CASE STUDIES OF PUBLIC HEALTH CASE STUDIES OF PUBLIC HEALTH RESEARCH THAT HAVE ALTERED RESEARCH THAT HAVE ALTERED

PUBLIC POLICY PUBLIC POLICY

THE NEW HAVEN SEP EVALUATIONTHE NEW HAVEN SEP EVALUATION

HIV-1 TRANSMISSION AMONG IDUs

Behavioral risk factors include: Syringe sharing Shooting gallery attendanceSharing drugs

Behavioral risks are driven by societal factors. Fear of arrestAversion to withdrawalScarcity of syringes

HISTORY OF SYRINGE EXCHANGE

Syringe exchange began in Holland in response Syringe exchange began in Holland in response to a hepatitis outbreak.to a hepatitis outbreak.

It is impossible to say when syringe exchange It is impossible to say when syringe exchange first began in the US.first began in the US.

The first openly operating initiative began in The first openly operating initiative began in Tacoma in 1988.Tacoma in 1988.

WHY A SYRINGE EXCHANGE PROGRAM WHY A SYRINGE EXCHANGE PROGRAM IN NEW HAVENIN NEW HAVEN

In contrast to In contrast to national data, national data, 70% of AIDS 70% of AIDS cases in New cases in New Haven could be Haven could be attributed to attributed to injection drug injection drug use.use.

ESTABLISHING THE SEP ESTABLISHING THE SEP IN NEW HAVEN, CONNECTICUTIN NEW HAVEN, CONNECTICUT

The city established a task force to seek solutions The city established a task force to seek solutions to the AIDS epidemic that lobbied for three years to the AIDS epidemic that lobbied for three years (1987-1990) to change the laws to start a SEP.(1987-1990) to change the laws to start a SEP.

By statute, customers could exchange no more than five By statute, customers could exchange no more than five syringes in a strict one-for-one fashion.syringes in a strict one-for-one fashion.

A evaluation report had to be produced and issued within A evaluation report had to be produced and issued within one year.one year.

The SEP, operated by the city health department, The SEP, operated by the city health department, opened on November 13, 1990.opened on November 13, 1990.

EVALUATING THE NEW HAVEN SEP

Minimize reliance on self-reported data.Minimize reliance on self-reported data.

Investigate the link between the operations of the Investigate the link between the operations of the program and its effects.program and its effects.

Maintain the anonymity of the participants.Maintain the anonymity of the participants.

Provide a timely analysis that measures the Provide a timely analysis that measures the program's effectiveness.program's effectiveness.

SYRINGE TRACKING AND TESTING

All outgoing syringes coded and exchanges All outgoing syringes coded and exchanges recorded. recorded.

All returned syringes recorded in second All returned syringes recorded in second database. database.

Nearly 50,000 syringes exchanged in first three Nearly 50,000 syringes exchanged in first three years of the SEP.years of the SEP.

Approximately one-tenth of all returned syringes Approximately one-tenth of all returned syringes tested for presence of blood from HIV-1 infected tested for presence of blood from HIV-1 infected individual.individual.

SEP FOUND TO PREVENT NEW HIV SEP FOUND TO PREVENT NEW HIV INFECTIONSINFECTIONS

The testing data were used to generate two models The testing data were used to generate two models to estimate the HIV incidence rate.to estimate the HIV incidence rate.

The first, an ecological model, assumed that in the The first, an ecological model, assumed that in the absence of exchange previously used syringes will absence of exchange previously used syringes will be used at random.be used at random.

The second, a changepoint model, assumed that The second, a changepoint model, assumed that sequential testing of syringes returned by sequential testing of syringes returned by individuals yields reliable longitudinal data.individuals yields reliable longitudinal data.

MODEL 1: TRANSMISSION OF MODEL 1: TRANSMISSION OF SYRINGE-BORNE INFECTIONSSYRINGE-BORNE INFECTIONS

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Incidence is equal to the rate at which an Incidence is equal to the rate at which an uninfected injector uses a potentially uninfected injector uses a potentially infectious syringe without first disinfecting it infectious syringe without first disinfecting it times the rate which the exposure results in times the rate which the exposure results in infection.infection.

INCIDENCE ESTIMATES BASED ON THE TWO MODELSTHE TWO MODELS

(HIV prevalence)

ε(incidence rate)

At start 67.5% 6.4%/year

After 5 months 52.1% 4.9%/year

After 19 months 40.9% 3.9%/year

After 34 months 38.2% 3.6%/year

Using model 2, the most likely incidence rate was Using model 2, the most likely incidence rate was estimated at 1.6% per year, less than half the estimated at 1.6% per year, less than half the estimate from model 1.estimate from model 1.

EFFECT OF SEP EVALUATION ON POLICY IN CONNECTICUT

In 1992, the state government reviewed the findings andRemoved the “demonstration” status. Increased syringe exchange limit from 5 to 10

syringes per visit.Added five new SEPs in other cities.Allowed syringes to be purchased from pharmacies.

In 1999, the state again increased the limit on syringes from 10 to 30 per visit.

EFFECT OF SEP EVALUATION ON POLICY IN OTHER STATES

Neighboring states of New York and Massachusetts legalize SEPs.

California legislation cites New Haven studies.

Only three states continue to keep SEPs illegal.

47%52%

37%

19%

12%

22%23%

28%

43%

41%

45%46%

0%

10%

20%

30%

40%

50%

60%

90 91 92 93 94 95 96 97 98 9920002001

% HIV+

HIV Prevalence among IDUsin New York City following SEP Legalization

EFFECT OF SEP EVALUATION ON EFFECT OF SEP EVALUATION ON FEDERAL GOVERNMENT POLICYFEDERAL GOVERNMENT POLICY

U. S. government reports repeatedly certify that U. S. government reports repeatedly certify that New Haven evaluation clearly demonstrated that New Haven evaluation clearly demonstrated that SEPs can reduce HIV transmission among IDUs.SEPs can reduce HIV transmission among IDUs.

Nevertheless, Congress refuses to change law Nevertheless, Congress refuses to change law that makes federal funding of SEPs illegal.that makes federal funding of SEPs illegal.

U. S. continues to seek international disapproval U. S. continues to seek international disapproval of syringe exchange.of syringe exchange.