Charles Darwin University

CDU eSpace
Institutional Repository

CDU Staff and Student only

Evaluation of a rapid dipstick (Crystal VC) for the diagnosis of cholera in Zanzibar and a comparison with previous studies

Ley, Benedikt, Khatib, Ahmed, Thriemer, Kamala, von Seidlein, Lorenz, Deen, Jacqueline L., Mukhopadyay, Asish, Chang, Na Yoon, Hashim, R., Schmied, Wolfgang, Busch, Clara, Reyburn, Rita, Wierzba, Thomas, Clemens, John D., Wilfing, Harald, Enwere, Godwin, Aguado, Theresa, Jiddawi, Mohamed Saleh, Sack, David and Ali, Said Mohammed (2012). Evaluation of a rapid dipstick (Crystal VC) for the diagnosis of cholera in Zanzibar and a comparison with previous studies. PLoS One,7(5):e36930.

Document type: Journal Article
Citation counts:
Google Scholar Search Google Scholar
Attached Files (Some files may be inaccessible until you login with your CDU eSpace credentials)
Name Description MIMEType Size Downloads
Download this reading vonSeidlein_38325.pdf Published version application/pdf 244.26KB 253
Reading the attached file works best in Firefox, Chrome and IE 9 or later.

IRMA ID bsmithxPUB66
Title Evaluation of a rapid dipstick (Crystal VC) for the diagnosis of cholera in Zanzibar and a comparison with previous studies
Author Ley, Benedikt
Khatib, Ahmed
Thriemer, Kamala
von Seidlein, Lorenz
Deen, Jacqueline L.
Mukhopadyay, Asish
Chang, Na Yoon
Hashim, R.
Schmied, Wolfgang
Busch, Clara
Reyburn, Rita
Wierzba, Thomas
Clemens, John D.
Wilfing, Harald
Enwere, Godwin
Aguado, Theresa
Jiddawi, Mohamed Saleh
Sack, David
Ali, Said Mohammed
Journal Name PLoS One
Publication Date 2012
Volume Number 7
Issue Number 5
ISSN 1932-6203   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-84861475502
Start Page e36930
Total Pages 8
Place of Publication United States
Publisher Public Library of Science
HERDC Category C1 - Journal Article (DIISR)
Abstract Background
The gold standard for the diagnosis of cholera is stool culture, but this requires laboratory facilities and takes at least 24 hours. A rapid diagnostic test (RDT) that can be used by minimally trained staff at treatment centers could potentially improve the reporting and management of cholera outbreaks.

We evaluated the Crystal VC™ RDT under field conditions in Zanzibar in 2009. Patients presenting to treatment centers with watery diarrhea provided a stool sample for rapid diagnostic testing. Results were compared to stool culture performed in a reference laboratory. We assessed the overall performance of the RDT and evaluated whether previous intake of antibiotics, intravenous fluids, location of testing, and skill level of the technician affected the RDT results.

We included stool samples from 624 patients. Compared to culture, the overall sensitivity of the RDT was 93.1% (95%CI: 88.7 to 96.2%), specificity was 49.2% (95%CI: 44.3 to 54.1%), the positive predictive value was 47.0% (95%CI: 42.1 to 52.0%) and the negative predictive value was 93.6% (95%CI: 89.6 to 96.5%). The overall false positivity rate was 50.8% (213/419); fieldworkers frequently misread very faint test lines as positive.

The observed sensitivity of the Crystal VC RDT evaluated was similar compared to earlier versions, while specificity was poorer. The current version of the RDT could potentially be used as a screening tool in the field. Because of the high proportion of false positive results when field workers test stool specimens, positive results will need to be confirmed with stool culture.
DOI   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)

© copyright

Every reasonable effort has been made to ensure that permission has been obtained for items included in CDU eSpace. If you believe that your rights have been infringed by this repository, please contact

Version Filter Type
Access Statistics: 209 Abstract Views, 253 File Downloads  -  Detailed Statistics
Created: Fri, 17 Jan 2014, 01:28:00 CST