Guidance

SIU dashboards: data limitations

Published 28 October 2024

The Surveillance Intelligence Unit (SIU) collects animal disease surveillance data and publishes it in dashboards.

There are some limitations in how the data in these dashboards can be interpreted.

The SIU is part of the Animal and Plant Health Agency (APHA). These dashboards are produced in partnership with Scotland’s Rural College (SRUC).

1. Dashboards

You can view each dashboard on Tableau:

• avian disease
• cattle disease
• pig disease
• sheep disease

1.1 Other dashboards

• Brachyspira hyodysenteriae isolate MLST in pigs
• porcine reproductive and respiratory syndrome
• bat rabies

2. How the data is collected

The dashboards are limited to diagnoses recorded in the GB diagnostic surveillance database, known as VIDA (Veterinary Investigation Diagnosis Analysis), from submissions to the GB veterinary diagnostic network.

The network includes:

• APHA’s Veterinary Investigation Centres in England and Wales
• Scotland’s Rural College Disease Surveillance Centres in Scotland operated by SRUC Veterinary Services
• APHA’s surveillance pathology partners who provide post-mortem examination services under contract
• APHA Lasswade (for poultry only)

Diagnoses are recorded for the month in which the submissions were received. The dashboards are updated on a monthly basis, adding all diagnoses allocated since the previous month’s update.

3. Data limitations

The data, dashboards and maps should not be used to make inferences or comparisons about levels of disease in different areas due to the following limitations:

• The data has been collected solely from the GB veterinary diagnostic network. The dashboards do not include diagnoses made by other laboratories. 
• A higher count of diagnoses in a county may occur for several reasons, including:
  • more submissions due to a larger number of livestock or livestock holdings
  • increased vigilance among the local farmers and vets in response to a threat
  • diagnostic investigations as part of disease control initiatives being implemented
  • regional increased use of the GB diagnostic network rather than commercial or veterinary practice laboratories
• Diseases not requiring a laboratory diagnosis or in herds whose veterinary practice has their own diagnostic facilities may be under-represented in the data.
• Submissions may represent more than one individual animal, and there may be more than one diagnosis allocated for a submission.

3.1 Other data limitations:

• APHA periodically has initiatives to collect data about specific diseases which will skew reported levels of disease  
• Particular diagnoses may be affected by a range of factors which can vary over time, such as improved scientific test methods and knowledge of these test methods
• APHA data only includes cases of diagnosed clinical disease. However, SRUC VS includes some non-diagnostic cases. As such, you should exclude any submissions with the codes “Diagnosis not applicable” (code 991) and “Screening– No clinical problem” (code 980) when comparing disease trends.