- Agent of disease
- Being the carriers/vectors of disturbing , destroying or causative agents
- vectors being
- any other species which carry the disease with in themselves
- insects
- causative agents
- non - cellular life
- Viral Infection , virology
- cellular life
- Bacterial Infection , microbiology
- Parasitic Infection , parasitology
- Fungal Infection , mycology
- Entry of either vectors or causative agents
- Mode of transmission of either vectors or causative agents
- water borne disease
- air borne diseases
- food borne diseases
- Minerals and nutrition
- contact with other hosts
- physical contact or sexual contact