PHSKC 4/01 11

Epidemiology of HIV/AIDSEpidemiology of HIV/AIDS Seattle-King County, WASeattle-King County, WA

HIV/AIDS Epidemiology ProgramHIV/AIDS Epidemiology Program

Public Health - Seattle & King Co.Public Health - Seattle & King Co.(206) 296-4645(206) 296-4645

On the web at www.metrokc.gov/health/apu/epiOn the web at www.metrokc.gov/health/apu/epi

PHSKC 4/01 22

Objectives of this slide seriesObjectives of this slide series

AIDS epidemiology in King County– Overall trends– Grouped data: exposure modes, gender, age,

race/ethnicity– Including recent HIV data

Estimates of local HIV prevalence

PHSKC 4/01 33

HIV/AIDS Epidemiology Program GoalsHIV/AIDS Epidemiology Program Goals

Assess the prevalence and incidence of HIV & AIDS; study and interpret patterns of the epidemic

Fulfill legal mandate for case reporting

Provide this information to guide planning and evaluation of prevention, care, and social services

Work in partnership with the community

PHSKC 4/01 44

HIV/AIDS Epidemiology HIV/AIDS Epidemiology Seattle-King County, WASeattle-King County, WA

PHSKC 4/01 55

Cumulative Incidence of AIDSCumulative Incidence of AIDS December 31, 2000December 31, 2000

King Co. WA State U.S.*King Co. WA State U.S.*

Adult/Adolescent 6,081 9,386 745,103 Pediatric (<13 yrs) 15 33 8,804

TOTAL CASES 6,096 9,419 753,907

Deaths 3,575 5,351 438,795(59%)(59%) ( 57%)( 57%) (58%)(58%)

*U.S. data as of 6/30/00*U.S. data as of 6/30/00

PHSKC 4/01 66

AIDS in Washington State by CountyAIDS in Washington State by County December 31, 2000 - N= 9419December 31, 2000 - N= 9419

Kingn=6096

65%

Clarkn=326

3%

Kitsapn=166

2%Spokane

n=3864%

Snohomishn=465

5%

All Othersn=1143

12%Piercen=837

9%

Also, 64% of cumulative HIV cases are from King County

PHSKC 4/01 77

AIDS Cases by Residence at DiagnosisAIDS Cases by Residence at DiagnosisWashington StateWashington State, 1986-2000 N=9,419, 1986-2000 N=9,419

0

10

20

30

40

50

60

70

80

86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000

Year of Diagnosis

Per

cent

of W

A c

ases

Seattle-King County (SKC)

non-SKC

PHSKC 4/01 88

AIDS Cases by Residence at DiagnosisAIDS Cases by Residence at DiagnosisKing County, 1986-2000 N=6,096King County, 1986-2000 N=6,096

0102030405060708090

100

86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000

Year of Diagnosis

Per

cent

of K

C c

ases

SeattleNon-Seattle in KCUnknown

PHSKC 4/01 99

AIDS Cases by Year of DiagnosisAIDS Cases by Year of Diagnosis King County, 1982-2000 N=6096King County, 1982-2000 N=6096

* Adjusted for reporting delay

0

100

200

300

400

500

600

700

82 84 86 88 90 92 94 96 98* 2000*

* *

Year of Diagnosis

Nu

mb

er

PHSKC 4/01 1010

AIDS Cases by GenderAIDS Cases by GenderGeographic Comparison, 1997-1999Geographic Comparison, 1997-1999

91

9

84

16

88

12

78

22

0

10

20

30

40

50

60

70

80

90

100

Percent

King County Other WACounties

WashingtonState

United States

MaleFemale

PHSKC 4/01 1111

Trends in AIDS Cases by Gender and Year Trends in AIDS Cases by Gender and Year King County, 1986-2000King County, 1986-2000

0

100

200

300

400

500

600

700

86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000

Year of Diagnosis

Num

ber

of C

ases

Males Females

PHSKC 4/01 1212

AIDS Cases by Gender and Year of DxAIDS Cases by Gender and Year of Dx King County, 1986-2000King County, 1986-2000

