CDC Yellow Book 2024

Popular Itineraries

Author(s): Michael C. Thigpen, Stacy L. Ali, Alyssa Finlay, Rachel Albalak

Destination Overview

Prior to the COVID-19 pandemic, >6 million international tourists traveled to Cambodia annually. Many tourists to Cambodia visit the Angkor temple complex (which includes Angkor Wat), a collection of approximately 1,000 ancient temples and other structures covering 400 km2 (250 mi2) in the northwestern Cambodia jungle. The Angkor temple complex, located 6 km (4 mi) north of Siem Reap, is considered one of the architectural wonders of the world and was designated a World Heritage site in 1992.

The temples were built between the 9th and 14th centuries at the height of the Khmer Empire and were part of the empire’s capital (Angkor means “capital city” in Khmer). These historical structures were decorated with intricately carved Khmer artwork depicting Hindu and Buddhist themes, providing an archaeological portrayal of the empire that ruled much of Southeast Asia for 5 centuries. After the decline of the Khmer Empire, the site was largely abandoned to the surrounding jungle and remained virtually untouched until descriptions of the ruined temples of Cambodia were published in a journal in the late 19th century.

Restorations commenced as international visitors began to arrive, but the emergence of the Khmer Rouge regime and the ensuing decades of civil war halted most tourist travel to the site until the late 1990s. As Cambodia emerged from >20 years of political and economic turmoil, the Angkor temples have become one of the most popular tourist destinations in Southeast Asia. Increasingly, tourists are also visiting other areas of Cambodia, including the capital Phnom Penh, the southern beaches, and the islands in the Gulf of Thailand. Adventure tourism in the rural and forested areas bordering Vietnam and Laos has also become popular.

Cambodia is one of the poorest countries in Southeast Asia but is currently experiencing a period of rapid economic development. As a result, business-related travel, in addition to tourism, is increasing. Visitors can fly directly to Phnom Penh, Siem Reap, or Sihanoukville from several international cities. Overland travel from surrounding countries is also possible via direct bus service to Siem Reap and Phnom Penh from Bangkok and Ho Chi Minh City. A network of interprovincial bus services connects Phnom Penh with Siem Reap and other Cambodian cities. Intercity transport usually involves taxis, tuk-tuks (motorbike taxis), bicycles, or buses (in Phnom Penh).

Map 10-20: Cambodia

Map 10-20: Cambodia

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Infectious Disease Risks

All travelers to Cambodia should be up to date with their routine immunizations, including seasonal influenza, and should be protected against hepatitis A, hepatitis B, and typhoid fever. Although yellow fever is not a disease risk in Cambodia, the government requires travelers arriving from countries with a risk of yellow fever virus transmission to present proof of yellow fever vaccination.

Enteric Infections & Diseases

Travelers’ Diarrhea

Diarrhea and foodborne infections in travelers are common in Cambodia. Advise travelers to avoid water that is not bottled, ice, and food from street vendors. Safe, bottled water is readily available. Travelers should practice safe food and water precautions (see Sec. 2, Ch. 8, Food & Water Precautions) and consider carrying an antibiotic and antidiarrheal for self-treatment (see Sec. 2, Ch. 6, Travelers’ Diarrhea for self-treatment recommendations). Because fluoroquinolone resistance is widespread in Cambodia and other areas of Southeast Asia, azithromycin is preferred.

Typhoid & Paratyphoid Fever

Typhoid and paratyphoid fever are endemic to Cambodia, and travelers are at risk. Antimicrobial resistance is common. Travelers should be vaccinated against typhoid fever, especially those planning extended stays or visiting remote regions (see Sec. 5, Part 1, Ch. 24, Typhoid & Paratyphoid Fever).

Respiratory Infections & Diseases

Coronavirus Disease 2019

For current information on coronavirus disease 2019 (COVID-19) in Cambodia, consult the US Embassy in Cambodia website. See the US government’s COVID-19 international travel requirements and recommendations.  All travelers going to Cambodia should be up to date with their COVID-19 vaccines.


