Travel Health Guide: Cambodia
What vaccines and medications do you need for Cambodia? A physician's complete travel health guide covering malaria, dengue, traveler's diarrhea, and rabies.
Travel Health Guide: Cambodia
Traveling to Cambodia means preparing for several real and overlapping health risks: traveler's diarrhea, malaria in rural and forested regions, dengue, Japanese encephalitis, and rabies. As a physician who treats travelers, here is what I tell my patients heading to Cambodia: most US visitors flying into Phnom Penh, Siem Reap, or the coastal towns need hepatitis A and typhoid vaccines at minimum. Malaria prophylaxis is generally not required for city stays or short Angkor Wat itineraries, but it becomes important for rural travel, jungle treks, or visits to forested areas near the Thai or Laotian border. According to the CDC, malaria transmission in Cambodia is concentrated in rural and forested regions, with documented resistance to several common antimalarials. Plan your health prep at least 4 to 6 weeks before departure, since some vaccines need time to take effect and a few medications need to be started before you arrive.
Quick Facts: Cambodia Travel Health
Overview: What Makes Cambodia Unique From a Health Standpoint
Cambodia sits at the heart of mainland Southeast Asia, sharing borders with Thailand, Laos, and Vietnam. Most US travelers come for Angkor Wat in Siem Reap, the capital Phnom Penh, the southern coast around Sihanoukville and Kampot, and increasingly the eco-tourism circuit through Mondulkiri and Ratanakiri in the northeast. Each of these regions carries different health risks.
The country has a tropical monsoon climate with two clear seasons. The rainy season runs from May through October, and the dry season from November through April. Mosquito-borne disease risk (dengue, Japanese encephalitis, malaria) is highest during and just after the rainy months. Heat and humidity stay high year-round.
In my experience treating travelers returning from Southeast Asia, Cambodia generates more rabies concern than most other destinations. Stray dogs are common in cities and rural areas, and Cambodia has one of the higher rabies burdens in the region. I also see traveler's diarrhea cases consistently from Cambodia, often tied to street food, ice in drinks, or unfiltered water used for fruit washing.
Antimalarial resistance is the other thing that makes Cambodia distinctive from a clinical standpoint. Western Cambodia is documented as a global epicenter of multi-drug-resistant malaria, which directly affects which prophylaxis options work and which do not.
Medications You May Need for Cambodia
Malaria: Itinerary Drives the Decision
Cambodia has malaria transmission, but it is unevenly distributed and the parasite has known drug resistance patterns that matter for prevention. The CDC reports that malaria risk is present in all rural areas of Cambodia below 1,500 meters elevation. Risk is highest in the forested regions along the borders with Thailand, Laos, and Vietnam. Major urban centers (Phnom Penh, Siem Reap, Battambang, Sihanoukville) and the immediate Angkor Wat temple complex are considered low-risk.
Bottom line: If your Cambodia itinerary stays in cities and the Angkor Wat area, malaria pills are generally not required. If you plan to visit Mondulkiri, Ratanakiri, the Cardamom Mountains, jungle trekking near the Thai border, or extended rural stays, malaria prophylaxis is recommended.
The two options I most commonly recommend for Cambodia are:
Atovaquone-proguanil (Malarone): Start 1 to 2 days before entering the malaria zone, take daily, and continue for 7 days after leaving. Generally well tolerated. Effective against the resistant strains seen in Cambodia.
Doxycycline: Start 2 days before entering the malaria zone, take daily, and continue for 4 weeks after leaving. Less expensive than Malarone, but causes photosensitivity, which is a real consideration in Cambodia's strong tropical sun.
Mefloquine (Lariam) is not recommended for travel to western Cambodia because of documented mefloquine resistance in the area along the Thai border. For travelers to other parts of the country, mefloquine may still be an option, but most physicians default to Malarone or doxycycline to keep the regimen consistent across the trip.
If you are unsure which option fits your trip and medical history, our physicians can review your itinerary and recommend a regimen.
