130.1 🎓 醫學生版

130.1.0.1 📌 一頁重點

• Travel clinic 三大支柱:
  1. Vaccines (依目的地: yellow fever, typhoid, Hep A/B, JEV, rabies, polio, meningococcal, cholera)
  2. Malaria prophylaxis (區域 + 抗藥 → atovaquone-proguanil / doxycycline / mefloquine)
  3. Traveler’s diarrhea (food/water hygiene + self-treatment kit)
• 常見回國發燒: malaria (#1), dengue, typhoid, viral hepatitis, leptospirosis, rickettsia
• Pre-travel timing: 4-6 週前 (有些 vaccine 需多劑)

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130.1.0.2 1️⃣ Vaccines for Travelers

疫苗	對象	區域
Yellow Fever	Endemic country travel	Sub-Saharan Africa, S. America (Brazil, Peru)
Typhoid (Vi inj or Ty21a oral)	Developing country, S. Asia 高風險	India, Pakistan, Bangladesh
Hep A	Any developing country	Universal
Hep B	If extended stay, sex, medical procedures	Asia, Africa
Polio booster	If travel to endemic / outbreak	Pakistan, Afghanistan
Meningococcal ACWY	Hajj, sub-Saharan meningitis belt, college dorm US
Men B	Outbreak, military, college outbreaks
JEV	Rural Asia >1 month	India, SE Asia, China
Cholera (oral)	Endemic + extended stay	Bangladesh, Haiti
Rabies pre-exposure	High-risk (veterinarian, animal handler, prolonged rural)	Asia, Africa

130.1.0.2.1 Yellow Fever 特點

• Single dose lifelong (2016 WHO update, 取代之前 10-yr booster)
• 唯一強制 entry vaccine for some countries (要 ICVP yellow card)
• Live vaccine — 禁忌: 孕婦 (caution), 免疫低下, > 60 first dose 風險

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130.1.0.3 2️⃣ Malaria Prophylaxis

📖 中文概念說明：Malaria 預防選藥主要看三個變數 — (1) 目的地抗藥 pattern (大部分地區 chloroquine 已失效，只有中美洲、加勒比、部分中東仍有效)、(2) 行程長短 (短期 atovaquone-proguanil 最方便、長期 doxycycline 便宜)、(3) 病人 comorbidity (mefloquine 精神病史禁用、tafenoquine/primaquine 需先驗 G6PD)。重點記憶：Atovaquone-proguanil = first-line, 出發前 1-2 天開始, 回國後只要 7 天（其他藥都要 4 週）— 出國前忘記吃藥的 traveler 救星就是它。個人防護 (DEET + permethrin + bed net) 與藥物同等重要 — malaria mosquito 不咬就不會感染，這是 stewardship + 防護的雙保險。

130.1.0.3.1 風險區

• High: sub-Saharan Africa, parts of SE Asia (Myanmar borders, PNG)
• Moderate: India, Indonesia, Philippines (rural), Brazil Amazon
• Low: most urban Asia, S. America cities

130.1.0.3.2 藥物選擇 (依抗藥 pattern)

藥物	Dosing	起時間	持續	適用
Atovaquone-proguanil (Malarone)	1 tab daily	1-2 d before	7 d after return	All regions; first-line
Doxycycline	100 mg daily	1-2 d before	4 weeks after	All regions; cheap; SE photosensitivity
Mefloquine	1 tab weekly	2-3 wk before	4 weeks after	Areas without mefloquine resistance; avoid in psychiatric history (neuropsychiatric SE)
Chloroquine	weekly	1-2 wk before	4 weeks after	Limited use — most regions resistant
Tafenoquine (Krintafel/Arakoda)	weekly post-loading	loading 3 d	7 d after	New 2018; G6PD test required (hemolysis)
Primaquine	daily 30 mg	1-2 d before	7 d after	P. vivax / P. ovale (radical cure for liver hypnozoites); G6PD test

130.1.0.3.3 Personal Protection

• DEET 30-50% repellent
• Permethrin-treated clothing
• Long sleeves dawn/dusk
• Bed nets (insecticide-treated)
• Avoid stagnant water

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130.1.0.4 3️⃣ Traveler’s Diarrhea

• 60-80% on tropical travel
• Pathogens: ETEC (most common), EAEC, Campylobacter, Shigella, Salmonella, Norovirus, Giardia, Cryptosporidium
• Prevention: “Boil it, cook it, peel it, or forget it”; Pepto-Bismol bid (mild)
• Self-treatment kit:
  • Loperamide (Imodium) 4 mg loading + 2 mg per stool (max 16 mg/d) — symptomatic
  • Antibiotic (azithromycin 1g single dose preferred — over Cipro due rising resistance) for moderate-severe (≥ 3 stools/24 hr + symptoms)
  • Oral rehydration

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130.1.0.5 4️⃣ Returned Traveler with Fever

📖 中文概念說明：Returned traveler 發燒第一鑑別永遠是 malaria — smear × 3 (q12h) 是黃金標準，前次 negative 也要重複，因為 parasitemia 有 cyclical pattern。第二常見：dengue (亞洲/南美/加勒比, 後眼痛 + 皮疹 + 血小板低)、typhoid (南亞 sustained fever)、Hep A (developing country)、leptospirosis (淹水 / 河遊)、rickettsia (eschar)、schistosomiasis (4-8 週 acute Katayama)。潛伏期是重要線索 — 短 (< 14 天) 想 dengue / lepto / rickettsia；中 (2-3 週) 想 malaria / typhoid；長 (> 30 天) 想 P. vivax 復發 / Hep B / schisto。通報義務：台灣 malaria + dengue + typhoid + Zika + Mpox 都是法定通報傳染病，回國發燒 + 旅遊史必須通報疾管署。

130.1.0.5.1 High-yield 鑑別 (重點！)

疾病	區域	潛伏期	特徵
Malaria (#1)	撒哈拉以南非洲, SE Asia	7-30 d (longer P. vivax)	發燒, 頭痛, 寒顫, 黃疸; smear
Dengue	Asia, S. America, Caribbean	4-14 d	發燒, 頭痛, 後眼痛, 皮疹 (sunburn-like), thrombocytopenia
Typhoid	S. Asia	7-21 d	Sustained fever, rose spots, bradycardia, GI
Viral hepatitis A	Any developing	15-45 d	Jaundice, fatigue, transaminase ↑↑
Leptospirosis	Tropics, swimming, flooding	7-14 d	Fever, conjunctival suffusion, AKI, jaundice
Rickettsia (RMSF, scrub typhus)	Forest, ticks	5-14 d	Fever, rash, eschar
Schistosomiasis	Africa (Nile, Lake Malawi), S. America	4-8 wk after exposure	Acute Katayama fever
Mpox	Central/W. Africa, MSM exposure	5-21 d	Vesicular rash, lymphadenopathy

130.1.0.5.2 Initial workup

• CBC (eosinophilia → parasite), platelets (low → dengue, malaria)
• LFT, BUN/Cr
• Blood cultures × 3
• Malaria smear × 3 (q12h) — 必做! ; rapid antigen test (HRP-2)
• Dengue NS1 antigen + IgM/IgG
• Stool: O&P, PCR multiplex
• HBV/HCV serology
• Rickettsia, leptospirosis serology if suspect

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