Reference
Glossary
Key terms used across the Hub’s epidemiology, FMD, and systems documentation.
Epidemiology terms
- Basic reproductive number
- In a fully susceptible population, R0 is the number of secondary infections generated by the first infectious individual over the course of the infectious period.
- Compartmental model
- A rule-based disease model that divides the population into compartments representing disease states (susceptible, infected, recovered, vaccinated).
- Herd immunity threshold
- The minimum proportion of a population that must be immune to prevent sustained spread.
- Incidence
- The number of new cases of a disease occurring during a specified period in a population at risk.
- Intervention
- An action implemented to alter the course of events within a system; in epidemiology, this includes vaccination, quarantine, and treatment. Interventions are tested within the model to evaluate their effectiveness.
- PatchSim
- A metapopulation modelling framework in which disease spreads across interconnected geographical patches. Each patch has its own dynamics but patches connect via movement, enabling study of localised outbreaks and spatially targeted control.
- Prevalence
- The total number of cases of a disease in a given population at a specific time.
- Scenario
- A specific set of assumptions and parameters used to explore potential outcomes of a system. Scenarios let researchers and policymakers evaluate different interventions.
- SIR model
- A compartmental model with three states (susceptible, infectious, recovered).
- SIRS model
- Extension of SIR where recovered individuals can return to susceptible, reflecting waning immunity.
- SIRSV model
- SIRS with an additional Vaccinated state. Vaccinated individuals have partial or full immunity; waning returns them to susceptible over time.
- Susceptible
- An individual who can become infected.
FMD terms
- Antibody
- A protein produced by the immune system in response to a specific antigen; found in serum, the liquid portion of blood after clotting.
- Antigen
- A substance (protein or polysaccharide) that triggers an immune response, typically by producing antibodies.
- DIVA
- Differentiating Infected from Vaccinated Animals. A diagnostic approach using NSP-ELISA that distinguishes infected from vaccinated animals based on antibodies to non-structural proteins.
- Immunity waning
- Gradual decrease in protective immune response over time following vaccination or natural infection.
- Non-structural proteins
- Proteins produced during viral replication that are not part of the final virus particle but are essential for replication.
- Seromonitoring
- Under the FMD Control Programme, collection and analysis of pre- and post-vaccination blood samples from randomly selected animals, used to assess vaccine and campaign efficacy.
- Seroprotection
- The percentage of individuals in a population with antibody titres above a defined threshold ( ≥ 1.65 log10 at 35% inhibition). Indicates herd-level immunity.
- Serosurveillance
- Systematic monitoring of antibodies against FMD structural and non-structural proteins in animal populations, used alongside DIVA to detect virus circulation.
- Serotype
- A distinct antigenic variation of a virus. FMD virus has seven serotypes: O, A, C, SAT 1, SAT 2, SAT 3, Asia 1.
- Serum
- The clear, yellowish fluid component of blood remaining after clotting; contains proteins and antibodies.
- Structural proteins
- Proteins forming the virus particle, including the capsid that encases the viral genetic material.
Systems terms
- GeoJSON
- A JSON-based format for encoding geographic data structures (points, lines, polygons) with associated attributes.
- Model
- A formal description of a system that uses precise language to describe its behaviour or inter-relationships.
- Network
- A collection of interconnected nodes and edges representing relationships, interactions, or pathways.
- Node
- A point within a network representing an entity or location (individual, household, district).
- Ordinary differential equation (ODE)
- A mathematical equation relating a function to its derivatives. In epidemiology, ODEs describe changes in compartments over time.
- Simulation time
- The timeline over which a simulation model’s processes and events are executed.
- Timescale parameter
- Quantifies the rate of temporal change for a process in the model (for example, recovery rate or infection progression rate).