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Traveler's Diarrhea: High Risk Throughout Cambodia
Traveler's diarrhea is the most common illness affecting visitors to Cambodia. The CDC classifies Cambodia as an intermediate to high-risk destination, which in clinical terms means roughly 20 to 50 percent of travelers experience some form of gastrointestinal illness. Risk goes up with street food, ice in drinks, raw vegetables, and unfiltered water, all of which are common in Cambodia.
The usual culprits are enterotoxigenic Escherichia coli (ETEC), Campylobacter, Salmonella, and norovirus, all transmitted through contaminated food or water. Cambodian food is excellent and street food culture is part of the experience, but it is also where most exposures happen.
What I recommend:
Carry a prescription antibiotic for emergency use, not as a daily preventive. Standard options are ciprofloxacin (500mg twice daily for up to 3 days) or azithromycin (1,000mg as a single dose, or 500mg daily for 3 days). For Southeast Asia, including Cambodia, azithromycin is often preferred because of growing fluoroquinolone resistance in regional Campylobacter strains. Loperamide (Imodium) helps manage symptoms in the short term but should not replace antibiotics if you have fever or blood in stool.
Standard food and water precautions still apply. Drink bottled or filtered water, avoid ice unless you trust the source, and stick to fruits you can peel yourself. The "boil it, cook it, peel it, or forget it" rule is repetitive for a reason: it works.
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Vaccines for Cambodia: What You Need and Why
Hepatitis A (Strongly Recommended for All Travelers)
Hepatitis A is transmitted through contaminated food and water, which makes it nearly unavoidable as a background risk in Cambodia. The CDC recommends hepatitis A vaccination for all unvaccinated travelers to Cambodia. The vaccine works well: a single dose provides protection within about 2 weeks and immunity for at least a year, while the full two-dose series confers long-term, likely lifelong protection.
If you have never been vaccinated and your trip is less than 2 weeks away, you can still get the vaccine. In some cases, your physician may add hepatitis A immunoglobulin (Ig) for faster initial protection.
Typhoid (Strongly Recommended)
Typhoid fever is caused by Salmonella typhi and spreads through contaminated food and water. Cambodia's risk is real, particularly for travelers eating street food or in smaller villages where sanitation infrastructure is limited. The CDC recommends typhoid vaccination for most travelers to Cambodia.
Two options exist: an oral live vaccine (Vivotif, taken as 4 capsules over 7 days) and an injected inactivated vaccine (Typhim Vi, single shot). Both need 1 to 2 weeks to reach full effectiveness.
The typhoid vaccine is approximately 50 to 80 percent effective, so it lowers but does not eliminate risk. Food and water hygiene still matter.
Japanese Encephalitis (Recommended for Some Travelers)
Japanese encephalitis (JE) is a mosquito-borne viral infection endemic in Cambodia, with the highest transmission risk in rural agricultural areas, especially around rice paddies and pig farms where the Culex mosquito vector breeds. Risk is present year-round but peaks during and just after the rainy season (roughly May through October).
The CDC recommends JE vaccination for travelers who:
- Spend a month or more in rural Cambodia
- Plan extensive time outdoors in rural areas
- Travel during the rainy season with rural exposure
- Are visiting smaller villages, farms, or rice-growing regions
For short urban trips (Phnom Penh, Siem Reap, Angkor Wat day-tripping) JE vaccine is generally not necessary. The Ixiaro vaccine, which is FDA-approved in the US, is given as two doses 28 days apart, with the series ideally completed at least 1 week before travel.
Rabies (Worth Considering for Cambodia)
Cambodia is one of the destinations where I genuinely think about pre-exposure rabies vaccination for many travelers. The country has a substantial stray dog population and a documented rabies burden. Bites and scratches from dogs, monkeys (Angkor Wat has wild macaques), and bats can all transmit rabies, and post-exposure care in rural Cambodia can be limited.