Cambodia has one of the region's highest rates of active tuberculosis (TB), with 46,000 cases annually. Travelers who plan to work in high-risk settings or in crowded institutions (e.g., medical facilities, prisons, or homeless shelter populations) are at risk for TB exposure (see Sec. 5, Part 1, Ch. 22, Tuberculosis). Travelers working in these settings in Cambodia should have a test for tuberculosis, either a tuberculin skin test or blood test, to screen for latent TB infection before leaving and upon returning to the United States (see Sec. 5, Part 1, Ch. 23, . . . perspectives: Testing Travelers for Mycobacterium tuberculosis Infection).

Sexually Transmitted Infections & HIV

Expanded HIV testing and treatment programs, along with strong prevention messaging, has reduced the number of newly diagnosed HIV infections in Cambodia to approximately 1000 cases annually. HIV prevalence remains high in certain key populations, however, including men who have sex with men, transgender women, and female sex workers. In addition, antimicrobial-resistant gonorrhea is widespread throughout the region.

Cambodia is a destination for tourists seeking sex (see Sec. 9, Ch. 12, Sex & Travel), and, although illegal, commercial sex work is practiced across the country. Travelers should be aware of these risks, always use condoms during sex, and avoid injecting drugs or sharing needles. Travelers whose practices put them at high risk for HIV infection should discuss preexposure prophylaxis with their primary care or travel medicine providers. High-quality condoms are readily available at a reasonable price.

Soil- & Waterborne Infections

Leptospirosis & Melioidosis

Leptospirosis (Sec. 5, Part 1, Ch. 10, Leptospirosis) and melioidosis (Sec. 5, Part 1, Ch. 12, Melioidosis) are endemic causes of illness in Cambodia. For both diseases, most cases occur during the rainy season, May through October, when flooding is common. Adventure travelers are at increased risk for these diseases because their activities expose them to soil and surface water. The risk of leptospirosis can be reduced by not swimming or wading in water that might be contaminated with animal urine and by eliminating contact with potentially infected animals.
People with open skin wounds and those with diabetes or chronic kidney disease are at increased risk for melioidosis and should avoid contact with soil and surface water. People who engage in agricultural work should wear boots, which can prevent infection through the feet and lower legs. Travelers should immediately and thoroughly clean abrasions, burns, or lacerations contaminated with soil or surface water.


Liver flukes (e.g., Schistosoma mekongi) are found in the Mekong River basin from the border of Laos to Kratie Province in Cambodia, where the freshwater dolphins attract tourists (see Liver fluke chapter). Swimming in natural freshwater settings such as lakes, rivers, and ponds should be avoided. Travelers developing a rash within hours or up to a week after freshwater exposure should be evaluated for acute schistosomiasis (see Sec. 5, Part 3, Ch. 20, Schistosomiasis).

Vectorborne Diseases

Chikungunya, Dengue & Zika

Chikungunya (Sec. 5, Part 2, Ch. 2, Chikungunya) was reintroduced into Cambodia in 2011, and large outbreaks now occur nearly annually. The risk of chikungunya occurs throughout Cambodia, including Phnom Penh.
Dengue (Sec. 5, Part 2, Ch. 4, Dengue) is endemic throughout Cambodia, and large epidemics occur every several years. Peak transmission occurs during the rainy season, although cases occur year-round, even in nonepidemic years. A dengue vaccine has been recently recommended for children aged 9–16 years with laboratory-confirmed evidence of prior dengue virus infection and living in areas where dengue is common. However, the vaccine is not recommended for residents in other age groups or travelers.

Zika virus (Sec. 5, Part 2, Ch. 27, Zika) was first detected in Cambodia in 2010. Since then, sporadic cases have been identified retrospectively. Because Zika virus infection in pregnant women can cause serious congenital disabilities, CDC encourages a pretravel discussion of risks with anyone who is pregnant or trying to become pregnant. See Zika travel information on the CDC Travelers’ Health website.

