HIVAIDS Surveillance in the United States: A Comprehensive Approach to Tracking the Epidemic

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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

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Acknowledgements

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

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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)

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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

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

• 1981 Reports of Pneumocystis carinii pneumonia
  (PCP) and Kaposis 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,
  CD4lt200
• www.thebody.com/encyclo/aids.html

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Key HIV/AIDS Data Collected

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

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Rationale for Transition to More Comprehensive
HIV/AIDS Surveillance

• 1980s and early 1990s - 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

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Pathway of HIV Infection

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

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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

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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
• - gt11,000 IDU interviewed in 24 U.S. cities

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

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HIV Incidence Surveillance Sites, 2006 (n34)
WA
CHI
MA
NYS
CT
MI
NYC
PA
SF
OH
NJ
IN
IL
PHIL
CO
CA
MO
VA
MD
NC
DC
TN
OK
AZ
LA
SC
AR
GA
AL
MS
LA
TX
FL
HOU
PR
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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

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3. HIV Case SurveillanceImplementation Status by
State, 2005
Washington, D.C.
Name-Based
Name-to-code
Code-Based
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Estimated Number of HIV/AIDS Diagnoses among
Adults and Adolescets, by Transmission Category,
in 33 States with Name-based Reporting, 2001-2004
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.
Statistically significant
EAPC, Estimated
Annual Percent Change
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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

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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

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Morbidity Monitoring Project 26 Sites - began
in summer 2005
WA
WA
CHI
OR
OR
MA
NY
NYS
MI
MI
NYC
PA
SF
PA
NJ
IN
IL
PHIL
IN
IL
CA
DE
VA
CA
VA
MD
NC
NC
LA County
SC
High
SC
GA
MS
MS
TX
Moderate
GA
TX
Low
FL
FL
HOU
PR
PR
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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

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

90
450
AIDS
Deaths
400
80
Prevalence
350
70
300
60
250
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No. of cases and deaths (in thousands)
Prevalence (in thousands)
200
40
150
30
100
20
50
10
0
0
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Year of diagnosis or death
Note. Data have been adjusted for reporting
delays.
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AIDS Case Rates in 2004United States
7.2
VT 2.7
4.6
0.8
2.7
7.8
4.3
3.2
NH
1.6
3.2
8.8
39.7
MA
1.6
3.6
6.5
12.2
RI
18.4
CT
2.2
13.1
3.9
21.2
NJ
13.1
5.8
6.3
13.2
18.9
DE
3.3
5.1
7.3
26.1
MD
13.0
10.7
6.8
4.2
6.1
179.2
DC
13.3
13.1
9.8
5.5
9.6
6.7
18.1
16.5
10.3
18.6
Rate (per 100,000
14.7
population)
33.5
22.4
lt5.0
Guam 0.6
8.4
5.0 - 15.0
Pacific Islands, US 0
gt15.0
Puerto Rico 23.4
10.8
Virgin Islands, US 18.4
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Number of cases
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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