Guidelines for STI surveillance

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Guidelines for STI surveillance

• UNAIDS/WHO Working Group on Global HIV/AIDS and
  STI Surveillance

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STIs 333 million curable cases/year

• major causes of acute illness
• may lead to infertility
• can impose long term disability
• have psychological consequences
• may result in death

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Estimated new cases of curable STD among adults,
1995
Eastern Europe and Central Asia 18 million
North America 14 million
Western Europe 16 million
East Asia Pacific 23 million
North Africa Middle East 10 million
South South-East Asia 150 million
Sub-Saharan Africa 65 million
Latin America The Caribbean 36 million
Australasia 1 million
Global total 333 million
gonorrhoea, chlamydial infection, syphilis and
trichomoniasis
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STI Surveillance Components

• 1 - Case reporting
• 2 - Prevalence assessment and monitoring
• 3 - Assessment of STI syndrome etiologies
• 4 - Antimicrobial resistance monitoring
• 5 - Special STI surveillance-related studies
• 6 - Evaluation

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Case Reporting

• The type of case reporting used depends on the
  availability of laboratory tests in clinical
  care.
• Types and formats of case reporting
• Syndromic vs. Etiologic
• Universal vs. Sentinel

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Objectives of case-reporting

• asses disease burden
• monitor trends in incidence
• provide information useful in programme planning
  and management
• provides info required for patient and partner
  management
• provide data necessary for managing health
  services

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Data Elements

• Core data elements
• Diagnosis
• Reporting site
• Date of visit
• Gender
• Age group or age
• Additional data (residence, treatment,...) may
  also be collected

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Syndromic case-Reporting

• Practical to establish
• No need of laboratory facilities
• Can be performed at any level
• Provides information to
• Assess disease burden,
• monitor trends in incidence,
• assist in programme planning and management
• plan and manage delivery of health services
• LIMITATIONS
• Only urethral discharge and genital ulcer disease
  (non-vesicular) are potentially useful for
  monitoring trends in STD incidence
• Provides poor assessment of disease burden and
  trends in women
• Syndromes are not pathogen specific

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Syndromic Management

• uses no laboratory diagnostic tests
• uses flow charts as a basis for diagnosis and
  treatment
• provides treatment for diagnosis with multiple
  causative agents
• syndromic reporting fits in the context of
  management

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Etiologic Case-Reporting

• requires well-developed systems of laboratory
  diagnosis incorporated into routine STD clinical
  care
• requires diagnosis based on laboratory testing
• LIMITATIONS
• Many STIs are not useful for monitoring trends in
  incidence
• More useful for monitoring trends in STI
  incidence in men as compared to women
• Availability of diagnostic tests does not assure
  quality

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Universal Case-Reporting

• Provides a minimum estimate of population based
  STI incidence
• Advantage
• Good for reporting ongoing information on the
  capacity of health care providers to report STIs

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Sentinel Case-Reporting

• Purposes include
• assessment proportion of clinic attendees with
  STI compared with other conditions
• determination of STI distribution seen at clinics
• assessment of trends in numbers of cases at
  sentinel sites, as a possible indication of
  trends in disease burden in the community

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Sentinel-Case Reporting

• Disadvantages
• cannot be used to provide minimum
  population-based rates of disease
• not representative of other clinics
• integration of quality STD care into primary care
  may suffer

• Advantages
• obtain higher quality data
• more detailed data on patients

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Case-Reporting in the Private Sector

• Can be difficult to co-ordinate but may be
  improved through
• site visits
• training courses
• provision of written updates on STI diagnosis and
  treatment

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Critical Components of Data Quality

• completeness the proportion of reported cases
  with completed information
• validity the proportion of each data element
  that is correctly reported
• timeliness the time intervals between
  surveillance steps

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Analysis of Case-Reports

• Quarterly
• comparison of quarterly number of case-reports
  with the same quarter from previous year
• examination of quarterly trends in number of
  cases and prevalence from past 1-2 years

• Annually
• annual case reports
• annual trend in overall population-based rates of
  reported cases, using available census data and
  stratified by basic demographic categories

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Prevalence Assessment and Monitoring

• Primary purposes
• identify population subgroups with high STI
  prevalence
• monitor trends in STI prevalence among defined
  populations
• Primary limitation
• no role in the management of individual patients
  and their partners

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Useful STIs for prevalence assessment and
monitoring
In settings where patients are seen without
relation to symptoms

• syphilis (m,f)
• gonorrhoea (m,f)
• chlamydia (m,f)
• trichomoniasis (f)
• genital ulcer disease (m,f)
• urethral discharge (m)

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Prevalence Assessment Studies

• best done among high risk populations which are
  likely to have high prevalence
• minimally, assessment of prevalence must be done
  in major cities
• assessment of STI prevalence among women should
  include syphilis, chlamydia, and genital ulcers.

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Elements of Prevalence Studies

• sample size
• data elements and reporting formats
• measuring test positivity vs. prevalence
• linkages with HIV seroprevalence surveys
• analysis and interpretation

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Assessing Syndrome Etiologies

• Objectives
• Provide data for guiding STI syndromic management
• Assist in the interpretation of syndromic
  case-reports
• Assist in the assessment of disease burden due to
  specific pathogens

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Laboratory Requirements for Assessing Syndrome
Etiologies

• For urethral discharge
• microscopy chlamydia testing in selected
  settings
• For genital ulcer disease
• syphilis serologic testing
• chancroid culture, HSV culture or antigen
  detection test available in selected settings
• For vaginal discharge syndrome
• Gram stain, wet mount, KOH prep
• diagnostic test for chlamydia and gonorrhea

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Sampling considerations

• Selecting Populations and frequency
• Ideally, syndrome etiologies should be assessed
  in different types of populations with high and
  low rates of disease and which are geographically
  distributed
• Sample Size
• A sample size of 50 - 100 specimens can provide
  adequate confidence limits in most cases although
  true sample size is dependent on specific
  etiologies and the expected prevalence of
  pathogens

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Antimicrobial Resistance Monitoring

• Neisseria gonorrhoeae/Haemophilus ducreyi
• As a core component of STI surveillance and
  because of the extensive use of antibiotics to
  treat gonococcal infections, it is important for
  all countries to monitor microbial resistance in
  N. gonorrhoeae. If chancroid is high, periodic
  assessment of resistance in H. ducreyi is also
  recommended.

• OBJECTIVES
• To obtain data necessary for developing
  guidelines for treatment
• Demographic and risk information obtained may
  also be used to further characterize risk factors
  for resistance
• Determine the local epidemiology of a disease

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Laboratory requirementsfor resistance monitoring

• ability to culture organisms
• perform biochemical and serologic confirmatory
  tests
• testing for the minimum inhibitory concentration
  on antimicrobial agents

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Special STI Surveillance -related Studies

• Used to address STI surveillance issues which
  are not part of routine case reporting or
  prevalence assessments.
• Examples
• outbreak investigations
• prevalence of viral STIs
• estimation of economic costs of STIs

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Evaluation of Surveillance Systems

• identification of all STI surveillance
  activities, characterized by components, and
  syndrome or disease
• initially evaluate each component separately,
  separate attention should be paid to each
  syndrome or disease
• overall assessment identifying gaps, duplication,
  and areas in need of strengthening

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Disseminating, communicating, and using STI
surveillance data

• disseminate to health centers and clinicians
• national STI programme managers
• In communicating consider using...
• annual reports
• newsletters
• press releases
• fact sheets