Acute HIV Infection: New Strategies for Detection Pragna Patel MD MPH Centers for Disease Control and Prevention Division of HIV/AIDS Prevention Behavioral and Clinical Surveillance Branch December 5, 2007

Acute HIV Infection HIV viral replication and shedding occurs before detectable antibody appears Viremia peaks in blood and genital fluid Contributes to the spread of HIV because individuals are: unaware of infection highly infectious Important opportunity for HIV prevention Diagnosis is challenging and requires modification of standard algorithms Studies have used pooled nucleic acid amplification testing (NAAT) to identify AHI Yield of screening for acute HIV infection may vary with different enzyme immunoassays (EIA) used to screen for HIV antibody

HIV markers during Acute HIV Infection HIV RNA (plasma) HIV Antibody 11 10 20 30 40 50 60 70 80 90 100 HIV p24 Ag 16 22 1st generation EIA 2nd generation EIA Days since infection 3rd generation EIA

AHI Study: Primary Objectives Assess feasibility and cost-effectiveness of pooled NAAT* relative to 3rd generation HIV antibody screening assays and rapid tests Evaluate effect of pool size on sensitivity and cost-effectiveness of pooled NAAT Identify HIV infections that would otherwise be missed by current testing Calculate NAAT sensitivity and specificity *NAAT = nucleic acid amplification testing for HIV-1 RNA

AHI Study: Secondary Objectives Describe AHI epidemiology & transmission risks Describe antiretroviral resistance in persons with AHI Estimate number of transmissions averted through diagnosis & subsequent risk reduction Describe outcomes of partner notification of persons with AHI Identify AHI transmission clusters using molecular testing and phylogenetic analyses Estimate entry into care and treatment outcomes

Methods: Study Components Add NAAT (Aptima®) to routine HIV screening Component 2: Study persons with AHI Baseline and 3 month follow-up surveys Specimen collection for gene sequencing Collection of partner counseling and referral services outcomes Component 3: Evaluate the performance of NAAT – follow-up EIA-RR and NAAT negative Specimen collection for further testing BioRad Genetic System HIV 1/2+O, Abbott, Western blot Roche Amplicor, Roche DNA PCR, Aptima Baseline, 3 and 6 month follow-up surveys

Methods: Project Areas Los Angeles Department of Health Services New York State Department of Health Wadsworth Center, Diagnostic HIV Laboratory 14 sexually transmitted disease clinics and one community center Vironostika HIV-1 Microelisa System (less sensitive EIA) Florida Department of Health Florida Bureau of Laboratories 80 public health clinics in 4 counties – Duval, Orange, Hillsborough, Pinellas BioRad Genetic Systems HIV-1/2 plus O (more sensitive EIA) New York City Department of Health and Mental Hygiene New York State Department of Health Wadsworth Center, Diagnostic HIV Laboratory 3 sexually transmitted disease clinics – Fort Greene, Morrisania, Chelsea Oraquick Advance Rapid HIV 1/2 (oral fluid) implemented separate consent/counseling for AHI screening

Methods: Testing Algorithm Screening EIA Negative Pooled NAAT Positive HIV-1 Western Blot Negative Indeterminate or indeterminate Pool Negative HIV negative Pool Positive Individual NAAT Positive HIV positive Individual NAAT Repeatedly Negative Repeatedly Positive Check VL presumptive AHI Negative HIV negative

Methods: pooling procedure 1-Stage Pooling 16 Individual Specimens A B C D E F G H I J K L M N O P 1 Master Pool

Acute HIV Infection Screening Results May 1, 2006 to October 31, 2007 Population # tested HIV Ab+ HIV% AHI+  HIV case LA* 30,289 354 1.2 28 8.0% Florida† 45,288 561 11 2.1% NYC STD‡ 3,624 15 0.4 4 26.7% * Results using Vironostika HIV-1 Microelisa System † Results using Bio-Rad Genetic Systems HIV 1/2 + O ‡ Results using Oraquick Advance Rapid HIV 1/2 (oral fluid) – data from June 4, 2007 to October 31, 2007

Acute HIV Infection Screening Results May 1, 2006 to October 31, 2007 Test Result Florida† Los Angeles* New York City‡ Presumptive AHIs 11 28 4 EIA-neg/ NAAT-pos 6 EIA-RR/WB-neg/NAAT-pos 2 EIA-RR/WB-ind/NAAT-pos 3 * Results using Vironostika HIV-1 Microelisa System † Results using Bio-Rad Genetic Systems HIV 1/2 + O ‡ Results using Oraquick Advance Rapid HIV 1/2 (oral fluid) – data from June 4, 2007 to October 31, 2007

