Jun 11, 2012
Medical Student
What is the immune response? Is it humoral or is it cell mediated? Are eosinophils involved?

Are there exceptions? (like bacteria is humoral except for atypicals- chlam etc- cell mediated).

I read that parasitic infections primarily cause damage via host immunity and not from parasite itself- only its larav/eggs etc cause mass effect damage. Is this correct?


Chief Derpologist
7+ Year Member
Jun 1, 2011
Resident [Any Field]
The primary immune response to fungal infection is cell-mediated, I believe. Think about chronic mucocutaneous candidiasis as an example. With decreased IL-2 and IFN-gamma (which stimulates macrophages), there is a decreased cellular immune response.

For USMLE purposes, I do not believe that eosinophils are involved. Causes of eosinophilia are NAACP (neoplasm, Addison's, asthma/allergy, connective tissue disease, parasites (helminths)).

With the bacteria, the difference between chlamydia and most other pathogens is that chlamydia is an obligate intracellular, which will provoke a cell-mediated response, whereas extracellular pathogens provoke a humoral response.

Parasites usually have systems that allow them to evade host defense so that they can set up long term infection in the body.