Los Angeles County Los Angeles County STD SurveillanceSTD Surveillance

Data Surveillance, Sources, Data Surveillance, Sources, Methods and IssuesMethods and Issues

Lisa V. Smith, MS, DrPHLisa V. Smith, MS, DrPH

Director, Epidemiology UnitDirector, Epidemiology Unit

Los Angeles County Los Angeles County Sexually Transmitted Disease ProgramSexually Transmitted Disease Program

OverviewOverview

What are active and passive surveillance?What are active and passive surveillance? Which STDs are reportable? Which STDs are reportable? What is the impact of LA County morbidity What is the impact of LA County morbidity

on state and national STD surveillance?on state and national STD surveillance? How are cases reported to LA County How are cases reported to LA County

(LAC), State, and CDC? (LAC), State, and CDC? What are “rates” and how are they used?What are “rates” and how are they used? What are the limitations and benefits of What are the limitations and benefits of

LAC STD surveillance data?LAC STD surveillance data?

What is Surveillance?What is Surveillance?SystematicSystematic collection and evaluation of: collection and evaluation of: Morbidity and mortality dataMorbidity and mortality data Special reports of field investigation of Special reports of field investigation of

epidemics and individual cases epidemics and individual cases Data on the isolation and identification of Data on the isolation and identification of

infectious agents by public or private infectious agents by public or private laboratorieslaboratories

Information regarding immunity levels in Information regarding immunity levels in certain populationscertain populations

What do we do with this What do we do with this information?information?

Estimate the magnitude of health conditions Estimate the magnitude of health conditions in at-risk populationsin at-risk populations

Detect sudden changes in occurrence and Detect sudden changes in occurrence and distributiondistribution

Detect changes in drug resistanceDetect changes in drug resistance Identify changes in health care practicesIdentify changes in health care practices Evaluate control strategiesEvaluate control strategies Allocate resourcesAllocate resources

Data SourcesData Sources

Active Surveillance Conditions of particular importance Conditions of particular importance (outbreaks and epidemics)(outbreaks and epidemics)

Passive Surveillance Routine notifiable disease surveillance Routine notifiable disease surveillance reported case by casereported case by case

Active SurveillanceActive Surveillance Casefinding:Casefinding:

– Prevalence MonitoringPrevalence Monitoring• Sentinel Surveillance: K-11, Juvenile Hall, Sentinel Surveillance: K-11, Juvenile Hall,

Family Planning Clinics, Bathhouses, Family Planning Clinics, Bathhouses, Syphilis Elimination Project (MSM)Syphilis Elimination Project (MSM)

• Mass Screening: Mobile testing, Adult Mass Screening: Mobile testing, Adult Movie IndustryMovie Industry

– Epidemiologic research: Primary HIV Epidemiologic research: Primary HIV infectioninfection

Passive SurveillancePassive Surveillance

Accounts for most of the reported casesAccounts for most of the reported cases Relatively simple compared to active Relatively simple compared to active

surveillancesurveillance Limited by variability and incompletenessLimited by variability and incompleteness May fail to identify outbreaks May fail to identify outbreaks Usually augmented by active surveillanceUsually augmented by active surveillance

Which STDs are reportable?

Health Care Provider Syphilis* Gonorrhea** Chlamydia** Chancroid** PID** NGU**

Clinical Laboratory Syphilis (Treponema

pallidum) Gonorrhea (Neisseria

gonorrhoeae) Chlamydia (Chlamydia

trachomatis)

California Code of Regulations, Title 17, Public Health, Section 2500, 1996*Report by FAX, telephone, or mail w/in one working day of identification*Report by FAX, telephone, or mail w/in seven working days of identification

Reported Sexually Transmitted Diseases United States, 2003

Source: CDC Sexually Transmitted Disease Report, 2001

AIDS

Gonorrhea335,104(26.4%)

P&S Syphilis

7,177(<1%)

Early Latent8,361(<1%)

Congenital Syphilis

413(<1%)

Chlamydia877,478(69.0%)

AIDS43,158(3.6%)

Reported Sexually Transmitted DiseasesLos Angeles County, 2003

*Provisional data due to reporting delaysSource: LAC DHS STD/ACD Programs Provisional Data, 2003

AIDS1,399*(3%)

Gonorrhea8,008

(17%)

P&SSyphilis

442(>1%)

Early Latent365

(>1%)

Congenital Syphilis

28(>1%)

Chlamydia36,555(78%)

What is the Impact of LAC What is the Impact of LAC Morbidity on STD ReportingMorbidity on STD Reporting

in CA & USin CA & US**

36,555 Chlamydia 36,555 Chlamydia (31% CA; 4% US)(31% CA; 4% US)

