Download A comprehensive HIV surveillance & disease control program

Combined Rapid and HIV RNA
Testing in a Public STD Clinic:
San Francisco, 2003-2006
Jeffrey D. Klausner, Susan Philip,
Katherine Ahrens, Giuliano Nieri,
Robert P. Kohn, Brian Louie,
Ernest Wong, Sally Liska
Session: Strategies for Targeted
Screening for Acute HIV Infection
Objectives:
• To describe how to combine POC Strategy #1
with Lab Strategy #4 (testing for Acute HIV
Infection).
• To present results from combined HIV Rapid
and RNA testing done at San Francisco’s
STD clinic (City Clinic) between November
2003 and December 2006.
Background
• STD clinic patients are at increased risk for
HIV infection, but may not return to receive
conventional testing results.
• Persons with acute HIV infection {HIV
antibody negative but detectable HIV
ribonucleic acid (RNA)} are at increased risk
of transmitting HIV because of high viral loads
and unknown infection status.
Background
•
Advances in HIV testing technology have
made available:
1. Rapid, point of care HIV Ab screening
2. Sensitive testing methods for HIV RNA;
allowing for identification and counseling of
patients with acute infection.
Methods
• All patients at risk of HIV infection are offered
confidential HIV testing (POC or Lab-based).
• Select high-risk patients (or high likelihood of
loss to follow up) are tested onsite (with
Oraquick Advance HIV-1/2)
• Target group identified as:
– unprotected anal sex,
– unprotected vaginal sex with HIV+ or unknown
partner with risk factors,
– concurrent STD
Methods
• Persons who are rapid test negative have
blood drawn for HIV RNA. Testing is
performed using Versant HIV-1 RNA 3.0
assay (Bayer Corp.) at the Public Health
Laboratory.
• A one-stage pooling of 10 serum specimens
is used, with results available within 10 days.
Rapid Test at clinic.
Draw Blood.
(by bDNA)
Methods
• Positive HIV RNA tests are confirmed by
follow-up antibody testing or viral load testing.
• We calculated the sensitivity and binomial
exact 95% confidence limits of the rapid HIV
test.
Results
Figure 1. Diagram of Rapid HIV Test Results, San Francisco
City Clinic, November 2003–December 2006, N=1092
RAPID HIV ANTIBODY TESTS
1092
POSITIVE
82
(7.5%)
NEGATIVE
1010
(92.5%)
HIV RNA TESTS
999
(98.9%)
POSITIVE
11
(1.1%)
NOT TESTED
FOR HIV RNA
11
(1.1%)
NEGATIVE
988
(98.9%)
Results
• Among the 1000 persons with rapid antibody
negative tests that were tested for RNA, 11
(1.1%) were RNA positive (figure 1). Of RNA
positives, 91% (10/11) were confirmed.
• HIV rapid testing had a sensitivity of 89.1%
(95% CI 82.7 - 95.5%) in terms of detecting
HIV infection.
Results
• All patients (100%), who received their positive RNA
result, were counseled and referred into care.
• Persons with newly identified HIV infection were
more likely to be a gay/bisexual man and to have an
STD diagnosis (genital, rectal or pharyngeal) at the
time of their HIV test than were HIV-negative
persons.
Results
Table 1. Rapid Testers Demographics and STD Infections at Time
of HIV Testing, San Francisco City Clinic, Nov. 2003–Dec. 2006,
N=1081
Total
Demographics
>30 years old
White
MSM or Transgender
STDs at Time of HIV Testing
Chlamydial infection
Gonococcal infection
Syphilis infection
Herpes Genital Ulcer
Disease
RNA
Positive
n (%)
11 (100)
Rapid
Positive
n (%)
82 (100)
Rapid/RNA
Negative
n (%)
988 (100)
All
N (%)
1081(100)
6 (55)
7 (64)
11 (100)
57 (70)
40 (49)
72 (88)
623 (63)
591 (60)
780 (79)
686 (63)
638 (59)
863 (80)
0 (0)
2 (18)
1 (9)
0 (0)
14 (17)
23 (28)
10 (12)
4 (5)
74 (7)
82 (8)
23 (2)
6 (1)
88 (8)
107 (10)
34 (3)
10 (1)
Results
Figure 2. Proportion of HIV Infections Detected by Each Test
Type Using a Rapid Antibody & RNA Testing Algorithm, San
Francisco City Clinic, Nov. 2003–Dec, 2006, N=92
HIV RNA+
RNA
12%
12%
88%
Rapid
Rapid
Ab+
Antibody
88%
• HIV RNA screening increased HIV case detection
by 12% (92/82).
Summary
1.
Acute HIV infection screening can be incorporated
successfully with rapid antibody testing with nearly
all (99%) patients agreeing to additional RNA
testing and blood draw.
2.
The combination of rapid HIV antibody testing and
HIV RNA screening assured that most infected
patients learned their test results immediately and
helped identify an additional 12% of those with HIV
infection.
3.
Patients with acute HIV infection were identified
and counseled while highly infectious, thereby
potentially averting transmission to their partners.
Implications
Wider use of combined rapid antibody
testing (Strategy #1) and RNA
screening (Strategy #4), particularly for
high risk individuals (e.g. STD clinic
settings), could contribute to the
reduction of HIV incidence and thus
transmission.
Acknowledgements
San Francisco Dept. of Public Health
• STD Prevention & Control
Andrew Reynolds
• PH Laboratory
Brian Louie
This project was supported
in part by the University of
California Universitywide AIDS
Research Program Grant
CH05-SMCHC-612.