Performance of the CareStart^TM G6PD Deficiency Screening Test, a Point-of-Care Diagnostic for Primaquine Therapy Screening

Authors

Saorin Kim, Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
Chea Nguon, National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
Bertrand Guillard, Medical Laboratory, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
Socheat Duong, National Center for Parasitology, Entomology, and Malaria Control, Phnom Penh, Cambodia
Sophy Chy, Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
Sarorn Sum, Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
Sina Nhem, Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
Christiane Bouchier, Genomic Platform, Institut Pasteur, Paris, France
Magali Tichit, Genomic Platform, Institut Pasteur, Paris, France
Eva Christophel, WHO Regional Office for the Western Pacific, Manilla, Philippines
Walter R.J. Taylor, Service de Me´decine Internationale et Humanitaire, Hopitaux Universitaires de Geneve, Geneva, Switzerland
J. Kevin Baird, ALERTAsia FoundationFollow
Didier Menard, Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia

Date of this Version

2011

Citation

Kim S, Nguon C, Guillard B, Duong S, Chy S, et al. (2011) Performance of the CareStartTM G6PD Deficiency Screening Test, a Point-of-Care Diagnostic for Primaquine Therapy Screening. PLoS ONE 6(12): e28357.

Comments

Copyright 2011 Kim et al.

Abstract

Development of reliable, easy-to-use, rapid diagnostic tests (RDTs) to detect glucose-6-phosphate dehydrogenase (G6PD) deficiency at point of care is essential to deploying primaquine therapies as part of malaria elimination strategies. We assessed a kit under research and development called CareStart^TM G6PD deficiency screening test (Access Bio, New Jersey, USA) by comparing its performance to quantitative G6PD enzyme activity using a standardized spectrophotometric method (‘gold standard’). Blood samples (n = 903) were collected from Cambodian adults living in Pailin province, western Cambodia. G6PD enzyme activities ranged from 0 to 20.5 U/g Hb (median 12.0 U/g Hg). Based on a normal haemoglobin concentration and wild-type G6PD gene, the normal values of G6PD enzymatic activity for this population was 3.6 to 20.5 U/ g Hg (95th percentiles from 5.5 to 17.2 U/g Hg). Ninety-seven subjects (10.7%) had ,3.6 U/g Hg and were classified as G6PD deficient. Prevalence of deficiency was 15.0% (64/425) among men and 6.9% (33/478) among women. Genotype was analyzed in 66 G6PD-deficient subjects and 63 of these exhibited findings consistent with Viangchang genotype. The sensitivity and specificity of the CareStart^TM G6PD deficiency screening test was 0.68 and 1.0, respectively. Its detection threshold was <2.7 U/g Hg, well within the range of moderate and severe enzyme deficiencies. Thirteen subjects (1.4%, 12 males and 1 female) with G6PD enzyme activities <2U/g Hg were falsely classified as ‘‘normal’’ by RDT. This experimental RDT test here evaluated outside of the laboratory for the first time shows real promise, but safe application of it will require lower rates of falsely ‘‘normal’’ results.