239.2 📚 國考版

239.2.0.1 必背 — 3 Main Filariae

Disease Pathogen Vector Geography
Lymphatic Filariasis Wuchereria bancrofti + Brugia Mosquito Africa, Asia, Pacific
Onchocerciasis Onchocerca volvulus Black fly (Simulium) Sub-Saharan Africa
Loiasis Loa loa Deer fly (Chrysops) W + C African rainforest

239.2.0.2 必背 — Lymphatic Filariasis

  • Mosquito-borne
  • Lymphedema + elephantiasis + hydrocele
  • Acute adenolymphangitis episodic
  • Tropical pulmonary eosinophilia (TPE) — hyperreactive S Asian form
  • Diagnosis: nocturnal blood microfilariae (W. bancrofti) + CFA ICT card + ultrasound (filaria dance sign)
  • Treatment: DEC + albendazole (individual); MDA with albendazole + ivermectin OR + DEC; doxycycline for Wolbachia adults

239.2.0.3 必背 — Onchocerciasis (“River Blindness”)

  • Black fly (Simulium) breeds in fast-flowing rivers
  • Subcutaneous nodules + skin disease (pruritus, leopard skin, hanging groin) + eye disease (river blindness)
  • Diagnosis: skin snip (microfilariae) + slit-lamp + serology + PCR
  • Treatment:
    • Ivermectin annually (kills microfilariae, not adults)
    • Doxycycline × 6 weeks kills Wolbachia → adult worms die
    • Combination for individuals
  • Mectizan Donation Program (Merck) — free ivermectin for endemic Africa since 1987

239.2.0.4 必背 — Loiasis

  • Deer fly (Chrysops) — Central + W African rainforest
  • Visible eye worm (pathognomonic) + Calabar swellings + microfilaremia
  • Daytime periodicity (Chrysops daytime biter)
  • Diagnosis: daytime microfilariae + visible eye worm + serology
  • Treatment: DEC with caution for high MF load (encephalopathy)
  • Pre-treatment albendazole / apheresis for high MF (> 8000/mL)
  • Ivermectin alternative; same caution

239.2.0.5 必背 — DEC + High Loa Load = Mazzotti Encephalopathy

  • 8000 MF/mL → severe encephalopathy + coma + death

  • Pre-treatment screening + staged approach + steroid + ICU monitoring
  • Major caveat for treatment + MDA programs

239.2.0.6 必背 — Ivermectin in Onchocerciasis MDA

  • Loa loa pre-screening in Central Africa
  • High MF load + ivermectin = encephalopathy risk
  • Pre-treatment albendazole for high MF
  • Implementation challenge

239.2.0.7 必背 — Mass Drug Administration

Disease MDA Drugs
Lymphatic Filariasis Albendazole + Ivermectin (where Loa absent); Albendazole + DEC (Asia, Pacific, Latin America); Triple IDA (newest)
Onchocerciasis Ivermectin (free from Mectizan Donation Program)
Loiasis No routine MDA (encephalopathy risk)

239.2.0.8 必背 — Wolbachia Endosymbiont

  • Bacterial endosymbiont of most filariae (Onchocerca, W. bancrofti, Brugia)
  • Targeted by doxycycline → kills adult worms + sterilizes
  • Major target for individual + targeted therapy

239.2.0.9 必背 — Tropical Pulmonary Eosinophilia (TPE)

  • Hyperreactive lymphatic filariasis form
  • South Asian males predominantly
  • Cough + wheeze + nocturnal symptoms + eosinophilia + IgE elevated
  • Often misdiagnosed as asthma
  • Response to DEC diagnostic
  • High eosinophilia (often > 3000/µL)

239.2.0.10 必背 — WHO Elimination Targets 2030

  • LF elimination as public health problem
  • Onchocerciasis elimination in S America (achieved in many) + Africa (ongoing)
  • Major progress through MDA programs