187.4 📌 章末速蚘

  • HME (E. chaffeensis): Lone Star tick, SE/SC USA, monocytes, severe
  • HGA (A. phagocytophilum): Ixodes tick (Lyme), NE/Midwest USA + Europe + Asia, PMNs, milder
  • Triad: leukopenia + thrombocytopenia + ↑ LFT + hyponatremia
  • Morulae intracellular (PMN for HGA visible; monocyte HME rare)
  • PCR gold standard for acute
  • Treatment: doxycycline 100 bid × 5-7d — all ages
  • Rifampin alt (pregnancy / allergy)
  • Defervescence 24-48 hr = diagnostic
  • Co-infections common (Lyme, Babesia same Ixodes tick)
  • Asplenic + tick exposure + severe → urgent Babesia + HGA workup
  • Pregnancy: rifampin first, doxy if life-threatening