Thailand
Southeast Asia · Asia· Physician brief
HIV entry restriction
Thailand may deny entry to travelers with confirmed or suspected HIV infection. Travelers with HIV should consult their travel medicine specialist before booking, particularly for long-term stays or work permits, as additional documentation may be required.
EKRM / Thai immigration guidance ↗ · Updated 2026
Yellow fever entry rule — T8 form required
Travelers arriving in Thailand within 10 days of leaving (or in transit through) a yellow-fever-risk country must carry a YF vaccination certificate AND complete the T8 health declaration form at thaihealthpass.com, uploading the certificate. Exempt: children under 1 year, passengers in transit who don't leave the airport transit zone, and passengers whose only YF-country contact was airport transit without disembarking. Direct travel from Switzerland is not affected.
Thailand Ministry of Public Health ↗ · Updated 2026
Vaccines
Disease-specific guidance
Malaria
LowRisk is limited to small border areas; the vast majority of tourist destinations are low- or no-risk. Moderate risk on Little Koh Chang (Andaman Sea, Ranong province near Myanmar border) and along the belt bordering Myanmar — emergency standby treatment may be discussed for these areas. The rest of the country including major beach destinations (Phuket, Koh Samui, Koh Phangan, Koh Phi Phi, Koh Yao Noi, Koh Yao Yai, Koh Lanta) is low risk with mosquito protection only. Bangkok, Chiang Mai, Chiang Rai, and Pattaya are no-risk.
- Moderate risk
- Little Koh Chang (Andaman); Myanmar border belt
- Low risk
- Rest of country incl. Phuket, Koh Samui, Koh Phangan, Koh Phi Phi, Koh Yao Noi, Koh Yao Yai, Koh Lanta, other islands
- No risk
- Bangkok, Chiang Mai, Chiang Rai, Pattaya
- Prevention
- Mosquito protection in low-risk areas; consider standby treatment for border areas
Yellow fever
NoneNo yellow fever risk in country. Thailand requires YF certificate plus T8 health declaration via thaihealthpass.com for travelers arriving within 10 days of YF-endemic country. See country alert for full details. Direct travel from Switzerland not affected.
Dengue
HighEndemic year-round throughout Thailand, with peaks during rainy season (May–November). All major tourist destinations including Bangkok, Chiang Mai, Phuket, and the southern islands have year-round transmission. Daytime mosquito-bite prevention is the main protection.
- Distribution
- Nationwide, all major cities and islands
- Season
- Year-round; peaks May–November (rainy season)
- Mosquito
- Aedes aegypti — bites during daytime
Chikungunya
HighSporadic transmission with periodic outbreaks, including notable activity in southern Thailand. Same daytime Aedes mosquito vector as dengue, so dengue prevention also protects against chikungunya. Vaccination considered in outbreak settings (see EKRM statement).
General prevention
Food & water
Use bottled or filtered water, avoid ice from unverified sources, and pay attention to food hygiene. Standard tropical precautions reduce risk of traveler's diarrhea, hepatitis A, and typhoid — especially relevant when eating outside major hotels and resorts.
Mosquito protection
Year-round dengue and chikungunya risk in urban and rural areas means daytime mosquito protection (DEET or picaridin repellent, long sleeves) is essential — including in tourist destinations like Phuket and Koh Samui. For travel near Myanmar border or rural rice-growing areas, also protect at dawn/dusk for malaria and Japanese encephalitis.
Sources
Based on CDC Travelers’ Health, CDC Yellow Book, and the Swiss Federal Vaccination Schedule (BAG). Always verify current recommendations before travel.
Visiting more than one country?
Build a combined itinerary and get merged recommendations across all destinations.
This brief is for informational purposes and does not replace personalized medical advice.
Consult a travel medicine specialist 4–8 weeks before departure.