The effect of viral suppression on cross-sectional incidence testing in the johns hopkins hospital emergency department.
OBJECTIVE
: To determine the effect of viral suppression on cross-sectional incidence testing.


METHODS
: In 2001 and 2003, patients entering the Johns Hopkins Hospital (JHH) Emergency Department (ED) were enrolled into an interview-based identity-unlinked serosurvey. All HIV-positive samples were tested by the Vironostika-less sensitive (LS) enzyme immunoassay (EIA) (Organon-Teknika, Charteston, SC) and an avidity assay to determine recent HIV infection. Additionally 16 samples from 8 previously characterized elite suppressors (ES) were tested by cross-sectional incidence assays.


RESULTS
: HIV prevalence was 12% for the 2001 survey and 11% for the 2003 survey. Of the HIV-infected subjects, 18% did not know they were infected. The Vironostika-LS EIA determined that 6% (11 of 183) and 7% (17 of 243) of HIV-positive individuals in 2001and 2003, respectively, were recently infected. Avidity testing confirmed that 6 of 11 in 2001 and 5 of 17 in 2003 were newly infected, leaving 17 discrepant samples. All 17 discrepant samples were Western blot-positive and viral load undetectable, and 7 of 17 had antiretroviral drugs (ARVs) in their serum. Ten individuals were virally suppressed without ARVs and seemed incident by the Vironostika-LS EIA but chronic by avidity testing. These 10 subjects had similar testing profiles to the known 16 ES samples, because 9 of 16 were incident by the Vironostika-LS EIA and 0 of 16 were incident by avidity testing.


CONCLUSIONS
: By removing the viral load-negative individuals and confirming the initial Vironostika-LS EIA results by avidity testing, the incidence estimate was lowered from 1.73% to 0.94% per year in 2001 and from 1.90% to 0.56% per year in 2003. Viral suppression affects the performance of the cross-sectional incidence tests, which rely on antibody titer. In addition, 2% (10 of 426) of all HIV-infected individuals who use the JHH ED for medical care seem to suppress HIV to undetectable levels without ARVs.
National Institute of Allergy and Infectious Diseases, National Institutes of Health, Baltimore, MD, USA. olaeyen1@jhmi.edu
Oliver
O
Laeyendecker
Richard E
RE
Rothman
Charlamaine
C
Henson
Bobbi Jo
BJ
Horne
Kerunne S
KS
Ketlogetswe
Chadd K
CK
Kraus
Judy
J
Shahan
Gabor D
GD
Kelen
Thomas C
TC
Quinn
D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000453:epidemiology*; D000465:Algorithms; D019380:Anti-HIV Agents / Q000627:therapeutic use; D004636:Emergency Service, Hospital; D015483:HIV Antibodies / Q000097:blood; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D007124:Immunoenzyme Techniques; D015994:Incidence
D019380:Anti-HIV Agents; D015483:HIV Antibodies