Infectious disease-associated encephalopathy
Infectious disease-associated encephalopathy is a form of encephalopathy caused by infectious disease. It can be caused by infectious diseases including bacterial, viral, and protozoal infections. In IDAE, systemic inflammation in response to such infections, such as production of pro-inflammatory cytokines, results in neuroinflammation and consequent neurological and cognitive deficits. This can occur even though the pathogen does not necessarily directly infect the central nervous system.
Many different pathogens have been implicated in causing IDAE. These include bacterial infections like Klebsiella pneumoniae, protozoal infections like Plasmodium falciparum, and viral infections like influenza and SARS-CoV-2. Post-COVID-19 syndrome may be a post-acute form of IDAE.
The hippocampus and associated processes like memory may be especially vulnerable in IDAE. Neurological and cognitive deficits associated with IDAE can persist for many years after the initial infection has been cleared or may be irreversible. IDAE may be associated with increased risk of neurodegenerative diseases.
A particularly well-known subtype of IDAE is sepsis-associated encephalopathy.
Causes
The following pathogens, among others, have specifically been implicated in causing IDAE:- Bacteria
- * Klebsiella pneumoniae
- * Chlamydia pneumoniae
- * Chlamydia psittaci
- * Leptospira spp.
- * Listeria monocytogenes
- * Mycobacterium tuberculosis
- * Mycoplasma pneumoniae
- * Streptococcus pyogenes
- * Other Streptococcus spp.
- Protozoa/parasites
- * Toxoplasma gondii
- * Trypanosoma cruzi
- * Cryptococcus neoformans
- * Cryptococcus gattii
- * Plasmodium falciparum
- * Plasmodium vivax
- Viruses
- * Herpes simplex virus
- * Human herpesvirus
- * Influenza A virus
- * Influenza B virus
- * Human immunodeficiency virus
- * Human T-cell lymphotropic virus
- * Chikungunya virus
- * Cytomegalovirus
- * Dengue virus
- * Rift valley fever virus
- * Varicella zoster virus
- * SARS-CoV-2