IAMAT |International Association of Medical Assistance to Travellers| IAMAT |International Association of Medical Assistance to Travellers|

Country Health Advice Thailand

Food & Water Safety: Overview

We are currently reviewing the food and water safety advice for this country.

All local water should be considered contaminated. All tap water used for drinking, brushing teeth, and making ice cubes should be boiled (bringing water to a good rolling boil is sufficient). Good brands of bottled water are available; check cap seal and ensure that the bottle is uncapped in your presence.

Milk should be boiled before consumption because of possible improper refrigeration during distribution. Powdered and evaporated milk are available and safe. Butter should not be used as a table food. Cream, ice cream, and whipped cream should not be consumed. Cheese, unless cured, is best avoided. Yoghurt is safe only if it is known to be made from pasteurized milk.

All meat, poultry, and fish must be well cooked and served while hot. Pork is best avoided; vegetables should be well cooked and served hot. Salads are best avoided. Fruits with intact skins should be peeled by you just prior to consumption. Avoid raw and undercooked eggs, and dishes prepared with raw eggs (steak tartar, mayonnaise, and dressings). Avoid cold buffets, uncured cheeses, custards, and any frozen desserts.

First rate hotels and restaurants serve purified drinking water and reliable food. However, the hazard is left to your judgement.

Chemicals found in food and water

Globalized food production and shipping are making it harder for consumers to know if their food and water is safe. Travellers should be aware that food and water contamination not only occurs through improper food handling or poor hygiene practices. Air, soil, and water pollution resulting from heavy metals, dioxins, pesticides, agro-chemicals, and drugs given to food-production animals, occurs worldwide. IAMAT recommends eating locally sourced foods from reputable growers as much as possible. We will post any new information on outbreaks resulting from environmental contamination on this page. Don’t forget to consult our website before your trip!

Food allergies

Being prepared is important to preventing allergic reactions or anaphylactic shock during your trip.

  • Research the common foods of your destination country and talk to your health practitioner about your travel plans.
  • Pack the medications you need to prevent an adverse reaction like antihistamines or epinephrine injectors with refills.
  • Find a reputable doctor or hospital prior to your trip in case of an emergency. Carry your IAMAT Traveller Clinical Record outlining your food allergies so that healthcare providers abroad are aware of your condition. 
  • If you’re grocery shopping abroad, read labels and be aware of packaging that does not list ingredients. Note that in many countries there are no or weak food labelling regulations and some products may be partially labelled.
  • Tell others about your food allergy. Carry a personalized translated card detailing your allergies to show restaurant waiters, grocery store clerks, or food vendors. SelectWisely offers a wide range of professionally translated cards.

Traveller’s Diarrhea

The term Traveller's Diarrhea is used to describe gastro-intestinal infections affecting travellers caused by ingesting bacteria, viruses, and protozoa. These micro-organisms are found worldwide and are typically transmitted from person to person via the fecal-oral route – an infected person who does not practice proper hand or body hygiene passes on the infection to another person when handling food and water. Traveller's Diarrhea is the most common illness among travellers.

Risk: Traveller’s Diarrhea can happen when:

  • Eating raw, undercooked, unwashed, or improperly handled meat, poultry products, dairy products, fruits, vegetables, shellfish, and seafood.
  • Drinking contaminated water or beverages.
  • Inadvertently ingesting fecal matter, protozoa eggs, or viruses by touching the mouth with dirty or improperly washed hands.
  • Eating out in restaurants, from buffets, or from street vendors where food handling and hygienic practices are not followed properly.

Prevention: The golden rule to prevent gastro-intestinal infections is: Boil it, Cook it, Peel it, or Forget it! However, it’s not just about what you eat, it’s also important to consider where you eat. It’s not always easy to know if a restaurant or food vendor follows proper food handling and hygienic practices (properly cleaning cutting boards, utensils, sink to wash hands, refrigeration). Be cautious of food that has been stored uncovered, has been improperly refrigerated, or has been standing out for a long time, such as buffets.

More information on Food and Water Safety:
>> How To Prevent Traveller's Diarrhea [PDF]
>> How To Prevent Food and Water Illnesses [PDF]
>> How To Prevent Illness by Washing Your Hands [PDF]

>> Guide to Healthy Travel

Bacteria
Approximately 85% of Traveller’s Diarrhea is caused by bacteria. Symptoms involving bacterial infections generally appear within hours of eating contaminated food or water and can last 3 to 7 days. Typical symptoms include diarrhea, abdominal pain, nausea, general weakness, headache, low fever, and possible vomiting. Severe cases can cause dehydration.

The following are common bacteria causing food and water illnesses in travellers:
Enterotoxigenic Escherichia coli (ETEC)
– Commonly known as ‘e. coli’ and responsible for the majority of Traveller’s Diarrhea cases. The illness is associated with contaminated food and water. Symptoms appear 1 to 3 days after infection. Treatment includes supportive care of symptoms and in severe cases antibiotics are prescribed.

