220.4 📌 章末速記

220.4.0.0.1 Zika

• ssRNA flavivirus, Aedes aegypti / albopictus
• 2015-2016 Americas epidemic
• 80% asymptomatic; mild illness when symptomatic
• Unique sexual transmission (semen 6+ months)
• Vertical → Congenital Zika Syndrome (microcephaly + brain defects + arthrogryposis)
• GBS post-Zika documented
• Diagnosis: PCR (blood + urine) + IgM (cross-reactive)
• No licensed vaccine yet
• Prevention: mosquito + DEET; pregnancy travel restrictions; condoms 3+ mo

220.4.0.0.2 Chikungunya

• ssRNA alphavirus, Aedes aegypti / albopictus
• “To walk bent over” — severe polyarthralgia + fever + rash
• Chronic arthralgia 30-60% weeks-years (mimics RA)
• Treatment chronic: NSAIDs + DMARDs (methotrexate, HCQ)
• Vaccine: Ixchiq (Valneva, FDA 2023) — first chikungunya vaccine, single dose live attenuated
• Vimkunya (Bavarian Nordic, FDA 2025) — VLP alternative

220.4.0.0.3 Three-Virus Differential

• All transmitted by Aedes; clinical distinctions:
  • Dengue: bone pain, hemorrhage, DSS
  • Chikungunya: severe + prolonged joint pain
  • Zika: mild + microcephaly + GBS