Pre-exposure rabies vaccination is recommended for travelers who:
- Will spend extended time in rural areas
- Are working with animals or doing wildlife tourism
- Are traveling with children, who are at higher risk for unreported animal contact
- Are doing long-term travel with limited medical access
Pre-exposure rabies vaccination simplifies post-bite care: it does not eliminate the need for treatment, but it removes the requirement for rabies immunoglobulin (which is often unavailable in Cambodia) and reduces the post-exposure shot series.
If you are bitten or scratched and you are not vaccinated, the standard approach is: wash the wound with soap and water for at least 15 minutes, get to a major hospital or evacuate as needed, and start post-exposure prophylaxis immediately. Hospitals in Phnom Penh and Siem Reap can usually provide care, but rabies immunoglobulin specifically is not always available.
Routine Vaccines to Verify Before Travel
Before any international trip, confirm you are current on:
- COVID-19: Check Cambodia entry requirements, which can change.
- Routine childhood vaccines: Measles-mumps-rubella (MMR), diphtheria-tetanus-pertussis (Tdap), varicella.
- Influenza: Recommended annually, since flu circulates year-round in tropical climates.
- Hepatitis B: Recommended if not previously vaccinated, particularly if you anticipate any medical care abroad.
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Dengue: Real Risk, No Pill to Prevent It
Dengue is endemic throughout Cambodia, with year-round transmission and seasonal peaks during and just after the rainy season. The WHO has tracked rising dengue activity across Southeast Asia in recent years, and Cambodia consistently reports thousands of confirmed cases annually.
There is no effective preventive medication for dengue, and the dengue vaccine (Dengvaxia) is not recommended for first-time travelers who have never been infected, because it can increase risk of severe dengue in seronegative individuals. Mosquito avoidance is the only meaningful protection.
What works:
- EPA-registered insect repellents containing DEET (30 to 50%), picaridin, or IR3535 on exposed skin
- Long sleeves and pants in lightweight, light-colored fabrics, especially at dawn and dusk
- Permethrin-treated clothing for travelers spending time outdoors
- Air-conditioned or well-screened accommodations
- Mosquito nets if sleeping in open-air or rural lodging
Dengue symptoms appear 4 to 10 days after a bite: high fever, severe headache, pain behind the eyes, joint and muscle pain, nausea, and rash. If you develop these after returning from Cambodia, tell your physician about your travel history immediately. Severe dengue is a medical emergency.
Food, Water, and General Safety in Cambodia
Water: Tap water in Cambodia is not safe to drink, including in major cities. Use bottled or properly filtered water consistently. Be cautious about ice in smaller establishments. Most reputable hotels, restaurants, and cafes catering to travelers serve filtered or bottled water; ask if you are unsure.
Food: Cambodian food is fantastic and street food is part of the cultural experience, but stick to vendors with high turnover where food is freshly cooked and served hot. Avoid raw shellfish, undercooked meats, and salads or fruits that cannot be peeled and that may have been washed in tap water. Unpasteurized dairy is uncommon but worth avoiding when present.
Sun and heat: Cambodia is hot and humid year-round, with peak heat from March through May (often above 95F / 35C with high humidity). Heat exhaustion is a real risk, particularly for travelers spending long days exploring Angkor Wat. Hydrate aggressively (with safe water), wear sun protection, plan temple visits for early morning or late afternoon, and seek shade or air conditioning during midday.
Road safety: Road traffic injuries are a leading cause of preventable travel emergencies in Southeast Asia. Cambodia has high motorbike traffic, inconsistent traffic enforcement, and roads that range from highway-grade to dirt track depending on where you are. Use Grab or PassApp (regional rideshare apps) where available. If you rent a motorbike, wear a helmet (the cheap rental ones are usually inadequate, so consider bringing your own), and drive defensively. Many rural roads are unlit at night.
Wildlife and animals: Stray dogs are common, including at temple complexes. Macaque monkeys at Angkor Wat are habituated to humans but not friendly. Do not feed them, do not get close enough for a photo with food in your hand, and do not let small children approach them. Bites from any of these animals require immediate medical evaluation for rabies risk.
