direct type

Indirect

insect borne diseases

The host can completely eliminate the parasite

The host can eliminate some parasites

The host cannot effectively control the parasite

elimination immunity

non-eliminating immunity

Isolation of anatomical parts

changes in surface antigens

Suppress host immune response

Antigens (dust mites, hydatid cysts, schistosomiasis) stimulate individuals to produce IgE

IgE binds to the IgE Fc receptor on the surface of mast cells and eosinophils

When the host is exposed to the same antigen again, the antigen binds to IgE that has been bound to mast cells/eosinophils, and a bridging reaction occurs.

Hypertrophy/eosinophil degranulation, release of inflammatory factors → telangiectasia, smooth muscle contraction, local inflammatory response, anaphylactic shock and death

(Kala-azar, malaria) parasite antigens adsorbed on the surface of red blood cells (target cells)

Target cell surface antigens bind to IgG and IgM

Complement activation, ADCC damages target cells

hemolysis, anemia

Parasite antigens and antibodies form immune complexes IC, which are deposited on the glomerular basement membrane/blood vessel wall → activate complement, inflammatory response with neutrophil infiltration → tissue necrosis

T cell mediated

Transmitted by water

transmitted through food

spread through soil

Transmitted through air (droplets)

Transmitted by arthropods

Directly transmitted through human body

mouth

skin

vector insect

placenta

respiratory tract

blood transfusion

autoinfection