni, Charlotte M. Taylor, Susan H. Bowers, Kevan L. Hanson, Jon E. Rosenblatt, David R. Boulware

Research output: Contribution to journalArticlepeer-review

88 Scopus citations

Abstract

Background. Approximately 4 million US travelers to developing countries are ill enough to seek health care, with 1500 malaria cases reported in the United States annually. The diagnosis of malaria is frequently delayed because of the time required to prepare malaria blood films and lack of technical expertise. An easy, reliable rapid diagnostic test (RDT) with high sensitivity and negative predictive value (NPV), particularly for Plasmodium falciparum, would be clinically useful. The objective of this study was to determine the diagnostic performance of a RDT approved by the US Food and Drug Administration compared with traditional thick and thin blood smears for malaria diagnosis. Methods. This prospective study tested 852 consecutive blood samples that underwent thick and thin smears and blinded malaria RDTs at 3 hospital laboratories during 2003-2006. Polymerase chain reaction verified positive test results and discordant results. Results. Malaria was noted in 95 (11%) of the 852 samples. The RDT had superior performance than the standard Giemsa thick blood smear (P = .003). The RDT's sensitivity for all malaria was 97% (92 of 95 samples), compared with 85% (81 of 95) for the blood smear, and the RDT had a superior NPV of 99.6%, compared with 98.2% for the blood smear (P = .001 ). The P falciparum performance was excellent, with 100% rapid test sensitivity, compared with only 88% (65 of 74) by blood smear (P = .003). Conclusions. This operational study demonstrates that the US Food and Drug Administration-approved RDT for malaria is superior to a single set of blood smears performed under routine US clinical laboratory conditions. The most valuable clinical role of the RDT is in the rapid diagnosis or the exclusion of P, falciparum malaria, which is particularly useful in outpatient settings when evaluating febrile travelers.

Original languageEnglish (US)
Pages (from-to)908-913
Number of pages6
JournalClinical Infectious Diseases
Volume49
Issue number6
DOIs
StatePublished - Sep 15 2009

Bibliographical note

Funding Information:
Financial support. W.M.S. and D.R.B. received support from the National Institute for Allergy and Infectious Disease (T32-AI055433, L30AI066779, and K12RR023247). Binax (Now, Inverness Medical Professional Diagnostics) supplied the NOW Malaria tests but no financial support. They were not involved in study design, data analysis, or manuscript preparation. Potential conflicts of interest. All authors: no conflicts.

Fingerprint

Dive into the research topics of 'Diagnostic performance of rapid diagnostic tests versus blood smears for malaria in US clinical practice'. Together they form a unique fingerprint.

Cite this