Speak Epidemiology

Epidemiology is:        The scien)ﬁc study of disease distribu)on and    the factors that cause diseases to spread in  communi)es

Eﬀec3ve research advocates  •  •  •  •  •  •

Analyze the facts  Educate others  Build partnership  Lend their perspec3ves  Raise cri3cal ques3ons  Seek knowledge

Useful Tools  Prevalence   Incidence  Rate  Aﬀected popula3ons  Discussions  Future Trends

HIV/AIDS Prevalence

The number of  people living with  HIV/AIDS during a  given year

In 2006, an es+mated  1,106,400 individuals  were living with HIV/ AIDS in the United  States

HIV Incidence  The annual number  of people who  become HIV infected  in a given period of  >me, typically a year.

In 2006, an es+mated  56,300 individuals became  HIV infected in the U.S.

Rate  A rate measures a certain  quan3ty or amount of one  thing considered in rela3on to  a unit of another thing.   In public health, rates help  describe the number of  events per popula+on unit,  typically expressed as  health events or disease  per 100,000 people.

Rate  A rate consists of a  numerator and a  denominator.  525,600 / 56,300  = 9.33  Annual minutes (numerator) divided by annual infec3ons  (denominator) equals a rate of 9 ½ minutes per infec>on

Rate  Rates allow us to  compare communi3es of  diﬀerent sizes.  The numerator is the number  of health events or disease  and the denominator is the  deﬁned popula+on at risk  (including those who  experience the event/disease):          numerator       ____________ x 100,000 = popula+on rate       denominator

HIV Rate for MSM  Based on meta‐analysis,  CDC es3mates that:  •  An es3mated 4% of U.S.  males had same‐sex  behavior in the past 5 yrs  •  7% of U.S. males have ever  had MSM behavior  •  MSM account for an  es3mated 2% of the total  U.S. popula3on

HIV Rate for MSM  CDC notes and disclaimers:  • •

•

These es3mates are  preliminary!    More complete analysis    – Reﬁne meta‐analysis  es3mates   – Re‐calculate rates; also do  by race and age    – May conduct separate  analysis for young MSM  Iden3fy popula3on  es3mates for IDU and HET

HIV Transmission Rate  Transmission Rate:  Represents the amount of  transmission that occurs  annually in rela3on to the  popula3on infected with HIV.  Technically, this is HIV  incidence divided by  prevalence in a given year.

HIV Transmission Rate (TR)  CDC published in 2008 back‐ calcula3on es3mates for HIV  incidence and prevalence  between 1977 and 2006.  The  new es3mates allow  retrospec3ve TR calcula3ons.

Hall et al. JAMA. 2008;

300: 520‐ 529.

HIV Transmission Rate, United States, 1977‐2006

Source: Holtgrave et al. JAIDS 2009

HIV Transmission Rate, United States, 1977‐2006

Source: Holtgrave et al. JAIDS 2009

Aﬀected Popula3ons  •  What are the characteris3cs  of people who become  infected with HIV?  •  How do we understand  popula3on trends in the  epidemic?

HIV Infec3ons by Subpopula3on, 2006 (es3mates)

Discussions: Cri3cal Thinking  Research advocates ask critical questions: •  Do the data give an accurate picture of the epidemic? •  Where/when/how was data collected? •  What methodologies were employed in data collection, analysis, and presentation? •  Who was involved? •  How might disease surveillance be improved?

Challenging   “No Iden>ﬁed Risk”  Change HIV/AIDS Surveillance System Categories to More  Accurately Reﬂect How Women Acquire HIV, Advocates Say  •  •  •

End the “seriously ﬂawed” CDC hierarchical classiﬁca3on system that  classiﬁes most cases of HIV among women as “no iden3ﬁed risk”  Allow health departments to classify cases as “presumed heterosexual” when  the male partner’s HIV status and/or risk factors are unknown  Collect “acquisi3on category” informa3on to reﬂect “sexual networks and/or  social networks” of elevated HIV prevalence.  New data might include:  –  –  –

Prevalence of HIV where the person lives  The area’s post‐incarcera3on rates  Drug/alcohol and homelessness partners for the area

ms.founda3on.org/File%20Library/NWAC/NWACpolicypropcharlormFINALforweb.pdf

Data Leave Some Groups Behind  Advocates Say Outreach and  Surveillance Programs Undercount:  •  •  •  •  •

Transgender popula3ons  Asian/Paciﬁc Islanders  Undocumented people  American Indians/Na3ve Hawaiians  Rural popula3ons

Without accurate surveillance, undercounted  popula>ons may receive fewer dollars for HIV  preven>on, care, and research ac>vi>es

It’s not who you are,   It’s where you live …   Person Living with AIDS in 2005 By Region  Region

Rank

Number

North

2

126,867

Midwest

4

45,666

South

1

169,972

West

3

83,405

http://www.southernaidscoalition.org/policy/southern_states_manifesto_2008.pdf

It’s not who you are,   It’s where you live …    San Francisco  Project maps  concentra>on of  HIV viral load  across the city to  determine where  expanded services  are needed

Future Trends

To alter the course of the epidemic,   We need to model where it is currently headed    Advocates shared a model with the White House comparing stable growth  in the epidemic against progress toward deﬁned goals    They call on the federal government to include a scien3ﬁcally rigorous  model in the Na3onal HIV/AIDS Strategy    The paper includes other important recommenda3ons  na3onalaidsstrategy.org/2010/advocates‐recommend‐key‐components‐of‐an‐eﬀec3ve‐strategy/

2007‐2016 Projected Epidemic Based on   A Constant 5% Transmission Rate  Year

Incidence

Deaths

Prevalence

Minutes per  Infec>on

2006

56,300

18,620

1,106,400

9.30

2007

58,086

19,000

1,145,486

9.00

2008

62,273

20,876

1,186,151

8.30

2009

62,273

20,876

1,227,548

8.00

2010

64,446

21,605

1,270,389

8.00

2011

66,695

22,359

1,314,726

7.30

2012

69,023

23,139

1,360,610

7.30

2013

71,432

23,947

1,408,095

7.30

2014

73,505

24,782

1,457,238

7.00

2015

76,505

25,647

1,508,095

7.00

2016

79,175

26,542

1,560,728

6.30

Thank you!  David Ernesto Munar  Vice President  AIDS Founda3on of Chicago  312‐334‐0933  dmunar@aidschicago.org  aidschicago.org  aidsconnect.net/dose

Speak Epidemiology

This helpful presentation goes over the epidemiological concepts most commonly used in AIDS advocacy.