Kelly A. BENNETT, Fiona R. PRABHU, L.S. Peter PRABHU1

Staying Healthy in Southeast Asia
A Primer on Tropical Diseases
Copyright © 2002, End-of-the-Tether Expeditions

Health Risks
Preventine Medicine
Common Diseases, Diagnosis, and Treatments
Medical Kit
Issues and Controversies
Further Reading
Medical Disclaimer


Most of the standard travel guides provide you with short descriptions of common ailments, but are lacking in practical advice. They typically suggest you seek medical assistance if you suspect serious illness, but it may not always be feasible (or, indeed, possible) to obtain such assistance. Moreover, the quality of medical care in many places in Southeast Asia can be questionable. Prudent adventurers should be equipped with a good basic awareness of common tropical diseases as well as guidelines on self-medication in the field, should this become necessary. With these pragmatic considerations in mind, we have taken the standard coverage of health risks in Southeast Asia a step further. Keep in mind that this article is not comprehensive coverage of this topic, is not professional medical advice, and that the public health situation can change very rapidly. Please refer to the important 'Medical Disclaimer' notice at the end of this article.

A. Introduction

Traveling, especially in an immersion environment such as an End-of-the-Tether Expedition, exposes you to fantastic new experiences. One of the few drawbacks, however, is that the change in environment and your normal hygienic practices exposes you to new health threats as well. Armed with advance knowledge of the common diseases and their prevention, diagnosis and treatment, you can be confident that your expedition will be a resounding success.

Most of the standard travel guides provide you with short descriptions of common ailments, but are lacking in practical advice. Their standard advice to 'seek medical attention' may not always be feasible (or indeed, possible or even advisable) off the beaten track. The quality of medical care in many places in Southeast Asia can be unreliable, and anthropological curiosities aside, we believe Western medicine is an essential tool in curing disease. With these pragmatic considerations in mind, we have taken the standard coverage of health risks in Southeast Asia a step further. Keep in mind that this article is not comprehensive coverage of the topic, is not professional medical advice, and that the public health situation can change very rapidly.

B. Health Risks

We have waited until Section B to show you this list, so you're not scared off right away! This useful classification was put together by the International Society for Travel Medicine. We will discuss some of the most common and important diseases you may encounter in Southeast Asia in Section D.

Diseases Associated with Vectors


  • Dengue
  • Encephalitis, Japanese
  • Encephalitis, tick-borne
  • Filariasis (eg. Loa loa, bancroftian, onchocerciasis)
  • Hemorrhagic fevers
  • Leishmaniasis
  • Lyme
  • Malaria
  • Plague
  • Rift Valley Fever
  • Trypanosomiasis, African
  • Trypanosomiasis, American
  • Typhus Fever
  • Yellow fever


Diseases Associated with Person-to-Person Contact

  • Diphtheria
  • Hepatitis B
  • Hepatitis C
  • Influenza
  • Measles
  • Meningococcal disease
  • Mumps
  • Pertussis
  • Pneumococcal disease
  • Rubella
  • Sexually transmitted diseases
  • Tuberculosis
  • Varicella

Diseases Associated with Ingestion of Food and Water

  • Amebiasis
  • Cholera
  • Cryptosporidiosis
  • Cyclosporiasis
  • Giardiasis
  • Hepatitis A
  • Hepatitis B
  • Poliomyelitis
  • Seafood poisoning/toxins
  • Transmissable spongiform encephalopathy
  • Travelers’ diarrhea
  • Typhoid fever

Diseases Associated with Bites and Stings

  • Envenomation (e.g. jelly fish, sea urchin, scorpion, snake)
  • Rabies



Diseases Associated with Water / Environmental Contact

  • Cutaneous larva migrans
  • Legionella
  • Schistosomiasis
  • Tetanus


C. Preventive Medicine

As is normally the case, preventive measures are the most effective in staying healthy during your travels.

You should have a thorough medical check-up 8-10 weeks before departing on your trip. This will allow sufficient time for recommended inoculations and possible follow-up booster shots to provide adequate immunity. You will also need a doctor's prescription for malaria-prophylaxis drugs such as Lariam™ or Fansidar™, which regimen should be commenced at least 1 week before your departure (and should also be continued for at least 4 weeks after your return). Your doctor will also need to write you a prescription for any other broad-based antibiotic you may desire to carry.

