Multi-Laboratory Evaluation of a Scrub Typhus Diagnostic Kit

Daryl J. KellyU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by Daryl J. Kelly in
Current site
Google Scholar
PubMed
Close
,
P. W. WongU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by P. W. Wong in
Current site
Google Scholar
PubMed
Close
,
Elsie GanU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by Elsie Gan in
Current site
Google Scholar
PubMed
Close
,
Chan Teik ChyeU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by Chan Teik Chye in
Current site
Google Scholar
PubMed
Close
,
David CowanU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by David Cowan in
Current site
Google Scholar
PubMed
Close
, and
George E. Lewis, JrU.S. Army Medical Research Unit, Institute for Medical Research, Walter Reed Army Institute of Research, Kuala Lumpur, Malaysia

Search for other papers by George E. Lewis, Jr in
Current site
Google Scholar
PubMed
Close
Restricted access

Scrub typhus is a major cause of febrile illness throughout the Asia-Pacific region. It is commonly undiagnosed, partly because of the lack of a simple, reliable diagnostic test which can be used in clinical laboratories. The indirect immunoperoxidase technique, configured into a test kit, was provided to technicians who were trained in its use. They used the kit during a 2 year field trial in their respective clinical hospital laboratories throughout Malaysia. In an evaluation using 1, 722 consecutive sera tested in those laboratories, the kit was found to have a median sensitivity for IgG detection of 0.85 (range 0.33–0.95), a median specificity of 0.94 (range 0.88–1.00), reproducibility of 0.86, and efficiency of 0.92 when compared to the reference laboratory. In a proficiency survey in which 10 laboratories received 3 coded test samples, all but 2 laboratories had results within 1 dilution of the reference laboratory in quantitating specific IgG, whereas 7 laboratories were within 1 dilution in quantitating IgM. The shelf life of the kit was at least 1 year at 4°C.

Save