About public health surveillance

Public health surveillance is the ongoing, systematic collection, analysis, and interpretation of data on specific health events for use in the planning, implementation and evaluation of public health programmes.

ESR runs New Zealand's public health surveillance systems which provide critical information about a number of priority infectious diseases that require public health action in New Zealand. These include diseases which are legally notifiable as well as other important diseases which are not (e.g. acute respiratory infections).

Communicable disease surveillance is the continuous monitoring of the frequency and the distribution of disease, and death, due to infections that can be transmitted from human to human or from animals, food, water or the environment to humans, and the monitoring of risk factors for those infections.

Why do we undertake surveillance?

• Estimate magnitude of the problem
• Determine geographic distribution of illness
• Portray the natural history of a disease
• Detect epidemics/define a problem
• Generate hypotheses, stimulate research
• Evaluate control measures
• Monitor changes in infectious agents
• Detect changes in health practices
• Facilitate planning

What surveillance is ESR currently responsible for?

• Notifiable Disease Surveillance
• Outbreak Surveillance
• Sexually Transmitted Infections
• Influenza viruses
• Respiratory, enteric and herpes viruses

• View the notifiable diseases dashboard
• Download the guidelines for the investigation and control of disease outbreaks
• Check the schedule of notifiable diseases for New Zealand
• Communicable disease control manual
• Methodology information for the STI dashboard
• Methodology information for the Influenza and respiratory illness dashboard 

You can view our most recent publications by date order, or by topic.

See the table below for case report forms, instructions and field names. Note that cases should be logged electronically in Episurv. If you want to check which form to use for a specific disease, check the reference table here: https://episurv.esr.cri.nz/help/resources/disease-list/

To download a zipped file of all report forms, instructions and/or field names, click the links below:

All case report forms

All CRF instructions

All CRF with field names

Surveillance for AIDS and HIV is undertaken by the AIDS Epidemiology Group based in Otago University. However AIDS cases need to be created in EpiSurv (triggering a notification to the AIDS Epidemiology Group via REDCap). 

The form for initial AIDS notifications can be found here: AIDS initial notification form.  Download this form and send it to:

AIDS Epidemiology group
Dept of Preventative and Social Medicine
University of Otago Medical School
PO Box 913
Dunedin

HIV infection results are notified to EpiSurv by direct laboratory notification.

Click here for the link to the case definition for gonorrhoea.

Health practitioners, please notify cases of gonorrhoea via ESR's web-based REDCap form. Follow these instructions to complete the REDCap 'quesionnaire'. 

An example copy of the gonorrhoea notification form is available for health practitioners to preview the questions before beginning the online notification process: view an example

Please note: ESR does not accept paper-based notifications for gonorrhoea. Case notifications must be completed online via the REDCap form.

Click here for the link to the New Zealand CDC Manual case definition for syphilis. Note that late latent and tertiary syphilis are not notifiable.

The majority of infectious syphilis cases are notified by sexual health clinics who have access to a web-based REDCap database to input their data directly. Click here to view the REDCap instructions for sexual health clinics.

Health practitioners working outside sexual health clinics who diagnose infectious or congenital syphilis cases are required to complete a questionnaire and send it to ESR for entry into REDCap (further instructions are in the form). Please select the appropriate form below.

Syphilis infectious form   Word | PDF
Syphilis congenital form  Word | PDF

Click here to view the STI case definitions for clinic-based surveillance.

Participating clinics send anonymised data on the age, sex and ethnicity of all cases meeting one or more of the STI surveillance case definitions to ESR. 

Likewise, each month participating laboratories across New Zealand send anonymised data on confirmed cases of chlamydia and gonorrhoea by age and sex, to ESR. Laboratories also provide the total number of specimens and/or patients tested.

After checking and cleaning the data, ESR produces a dashboard and annual reports with all data reported during the previous year.

The current list of notifiable diseases can be found on the Ministry of Health website: http://www.health.govt.nz/our-work/diseases-and-conditions/notifiable-diseases. 

