Evaluation of the Ultrasensitive Human Immunodeficiency Virus Type 1 (HIV-1) p24 Antigen Assay Performed on Dried Blood Spots for Diagnosis of HIV-1 Infection in Infants

DOI: 10.1128/CVI.00265-07

Article Figures & Data

TABLE 1.

Performance of the p24 Ag assay on all DBS after short- and long-term storage

Assay^a	No. of children		% Sensitivity^e	% Specificity^e	% Prevalence	LR
Assay^a	Total	With false-negative results	% Sensitivity^e	% Specificity^e	% Prevalence	Positive	Negative
First
Grade 1 paper
Without desiccant	124^b^,^c	2	96.5 (87.4, 99.7)	100 (93.7, 100)	44.4	∞	0.0351
With desiccant	121^d	2	96.6 (87.6, 99.7)	100 (93.3, 100)	46.3	∞	0.0345
903 card
Without desiccant	125^b	2	96.6 (87.6, 99.7)	100 (93.7, 100)	44.8	∞	0.0345
With desiccant	121^d	1	98.3 (89.3, 99.9)	100 (93.3, 100)	46.3	∞	0.0175
Second
Grade 1 paper
Without desiccant	124^b^,^c	3	94.8 (85.3, 98.8)	100 (93.7, 100)	44.4	∞	0.0517
With desiccant	121^d	7	88.9 (78.8, 94.8)	100 (93.3, 100)	46.3	∞	0.1111
903 card							0.082
Without desiccant	125^b	5	91.8 (81.8, 96.8)	100 (93.7, 100)	44.8	∞
With desiccant	121^d	1	98.3 (89.8, 99.9)	100 (93.3, 100)	46.3	∞	0.0175

↵ a The first assay was performed within 6 weeks of sample collection, and the second assay was performed 6 weeks after the first.
↵ b DBS from the first 125 children enrolled.
↵ c No DBS on grade 1 paper from one child.
↵ d DBS from the last 121 children enrolled.
↵ e Values in parentheses are 95% confidence intervals.

TABLE 2.

Performance of the first p24 assay on DBS from 6-week-old infants and from children between 6 weeks and 6 years of age

↵ a False-negative p24 result on DBS on both filter paper types from the same child.
↵ b False-negative result on DBS on 903 card but not on grade 1 paper from the same child.
↵ c False-negative result on DBS on grade 1 paper but not on 903 card from the same child.
↵ d Values in parentheses are 95% confidence intervals.