The Centers for Disease Control ("CDC" -- part of the US Department of Health and Human Services) recommends the following inoculations for travelers to Southeast Asia:

It is also recommended that you receive booster doses for tetanus-diphtheria and measles and, for adults, a single dose of oral polio vaccine.

D. Common Diseases, Diagnosis, and Treatments

Setting aside those tropical diseases for which you should be vaccinated (as recommended above) as there is only a slim (repeat 'slim', not 'nil') chance that you may contract one of these diseases after effective inoculation, we briefly discuss the causes, symptoms, degree of severity, and recommended 'field' treatments for some of the more common and serious diseases you may encounter.

  1. Diarrhea

  2. 'Travelers diarrhea' brought on by consuming fecal-contaminated food or water, is perhaps the most common health problem for travelers to Southeast Asia. Luckily, it is rarely a life-threatening condition. Where possible, you should drink only bottled or boiled water (or better yet, beer!), and always be wary of ice. Peelable fruit is also preferable to roadside snacks. Be wary of raw vegetables and fruit (including salads), milk, raw meat, and shellfish. Those who are overly sensitive or wary of diarrhea may consider taking Pepto Bismol™ as a preventive measure. Diarrhea usually runs its course in 3-7 days. Sufferers should drink plenty of fluids to guard against dehydration; you may also want to consider taking oral electrolytes in extreme circumstances. Foods easy on the stomach include salted crackers and oatmeal. You may also want to keep supply of Imodium™ to relieve the symptoms. In severe cases, or diarrhea associated with fever, or bloody stools, a broad-based antibiotic such as doxycycline, ciprofloxacin, or azithromycin may be needed. You may want to ask your health care provider for a prescription for one of these antibiotics to have on hand if these do symptoms occur.

  3. Malaria

  4. Malaria is contracted through being bitten by a malarial-infected female anopheles mosquito. Malaria is one of the most serious diseases you may contract on your trip – if not treated promptly it can be fatal. On the positive side, it is rare in urban areas. After introduction via a mosquito bite, the malaria parasites initially attack your liver, where they grow and multiply, and eventually enter the bloodstream. At this stage, you will experience symptoms of the illness. Malaria may manifest itself as flu-like symptoms (eg. fever and chills), but will only occur after a gestation period of at least 7-9 days following an infected mosquito bite. Precautions to take when traveling in rural areas include limiting outdoor exposure during the most active periods for anopheles mosquitoes – dusk through dawn. If traveling in rural areas will be a significant part of your vacation, consider taking mefloquine as a prophylactic, available under the brand name Lariam™. Another alternative, but less effective prophylactic, is chloroquine. Certain strains of malaria have demonstrated resistance to mefloquine and chloroquine (see also below under "Issues and Controversies").

  5. Dengue Fever

  6. Dengue fever and dengue hemorrhagic fever (DHF) are fairly common diseases in Southeast Asia. Outbreaks have occurred from time to time throughout the region, even in antiseptic Singapore, and are more apt during the monsoon season. Again, the disease-carrying culprit is the mosquito, but a different variety from the malaria-carrying species. The 'Aedes aegypti' mosquito is commonly found in urban areas (both indoors and outdoors), and usually bites during daylight hours.Dengue is a serious disease, although unlikely to be fatal to the typical End-of-the-Tether Expedition member (the CDC reports a 5% fatality rate, concentrated amongst children and young adults). Symptoms can be similar to malaria – eg. fever, chills. You may also develop a rash. Given the similarity of symptoms it is virtually impossible to 'field diagnose' whether you have dengue fever as opposed to malaria. A blood test is required. As a precautionary measure, we suggest you commence a round of antibiotics as if you had malaria, and seek out medical attention as soon as possible. There is no vaccine available to prevent this disease.

  7. Cholera

  8. Cholera is a severe intestinal infection and is contracted by consuming contaminated food. Symptoms include profuse diarrhea and vomiting. It can be a very serious illness (possibly fatal) but that is quite rare for otherwise healthy foreign travelers. Proper diagnosis requires culturing of a stool sample; if you don't have access to such lab facilities, the recommended course of initial action is to treat with a broad-based antibiotic such as tetracycline or doxycycline, which will somewhat shorten the length of illness. As with traveler’s diarrhea, you should also drink plenty of fluids and consider oral electrolytes. Cholera epidemics are more prevalent during the monsoon season, where it can be present in shellfish and possibly rice. The organisms are killed by heat, so your most effective preventive action is to ensure your food is well cooked.