Case classifications (including laboratory and clinical criteria) for notifiable diseases and/or conditions are published in the Communicable Disease Control Manual. Trigger points for the notification of a laboratory test result are detailed in Appendix 4.

Data is recorded on EpiSurv (a national web-based database) for all notifiable diseases in NZ, with the following exceptions: 

• Acquired Immunodeficiency Syndrome (AIDS)
• Creutzfeldt-Jakob disease (CJD) and other spongiform encephalopathies
• Human Immunodeficiency Virus (HIV) infection
• lead absorption equal to or in excess of 0.24µmol/L 
• poisoning arising from chemical contamination of the environment.

For a summary of notification procedures, design and collection methods, quality control and editing procedures, and information specific to each disease, see the latest edition of the Notifiable Diseases in New Zealand Annual Report.

The data collected depends on the disease, but generally include case demography, health outcome, basis of diagnosis, risk factors and some clinical management information. Copies of the case report forms for each disease are loaded higher up on this page.

Under the Health Act 1956, health professionals are required to inform their local Medical Officer of Health of any suspected or diagnosed notifiable disease. Laboratories are also required to report any positive laboratory results for notifiable diseases to their local Medical Officer of Health.

Notifiable disease data reported to the Medical Officer of Health at each public health unit (PHU) is entered via a secure web-based portal into the EpiSurv national database. The near real-time data is collated and analysed by the Institute of Environmental Science and Research Ltd (ESR) on behalf of the Ministry of Health. 

ESR runs a comprehensive quality programme for the collection and reporting of notifiable disease data. This includes publishing and maintaining standards and manuals for reporting of disease, validation on data entry, regular analysis and follow-up with PHU staff to ensure completeness of key surveillance data fields (e.g. date of birth, sex, and ethnicity).

Regular surveillance reports on notifiable diseases are produced by the Institute of Environmental Science and Research Ltd (ESR) for the Ministry of Health as part of a contract for scientific services. 

The latest published data and reports can be found here.

Tier 1 statistical tables are released at the end of February each year for the calendar year prior. Annual notifiable disease reports are due for publication by December for the calendar year prior and the data tables contained in the reports replace the Tier 1 statistics. The annual notifiable disease dashboard is updated around July each year and can be found here.

As EpiSurv is a live database, data is extracted at a point in time that reflects the available information at that time. Every effort is made prior to publication to ensure that any anomalies and missing data are addressed. However, data extracted at a later date may be different to the data that was previously published. If a report includes historical data, this is updated each time a new report is published.

For most diseases, the case classification and investigations are finalised within one month. However, for some notifiable diseases (e.g. tuberculosis or legionellosis) it may take longer to obtain complete laboratory tests or all relevant clinical details. If the classification for a case is changed to ‘not a case’), the case will excluded from future reports.

Disease outbreaks are increases in the occurrance of a disease in excess of normally expected levels. Outbreaks are often related to contaminated food or water, or to illnesses spread from person to person. Every year, hundreds of people in New Zealand become unwell due to disease outbreaks, most of which are preventable.

The Institute of Environmental Science and Research Limited (ESR) has a central role in outbreak surveillance. This work includes:

• Regular analysis of notification, laboratory and other surveillance data to identify disease outbreaks early and minimise further spread of disease. 

• Operation of an outbreak surveillance system on behalf of the Ministry of Health. Outbreaks reported to, and investigated by, public health units are recorded on the outbreak report form in EpiSurv. This data is a resource for multiple agencies seeking to understand local and national patterns of disease in New Zealand and develop strategies for disease outbreak prevention. Information about outbreaks is reported in the monthly and annual surveillance summaries.

• Publication of the Guidelines for the surveillance and control of disease outbreaks to assist action at district or national level by streamlining particular processes according to a set routine or sound practice.

• ESR provides advice on outbreak detection and investigation to public health unit staff.
• ESR may contribute to and coordinate the investigation of, disease outbreaks of national importance, particularly those involving more than one health district.    

EARS is an Early Aberration Reporting System. You can find more information and methodology here.

If you need further information about notifiable diseases please contact us here