Activated lymphocytes are often indicative of inflammation. Once activated, they trigger the release of inflammatory cytokines, causing various chronic conditions in the body. It sounds to me that you may have the beginnings of an auto-immune condition of some sort.
It's also possible the salmonella re-awakenened a latent virus in your body. If you find you have EBV, HHV6, parvovirus, or CMV, I suggest also getting tested for Lyme through IgeneX lab. Those viruses are often (but not always) found in conjunction with Lyme.
I'm a music teacher, and not a doctor. Anything I post is based on my own experience and lay opinion.
Lyme, Babesiosis, Mycoplasma (Asthma), Fibromyalgia (Soft Tissue Injury), Costochondritis,
CFS (Mitochondrial Dysfunction), IBS (Candida & Leaky Gut), Hashimoto's Thyroiditis, Adrenal Fatigue,
ITP (Low Platelets), TMJ, Plantar Fasciitis, Schamberg Purpura, Tinnitis, Allergies, MCS