What is "superinfection"

n. An infection which follows or occurs during another infection or disease process.

n. infection that occurs while you are being treated for another infection

A superinfection is generally defined as a second infection superimposed on an earlier one, especially by a different microbial agent of exogenous or endogenous origin, that is resistant to the treatment being used against the first infection. Examples of this in bacteriology are the overgrowth of endogenous Clostridium difficile which occurs following treatment with a broad-spectrum antibiotic, and pneumonia or septicemia from Pseudomonas aeruginosa in some immuno-compromised patients.

In virology, the definition is slightly different. Superinfection is the process by which a cell that has previously been infected by one virus gets co-infected with a different strain of the virus, or another virus, at a later point in time. Viral superinfections may be resistant to the antiviral drug or drugs that were being used to treat the original infection. Viral superinfections may also be less susceptible to the host's immune response.