Surveillance

What are the advantages of sentinel surveillance?

-Cheaper than population-based surveillance -Easier to run than population-based surveillance

What are some advantages of syndromic surveillance?

-Diverse: it can be applied to monitor environmental hazards such as flooding -Can be used to identify new hazards early on, as less time is needed to assess each case than with a disease surveillance system -Much more data can be used than with disease surveillance: e.g. NHS 111 calls, GP records, A+E attendances, Google searches

What are some requirements for an effective surveillance system?

-JUSTIFIED: it should be contributing sufficiently to protecting the health of the population -TARGETED: it must address a certain activity or question -CONSISTENT: methods of data collection, analysis and reporting must be consistent -RESOURCES: sufficient resources must be available -TRANSPARENT: impartial quality assurance processes should be in place -APPROPRIATE: the output should be relevant to the question(s) being addressed -WELL-FORMATTED: analysis and reporting must be done in a transparent and accurate manner which informs action -LEGAL: it must work within the legal framework for collecting, storing and using the data of individuals

When might a sentinel surveillance system be used?

-When a sample is likely to accurately represent the whole population -When the sub-population is identifiable and testing the whole population would be wasteful

When might a syndromic surveillance system be used?

-When the infectious agent is not yet known -To identify conditions associated with environmental factors such as water or air pollution

Give five uses for surveillance, with examples.

Detection of outbreaks and ensuring those in contact with certain diseases can receive appropriate interventions e.g. for meningococcal meningitis and subsequent antibiotic prophylaxis To monitor trends in disease and identify emerging threats e.g. monitoring emerging strains of influenza to direct vaccine development To inform infection control and prevention programmes, and evaluate public health policy e.g. to evaluate the efficacy of vaccination programmes, to identify the emergence of new strains To inform decisions about prioritisation so that limited health resources can be used effectively e.g. discontinuation of mobile TB screening services in the 1970s as it was shown that this was no longer cost-effective To monitor disease outcomes in order to inform interventions e.g. using MMR catch-up programmes in areas where measles outbreaks are occurring

Give an example of a surveillance system designed to monitor STIs in general.

Genitourinary Medicine Clinic Activity Dataset (GUMCADv2) -This collects data sent from all Level 2 and Level 3 sexual health services in England -Reporting is mandatory and occurs on a quarterly basis -Data is published annually -Collects information on services, diagnoses, demographics and sexual orientation GUMCADv3 will collect detailed behavioural data, and is currently being piloted.

What would an ideal surveillance system be like? What happens in reality?

IDEAL -Reliable -Accurate -Cost-effective -Flexible -Provides detailed data on every individual within the population REALITY A compromise must be made between detail and cost.

Why was syndromic surveillance developed?

Initially due to fears surrounding bioterrorism.

What is a disadvantage of syndromic surveillance?

Lacks in specificity.

What are the two primary types of data collected during surveillance?

MICROBIOLOGY Allows detection of an infectious agent. -Culture: the pathogen is grown and detected in an appropriate medium -Serology: patients can be tested for antibodies against the pathogen -Sequencing: the DNA or RNA of the pathogen can be sequenced; Next-Generation Sequencing can provide information on disease severity and susceptibility to treatment and/or vaccines INFORMATION TECHNOLOGY Large amounts of data can be transmitted rapidly, stored securely and analysed effectively.

What are the two types of surveillance in terms of detail?

POPULATION-BASED Every new case of a disease in a population is identified using the surveillance system. SENTINEL The disease is monitored at only a small number of facilities.

Combining the two types of each form of surveillance, give an example of how each combination may be used.

SENTINEL DISEASE SURVEILLANCE Monitoring of treatment efficacy (e.g. testing for HCV RNA) SENTINEL SYNDROME SURVEILLANCE Monitoring of intervention effects (e.g. vaccine efficacy for certain age groups with respect to influenza) POPULATION DISEASE SURVEILLANCE Outbreak identification (e.g. linking different cases of E.coli infection across the country) POPULATION SYNDROME SURVEILLANCE Incident monitoring (e.g. monitoring NHS 111 calls to see if outbreaks of gastrointestinal diseases were occurring during major flooding)

What are the two types of surveillance with respect to how the disease is detected?

SYNDROMIC Uses methods that rely on detecting indicators of disease before the official diagnosis is made. DISEASE Uses methods that rely on direct diagnosis of the disease.

Give four examples of surveillance systems used to monitor HIV/AIDS. What is the data used for?

Survey of prevalent HIV infections diagnosed (SOPHID) -Information from all people living with a diagnosed HIV infection and accessing NHS care in England, Wales and Northern Ireland is reported to SOPHID -This is used to plan services and monitor the quality of care provided to patients HIV and AIDS new diagnoses database (HANDD) -Reports new HIV diagnoses, AIDS cases and deaths received from clinicians and microbiologists -Data contributes to understanding of HIV transmission, and monitors exposure to HIV Recent infection testing algorithm (RITA) -Monitors the number of patients that have recently acquired HIV infections (though this is based on the point of diagnosis rather than the true point of acquisition) -Data is used to understand trends in HIV transmission CD4 surveillance scheme -Monitors CD4 cell count among drug-naive HIV diagnosed individuals who have a known seroconversion date -This is used to model CD4 decline, allowing estimation of the clinical outcome for individuals living with HIV

What is surveillance?

Systematic, continuous collection of data for analysis and interpretation, to assess and inform public health action.