All travelers to Cambodia should take measures to protect themselves from mosquito bites (see Sec. 4, Ch. 6, Mosquitoes, Ticks & Other Arthropods).

Japanese Encephalitis

Japanese encephalitis (JE) is considered endemic throughout Cambodia; transmission occurs year-round but peaks during the rainy season from May to October (see Sec. 5, Part 2, Ch. 13, Japanese Encephalitis). The vaccine is recommended for travelers who are moving to an area with JE to live or plan to spend ≥1 month in rural areas. The vaccine should be considered for short-term travelers who may be at increased risk for JE virus exposure (e.g., those who will spend substantial time outdoors in rural or agricultural areas, especially during the rainy season). Travelers on a typical 2- to 4-day visit to the main (nonremote) Angkor temples and staying in air-conditioned hotels in Siem Reap are at minimal risk, but mosquito prevention measures should be employed (see Sec. 4, Ch. 6, Mosquitoes, Ticks & Other Arthropods).


Nearly 90% of malaria in Cambodia is Plasmodium vivax, with the remainder P. falciparum and mixed infections. The highest risk of malaria infection for the traveler in Cambodia is in forested areas, especially in Kampong Speu, Kratie, Mondulkiri, Ratanakiri, and Stung Treng Provinces. There is little malaria transmission around the main temples of Angkor Wat, Phnom Penh, Siem Reap city, and Tonle Sap Lake. Malaria risk is minimal on a typical visit that involves exploring the main temples of the Angkor temple complex during the day and staying in an air-conditioned hotel in Siem Reap at night. Risk can be further minimized by following mosquito prevention measures (see Sec. 4, Ch. 6, Mosquitoes, Ticks & Other Arthropods). Eco-travelers planning to visit and sleep in deeply forested areas should receive malaria chemoprophylaxis. Recommended chemoprophylaxis regimens include atovaquone-proguanil, doxycycline, or tafenoquine. (see Sec. 2, Ch. 5, Yellow Fever Vaccine & Malaria Prevention Information, by Country and Sec. 5, Part 3, Ch. 16, Malaria).

Environmental Hazards & Risks

Air Quality

Monitoring of air quality in Cambodia is limited. Similar to other countries in the region, fine particulate matter levels exceed both the World Health Organization annual standard, with an annual mean estimated to be 25–35 μg/m3, and the US government daily standard for fine particulate matter (PM2.5) during parts of the year. For additional information on real-time monitoring, see, and Sec. 4, Ch. 3, Air Quality & Ionizing Radiation.  When the Air Quality Index is over 100, people with heart or lung disease, older adults, children, and teenagers should reduce prolonged outdoor exertion and follow their healthcare provider’s advice.

Animal Bites


Rabies (Sec. 5, Part 2, Ch. 18, Rabies) is endemic throughout Cambodia, where infection results in over 400 human deaths from canine rabies annually. The chief risk to humans is from dog bites; there are over 100,000 dog bites annually in Cambodia. For most travelers on a short tour of the Angkor temple complex, the risk is minimal. Travelers planning more extensive travel in Cambodia, particularly to rural areas, should consider rabies pre-exposure prophylaxis before arrival. The Institute Pasteur of Cambodia in Phnom Penh and many private clinics can provide rabies vaccine and consultation after an exposure. In addition, rabies immune globulin is available to the public at the Institute Pasteur of Cambodia and Royal Phnom Penh Hospital.


At least 17 known venomous snake species are found in Cambodia; therefore, travelers should use precautions to avoid snakebites (Yellow Book chapter, Toxic Exposures). A snakebite is a medical emergency, and a bitten traveler needs to proceed as quickly as possible to a hospital for antivenom. Antivenom is available at Royal Angkor International Hospital in Siem Reap and the Calmette Hospital in Phnom Penh. Traditional medicine (thnam boran) is popular in rural Cambodia but should not be used to treat snakebites because it often causes increased harm and delays effective treatment.

