# Presentation: 547869

## HIV/AIDS Surveillance in the United States:  A Comprehensive Approach to Tracking the Epidemic

**Alan E. Greenberg, MD, MPH**
**Professor and Chair**
**Department of Epidemiology and Biostatistics**
**School of Public Health and Health Services George Washington University**

## Acknowledgements

- Division of HIV/AIDS Prevention, CDC
- Dr Matt McKenna
- Dr Patrick Sullivan
- Dr Tim Mastro
- Dr Rob Janssen

## HIV/AIDS Surveillance...

- ...is the ongoing and systematic collection, analysis, interpretation, dissemination and evaluation of population-based information about persons infected with HIV or diagnosed with AIDS  (CDC)

## Why is HIV/AIDS Surveillance Important?

**To understand the epidemiology and magnitude of the HIV/AIDS epidemic in the United States**
**To monitor trends in affected populations**
**To target HIV prevention and treatment services**
**To guide the development of new interventions and approaches to HIV prevention**
**To provide data upon which funding decisions for HIV/AIDS programs (e.g. Ryan White) are based**

## History of CDC AIDS Case Definition for Surveillance in the U.S.*

**1981 –Reports of Pneumocystis carinii pneumonia (PCP) and Kaposi’s sarcoma (KS) in young gay men in SF, NY and LA**
**1982 –  CDC clinical AIDS case definition developed including 20 opportunistic illnesses, including infections (bacteria, fungi, protozoa) and cancers (KS and lymphoma)**
**1987 – Case definition expanded to include TB, wasting syndrome, and dementia**
**1993 – Expanded again to include cervical cancer, bacterial pneumonia, pulmonary TB, and HIV+, CD4<200**
***www.thebody.com/encyclo/aids.html**

## Key HIV/AIDS Data Collected

- Demographics – gender, age, race-ethnicity, residence
- Mode of HIV exposure
- Opportunistic illnesses
- Viral and immunologic lab data

## Slide 7

## Rationale for Transition to More Comprehensive HIV/AIDS Surveillance

**1980’s and early 1990’s - AIDS case surveillance primarily used to monitor U.S. epidemic trends**
**HAART introduced in 1996 - interval between HIV infection and disease increased greatly, and AIDS case surveillance was inadequate to monitor more recent trends in HIV infection and the impact of HIV prevention programs**
**CDC and its partners developed new population-based surveillance systems to monitor the epidemic in a more comprehensive and timely manner**

## “Pathway” of HIV Infection

- High-risk behaviors
- HIV incidence
- HIV prevalence
- HIV disease
- AIDS
- Death

## Comprehensive National Surveillance System to Monitor the “Pathway” of HIV

**1.  National Behavioral Surveillance System**
**2.  HIV Incidence Surveillance System**
**3.  HIV Case Surveillance**
**4.  HIV Prevalence Estimates**
**5.  Morbidity Monitoring Project**
**6.  AIDS Case and Death Surveillance **

## 1. National HIV Behavioral Surveillance System (NHBS)

**Objectives:  To assess prevalence of and trends in HIV risk behaviors, HIV testing behaviors, and exposure to and use of prevention services among MSM, IDU, and HRH**
**Conducted in alternating 12-month cycles, one group per cycle**
**-  2004-2005 MSM cycle completed **
**	****- 14,298 MSM interviewed in 17 U.S. cities**
**-  2005-2006 IDU cycle completed**
**	****- >11,000 IDU interviewed in 24 U.S. cities**

**Notes:**
The National HIV Behavioral Surveillance System is our newest and most comprehensive system for conducting behavioral surveillance among high risk populations in the US.

The objectives of the new National HIV behavioral Surveillance system include assessing the prevalence of and trends in
risk behaviors, HIV testing behaviors and exposure to and use of prevention services

Data are collected from three groups of persons at high risk of infection: 
Men who have sex with men (MSM)
Injection drug users (IDU)
High risk heterosexuals (HRH)

## HIV Prevalence and Proportion with Undiagnosed HIV Infection in MSM in 5 Cities – NHBS, 2004-2005

| 
Characteristic | 
Total Tested | 
HIV Prevalence 
   N               (%) |  | Undiagnosed HIV Infection
      N           (%) |  |
| --- | --- | --- | --- | --- | --- |
| Total | 1767 | 450 | (25) | 217 | (48) |
| Age
    18-24
    25-29
    30-39
    40-49
    ≥ 50  |  
410
303
585
367
102 | 
   57
   53
 171
 137
   32  | 
(14)
(17)
(29)
(37)
(31)  | 
  45
  37
  83
  41
  11  | 
 (79)
 (70)
 (49)
 (30)
 (34)  |
| Race
    White
    Black
    Hispanic
    API
    NA/AN
    Multiracial/Other  | 
 616
 444 
 466
   95
<10 
 123 | 
 127
 206
  80 
    7
<10 
   25 | 
(21)
(46)
(17)
  (7)
(29)
(20) |  
  23
139
  38
    2
<10
   13 | 
  (18)
  (67)
  (48)
  (29)
(100)
  (52) |

