acute hiv infection: new frontiers for hiv prevention antonio e. urbina, md medical director hiv...
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Acute HIV Infection: New Frontiers for HIV Prevention
Antonio E. Urbina, MDMedical Director HIV Education and Training
St. Vincent Catholic Medical Center-ManhattanMay 17, 2006
St. Vincent Catholic Medical Center is a
Local Performance Site of the NY/NJ AETC
Lifetime Cost of HIV Care in the US in the Current Treatment Era
$500,000
B R Schackman, et al Abstract, 3rd IAS Conference
HIV Incidence
Since 1999, HIV infections have remained steady at 40-45,000/year
CDC HIV/AIDS Surveillance Report
CDC HIV/AIDS Surveillance Report 2003
12% of US population
Prevention vs. Treatment
• Structure of US health system favors treatment over prevention
• Access to healthcare is tied to labor market and not citizenship
• Our for-profit health system favors treatment over prevention– More profits are generated when people are ill
as opposed to when they are well
Improve HIV Detection
• Normalize HIV Testing– outpatient and inpatient settings
• Increase detection of persons in acute HIV infection (AHI)
• Use pooled plasma viral load testing (PPLVT) in high risk settings, i.e. STD clinics
Leone P UNC
Primary HIV-1 InfectionAcute + Recent (4-6 months)
Time in YearsInfection
CD4Cells
1000
800
600
400
200
0
Early Opportunistic Infections
Late Opportunistic Infections
+
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Leone P UNC
Schacker, T. et. al. Ann Intern Med 1996;125:257-264
Days from sexual exposure to onset of symptoms in 12 patients who could identify the exact date and time of the sexual exposure that led to acquisition of
human immunodeficiency virus
Detection of HIV by Diagnostic Tests
0 1 2 3 4 5 6 7 8 9 10
Symptoms
p24 Antigen
HIV RNA
HIV EIA*
Western blot
Weeks Since Infection
*3rd generation, IgM-sensitive EIA
After Fiebig et al, AIDS 2003; 17(13):1871-9
*2nd generation EIA*viral lysate EIA
Acute HIV Infection(www.hivguidelines.org)
How effective are we at capturing AHI?
Acute HIV Infection (AHI)
• Nearly 60 million individuals diagnosed with HIV, fewer than 1,000 cases have been diagnosed in AHI [1]
– 1/60,000 detection rate
• In NYC, fewer than 20 cases of AHI have been diagnosed [2]
[1] Pilcher, et al AIDS 2004
[2] NYC DOH STARHS Program
Why so lax in diagnosing AHI?
• 1. Treatment and diagnosis of HIV infection has been relegated to specialists– Lack of education of how to diagnose AHI– Discomfort related to difficult issues
surrounding HIV
• 2. Clinicians inability to spend the additional time
Flanigan T, et al Annals of Int Med 2001
AHI
• 1% of patients with negative tests for EBV had AHI [1]
• 1% of patients with “any viral syndrome” in a Boston urgent care center had AHI [2]
• In a Malawi STD clinic, 2.8% of all male clients with acute STD had AHI [3]
[1] Rosenberg, et al N Engl J Med 1999
[2] Pincus, et al Clin Infect Dis 2003
[3] Pilcher, et al AIDS 2004
Schacker, T. et. al. Ann Intern Med 1996;125:257-264
Clinical Presentation of HIV Seroconversion*
How do you diagnose?
