What is an IACC?

Long COVID is a broad term for conditions that persist following COVID, and some of those conditions aren't chronic illnesses that affect multiple body systems so are not IACCs.IACCs are highly varied. Different conditions can have very different symptoms and possible causes. Even people with the same condition can have very different symptoms, affected body systems, severity, and courses of illness. A person's symptoms can also change over time, with some symptoms becoming more or less prominent and different body systems becoming involved.

Some IACCs involve post-exertional malaise (PEM) or other forms of exertion intolerance, in which physical or mental activity can worsen symptoms. PEM and exertion intolerance are important features of some IACCs, but they are not present in every IACC or in every person with an IACC.

The illness may be associated with an identified infection or with another potential trigger, such as physical trauma, an accident, environmental exposure, or psychological or physical stress. Different triggers may be associated with similar illnesses, and the same trigger may be associated with different illnesses. We often do not know what role the trigger plays. It may bring a previously unrecognized illness to the surface, start the illness, or change how it develops or presents.

IACCs include conditions such as ME/CFS, persistent or chronic Lyme disease, and fibromyalgia, as well as chronic illnesses associated with other infections. Long COVID is a broad term for conditions that persist following COVID, but only those conditions that are chronic illnesses which affect multiple body systems are IACCs.

Sources Include:

• https://wwwnc.cdc.gov/eid/article/31/14/25-1187_article

• https://en.wikipedia.org/wiki/Post-acute_infection_syndrome

• https://www.cdcfoundation.org/programs/strengthening-partnerships-address-infection-associated-chronic-conditions

• https://pmc.ncbi.nlm.nih.gov/articles/PMC12421693/