## 2. HIV Incidence Surveillance System

**Background – 40,000 persons in U.S. estimated to be newly infected annually, but more precise estimates needed**
**Objective – To provide national and area-specific population-based estimates of the number of new HIV infections per year**
**Methods**
**For all newly reported HIV cases in funded areas**
**demographic and clinical information**
**supplemental HIV testing information**
**blood test to detect recent HIV infection**
**Using the above information and statistical methodology, an overall HIV incidence estimate is being developed**

**Notes:**
Now let’s talk a little bit about how we’re going to do that.

The goal of incidence surveillance is to obtain the data needed to provide national and area -specific population-based estimates of the number of new HIV infections per year.   This means we are estimating the number of recent infections in the whole population and NOT just among those that get tested for HIV in a given year.

To do this, we are going to apply a method called the Serologic Testing Algorithm for Recent HIV Seroconversion, or STARHS, described by Jannsen and colleagues in a 1998 JAMA article.  In this article they describe a method of repeated testing using first, a sensitive assay to detect HIV antibodies, followed by a less sensitive one that can only detect a higher level of antibodies.  Thus, if an individual were to test positive on the sensitive antibody test, but negative on the less sensitive test it could be assumed that his/her immune system had not yet had time to create a large number of antibodies, and his/her infection was therefore recent. 

We will be using a slightly different test than the one described in the article.  We will be using the Calypte HIV-1 BED Capture EIA.  I will go a little more in detail about this assay in a few minutes.  

The CDC’s human subjects system has deemed it to be a non-research activity, thereby allowing HIV incidence surveillance to be fully integrated into national and local core HIV case surveillance.

## HIV Incidence Surveillance Sites, 2006 (n=34)

- TX

- AZ

- CA

- SF

- LA

- PR

- FL

- GA

- AL

- MS

- LA

- SC

- NC

- VA

- PA

- NYS

- OH

- IN

- MI

- IL

- MO

- AR

- TN

- OK

- CO

- WA

- CHI

- HOU

- MA

- CT

- NJ

- NYC

- MD

- DC

- PHIL

## Current Status of System

**As of October 2006, all 34 sites are implementing HIV incidence surveillance**
**HIV incidence estimates for 2005 will be developed by CDC in the months ahead**
**The quality, timeliness, and usefulness of incoming incidence data will be evaluated**

## 3. HIV Case SurveillanceImplementation Status by State, 2005

**Name-Based**

**Name-to-code **

**Code-Based**

- Washington, D.C.

## Estimated Number of HIV/AIDS Diagnoses among Adults and Adolescets, by Transmission Category, in 33 States with Name-based Reporting, 2001-2004

*** Statistically significant**                                                        **EAPC, Estimated Annual Percent Change**

**Men who had sex with men (MSM)**

**High-risk heterosexual contact**

**Injection drug use (IDU)**

**MSM / IDU**

**Note: Estimates are adjusted for reporting delays and redistribution of **
**transmission category for cases without risk factor information.****  **

## 4. Estimated HIV Prevalence in the United States at the End of 2003

**HIV surveillance data and two statistical modeling procedures were used to calculate HIV prevalence  estimates**
**Through the end of 2003, CDC estimated that: **
**1,039,000 – 1,185,000 HIV-infected persons were living in the U.S.**
**24-27% were undiagnosed and unaware of their HIV infection**

## 5. Morbidity Monitoring Project (MMP)

**Objectives - in a nationally representative sample of HIV-infected adults in-care **
**Monitor clinical outcomes, quality of care and HIV risk behaviors**
**Identify met and unmet needs for HIV care and prevention services**
**Substudy of HIV-infected adults out-of-care **
**Determine why these persons are not in-care**
**Monitor HIV risk behaviors**
**Methods**
**Annual medical record abstraction (in-care) – demographics, illnesses, laboratory data, antiretroviral drug  history**
**Interviews (in- and out-of-care) - demographics, HIV risk behaviors, access to health care and HIV prevention services **

**Notes:**
The Morbidity Monitoring Project is a matched interview and medical record abstraction project
It will be conducted in 26 sites (20 states and 6 independently funded cities) beginning in 2005
The project is an annual multi-stage probability sample of adults in care for HIV in the US
These methods will result in a representative sample of HIV-infected adults in care both locally and nationally
Data collected will include behaviors, clinical outcomes, the type and quality of care received, and will be able to identify both met and unmet needs for HIV care and prevention services which can be used to inform community and care planning groups, health care providers and other stakeholders

