Our immune systems are incredibly intelligent and adaptable and when functioning optimally are able to identify and eliminate pathogens that may cause us harm and then clean up the mess left behind. This is all carried out on two fronts that work in tandem – innate immunity, which is our first-line of defence and adaptive immunity, which has a specific response that learns via exposure and memory over a period of time. 

Stealth pathogens are persistent parasitic, viral or bacterial infections that can lurk in our bodies undetected by the immune system over long periods of time, evading both the innate and adaptive immune responses. These stealth pathogens can trick the immune system and hide or lie dormant until the immune system is further compromised or challenged (Harley et al. 2018). They then cause an inflammatory process and confuse cell signalling to cause immune dysregulation and suppression. Sometimes stealth pathogens can lead to symptoms of fatigue, cognitive decline, insomnia, muscle aches and pains, anxiety and may result in autoimmunity (Harley et al 2018). 

For example, the Epstein-Barr Virus (EBV) also referred to as glandular fever or mononucleosis increases the risk of developing multiple sclerosis (MS), systemic lupus erythematosus (SLE) and possibly inflammatory bowel diseases (IBD) and coeliac disease. Paediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) is an autoimmune condition linked to the Streptococcus bacteria, more specifically Group A Streptococcus (GAS) infection, which can lead to a variety of neurological abnormalities.

References:

Harley, J.B. Chen, X. Pujato, M. Miller, D. Maddox, A. Forney, C. Magnusen, A.F. Lynch, A. Chetal, K. Yukawa, M. Barski, A. Salomonis, N. Kaufman, K.M. Kottyan, L.C. Weirauch, M.T. (2018). Transcription factors operate across disease loci, with EBNA2 implicated in autoimmunity. Nature Genetics. 50(5), 699-707. Doi: 10.1038/s41588-018-0102-3. https://sci-hub.tw/10.1038/s41588-018-0102-3