0

10

20

30

40

50

86 88 90 92 94 96 98 '0050

60

70

80

90

100

86 88 90 92 94 96 98 '00

Percent in Men Percent in Women

Year Year

PHSKC 4/01 1313

HIV/AIDS Cases by GenderHIV/AIDS Cases by GenderEarly AIDS vs. recent AIDS and HIV cases, King County

97%

3%

90%

10%

83%

17%

0%

10%

20%30%

40%

50%

60%

70%80%

90%

100%

AIDS 83-92 AIDS 97-00 HIV 99-00

MaleFemale

N=3148N=3148 N=838N=838 N=304N=304

PHSKC 4/01 1414

AIDS Cases by HIV Exposure ModeAIDS Cases by HIV Exposure Mode King County, 1983-2000 King County, 1983-2000

MSM75%

IDU6%

HET3%OTH

6%

MSM/IDU10%

PHSKC 4/01 1515

Trends in AIDS Cases by Exposure Mode Trends in AIDS Cases by Exposure Mode (cases with known risk)(cases with known risk) King County, 1986-2000 - N=5,860King County, 1986-2000 - N=5,860

0

100

200

300

400

500

600

86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000

Year of Diagnosis

Num

ber

of C

ases

MSM MSM & IDUNon-MSM

PHSKC 4/01 1616

Trends in AIDS Cases by Exposure Mode Trends in AIDS Cases by Exposure Mode (cases with known risk) King County, 1986-2000 - N=5,860(cases with known risk) King County, 1986-2000 - N=5,860

0102030405060708090

100

86 87 88 89 90 91 92 93 94 95 96 97 98 99 2000Year of Diagnosis

Per

cen

t o

f C

ases

MSM MSM & IDUNon-MSM

PHSKC 4/01 1717

HIV/AIDS Cases by Exposure ModeHIV/AIDS Cases by Exposure ModeEarly AIDS vs. recent AIDS and HIV cases, King CountyEarly AIDS vs. recent AIDS and HIV cases, King County

0%

10%

20%

30%

40%

50%

60%

70%

80%

AIDS 83-92 AIDS 97-00 HIV 99-00

MSM

IDU

MSM/IDU

Hetsex

Undet.

N=3148N=3148 N=838N=838 N=304N=304

PHSKC 4/01 1818

HIV/AIDS Cases by Age at DiagnosisHIV/AIDS Cases by Age at DiagnosisEarly AIDS vs. recent AIDS and HIV cases, King County

0%

10%

20%

30%

40%

50%

AIDS 83-92 AIDS 97-00 HIV 99-00

<2020-2930-3940-49>49

N=3148N=3148 N=838N=838 N=304N=304

PHSKC 4/01 1919

Cumulative AIDS cases by race/ethnicityCumulative AIDS cases by race/ethnicityKing County, 1982-2000King County, 1982-2000

0

5001000

1500

20002500

3000

35004000

4500

5000

White

African American

Hispanic

Asian/Pacific Islander

AmericanIndian/Alaska Native

Number of CasesNumber of Cases

PHSKC 4/01 2020

Racial/Ethnic Composition of King CountyRacial/Ethnic Composition of King County1997 Population: 1,652,7751997 Population: 1,652,775

White, non-Hispanic 85% 68% 79%

African American, non-Hispanic 3% 11% 5%

Hispanic 4% 5% 4%

Asian/Pacific Islander 8% 15% 10%

American Indian/AK Native 1% 1% 1%

Population DistributionPopulation DistributionCity of Seattle: 32%Incorporated Cities: 41%Unincorporated Areas: 27%

Outside SeattleOutside Seattle SeattleSeattle King Co.King Co. King Co. City of King Co. City of Total Total

PHSKC 4/01 2121

Ave. annual AIDS rates by race/ethnicityAve. annual AIDS rates by race/ethnicityKing County, 1997-1999King County, 1997-1999

10

36 36

3

33

0

5

10

15

20

25

30

35

40

Ca

ses

per

10

0,0

00

po

p.