Climate & Sun Exposure

Cambodia’s tropical climate is generally hot and humid throughout the year. The hottest months are March through May, but heat precautions should be taken year-round when exploring the temples or visiting other tourist areas (see Sec. 4, Ch. 2, Extremes of Temperature). Travelers should stay hydrated, especially during midday. Many travelers explore the temples in the early mornings and late afternoons, taking a midday break in the comfort of an air-conditioned restaurant. The rainy season is from late April or early May through October. During this time, the risk of vectorborne disease transmission increases.


More than 64,000 people have been killed or injured from landmines and unexploded ordnance since the end of the Khmer Rouge in 1979. Although the areas around the Angkor temple complex and major towns have been cleared, landmines and unexploded ordnance from the decades of conflict are still found in rural areas in Cambodia, especially along the Cambodia-Thailand border. Travelers to those areas should exercise caution, especially when venturing out to the more remote temples and forests, by staying on roads and paths and using a guide with knowledge of local hazards. Travelers should not touch anything resembling a mine or unexploded ordnance. Alert travelers to notify the Cambodia Mine Action Centre should they observe these items.

Safety & Security


Travelers should use common-sense measures such as not walking or traveling alone at night. Travelers are also advised to only carry what they are willing to lose. The most common type of theft is “snatch and grab” robbery. Travelers should keep belongings out of sight if traveling by tuk-tuk and carry items and bags away from the street side while walking.

Traffic-Related Injuries

Road traffic accidents are one of the leading causes of death in Cambodia (Sec. 8, Ch. 5, Road & Traffic Safety). Deaths related to traffic accidents have increased by nearly 25% between 2009 and 2019. The most common means of transport in Cambodia is by motorbike, and although both drivers and passengers are required to wear helmets, this law is infrequently followed or enforced. Travelers should always wear a helmet when on a motorbike. In addition to the ever-growing number of cars and motorbikes, there is lax enforcement of traffic laws and a scant understanding of the rules of the road. Travelers should carefully look in every direction before crossing the street.

In cities and at the Angkor temple complex, most travelers use tuk-tuks, which are readily available, or hire cars with a driver guide. Advise travelers to negotiate the fare at the outset and avoid using tuk-tuks after dark, when limited street lighting and inadequate enforcement of impaired driving laws make this mode of transportation unsafe. Ride-hailing apps such as Grab, Pass App, and TADA are frequently used locally because they use fixed prices and help prevent overcharging. In addition, it is increasingly common to rent bicycles to get around the cities and the Angkor temple complex. Forewarn travelers planning to rent bicycles to yield to motorized traffic and use extreme caution.

Six national highways link Cambodia’s capital city, Phnom Penh, to other cities and beach resorts. During the rainy season, road conditions deteriorate rapidly; discourage travel after dark on the highways. Intoxicated drivers are common during the evening hours, and tourists should stay off the road at night whenever possible. In addition, counsel travelers to avoid traveling by boat, which often lack safety equipment and are overcrowded.

Availability & Quality of Medical Care

Counterfeit Drugs

Local pharmacies provide a variety of imported prescription and over-the-counter medications. Due to variable quality, improper storage, and lack of proper ingredients in some formulations, travelers should bring an adequate supply of their regular medications. In addition, counterfeit drugs are commonly found and often indiscernible from authentic medication (see Sec. 6, Ch. 3, …perspectives: Avoiding Poorly Regulated Medicines & Medical Products During Travel).

Medical Care

Most medical facilities in Cambodia do not meet international standards. A few internationally run clinics and hospitals in Siem Reap and Phnom Penh can provide basic medical care and stabilization. Some information on health facilities and pharmacies in Cambodia can be found on the website of the US embassy in Phnom Penh. For anything other than basic care and stabilization, travelers should seek medical care in Bangkok or Singapore. For this reason, strongly encourage travelers to purchase travel health insurance that includes medical evacuation (Sec. 6, Ch. 1, Travel Insurance, Travel Health Insurance & Medical Evacuation Insurance).

The following authors contributed to the previous version of this chapter: Kristina M. Angelo, Michael C. Thigpen, Dora Warren, Grant Ludwig

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