  9. Schistosomiasis (Schistosoma mekongi)

  10. Schistosomiasis is a parasitic disease transmitted through human contact with parasite-infested freshwater. The parasites are hosted by a certain species of snails; they are released as free-swimming larvae (cercariae) and are absorbed through unbroken skin. You may contract it, for example, by bathing or wading in contaminated lakes or rivers. It is not possible to contract schistosomiasis in salt water. Although possible, it is unlikely that you will contract schistosomiasis in Southeast Asia. It is far more common in South America and Africa. Many infections are asymptomatic, and occur several weeks after initial contact. There is a wide range of possible symptoms including fever, chills, sweating, headache, cough, enlarged lymph nodes, stomach pain, joint and muscle pain, lack of appetite, and nausea. The majority of time, the disease is self-limited. Due to this broad scope of possible symptoms, travelers should keep the possibility of schistosomiasis in their minds as it may not spring to your physician's mind back home. Diagnosis of the infection is generally confirmed by serologic studies or by identifying schistosome eggs on laboratory examination of stools or urine. Schistosomiasis is treated with the drug praziquantel, which is considered safe and effective.

  11. Tuberculosis

  12. Once considered eradicated, the widespread threat of contracting tuberculosis (TB) has been revived in recent years. As a region, Southeast Asia has the highest concentration of TB sufferers and it is a major public health issue. The WHO reports over 3 million cases per year in Southeast Asia. TB disease commonly spreads to the lungs and other vital organs. TB is contagious. The TB germs (bacilli) spread through the air similar to transmission of the common cold. There is a difference between being infected by TB bacilli and actually contracting the disease. Tuberculosis is not generally spread by casual personal contact, so travelers need not be too concerned about actually contracting the disease while traveling, unless they have particularly weak immune systems. TB infection is asymptomatic. If you have contracted the disease, you may experience a hacking cough with mucus or blood (in the case of TB lung disease) or more general symptoms like fever, weight loss, or sweating at night. Even if you don't have symptoms, you should consider screening for TB after returning from an endemically infected area, during a regular checkup with your family physician (no need to run to the emergency room!). Reliable diagnosis can only be done through a skin test. It is normally treated with a 6-12 month regimen of the drug Isoniazid (INH) and is rarely fatal, if treated in time.For more information, refer to the WHO site.

  13. Skin Infections

Otherwise-minor cuts and abrasions are more likely to become infected in the tropics due to the more humid environment as well as the traveler's lack of opportunity to properly and regularly clean the cut. Take extra precautions to ensure that your feet are well protected and dry – going barefoot is a bad idea.If left untreated, skin infections will only worsen and detract from your enjoyment of the expedition. They are normally cleared up with either an antibiotic topical ointment such as Neosporin, or for more serious cases, orally administered erythromycin.


Cause and degree of seriousness

Preventive measures




  • water-borne bacteria
  • unlikely to be serious
  • drink bottled or boiled water
  • Pepto Bismol ™ prophylaxis taken four times daily
  • runny, foul smelling feces
  • gastrointestinal discomfort
  • maintain sufficient hydration
  • Imodium™or Lomotil
  • doxycycline, ciprofloxacin, or azithromycin in severe cases


  • anopheles mosquito, bites at dawn and dusk
  • can be fatal if not treated promptly
  • limit exposure during dawn and dusk
  • mefloquine, chloroquine, or other prophylaxis
  • flu-like symptoms – eg. alternate between fever and chills exhibit themselves 7-9 days after infected mosquito bite
  • mefloquine is recommended, malarone or doxycycline may be used for resistance strains

Dengue Fever

  • Aedes aegypti mosquito
  • limit exposure to mosquitoes
  • mefloquine, chloroquine, or other prophylaxis
  • fever
  • chills
  • rash (possibly)
  • mefloquine
  • avoid aspirin


  • contaminated food, esp. shellfish and rice
  • severe cases can be life-threatening
  • consume only well-cooked food
  • diarrhea, vomiting
  • tetracycline or doxycycline
  • oral electrolytes for rehydration


  • contaminated fresh water
  • do not bathe in fresh water
  • usually none
  • possibly fever, nausea, sbdominal pain, joint and muscle pain
  • praziquantel


  • tuberculosis bacilli
  • unlikely to be contracted while travelling
  • avoid possible transmission by coughers
  • coughing of mucus and/or blood (for lung TB disease)
  • isoniazid after infection has been diagnosed

Skin Infection

  • various bacteria
  • can be serious
  • avoid cuts
  • clean cuts and abrasions promptly with sterile solution
  • swelling, pain
  • yellow secretion
  • Neosporin™ (topical)
  • erythromycin (oral)


E. Medical Kit

An effective medical kit for travelers to Southeast Asia would include:

Medicines and First Aid


For more ideas on what else you might consider bringing, refer to:

Jong, Elaine C. and McMullen, Russell (eds.), The Travel and Tropical Medicine Manual, 2nd ed. (Philadelphia: W.B. Saunders Company), 1995.