Campylobacter jejuni– Associated with contaminated water, undercooked poultry, unpasteurized milk. Symptoms appear 1 to 7 days after being infected and can last 2 to 3 weeks without treatment. Some patients also have bloody diarrhea. Post-infection complications can lead to Guillain-Barré Syndrome, where the immune system attacks the nerves and causes paralysis, or irritable bowel syndrome. Treatment includes antibiotics.

Salmonella enteritidis – Associated with eggs, poultry, meat, raw fruits and vegetables. Symptoms usually appear 1 to 3 days after infection and can last up to 7 to 14 days. Infected persons can become asymptomatic carriers and shed the bacteria for weeks or months, becoming the source of infection for others through poor hygiene practices. Treatment includes supportive care of symptoms. Salmonella typhi is the cause of Typhoid Fever.

Shigellosis – Associated with contaminated food and water and caused by one of four Shigella species that spreads as a result of unsanitary conditions, contaminated food and water, and overcrowded living conditions. Symptoms usually last 4 to 7 days. The illness may progress to bloody diarrhea with mucous and the constant urge to pass stools. Shigella bacteria can be shed from your gastro-intestinal system for up to 3 months after symptoms disappear. Treatment includes antibiotics.

Vibrio cholera, Vibrio parahaemolyliticus, Vibrio vulnificus – Associated with contaminated water, raw or undercooked fish and shellfish and causes Cholera, an acute gastro-intestinal infection. Risk to travellers is low and vaccination is advised only for medical and rescue personnel working in endemic areas. The infection can lead to severe dehydration and death in undernourished persons or those with compromised immune systems or kidneys.  Vibrio vulnificus has caused septicemia (blood poisoning) in persons with liver disorders.

Viruses

Approximately 5% of Traveller’s Diarrhea is caused by viruses. A person can become ill when touching contaminated surfaces with the virus (railings, door knobs), shaking hands, or coming into close contact with an infected person and then touching your mouth and eyes.

The most common viruses causing food and water illnesses in travellers are:
Norovirus
– Associated with outbreaks at large gatherings or on cruise ships. The illness is also caused by contaminated water and foods like salads, clams, and oysters. Symptoms can appear 10 hours to 2 days after infection and include nausea, vomiting, abdominal pain, diarrhea, and sometimes fever and dehydration. The illness usually last 1 to 4 days and treatment includes supportive care of symptoms.

Rotavirus – Particularly affects children less than 5 years old and is also associated with contaminated food and water. Symptoms appear 1 to 3 days after being infected and include vomiting, diarrhea, fever, abdominal pain, and headache. Dehydration and body limpness are characteristics of this illness which typically lasts 4 to 8 days. Vaccination is recommended for children. Treatment includes supportive care of symptoms for both children and adults.

Protozoa
Approximately 10% of Traveller’s Diarrhea is caused by protozoa. In addition to contaminated food and water, these one-celled microscopic organisms are also transmitted to humans by swallowing contaminated water from lakes, rivers, fountains, ponds, and other bodies of water or accidentally swallowing soil or sand containing protozoa eggs. Typical symptoms include abdominal pain and cramps, diarrhea, bloating, nausea, lack of appetite, fatigue, headache, and light fever. Prolonged infection causes dehydration and weight loss.

The most common protozoa causing food and water illnesses in travellers are:
Amoebiasis – Caused by Entamoeba histolytica protozoa. The majority of cases are asymptomatic (persons do not exhibit symptoms). Those who do exhibit symptoms usually develop them 2 to 4 weeks after being infected. Amoebic Dysentery is the more severe form of the illness where patients develop fever and blood in their stools. In rare cases, the protozoa can cause lesions in the liver. Treatment includes taking medication belonging to the nitroimidazole family of drugs.

Cryptosporidiosis –The infection, commonly referred to as ‘Crypto’, is primarily caused by Cryptosporidium hominis protozoa. The illness is associated with contaminated food or water, including swimming pools and other water bodies. Some people are asymptomatic (do not exhibit symptoms). Those who do exhibit symptoms usually develop them 2 to 10 days after being infected. Some patients may also have a cough, recurring headache, dizziness, eye pain, and joint pain. The illness can trigger irritable bowel syndrome and inflammatory bowel diseases. Symptoms usually disappear after 1 to 2 weeks as the protozoa are shed through feces. Treatment includes anti-protozoal medication or antibiotics.

Cyclosporiasis – Caused by the Cyclospora cayetanensis protozoa and associated with fresh produce like berries and lettuce. Symptoms usually appear 2 to 7 days after infection. Some patients may develop fever after a few days. The diarrhea may come and go throughout the duration of the illness which can last from 2 to 12 weeks if untreated. The infection tends to be seasonal for reasons yet unknown and disinfecting agents like chlorine do not seem to kill the protozoa. Treatment includes taking antibiotics.   

Giardiasis–Caused by Giardia intestinalis protozoa and associated with contaminated food and water. Symptoms usually appear 1-2 weeks after infection. The symptoms usually disappear 2-4 weeks later as the protozoa are shed through feces. Treatment includes taking medication belonging to the nitroimidazole family of drugs. Treatment includes taking medication belonging to the nitroimidazole family of drugs.