HIV case detection in LA and NYC using BioRad Genetic Systems 1/2 + O Tested all acute specimens from LA and NYC using BioRad Genetic Systems 1/2 + O Los Angeles (n=28) 12 detected and 16 undetected Yield of AHI screening would decrease from 8.0% to 4.4% New York City (n=4) 3 detected and 1 undetected Yield of AHI screening would decrease from 26.7% to 5.5% Yield of AHI screening higher in LA and NYC compared to FL (2.1%)

Epidemiology of Acute HIV Infection Overall (n=43) White (40%), Homosexual (48%), Male (95%) Median age = 30 years old (range 19-56) Florida (n=11) African American (64%), Male (82%) Heterosexual (50%) Median age = 39 years old (range 19-56) Los Angeles (n=28) White (40%) and Hispanic (46%), Male (100%) Homosexual (54%) Median age = 29 years (range 18-50) New York City (n=4) White (50%) and Hispanic (50%), Male (100%) Homosexual (75%) Median age = 26.5 years old (range 23-29)

Partner Notification and Testing Total number of partners named = 50 2 pregnant women Total number of partners tested = 17 5 tested HIV positive Both pregnant women tested HIV negative

Aptima® Performance Characteristics† Individual Specimens Florida Los Angeles TP = 538 FP = 3 FN = 1 TN = 44696* TP = 374 FP = 1 FN = 2 TN = 29608* Sensitivity = 538/539 = 99.81% Specificity = 44696/44699 = 99.99% PVP = 538/541 = 99.45% Sensitivity = 374/376 = 99.47% Specificity = 29608/29609 = 99.99% PVP = 374/375 = 99.73% Given successful validation of pooling scheme, we assume that a negative pool constitutes 16 negative specimens † Gold Standard = Western blot ‡ TP = true positive, FP = false positive, TN = true negative, FN = false negative

Aptima® Performance Characteristics† Pools Florida Los Angeles TP = 5 FP = 0 FN = 0 TN = 2483 TP = 22 FP = 1 FN = 0 TN = 1668 Sensitivity = 5/5 = 100% Specificity = 2483/2483 = 100% PVP = 5/5 = 100% Sensitivity = 22/22 = 100% Specificity = 1668/1669 = 99.94% PVP = 22/23 = 95.65% Given successful validation of pooling scheme, we assume that a negative pool constitutes 16 negative specimens † Gold Standard = Western blot ‡ TP = true positive, FP = false positive, TN = true negative, FN = false negative

Cost Analysis* May 1, 2006 to August 31,2007 Florida† Los Angeles* New York City‡ Total program costs $229,932 $186,509 $25,692 Cost per specimen tested $5.77 $7.96 $11.35 Cost per AHI (n) $45,986 (5) $8,478 (22) $12,846 (2) Cost per AHI notified within 14 days (n) $114,966 (2) $18,651 (10) * Results using Vironostika HIV-1 Microelisa System † Results using Bio-Rad Genetic Systems HIV 1/2 + O ‡ Results using Oraquick Advance Rapid HIV 1/2 (oral fluid) – data from June 4, 2007 to August 31, 2007 *A. Hutchinson et al. A Micro-costing study of Acute HIV Infection screening in Florida, Los Angeles and New York City, 2006-2007. (Poster # 59)

Conclusions Pooled NAAT in addition to 3rd generation and rapid EIA screening increases HIV case detection Routine pooling will be most successful with timely notification of results Aptima® performed well on pooled specimens from routine testing populations AHI screening using pooled NAAT can be implemented at a cost similar to other HIV screening programs

Acknowledgements CDC Duncan Mackellar Patrick Sullivan Steven Ethridge Steven McDougal Michele Owen Walid Heneine Clyde Hart Angela Hutchinson Stephanie Sansom Paul Farnham Florida BOL Berry Bennett Florida DOH Marlene LaLota Pat Simmons Dan George Melinda Waters Dan Pope Robert Chen Stacy Shiver Los Angeles DHS STD Peter Kerndt Apurva Uniyal Ali Stirland Michael Chen Stacei Morita LaShawnda Royal Kai-Jen Chang NYS Wadsworth Lab Monica Parker Tim Sullivan Kathy Gombel NYC DOHMH Kate Gallagher Alexis Kowalski Steven Rubin Susan Blank

Epidemiology of Acute HIV Infection Characteristics Florida n=11 Los Angeles n=28 New York City n=4 Total n=43 Median age (years) 39 29 26.5 30 Gender Male 82 100 95 Female 18 5 Race (%) * White 36 40 50 Black 64 14 23 Hispanic 46 35 Sexual Orientation (%) Bisexual 33 Heterosexual 7 25 19 Homosexual 20 54 75 48 Viral Load >500K 55 Let’s look at the epidemiology of acute HIV infection in this study. Here we have basic characteristics of persons with acute HIV infection. You can see that overall (in the last column) their median age was 30 years old (range, 19-56) and that they were predominately male (95%), white (40%), and homosexual (48%). As you can see, the majority of African Americans, heterosexuals and females with acute HIV were identified in Florida. While in LA and NYC most acute cases were either White or Hispanic men who have sex with men. Interestingly, a number of these men were also bisexual increasing the risk of transmitting HIV to women. Also, half of the persons with AHI had a viral load >500,000 copies/mL (range 8,700 – 6,300,000) at their initial screening. *‘Other’ race category not represented

