A superinfection is 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 that occurs following treatment with a broad-spectrum antibiotic, and pneumonia or sepsis from Pseudomonas aeruginosa in some immunocompromised 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. Recent metagenomic analyses have demonstrated that the novel coronavirus, SARS-CoV-2 can be associated with superinfection and colonization of other pathogens, such as rhinovirus species and Moraxella spp.
- "Superinfection". Merriam-Webster Inc. Retrieved 14 March 2014.
- "Treatment of neutropenic fever syndromes in adults with hematologic malignancies and hematopoietic cell transplant recipients (high-risk patients)". www.uptodate.com. Retrieved 2016-02-09.
- "HIV types, subtypes groups and strains: Is it possible to be infected more than once?". www.avert.org. AVERT. Retrieved 2010-11-23.
- Robert M. Grant; J. Jeff McConnell (May 2006). "What do we know about HIV superinfection?". www.ucsf.edu. University of California, San Francisco. Retrieved 2010-11-23.
- Peddu V.; Shean R.C.; Shrestha L.; Perchetti G.A.; Minot S.; Roychoudhury P.; Huang M.L.; Nalla A.K.; Reddy S.B.; Reinhardt A.; Jerome K.R.; Greninger A.L (May 2020). "Metagenomic analysis reveals clinical SARS-CoV-2 infection and bacterial or viral superinfection and colonization". Clinical Chemistry. 66 (7): 966–972. doi:10.1093/clinchem/hvaa106. PMC 7239240. PMID 32379863.