8,008 Gonorrhea 8,008 Gonorrhea (31% CA; 2% US)(31% CA; 2% US)

442 P&S Syphilis 442 P&S Syphilis (34% CA; 6% US)(34% CA; 6% US)

365 Early Latent 365 Early Latent (54% CA; 4% US)(54% CA; 4% US)

28 Congenital Syphilis 28 Congenital Syphilis (47% CA; 7% US)(47% CA; 7% US)

*LA, CA, CDC STD Surveillance, 2003*LA, CA, CDC STD Surveillance, 2003P&S:chancres/lesions (90 days-6 months); EL asymptomatic (w/in 12 months)

How are cases reported How are cases reported to the STD Program?to the STD Program?

Health providers use forms to report STD Health providers use forms to report STD cases to the health department cases to the health department

STDP uses a “dual” reporting system to STDP uses a “dual” reporting system to gather information on STD morbiditygather information on STD morbidity– Confidential Morbidity Forms (CMRs)Confidential Morbidity Forms (CMRs)

• Submitted by health providersSubmitted by health providers– Laboratory Report FormsLaboratory Report Forms

• Submitted by laboratory facilitiesSubmitted by laboratory facilities

Medical Provider’s STD Reporting Form

Medical Provider’s STD Reporting Form

Example of Laboratory STD Reporting Form for CT/GC

STD Surveillance ProcessSTD Surveillance Process

Case Definition: Differential clinical diagnosis of reportable STDs to distinguish between cases and noncases

Population Definition: Identify area of interest to determine residency and population denominators

LAC STD ProgramLAC STD ProgramData Entry/ Field ServicesData Entry/ Field Services

Data Cleaning / TransmissionData Cleaning / Transmission

ConfidentialConfidentialMorbidityMorbidityReports (CMR)Reports (CMR)

Laboratory Laboratory SlipsSlips California DepartmentCalifornia Department

Of Health ServicesOf Health ServicesSTD Control BranchSTD Control Branch

Centers of Control Centers of Control and Prevention (CDC)and Prevention (CDC)

1. MMWR (Morbidity and Mortality Weekly Report)1. MMWR (Morbidity and Mortality Weekly Report)2. Requests for Proposals2. Requests for Proposals3. Healthy People 20103. Healthy People 2010

++

STD SurveillanceSTD Surveillance

All CA All CA countycountyreportsreports

Public HealthPublic HealthActionAction

85.2LA

(2003)

73.9CA

(2003)

116.2US

(2003)

Why do we use rates Why do we use rates and not absolute numbers? and not absolute numbers?

Total number of reported cases appears to Total number of reported cases appears to be adequate, but are these numbers be adequate, but are these numbers comparable?comparable?

Absolute NumbersAbsolute Numbers(Males Only)(Males Only)

BlackBlack HispanicHispanic AsianAsian WhiteWhite

Reported Reported Chlamydia Chlamydia Cases in Cases in 20012001

1,9651,965 2,7202,720 181181 622622

STD RatesSTD Rates

Number of new events in specific periodNumber of new events in specific period

Average population* during specific periodAverage population* during specific periodX X 1010nn

Essential for comparing dx in different populationsEssential for comparing dx in different populations::

Pop A: 1,000/10,000 = Pop A: 1,000/10,000 = 100100 cases per 1000 population cases per 1000 population

Pop B: 1,000/1,000,000 = Pop B: 1,000/1,000,000 = 11 case per 1000 population case per 1000 population

*Assumes average population and “population at risk” are comparable.

=

multipliermultiplier

Population RatesPopulation Rates(Males Only)(Males Only)

BlackBlack HispanicHispanic AsianAsian WhiteWhite

Reported Reported ChlamydiaChlamydiaCases in Cases in 20012001

1,9651,965 2,7202,720 181181 622622

*Population *Population EstimatesEstimates

396,614396,614 2,297,2082,297,208 593,633593,633 1,590,5861,590,586

Rate per Rate per 100,000100,000

PopulationPopulation

495495 118118 3030 3939

*2000 Estimates*2000 Estimates

How are these rates used?

Figure 1. Chlamydia Reported Rates by Year, United States, California, and Los Angeles County (LAC), 1997-2001

260258

252

234

207

208

229

251

277

294

239

249

283

310

332

150

200

250

300

350

1997 1998 1999 2000 2001

Year

Ra

tes

pe

r 1

00

,00

0 p

op

ula

tio

n

United States (1)

California (2)

LA County (2)

(1) CDC. Sexually Transmitted Disease Surveillance, 2000 , September 2001, p. 83.(2) California Department of Health Services, STD Control Branch, Chlamydia, Cases and Rates by Health Jurisdiction, California, 1997-2001 Provisional Data. Note: The 2001 US rate w as extrapolated from the 1997-2000 rates since the 2001 CDC rate w as not at available at the time of this w riting.

