Los Angeles County STD Surveillance Data Surveillance, Sources, Methods and Issues Lisa V. Smith, MS, DrPH Director, Epidemiology Unit Los Angeles County Sexually Transmitted Disease Program

Overview  What are active and passive surveillance?  Which STDs are reportable?  What is the impact of LA County morbidity on state and national STD surveillance?  How are cases reported to LA County (LAC), State, and CDC?  What are “rates” and how are they used?  What are the limitations and benefits of LAC STD surveillance data?

What is Surveillance? Systematic collection and evaluation of:  Morbidity and mortality data  Special reports of field investigation of epidemics and individual cases  Data on the isolation and identification of infectious agents by public or private laboratories  Information regarding immunity levels in certain populations

What do we do with this information?  Estimate the magnitude of health conditions in at-risk populations  Detect sudden changes in occurrence and distribution  Detect changes in drug resistance  Identify changes in health care practices  Evaluate control strategies  Allocate resources

Data Sources Conditions of particular importance (outbreaks and epidemics)  Active Surveillance Conditions of particular importance (outbreaks and epidemics) Routine notifiable disease surveillance reported case by case  Passive Surveillance Routine notifiable disease surveillance reported case by case

Active Surveillance  Casefinding: –Prevalence Monitoring Sentinel Surveillance: K-11, Juvenile Hall, Family Planning Clinics, Bathhouses, Syphilis Elimination Project (MSM)Sentinel Surveillance: K-11, Juvenile Hall, Family Planning Clinics, Bathhouses, Syphilis Elimination Project (MSM) Mass Screening: Mobile testing, Adult Movie IndustryMass Screening: Mobile testing, Adult Movie Industry –Epidemiologic research: Primary HIV infection

Passive Surveillance  Accounts for most of the reported cases  Relatively simple compared to active surveillance  Limited by variability and incompleteness  May fail to identify outbreaks  Usually 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 43,158 (3.6%)

Reported Sexually Transmitted Diseases Los Angeles County, 2003 *Provisional data due to reporting delays Source: LAC DHS STD/ACD Programs Provisional Data, 2003

What is the Impact of LAC Morbidity on STD Reporting in CA & US*  36,555 Chlamydia (31% CA; 4% US)  8,008 Gonorrhea (31% CA; 2% US)  442 P&S Syphilis (34% CA; 6% US)  365 Early Latent (54% CA; 4% US)  28 Congenital Syphilis (47% CA; 7% US) *LA, CA, CDC STD Surveillance, 2003 P&S:chancres/lesions (90 days-6 months); EL asymptomatic (w/in 12 months)

How are cases reported to the STD Program?  Health providers use forms to report STD cases to the health department  STDP uses a “dual” reporting system to gather information on STD morbidity –Confidential Morbidity Forms (CMRs) Submitted by health providersSubmitted by health providers –Laboratory Report Forms Submitted by laboratory facilitiesSubmitted by laboratory facilities

Medical Provider’s STD Reporting Form

Example of Laboratory STD Reporting Form for CT/GC

STD 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 Program Data Entry/ Field Services Data Cleaning / Transmission ConfidentialMorbidity Reports (CMR) LaboratorySlips California Department Of Health Services STD Control Branch Centers of Control and Prevention (CDC) 1. MMWR (Morbidity and Mortality Weekly Report) 2. Requests for Proposals 3. Healthy People STD Surveillance All CA countyreports Public Health Action

85.2 LA (2003) 73.9 CA (2003) US (2003)

Why do we use rates and not absolute numbers?  Total number of reported cases appears to be adequate, but are these numbers comparable?

Absolute Numbers (Males Only) BlackHispanicAsianWhite Reported Chlamydia Cases in ,9652,

STD Rates Number of new events in specific period Number of new events in specific period Average population* during specific period X 10 n Essential for comparing dx in different populations: Pop A: 1,000/10,000 = 100 cases per 1000 population Pop B: 1,000/1,000,000 = 1 case per 1000 population *Assumes average population and “population at risk” are comparable. = multiplier

Population Rates (Males Only) BlackHispanicAsianWhite Reported Chlamydia Cases in ,9652, *Population Estimates 396,6142,297,208593,6331,590,586 Rate per 100,000 Population *2000 Estimates

How are these rates used?

1. Identify overall trends

Chlamydia Rates by Gender 2. Describe disease patterns patterns

3. Describe spatial distributions distributions

4. Target interventions

Additional Resources National Center for Health Statistics  Nation’s principal health statistics agency  Data are used to guide actions and policies, as well as: –Document health status of populations and important subgroups –Identify disparities in health status by race/ethnicity, socio-economic status, region, etc. –Monitor trends in health status and health care delivery –Support biomedical and health research –Evaluate the impact of health care

National Surveillance Reports (  National Health and Nutrition Examination Survey (NHANES) –Contains important information on sexual behaviors  National Health Interview Survey (NHIS) –AIDS Knowledge and Attitudes Supplement  Young Risk Behavior Surveillance System (YRBSS) ( –Survey monitors sexual behaviors that contribute to unwanted pregnancies and STD/HIV  UCLA ISSR website:

Data Limitations  Incomplete case reporting –Reporting delays –Missing information –Underreporting (asymptomatic cases)  Reporting bias –Stigmatized condition –Public vs. Private

How Can We Improve Data Quality?  Improve data retrieval system –Phone Shop  Increase provider awareness of reporting regulations –In-services –Mass Mailings –In person visits  Implement CDC NEDSS web-based surveillance

What are the Benefits of STD Surveillance?  Though flawed, STD surveillance data provides –the “best estimate” of magnitude of disease in at-risk populations Numbers are the “tip” of the icebergNumbers are the “tip” of the iceberg –the basis for epidemiologic research –a system to monitor compliance with CDC treatment guidelines

Key Points to Ponder  To date, six STDs are reportable in California  Chlamydia is the most frequently reported STD in the United States  Los Angeles accounts for 1 of 3 STD cases in California and 1 of 25 cases in the United States  Most of the STD data come from passive surveillance systems and “dual” reporting  Data limitations include incomplete case reporting and reporting bias STD surveillance data provides the “best estimate” of magnitude of disease in at- risk populations  Nevertheless, STD surveillance data provides the “best estimate” of magnitude of disease in at- risk populations

Resources  Los Angeles County  California 03.pdf  Centers for Disease Control and Prevention 