F. Issues and Controversies

Mefloquine: There have been reports of occasionally serious side effects, including hallucinations and severe anxiety. Minor side effects can include nausea, dizziness, and difficulty sleeping.

Antimicrobial Resistance: The World Health Organization issued an advisory in January 2002 outlining their concerns over the alarming increase in antimicrobial resistant diseases. In the context of travelers to Southeast Asia, the greatest risk is contracting microbial-resistant malaria, particularly towards mefloquine. The alternative therapies of malarone or doxycycline are effective in treating such strains.

Travelers Diarrhea: Treat or let it run its course? If you're like us, taking medications is a reluctant act. In the vast majority of cases, traveler’s diarrhea will resolve itself once the contaminants have passed through your system. Should you take anti-diarrhea medicine such as Imodium or Lomotil? The effect of these drugs is to 'block-up' your gastrointestinal system. While they undoubtedly reduce the amount of diarrheal stools, they also affect your body's normal metabolism, which would otherwise work to expel the toxins. Moreover, these drugs can introduce complications to persons with serious gastrointestinal infections.

G. Conclusion

We firmly believe that "knowledge is power" and hope that this article has imparted to you sufficient information for you to be prepared to deal with the health issues which may arise in traveling in Southeast Asia, without of course adding to your health worries by turning you into a hypochondriac!

One final word of advice: don't forget to purchase quality health insurance for your trip. While the need may be remote, it is a small price to pay for the peace of mind that you will have access to emergency evacuation resources as well as a high standard of medical care.

Further Reading

Should you wish more information on tropical diseases in Southeast Asia, as well as ongoing updates, we suggest the following sources:

Centers for Disease Control

Swiss Government

World Health Organization

International Society for Travel Medicine

American Society of Tropical Medicine and Hygiene




As noted throughout this article, the Information is provided for educational and informational purposes only, and is not intended to be a substitute for a health care provider's consultation. Please consult your own physician or appropriate health care provider about the applicability of any opinions or recommendations with respect to your own symptoms or medical conditions as these diseases commonly present with variable signs and symptoms.

Check with a physician if you suspect you are ill, or believe you may have one of the problems discussed in this article, as many problems and disease states may be serious and even life-threatening. Also note that we do not undertake to post regular updates to this article and that medical information can change rapidly. Therefore, some information may be out of date or even possibly inaccurate and erroneous. If you find Information that you believe is in error, please let us know.

The Information should not be considered complete, nor should it be relied on to suggest a course of treatment for a particular individual. It should not be used in place of a visit, call, consultation or the advice of your physician or other qualified health care provider. The Information is not exhaustive and does not cover all diseases, ailments, physical conditions or their treatment. Should you have any health care related questions, please call or see your physician or other qualified health care provider promptly. Always consult with your physician or other qualified health care provider before embarking on a new treatment, diet or fitness program.

The authors and End-of-the-Tether Expeditions do not recommend or endorse any specific tests, products, or procedures that may be mentioned in the Information. Any opinions expressed in the Information are the opinions of the authors. Neither the authors nor End-of-the-Tether Expeditions assume any liability for the contents of any Information. Reliance on any Information is solely at your own risk. The authors and End-of-the-Tether Expeditions assume no liability or responsibility for damage or injury to persons or property arising from any use of any product, information, idea, or instruction contained in the materials provided to you.

You access this Information at your own risk. The authors and End-of-the-Tether Expeditions accept no responsibility whatsoever for such materials.


  1. Kelly A. Bennett, MD is Chief of Staff, Texas Tech University Student Health Department and Clinical Assistant Professor, Texas Tech University School of Medicine, Lubbock, Texas, USA. Fiona R. Prabhu, MD is Assistant Professor, Texas Tech University School of Medicine, Lubbock, Texas, USA. L.S. Peter Prabhu, M.Phil (Cantab) is Senior Expedition Leader, End-of-the-Tether Expeditions and Member of the BDICFA, Cambridge, UK.