An Introduction to An Introduction to HIV Incidence HIV Incidence

Surveillance (HIS) in Surveillance (HIS) in CaliforniaCalifornia

California Department of Public California Department of Public HealthHealthOffice of AIDSOffice of AIDS

An Introduction to HIV Incidence Surveillance An Introduction to HIV Incidence Surveillance (HIS) in California(HIS) in California

Primary Primary Target Target AudienceAudience

HIV/AIDS Surveillance Coordinators HIV/AIDS Surveillance Coordinators and other health department staff and other health department staff working in HIV surveillance working in HIV surveillance programs in California.programs in California.

Training Training GoalGoal

Provide a general overview of the Provide a general overview of the surveillance model used to surveillance model used to estimate HIV incidence. estimate HIV incidence. Provide an overview of data Provide an overview of data requirements for estimating HIV requirements for estimating HIV incidence.incidence.

Timeline of HIV Surveillance in Timeline of HIV Surveillance in CaliforniaCalifornia

Comparing Core & HIV Incidence Comparing Core & HIV Incidence Surveillance (HIS)Surveillance (HIS)

Core SurveillanceCore Surveillance HISHIS

Measures New New diagnosesdiagnoses

HIV PrevalenceHIV Prevalence Existing cases Existing cases

New New infectionsinfections

HIV IncidenceHIV Incidence New casesNew cases

Data collected

Demographic Demographic informationinformation HIV risk HIV risk HIV test resultHIV test result AIDS Indicators AIDS Indicators

Also:Also: Past HIV testing historyPast HIV testing history Medications to treat or Medications to treat or

prevent HIV (ARV) prevent HIV (ARV) STARHS test result from STARHS test result from

remnant blood specimenremnant blood specimen

Uses of data Both important to guiding prevention and care; Both important to guiding prevention and care;

resource allocation. resource allocation.

Changes in burden of Changes in burden of disease.disease.

Where infection is Where infection is spreadingspreading

Requirements for HIV Incidence Requirements for HIV Incidence SurveillanceSurveillance

Remnant HIV+ SerumSTARHS Testing

Patient Testing and Treatment History

HIV Incidence Estimation

Core demographic& clinical data from

HIV/AIDS case reports

Remnant HIV+ SerumSTARHS Testing

Patient testing and Treatment History

HIV Incidence Estimation

Core demographic& clinical data from

HIV/AIDS case reports

Requirements for HIV Incidence Requirements for HIV Incidence SurveillanceSurveillance

Antibody-based laboratory testing Antibody-based laboratory testing method that allows CDC to identify, method that allows CDC to identify, with reasonable probability, how with reasonable probability, how many newly reported HIV diagnoses many newly reported HIV diagnoses represent recent infections.represent recent infections.

STARHSSTARHS

Serologic Testing Algorithm for Recent HIV Seroconversion

Combination of two HIV antibody tests Combination of two HIV antibody tests can detect recent HIV infectioncan detect recent HIV infection

– Standard HIV antibody test (EIA)Standard HIV antibody test (EIA)– STARHS test (HIV-1 BED Capture STARHS test (HIV-1 BED Capture

EIA)EIA)

Average window period of 5 months to Average window period of 5 months to detect recent HIV-1 seroconversion.detect recent HIV-1 seroconversion.

STARHSSTARHS

Serologic Testing Algorithm for Recent HIV Seroconversion

Only approved for public health Only approved for public health surveillance purposes.surveillance purposes.

Test results are not returned to the Test results are not returned to the patient.patient.

STARHSSTARHS

Serologic Testing Algorithm for Recent HIV Seroconversion

STARHS Window Period

HIV IgG / Total IgG

INFECTION

Incident case

Standard EIA

Prevalent case

BED HIV-1 Capture EIA

Ave. Window Period = 153 days (~5 months); 95% CI 146 – 168 days

TIMETIME

RECENT SEROCONVERSION

(STARHS reactive)

NOT RECENT

Remnant HIV+ SerumSTARHS Testing

Patient Testing and Treatment History

HIV Incidence Estimation

Core demographic& clinical data from

HIV/AIDS case reports

Requirements for HIV Incidence Requirements for HIV Incidence SurveillanceSurveillance

Patient Testing Patient Testing and Treatment Historyand Treatment History

Calculate appropriate statistical weights to Calculate appropriate statistical weights to ensure incidence estimates can be ensure incidence estimates can be generalized to the California population. generalized to the California population.

Identify people with previous positive HIV Identify people with previous positive HIV test results and those already being treated test results and those already being treated for HIV infection.for HIV infection.

Distinguish between repeat HIV testers and Distinguish between repeat HIV testers and new HIV testers; and measure HIV testing new HIV testers; and measure HIV testing frequency.frequency.

Allows us to:Allows us to:

Key Non-Health Key Non-Health Department PartnersDepartment Partners

Providers: Providers: – Ensure records for newly diagnosed HIV Ensure records for newly diagnosed HIV

cases include testing and treatment history.cases include testing and treatment history.– First positive HIV TestFirst positive HIV Test– Last negative HIV test, if anyLast negative HIV test, if any– Exposure to antiretroviral medication(s)Exposure to antiretroviral medication(s)

– Facilitate completion of HIV/AIDS case Facilitate completion of HIV/AIDS case report form when new HIV case is report form when new HIV case is diagnosed.diagnosed.

Key Non-Health Key Non-Health Department PartnersDepartment Partners

Laboratories:Laboratories:– Ship remnant serum samples to central Ship remnant serum samples to central

facility for STARHS testingfacility for STARHS testing

Key Health Key Health Department PartnersDepartment Partners

Local Health DepartmentsLocal Health Departments– Collect core surveillance variables and TTH Collect core surveillance variables and TTH

data from providers and active surveillance data from providers and active surveillance

Office of AIDSOffice of AIDS– Raise awareness and interestRaise awareness and interest– Guidance, technical support and monitoringGuidance, technical support and monitoring– Data management and transfer to CDCData management and transfer to CDC– Complete California incidence estimationComplete California incidence estimation

Thank You!Thank You!

For more information please visit our For more information please visit our websites: websites:

HIV/AIDS Surveillance in CaliforniaHIV/AIDS Surveillance in Californiawww.cdph.ca.gov/programs/OAHISwww.cdph.ca.gov/programs/OAHIS

HIV Incidence Surveillance in the U.S.HIV Incidence Surveillance in the U.S.www.cdc.gov/hiv/topics/surveillance/incidence.htmwww.cdc.gov/hiv/topics/surveillance/incidence.htm