ICD-9 Code for AHI(exposure to HIV)
VO1.7
AHI and Hyperinfectiousness
• Growing evidence that persons in AHI are very infectious– High-titer viremia in plasma and genital fluids
[1,2]
– Absence of immune factors that may neutralize infectivity [2]
Kahn JO, et al N Engl J Med 1998
Quinn TC, et al N Engl J Med 2000
AHI and Sexual Risk Behavior
Colfax, G et al AIDS 2002
MSM seroconverters from HIVNet Vaccine Trial
Role of AHI in Secondary Transmissions
• Koopman [1] and Jacquez [2] used population modeling to argue that the spread of HIV from patients in AHI could contribute disproportionately to the epidemic– suggested that patients in AHI could be up to
1,000 x more infectious than those in chronic infection
Koopman JS, et al J Acquir Immune Defic Synd Hum Retrovirol 1997
Jacquez JA, et al J Acquir Immune Defic Syndr 1994
012345678
3002001000
log
10
HIV
RN
A
Days from Infection
Blood viral load in acute HIV (n=171) Average fitted curve, with 95% confidence intervals
Peak: day 23Pilcher, et al JID 2004
8-10 fold increase risk from peak to day 54
1009080706050403020100
7
6
5
4
3
2
1
0
log
10
HIV
RN
A
Days from Infection
Semen viral load in acute HIV (n=30)
Pilcher, et al JID 2004
Rates of HIV-1 Transmission per Coital Act, by Stage of HIV-1 Infection, in Rakai, Uganda
• Retrospectively identified 235 monogamous, HIV-discordant couples in Ugandan population-based cohort from 1994-1999
• Estimated rates of HIV transmission per coital act in HIV discordant couples by stage of infection in the index partner– Recent seroconversion vs. chronic vs. late stage
– HIV transmission within pairs was confirmed by sequence analysis
Wawer, et al JID, 2005
Wawer, et al JID, 2005
Transmission Of HIV During AHI: Relationship To Sexual Risk And STI
• 103 individuals with AHI were followed from 1999-2003
• Viruses from 34% were related• Significant associations with clustering were:
– Young age– High CD4 count– Number of sexual partners– UAI– STIs
Pao P et al AIDS 2005
“Acute Case”
“Efficient disseminator”
Clustering: efficient dissemination by core groups and identification of
networks
Identification via PHI
Identification of network
Why isn’t individual viral load testing incorporated into HIV Testing?
• Direct HIV detection methods (RNA testing) are expensive—5 to10 x more than Ab tests
– Cost range from $60-$290
• Decreased specificity– False positives– Typically viral loads <5000 are FP
• Pooling specimens improves specificity and greatly reduces cost
Individual specimens
Pools of 10
Pooling schema
A B C D E
Pooling schema
A B C D E
Individual specimens
N=100
Pools of 10
F G H I J K
F G H I J K
Master pool
Pooling schema
Individual specimens
N=100
Pools of 10
A B C D E
A B C D E
F G H I J K
F G H I J K
A
Individual testing on 10 specimens
Pools of 10 screened
Master pools screened
Resolution Testing
A B C D E
Detection of AHI during HIV Testing in North Carolina
• 12 month observational study to evaluate this strategy for HIV testing at 110 publicly funded sites in NC
• Primary objective was to compare the performance and yield of standard AB testing with algorithm that included both standard AB testing and PPVLT
Pilcher, et al NEngl J Med 2005
Performance of Algorithm
• Sensitivity for standard AB testing (sAb) was 0.962
• Use of PPLVT increased rate of HIV case identification by 3.9% over that sAB
• Specificity and positive predictive value (PPV) of combined testing (Ab + PPVLT) with pooling was 0.999 and 0.997
6% in AHI
Interventions Targeting Acute Infection
• All subjects (n=23) with AHI were notified (within 72 hours after test results)– No adverse events were reported (e.g.,
psychological trauma, violence against or from partners, etc)
– 21/23 subjects with AHI began specialty medical care, including 1 pregnant woman who received ARVS (baby was negative)
Pilcher, et al NEngl J Med 2005
Interventions Targeting Acute Infection
• 48 sexual partners of subjects with AHI received counseling for risk reduction– 18 of these (38%) had HIV infection
• 13 (27%) previously recognized• 5 (10 %) newly diagnosed
• 11 were probably the source of the AHI– 10 were aware of their status, but only 3 disclosed to
partners– 3 of possible transmitters had been named in
surveillance records as potential source of infection in 3 other cases suggesting roles as “core transmitters”
Pilcher, et al NEngl J Med 2005
Social Networks and Risk Association
• Designated case managers collected data on social networks of acutely infected subjects
• 4 were college students; 2 in one town were identified within 1 month of each other– Revealed a new HIV outbreak among young
black MSMs in these colleges
Pilcher, et al NEngl J Med 2005
Costs
• PPLVT added an additional $3.63 per specimen and $17,515 per additional index case identified
• Added only 3.3% increase over annual budget
Pilcher, et al NEngl J Med 2005
Thanks
• Frederick Siegal, MD
• Barbara Johnston, MD
• Paul Galatowitsch, PhD
• All staff at the HIV Center
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