Unexploded ordnance and remote areas: Some rural areas of Cambodia, particularly along borders, still have residual unexploded ordnance from past conflict. Stay on marked paths if hiking in rural regions, and follow local guides.
Travel Insurance for Cambodia
I recommend travel health insurance for every international traveler, and Cambodia is a destination where it matters more than average. Medical care in Phnom Penh and Siem Reap has improved substantially in recent years, but serious illness or injury often requires medical evacuation to Bangkok or Singapore for advanced care. Air ambulance evacuation can run USD 50,000 to 100,000 or more without coverage.
Your US health plan almost certainly does not cover international care, and Medicare never does. A travel insurance policy with medical evacuation coverage is one of the most cost-effective protections you can put in place before a trip.
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Cambodia Travel Health Packing Checklist
- Prescription malaria medication (if rural itinerary)
- Prescription antibiotic for traveler's diarrhea (azithromycin preferred for SE Asia, or ciprofloxacin)
- Loperamide (Imodium) for short-term symptom management
- Oral rehydration salts (ORS packets)
- DEET-based insect repellent (30 to 50%)
- Permethrin spray for clothing if doing rural or jungle travel
- Sunscreen (SPF 30 or higher, water resistant)
- Hand sanitizer (alcohol-based, at least 60%)
- Basic first aid kit (bandages, antiseptic wipes, blister care, moleskin for temple-walking blisters)
- OTC antihistamines for bites and allergic reactions
- Any prescription medications for chronic conditions (bring extra supply, plus copies of prescriptions)
- Travel health insurance documents
- Copies of vaccine records, particularly hepatitis A, typhoid, and any rabies pre-exposure documentation
FAQ: Cambodia Travel Health
Do I need malaria pills for Cambodia? It depends on your itinerary. If you are visiting Phnom Penh, Siem Reap, Angkor Wat, and major coastal areas, malaria prophylaxis is generally not required. If you plan to travel to Mondulkiri, Ratanakiri, the Cardamom Mountains, jungle areas near the Thai or Laotian border, or rural villages off the standard tourist trail, the CDC recommends taking malaria medication. Atovaquone-proguanil (Malarone) or doxycycline are the standard options. Mefloquine is not recommended for western Cambodia because of documented resistance.
What vaccines do I need for Cambodia? The CDC strongly recommends hepatitis A and typhoid vaccines for all travelers to Cambodia. Japanese encephalitis vaccine is recommended for travelers spending extended time in rural areas, particularly during the rainy season. Rabies pre-exposure vaccination is worth considering for long-term travelers, those with significant rural exposure, families with young children, and anyone working with animals. Verify routine vaccines (MMR, Tdap, influenza, hepatitis B) before any international trip.
Is the water safe to drink in Cambodia? No. Tap water is not safe to drink, including in Phnom Penh and Siem Reap. Use bottled or properly filtered water consistently. Be cautious with ice and with raw fruits or vegetables that may have been washed in tap water.
What should I do if I get bitten by a dog or monkey in Cambodia? Wash the wound thoroughly with soap and running water for at least 15 minutes, apply an antiseptic if available, and seek medical care immediately. Rabies post-exposure prophylaxis (PEP) needs to start as soon as possible. Hospitals in Phnom Penh and Siem Reap can typically provide rabies vaccine, but rabies immunoglobulin is not always available. If you have not had pre-exposure vaccination, you may need medical evacuation or transfer for full PEP. Travel insurance with evacuation coverage is essential for this scenario.
What should I do if I get traveler's diarrhea in Cambodia? Hydrate with bottled water and oral rehydration salts. Take your prescribed antibiotic if you have moderate to severe symptoms, fever, or blood in your stool. For Cambodia and most of Southeast Asia, azithromycin is often preferred over ciprofloxacin because of regional Campylobacter resistance. Loperamide (Imodium) can reduce symptoms but should not be used alone if you have fever or bloody stool. If symptoms persist beyond 3 to 5 days, get medical evaluation.