1. Identify overall trends1. Identify overall trends

Chlamydia Rates by GenderChlamydia Rates by Gender

0

50

100

150

200

250

300

350

400

450

500

Pop

ula

tion

per

100

,000

Male Female

Age Group

US

CA

LA

2. Describe disease2. Describe disease patternspatterns

3. Describe spatial3. Describe spatial distributionsdistributions

4. Target interventions4. Target interventions

Additional Resources Additional Resources National Center for National Center for

Health StatisticsHealth Statistics Nation’s principal health statistics agencyNation’s principal health statistics agency Data are used to guide actions and policies, as Data are used to guide actions and policies, as

well as:well as:– Document health status of populations and important Document health status of populations and important

subgroupssubgroups– Identify disparities in health status by race/ethnicity, socio-Identify disparities in health status by race/ethnicity, socio-

economic status, region, etc.economic status, region, etc.– Monitor trends in health status and health care deliveryMonitor trends in health status and health care delivery– Support biomedical and health researchSupport biomedical and health research– Evaluate the impact of health careEvaluate the impact of health care

National Surveillance ReportsNational Surveillance Reports(www.cdc.gov/nchs)(www.cdc.gov/nchs)

National Health and Nutrition Examination Survey National Health and Nutrition Examination Survey (NHANES)(NHANES)– Contains important information on sexual behaviorsContains important information on sexual behaviors

National Health Interview Survey (NHIS)National Health Interview Survey (NHIS)– AIDS Knowledge and Attitudes SupplementAIDS Knowledge and Attitudes Supplement

Young Risk Behavior Surveillance System (YRBSS) Young Risk Behavior Surveillance System (YRBSS) (www.cdc.gov/yrbss)(www.cdc.gov/yrbss)– Survey monitors sexual behaviors that contribute to Survey monitors sexual behaviors that contribute to

unwanted pregnancies and STD/HIVunwanted pregnancies and STD/HIV UCLA ISSR website: UCLA ISSR website:

http://www.sscnet.ucla.edu/issr/da/catalog.htmhttp://www.sscnet.ucla.edu/issr/da/catalog.htm

Data LimitationsData Limitations Incomplete case reporting

– Reporting delays

– Missing information

– Underreporting (asymptomatic cases) Reporting bias

– Stigmatized condition

– Public vs. Private

How Can We Improve Data How Can We Improve Data Quality?Quality?

Improve data retrieval systemImprove data retrieval system– Phone ShopPhone Shop

Increase provider awareness of reporting Increase provider awareness of reporting regulationsregulations– In-servicesIn-services– Mass MailingsMass Mailings– In person visitsIn person visits

Implement CDC NEDSS web-based surveillanceImplement CDC NEDSS web-based surveillance

What are the Benefits of What are the Benefits of STD Surveillance?STD Surveillance?

Though flawed, STD surveillance data Though flawed, STD surveillance data provides provides – the “best estimate” of magnitude of the “best estimate” of magnitude of

disease in at-risk populations disease in at-risk populations • Numbers are the “tip” of the icebergNumbers are the “tip” of the iceberg

– the basis for epidemiologic researchthe basis for epidemiologic research– a system to monitor compliance with a system to monitor compliance with

CDC treatment guidelinesCDC treatment guidelines

Key Points to PonderKey Points to Ponder To date, six STDs are reportable in CaliforniaTo date, six STDs are reportable in California Chlamydia is the most frequently reported STD in the Chlamydia is the most frequently reported STD in the

United StatesUnited States Los Angeles accounts for 1 of 3 STD cases in Los Angeles accounts for 1 of 3 STD cases in

California and 1 of 25 cases in the United StatesCalifornia and 1 of 25 cases in the United States Most of the STD data come from passive surveillance Most of the STD data come from passive surveillance

systems and “dual” reportingsystems and “dual” reporting Data limitations include incomplete case reporting and Data limitations include incomplete case reporting and

reporting bias reporting bias Nevertheless, STD surveillance data provides the “best STD surveillance data provides the “best

estimate” of magnitude of disease in at-risk populationsestimate” of magnitude of disease in at-risk populations

ResourcesResources Los Angeles County

http://lapublichealth.org/std/

California http://www.dhs.ca.gov/ps/dcdc/pdf/cdtables/febcm03.pdf

Centers for Disease Control and Prevention http://www.cdc.gov/

http://www.cdc.gov/nedss/