Urethritis remains the most common treatable sexually transmitted disease (STD) among tourists to Asia. Gonorrhea from Southeast Asia is frequently multi-drug resistant. While syphilis become less common, HIV/AIDS is spreading at worrisome speeds in most Asian countries, resulting mostly from unprotected sexual contacts. Promiscuous sex anywhere can be dangerous. For travelers, local sex workers, either of explicit or concealed types, are potential sources of STDs and HIV/Aids. All casual sex should be avoided or strictly protected with the use of condoms.

Bangkok and most provinces in the central region as well as major tourist resorts such as Chiangmai, Phuket, Hua-Hin and Koh Samui have been free from malaria for decades. Now all cities in Thailand are malaria free. However, tourist destinations in rural neighborhoods, especially those in the mountainous and border areas are still at certain risks. Chloroquine and most other chemo prophylactic drugs have proved to be ineffective against falciparum malaria in Thailand. Tourists visiting these endemic areas are rather recommended to take general precautions against mosquito bite. After sunset, they should stay in screened quarters or mosquito nets, wear long-sleeved shirts and pants, and may apply mosquito repellents. Those who develop fever within two weeks of entry to risk areas should seek prompt medical examination and treatment.

These diseases are endemic in Southeast Asia. They are caused by dengue virus from the bite of aedes mosquito that lives in the houses and their neighborhood. This mosquito bites during the day time- Dengue infection in local people, mostly children, often results in fever with bleeding in the skin and other organs (dengue hemorrhagic fever) which is sometime fatal; but for travelers from non-endemic areas, the infection usually manifests as fever with rash in the skin, severe headache and muscle and pains (dengue fever), which is usually non-fatal.

Dengue infection is common in the rainy season (approximately May to September in Thailand) when aedes mosquito is abundant. Travelers visiting local households or their vicinity, especially in the rainy season, should be using mosquito repellent even in the day time. Ones who are ill with symptoms suspected of dengue infection should seek medical consultation to establish the cause of the illness.

Rabies can be found mainly in dogs . Although Thailand has been working toward elimination of the disease and the situation has been much improved, travelers are recommended to take prevention if their travel itineraries allow possible exposure to animal bites. Those who plan walking sight-seeing in local communities should consider having pre-exposure rabies vaccination before starting off. Three intramuscularly injections of cell-culture rabies vaccine are required. In case of exposure to animals without prior vaccination, the pose-exposure vaccination is usually effective if it is initiated without delay. However, for those who have had pre-exposure vaccination, if they are bitten, they should also seek prompt consultation with the physician for evaluation and consideration for booster vaccination.

This viral infection of the brain, is contracted through the bite of mosquitoes that prevail in rural agricultural areas. It is found in many Eastern and Southeastern Asian countries, primarily in the rural and suburban areas. Similar to malaria, the disease can be prevented by avoiding mosquito bite during the night time- Travelers who plan to spend their time exposing to rural environment in these regions for over several months are recommended to take Japanese encephalitis vaccination before entry.

Typhoid fever has become uncommon among Thai people. However, travelers should not neglect taking prevention against this food and water borne disease. Precaution measures for diarrhea, as mentioned later, are effective for typhoid as well. It is also recommended that the travelers receive typhoid vaccination, in injectable or oral form, before start of the journey. However, those who need initiation or booster vaccination can find the service at most hospitals and clinics in Thailand, Diarrhea is mostly caused by ingestion of food and drinks contaminated with bacteria or viruses. To prevent diarrhea, avoid uncooked food and drink only boiled or bottled or carbonated water. Food served at street vendors should be considered at risk. Fresh vegetables and fruits should be adequately washed with clean water. Fresh salad should be taken only from a salad bar or a restaurant of hygienic standard. Tap water in many Southeast Asian cities is claimed to be safe for drinking, but it is still advisable to stick to safety precautions. Danger from diarrhea primarily is the result of the loss of water and electrolytes from the body. If you happen to have diarrhea during your travel, the most helpful remedy is drinking electrolyte solution to replace the loss. Therefore, it is always useful to keep some electrolyte solution packets in your first-aid kit. If your diarrhea gets worse or does not improve within 12-24 hours, consult the physicians for proper investigation and treatment. 

Viral hepatitis

There are two major groups of viral hepatitis. Hepatitis spread by contaminated food and water, hepatitis A and E, are endemic in many parts of Asia. Most local people are immune to these types of hepatitis through natural infection, but travelers from better hygienic environments can be receptive to infection- Therefore, travelers are recommended to practice prevention measures against food and water borne diseases, as suggested for diarrhea. An alternative protection for hepatitis A is the immunization with hyper immune serum or hepatitis A vaccine. Consult with the physician at an established medical service for the immunization.
Another group of hepatitis; hepatitis B, C and D; are transmitted through contaminated blood and sexual contacts, or passed from infected mothers to their babies at the time of birth; similar to the ways HIV/AIDS is transmitted. This group of hepatitis can be simultaneously and effectively avoided if precautions immunization against HIV/AIDS are strictly taken. However, for those who require immunization, effective vaccine against hepatitis B is available at most medical services.

For more information, please contact:
International Communicable Disease Control Section, Division of General Communicable Diseases, Department of Communicable Disease Control Ministry of Public Health, Tel. 286-5114
Airport Health Office, Tel. 535-1482
Port Health Office, Tel. 249-4110