Foodborne Toxins

Another source of gastro-intestinal illness are foodborne toxins produced by bacterial spores that germinate on food – particularly meat, poultry, salads, baked goods, and dairy products – that is improperly stored or refrigerated, usually standing at room temperature for a prolonged period of time.Symptoms can appear within hours of ingesting contaminated food and include abdominal pain, diarrhea, nausea, and vomiting. The infection usually lasts 1 or 2 days and treatment includes supportive care of symptoms. Antibiotics are not recommended.

Common foodborne toxins affecting travellers include:
Clostridium perfringens – Associated with meat and poultry and is the most important agent causing food poisoning in industrialized countries. Symptoms appear within 6 to 24 hours after ingestion.

Staphylococcus aureus – Associated with creamy desserts, custards, meats, and baked goods. Enterotoxins are transmitted via unsanitary practices by infected persons. Symptoms appear within 30 minutes to 8 hours after ingestion.

Clostridium botulinum – Associated with improperly canned food, lightly preserved vegetables, salted fish, and meats. Symptoms usually appear within 12 to 48 hours and include nausea, vomiting, blurred and double vision, paralysis of respiratory and motor muscles that may progress rapidly.

Seafood and Shellfish Poisoning

Seafood and shellfish poisoning occurs as a result of eating marine food products contaminated with naturally occurring toxins in sea water. Travellers are at risk in any country as a result of the availability of these products (fresh or frozen) around the world.

The most common seafood and shellfish related illnesses in travellers are:
Ciguatera Fish Poisoning – Occurs when toxins created by dinoflagellate micro-organisms are passed up the marine food chain and bio-accumulate in large fish like barracuda, grouper, red snapper, moray eel, amberjack, parrotfish, hogfish, sturgeonfish, kingfish, coral trout, and sea bass. The toxins are not destroyed through cooking, smoking, or freezing, they are odorless and tasteless, and do not alter the appearance of the fish. For information on symptoms and prevention, see Ciguatera Fish Poisoning

Scombroid Poisoning – Results from improper handling and refrigeration of fish containing high levels of natural occurring histidine (amino acid in protein). Contamination with bacteria will convert histidine to histamine causing symptoms similar to allergic reactions, which occur very rapidly and include headache, abdominal cramps, diarrhea, itching, flushed face, dry mouth, heart palpitations, difficulty breathing. Symptoms rarely last over 8 to 12 hours. Scombroid poisoning affects fish from the Scombridae family: Tuna, mackerel, skipjack, and bonito. It can also affect other species such as herring, bluefish, sardine, anchovy, amberjack, and mahi-mahi. Treatment includes taking anti-histamines and supportive care of symptoms. Treatment in severe cases may include anti-inflammatory steroids and epinephrine related medication.

Shellfish Poisoning – Associated with the algal blooms (red tides) occurring in temperate and tropical areas. Oysters, clams, cockles, mussels, scallops, crabs, and lobsters filter or ingest toxins produced by dinoflagellates micro-organisms. There are four different illnesses associated with shellfish poisoning:

  1. Diarrheic shellfish poisoning can occur hours or days after eating contaminated shellfish. Symptoms include abdominal pain, nausea, vomiting, and diarrhea. Recovery occurs within 2 to 3 days and treatment includes supportive care of symptoms.
  2. Neurotoxic shellfish poisoning can occurs 1 to 6 hours after ingestion. Symptoms include nausea, vomiting, diarrhea, reversal of hot and cold temperature sensation, and involuntary muscle movement. Recovery occurs within 2 to 3 days and includes supportive care of symptoms.
  3. Paralytic shellfish poisoning can occur 30 minutes after eating contaminated shellfish. Symptoms include nausea, numbness of face arms and legs, headache, loss of coordination and dizziness. In severe cases respiratory failure and paralysis may lead to death.
  4. Amnesic shellfish poisoning can occur within 24 hours of ingestion and include nausea, vomiting, abdominal pain, and diarrhea. Within 48 hours, symptoms include headache, seizures, muscle weakness or paralysis, and disorientation. Permanent short-term memory loss has been observed, and in severe cases can lead to coma or death. Treatment includes supportive care of symptoms.

Puffer (Fugu) Fish Poisoning – Caused by a tetrodotoxin accumulating mainly in the liver, intestines and ovaries of puffer fish, ocean sunfish, globe fish, and porcupine fish. Symptoms appear between 6 and 20 hours and include nausea, abdominal pain, diarrhea, vomiting, profuse sweating, salivation, headache, hypothermia, heart palpitation. Neurological symptoms include numbness, loss of coordination, tremors, and paralysis. The illness can also cause respiratory failure and approximately 60% of patients die. Treatment involves supportive care of symptoms and may include cholinesterase inhibitors (anti-poisoning agents).


Travel Health Journal

ALL BLOG POSTS