- Hallmark of this stage = Gummas
~Gummas are granulomatous lesions that destroy soft tissue, cartilage, and bone
~Can occur in skeletal, spinal, and mucosal areas; the eyes, and viscera (lung, stomach, liver, genitals, breast, brain, and heart)
- Transmitted to humans from dogs, cattle, skunks, raccoons, foxes, rats, mice, guinea pigs, gerbils, rabbits, hamsters and reptiles
- No human-to-human transmission
- Mammalian reservoirs - squirrels, chipmunks, wild rodents. Vector is a tick.
- After 2-15 day incubation, patients have high fever, shaking, chills, headache, & fatigue
- Then nausea, vomiting, muscle aches, abdominal pain; extensive damage to liver, spleen, heart, kidneys, & cranial nerves.
- Parasite changes & immune system tries to control it - recurrent relapses
- Treatment of choice is tetracycline
- Both diseases cause acute, febrile, systemic illnesses similar to Rocky Mountain spotted fever but also have leukopenia, anemia, hepatitis
- Both disease forms have similar presentations - fever, headache, muscle aches, nausea, vomiting; both can progress to pneumonia, meningitis, renal failure and death
- Human monocytic ehrlichiosis occasionally manifests with a rash and also carries a higher mortality rate
- Both usually last 1 to 2 weeks; treated with doxycycline to prevent complications