## Morbidity Monitoring Project 26 Sites - began in summer 2005

- TX

- CA

- SF

- LA County

- PR

- FL

- GA

- MS

- SC

- NC

- VA

- PA

- NYS

- IN

- MI

- IL

- WA

- CHI

- HOU

- MA

- NJ

- NYC

- MD

- OR

- DE

- PHIL

- TX

- High

- Moderate

- Low

- WA

- OR

- CA

- IL

- FL

- MS

- GA

- SC

- NC

- VA

- PA

- NY

- PR

- MI

- IN

**Notes:**
The following are the 20 states and 6 independently funded cities that were sampled
These sites were selected to include different geographic areas, and high, medium and low prevalence areas

## Current Status of MMP

- As of April 2006, all 26 sites have begun MMP activities
- Currently, ten sites are collecting data on patients who received care in 2005
- By May 2007, all 26 sites will have begun data collection

## 6. AIDS Cases, Deaths of Persons with AIDS, and Persons Living with AIDS in the United States, 1985-2004

- Prevalence (in thousands)

- Year of diagnosis or death

- 0

- 0

- 90

- 400

- 450

- 10

- 20

- 50

- 30

- 100

- 40

- 150

- 50

- 200

- 60

- 250

- 70

- 300

- 80

- 350

- 1985

- 1986

- 1987

- 1988

- 1989

- 1990

- 1991

- 1992

- 1993

- 1994

- 1995

- 1996

- 1997

- 1998

- 1999

- 2000

- 2001

- 2002

- 2003

- 2004

- Deaths

- Prevalence

- AIDS

- Note. Data have been adjusted for reporting delays.

**6. AIDS Cases, Deaths of Persons with AIDS, and Persons Living with AIDS in the United States, 1985-2004**

## Slide 23

**Notes:**
The proportional distribution of AIDS cases by transmission category has shifted since the beginning of the epidemic. In 1985, male-to-male sexual contact accounted for 65% of all AIDS cases; in 2004, this transmission category accounted for 42% of all AIDS cases.
The proportion of AIDS cases attributed to injection drug use increased during 1985–1994 and then slightly decreased, accounting for 22% of cases in 2004. 
The proportion of AIDS cases attributed to male-to-male sexual contact and injection drug use decreased from 9% in 1985 to 5% in 2004. 
The proportion of AIDS cases attributed to heterosexual contact with a person known to have or at high risk for HIV infection (high risk heterosexual) increased from 3% in 1985 to 31% in 2004. 
The remaining AIDS cases were those attributed to hemophilia or the receipt of blood or blood products and those in persons without an identified risk factor.
The data have been adjusted for reporting delays and cases without risk factor information were proportionally redistributed. 

## Slide 24

## Slide 25

## AIDS Case Rates in 2004—United States

- 10.8

- DE

- MA

- RI

- CT

- NJ

- MD

- DC

- NH

- 3.2

- 21.2

- 18.9

- 18.4

- 8.8

- 12.2

- 26.1

- 179.2

- 33.5

- 16.5

- 39.7

- 13.1

- 18.1

- 18.6

- 22.4

- 14.7

- 9.8

- 8.4

- 13.0

- 5.1

- 5.8

- 3.2

- 2.2

- 4.3

- 5.5

- 3.9

- 1.6

- 2.7

- 3.6

- 0.8

- 1.6

- 7.2

- 7.8

- 13.1

- 3.3

- 9.6

- 7.3

- 4.2

- 6.7

- 6.8

- 13.2

- 6.5

- 6.3

- 6.1

- 13.1

- 10.3

- 13.3

- 10.7

- 4.6

- <5.0

- 5.0 - 15.0

- >15.0

- Rate (per 100,000

- population)

- Guam 0.6

-  Pacific Islands, US 0

-  Virgin Islands, US  18.4

- Puerto Rico  23.4

- VT 2.7

**Notes:**
For cases reported in 2004, AIDS rates (cases per 100,000) are shown for each state, the District of Columbia, Puerto Rico, the US Virgin Islands, Guam, and the US Pacific Islands.
Areas with the highest rates in 2004 were the District of Columbia, New York, Florida, and Maryland. The District of Columbia is a metropolitan area, use caution when comparing its AIDS rate to state AIDS rates. Every state reported some AIDS cases in 2004.

## Slide 27

**Notes:**
The estimated number of AIDS cases diagnosed among persons perinatally exposed to HIV peaked in 1992 and has decreased in recent years.  
The decline in these cases is likely associated with the implementation of Public Health Service guidelines for the universal counseling and voluntary HIV testing of pregnant women and the use of antiretroviral therapy for pregnant women and newborn infants (MMWR 2002;51(No. RR-18)). Other contributing factors are the effective treatment of HIV infections that slow progression to AIDS and the use of prophylaxis to prevent AIDS opportunistic infections among children.

## Summary

**HIV/AIDS case surveillance provides critical public health data to monitor the epidemic in the U.S. and to inform prevention efforts  **
**The introduction of HAART led CDC to develop a more comprehensive national HIV/AIDS surveillance system**
**The entire pathway of HIV, from high risk behaviors to HIV incidence and prevalence, to HIV illness, AIDS and death, is now being monitored**