Summary of false-positive NAAT results, Florida and Los Angeles Client Initial Results Signal to cutoff ratio Follow-up Results 1 EIA-RR/WB-Neg/NAAT+ VL<75 3.49 (171, 335/49, 008) EIA-NR/NAAT- VL not done 2 14.15 (531, 341/37,547) EIA-RR/WB-Neg/NAAT- 3 EIA-RR/WB-Ind/NAAT+ 14.1 (523, 386/37, 181) 10.3 (278, 292/27, 030) EIA-RR/WB-Ind/NAAT- 4* EIA-NR/NAAT+ Initial pool = 25.08 Rpt. Pool = 22.43 Individual = 20.85 *pooled and individual testing

Summary of false-negative NAAT result, Florida Initial Results Signal to cutoff ratio Follow-up Results EIA-RR/WB-Ind/NAAT- 0.76 (32,220/44,555) EIA-RR/WB-pos/NAAT+ 7.9 (326,101/41,249)

Acute HIV Infection Screening Results May 1, 2006 to October 31, 2007 Test Result Florida* Los Angeles† New York City‡ Total # tested 45,288 30,289 3,624 EIA-neg/NAAT-neg 44,638 29,589 3,597 EIA-RR/WB-pos/NAAT-pos 528 352 15 Presumptive AHIs 11 28 4 EIA-neg/ NAAT-pos 6 EIA-RR/WB-neg/NAAT-pos 2 EIA-RR/WB-ind/NAAT-pos 3 EIA-RR/WB-neg/NAAT-neg 58 19 EIA-RR/WB-ind/NAAT-neg 16 9 EIA-RR/WB-pos/NAAT-neg 33 So, here are our preliminary results…79,201 total tested Point out categories of presumptive AHIs 1 EIA-RR/WB-ind/NAAT-pos in Florida later tested EIA-RR/WB-ind/NAAT-neg has been reported in HARS as HIV positive previously – therefore, we excluded this person 38 seroconverted – FL 10, LA 22, NYC 4 * Results using BioRad HIV-1/2 plus O † Results using Vironostika HIV-1 Microelisa System ‡ Results using Oraquick Advance Rapid HIV 1/2 (oral fluid) – data from June 4, 2007 to October 31, 2007

Acute HIV Infection Screening Results May 1, 2006 to October 31, 2007 Population # tested HIV Ab+ HIV% AHI+  HIV case Overall 79,201 930 1.2 43 4.6% LA* 30,289 354 28 8.0% Florida† 45,288 561 11 2.1% NYC STD‡ 3,624 15 0.4 4 26.7% This slide depicts acute HIV infection screening results from May 1, 2006 to October 31, 2007. Overall, we tested 79,200 persons, of whom 930 were HIV antibody positive and 43 were acutely infected with HIV. Overall we had a 4.6% increase in HIV case detection. However, we really need to look at the yield of acute HIV screening by project area since each area used a different assay to screen for HIV antibodies. In LA, where Vironostika was used, 30,289 persons were tested, of whom 354 were HIV antibody positive and 28 were acute HIV cases with an 8% increase in HIV case detection. This is very similar to published estimates from California and Seattle. In Florida, where BioRad a 3rd generation HIV antibody test was used to screen for HIV antibody, 45,288 persons were tested of whom 561 were HIV antibody positive and 11 were acute HIV cases with a 2.1% increase in HIV case detection. In NYC, where the project started in June of this year, Oraquick Advance on oral fluid was used to screen for HIV antibody, 3,624 persons were screened of whom 15 were HIV antibody positive and 4 acute HIV cases for a 26.7% increase in HIV case detection. This large increase in case detection is based on a subset of the entire testing population because NYC implemented a separate consent for acute HIV screening. Kate Gallagher will present the differences between the persons who accepted NAAT and those who refused later on in this session. We could have missed persons at risk for AHI due to this opt-in model. Also note, that the HIV prevalence in LA and Florida are similar and in NYC this prevalence does not reflect the prevalence in the total testing population. Total pop = 8,421; HIV positive =132; 1.6% HIV prevalance * Results using Vironostika HIV-1 Microelisa System † Results using Bio-Rad Genetic Systems HIV 1/2 + O ‡ Results using Oraquick Advance Rapid HIV 1/2 (oral fluid) – data from June 4, 2007 to October 31, 2007