White

African Am

Hispanic

Asian/PI

Am. Indian/AKNative

PHSKC 4/01 2222

AIDS Cases by Race and YearAIDS Cases by Race and YearKing County, 1986-2000King County, 1986-2000

0

20

40

60

80

100

86 87 88 89 90 91 92 93 94 95 96 97 98 99 '00

Year of Diagnosis

Pe

rce

nt

of

Ca

se

s

People of color n=1214 White n=4882

PHSKC 4/01 2323

HIV/AIDS Cases by Race/EthnicityHIV/AIDS Cases by Race/EthnicityEarly AIDS vs. recent AIDS and HIV cases, King CountyEarly AIDS vs. recent AIDS and HIV cases, King County

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

AIDS 83-92 AIDS 97-00 HIV 99-00

WhiteBlackHispanicAsianIndian

N=3148N=3148 N=838N=838 N=304N=304

PHSKC 4/01 2424

Deaths of Reported AIDS Cases by YearDeaths of Reported AIDS Cases by Year King County, 1982-2000 N=3,575King County, 1982-2000 N=3,575

050

100150200250300350400450500

82 84 86 88 90 92 94 96 98* 2000*

Year of Death

*Provisional data due to delayed ascertainment of deaths outside of King County

Nu

mb

er

PHSKC 4/01 2525

Persons Alive with AIDS at Year’s End & DeathsPersons Alive with AIDS at Year’s End & Deaths per Year, King County, 1994-2000 per Year, King County, 1994-2000

0

500

1000

1500

2000

2500

3000

1994 1995 1996 1997 1998 1999 2000

Est. PLWA at Year's End Deaths during the year

Nu

mb

er

PHSKC 4/01

2626

0

20

40

60

80

100

120

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Ra

te p

er

10

0,0

00

M UI

M All CA

M HIV

M Suicide

M HD

M Firearms

M Homicide

M Chr Liver

M Diabetes

M Pneum

M CVD

Leading Causes of Deaths for Males Leading Causes of Deaths for Males Age 25-44 -- King County, 1988-98Age 25-44 -- King County, 1988-98

PHSKC 4/01 2727

Leading Causes of Death for Leading Causes of Death for Females Age 25-44, King CountyFemales Age 25-44, King County

0

5

10

15

20

25

30

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Unintent. Injury All Cancer HIV Infection Suicide Heart Disease Homicide Liver Disease

PHSKC 4/01 2828

Summary of Key Points (1)King County HIV/AIDS

Most new cases continue to be White males, infected through male-to-male sex, but

% of cases infected by IDU and heterosexual sex may be increasing

Increasing % of AIDS cases are women Increasing % of AIDS cases are people of color

PHSKC 4/01 2929

Summary of Key Points (2)King County HIV/AIDS

Dramatic decrease in deaths since 1995

Number of people living with AIDS in KC increases each year

PHSKC 4/01 3030

Estimating HIV Prevalence

PHSKC 4/01 3131

Estimating HIV Prevalence in King Co.Estimating HIV Prevalence in King Co.

We have no direct measurement of the number of people with HIV infection in King County (or elsewhere)

Prevalence in the County dependent on inflow (new HIV infections, in-migration) and outflow (deaths, out-migration)– Except for deaths, all are difficult to measure

PHSKC 4/01 3232

Estimating HIV Prevalence: MethodsEstimating HIV Prevalence: Methods

Back-calculation: # AIDS cases used to extrapolate back to # HIV cases needed generate AIDS – Needs a consistent case series -- major changes in case

definition of AIDS causes problems – Needs consistent progression rate from HIV to AIDS --

this has changed substantially with HAART

PHSKC 4/01 3333

Estimating HIV Prevalence: Methods (2)Estimating HIV Prevalence: Methods (2)

Extrapolation from the state-wide Survey of Childbearing Women

– HIV status of all women giving birth was established anonymously via routine screening of neonates

– Assumed the ratio of male:female AIDS equaled ratio of male:female HIV; fertility adjustment

