Detection of acute HIV infection: a field evaluation of the determine® HIV-1/2 Ag/Ab combo test.
BACKGROUND
Most human immunodeficiency virus (HIV) point-of-care tests detect antibodies (Ab) but not p24 antigen (Ag) or RNA. In the absence of antibodies, p24 antigen and RNA typically indicate acute HIV infection. We conducted a field evaluation of the Determine® HIV-1/2 Ag/Ab Combo rapid test (Combo RT).


METHODS
The antigen portion of the Combo RT (for acute HIV infection) was compared with a Roche Monitor HIV RNA polymerase chain reaction assay. The antibody portion of Combo RT (for established HIV infection) was compared with rapid test algorithms. Participants were enrolled at a sexually transmitted infection clinic and HIV testing and counseling center in Lilongwe, Malawi. Rapid testing was conducted with parallel testing in the clinic and serial testing in the center. The Combo RT was performed in clinic participants with negative or discordant antibody results and in all center participants.


RESULTS
Of the participants 838 were HIV negative, 163 had established HIV infection, and 8 had acute HIV infection. For detecting acute HIV infection, the antigen portion had a sensitivity of 0.000 and a specificity of 0.983. For detecting established HIV infection, the antibody portion had a sensitivity of 0.994 and a specificity of 0.992.


CONCLUSIONS
Combo RT displayed excellent performance for detecting established HIV infection and poor performance for detecting acute HIV infection. In this setting, Combo RT is no more useful than current algorithms.
Departments of Epidemiology, University of North Carolina, Chapel Hill 27599, USA. nora_rosenberg@unc.edu
Nora E
NE
Rosenberg
Gift
G
Kamanga
Sam
S
Phiri
Dominic
D
Nsona
Audrey
A
Pettifor
Sarah E
SE
Rutstein
Deborah
D
Kamwendo
Irving F
IF
Hoffman
Maria
M
Keating
Lillian B
LB
Brown
Beatrice
B
Ndalama
Susan A
SA
Fiscus
Seth
S
Congdon
Myron S
MS
Cohen
William C
WC
Miller
D000293:Adolescent; D000328:Adult; D000956:Antigens, Viral / Q000097:blood*; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008295:Malawi; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D055815:Young Adult
D000956:Antigens, Viral; D015483:HIV Antibodies