Answer:
availability of surveillance data
Step-by-step explanation:
Factors that influence the seasonal variation of disease are;
1. The host behaviour
2. Virulence of the infectious agent, the higher the virulence, the higher the spread of the disease.
3. Climate change, climate change may or may not favour the spread of certain diseases.
Availability of surveillance data does not influence seasonal variation of diseases. They are mainly influence by abiotic and biotic factors of the ecosystem.