– Survey stopped by federal mandate in 1995

PHSKC 4/01 3434

Estimating HIV Prevalence: Methods (3)Estimating HIV Prevalence: Methods (3)

HIV case surveillance data can be used if:

– Complete reporting of HIV+ persons receiving health care (or good estimate of reporting fraction & reporting delay)

– Estimate of % of HIV infections that are diagnosed– Estimate of % of HIV + testing anonymously and not

receiving health care (and therefore not reportable)– Knowledge of in- and out-migration

PHSKC 4/01 3535

Estimating HIV Prevalence: Methods (4)Estimating HIV Prevalence: Methods (4)

Sampling and enumeration of cases– Requires rigorous statistical methods to allow

valid extrapolation to overall HIV-infected population

PHSKC 4/01 3636

Current estimates of the number of Current estimates of the number of HIV infections in King CountyHIV infections in King County (1) (1)

7,500 (range 6,000 - 9,000)

Estimate was derived from:

– CDC’s backcalculation estimates of U.S. infections x proportion of U.S. AIDS cases in King County (1995-96)

– extrapolation of Survey of Childbearing Women (1995)

– a “components” analysis by CDC (1996)

PHSKC 4/01 3737

Current estimates of the number of Current estimates of the number of HIV infections in King County HIV infections in King County (2)(2)

Survey of HIV Disease and Care (SHDC)

– New method recently piloted in King county by CDC and Public Health used 2-stage cluster sample of clinics and health care providers

– Estimated 4,358 HIV+ persons in care (1998)

» If 75% of HIV+ in care: 5,810 total HIV+

» If 60% of HIV+ in care: 7,263 total HIV+

PHSKC 4/01 3838

Current estimates of the number of Current estimates of the number of HIV infections in King County HIV infections in King County (3)(3)

4,225 persons alive with HIV or AIDS as per Public Health reports received as of 4/19/01

– Assuming completeness of AIDS data at 90% & HIV at 70%, then 5,202 HIV+ in care (2,626/0.9 AIDS) + (1,599/0.7) = 5,202

» If 75% of HIV+ are in care: 6,936 total HIV+

» If 60% of HIV+ are in care: 8,670 total HIV+

PHSKC 4/01 3939

Category% of personsliving withHIV/AIDS **

Range of estimatedHIV infections in1995-96*

Range of estimatedHIV infections in2001*

Change inestimate1995-2001

Gender Males, all 91% 5,650-8,450 5,460-8,190 Decrease Females, all 9 350-550 540-810 Increase

HIV exposure MSM 70% 4,600-6,850 4,200-6,300 Decrease IDU (heterosexual) 7 400-650 400-650 No change MSM/IDU 10 600-900 600-900 No change Hetero. Contact 5 250-350 300-450 Increase Pediatric exposure 0.6 20-40 35-55 Increase Other or unknown 7 not estimated 420-630 --

Race/ethnicity White, non-Hisp. 74% 4,800-7,200 4,440-6,660 Decrease Black, non-Hisp. 14 650-1,000 840-1,260 Increase Hispanic 8 400-600 480-720 Increase Asian/Pacific Is. 2 75-125 120-180 Increase Am. Ind./AK Nat. 2 75-125 120-180 Increase

TOTAL 6,000 - 9,000 6,000 - 9,000 No change

*Numbers of individual categories may not equal total because of rounding.**Percent of presumed living HIV and AIDS cases in King County reported to Public Health through 3/7/01.

Comparison of Est. HIV Infections in King Co. 1995-96 and Comparison of Est. HIV Infections in King Co. 1995-96 and 20012001

PHSKC 4/01 4040

Summary of current estimates of prevalent Summary of current estimates of prevalent HIV infections in King CountyHIV infections in King County

Total 7,500 (range 6,000 - 9,000)

– Gender

» 91% male, 9% female

– Exposure Mode

» 70% MSM, 10% MSM/IDU, 7% IDU, 5% Heterosexual

– Race/ethnicity

» 74% White, 14% Black, 8% Hispanic, 2% A/PI, 2% Am Ind/NA