Is dengue a serious concern in Cambodia? Yes. Dengue is endemic in Cambodia year-round, with seasonal peaks during the rainy season. There is no effective preventive medication and the dengue vaccine is not recommended for first-time travelers. Mosquito avoidance through DEET-based repellent, long sleeves, permethrin-treated clothing, and screened accommodations is your primary protection. If you develop high fever, severe headache, or pain behind the eyes within 2 weeks of returning, tell your doctor about your travel history.
How far in advance should I prepare for a Cambodia trip? At least 4 to 6 weeks before departure. Some vaccines (hepatitis A, typhoid, JE, rabies) take time to reach full effectiveness, and the Japanese encephalitis and rabies series both require multiple doses spaced over weeks. Malaria medication also needs to be started before entering risk areas. See our pre-trip health checklist for a full timeline.
Do I need travel insurance for Cambodia? Yes. Medical care in Cambodia ranges from solid in Phnom Penh and Siem Reap to limited or absent in rural areas. Serious illness or injury often requires evacuation to Bangkok or Singapore, with costs that can easily reach USD 50,000 to 100,000 without insurance. Standard US health plans and Medicare do not cover international care.
Are there altitude concerns in Cambodia? No. Cambodia is largely a low-elevation country. The highest accessible point most travelers reach is in the Cardamom Mountains, well below altitudes that cause altitude sickness. Heat-related illness is a much bigger concern than altitude in Cambodia.
About the Author
This guide was written by Dr. Alec Freling, an emergency medicine physician with direct experience treating travelers with preventable illness. Wandr Health is a physician-founded travel health platform offering online consultations, prescription travel medications, vaccine booking, and travel insurance, all in one place. Most patients save several hundred dollars compared to a traditional travel clinic visit and skip the multi-week scheduling hassle.
Medical information in this guide is based on current CDC, WHO, and peer-reviewed clinical guidelines. This content is for informational purposes and does not constitute medical advice for your individual situation. Consult a licensed physician before starting any medication or travel health regimen.
Medical Disclaimer
The information in this guide is based on current guidelines from the CDC and WHO and is intended for general informational purposes only. It does not replace individualized medical advice from a licensed healthcare provider. Your health history, medications, and specific itinerary affect which precautions are right for you. Wandr Health's physicians can review your situation and provide personalized recommendations.
Sources
- Centers for Disease Control and Prevention. "Cambodia Traveler's Health." CDC Yellow Book. https://wwwnc.cdc.gov/travel/destinations/traveler/none/cambodia
- Centers for Disease Control and Prevention. "Malaria Information and Prophylaxis, by Country." CDC Travelers' Health. https://www.cdc.gov/malaria/travelers/country_table/a.html
- World Health Organization. "Dengue and Severe Dengue." WHO Fact Sheet. https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
- Centers for Disease Control and Prevention. "Japanese Encephalitis." CDC Travelers' Health. https://wwwnc.cdc.gov/travel/diseases/japanese-encephalitis
- Centers for Disease Control and Prevention. "Rabies." CDC Travelers' Health. https://wwwnc.cdc.gov/travel/diseases/rabies
- Centers for Disease Control and Prevention. "Typhoid Fever Vaccination." CDC Travelers' Health. https://wwwnc.cdc.gov/travel/diseases/typhoid
- Centers for Disease Control and Prevention. "Hepatitis A." CDC Travelers' Health. https://wwwnc.cdc.gov/travel/diseases/hepatitis-a
- World Health Organization. "Artemisinin Resistance and Artemisinin-Based Combination Therapy Efficacy." WHO Status Report. https://www.who.int/publications/i/item/9789240012813
- Steffen R, et al. "Traveler's Diarrhea: A Clinical Review." JAMA. 2015;313(1):71-80. doi:10.1001/jama.2014.17006