Malaria: Cambodia, Laos, Thailand, Vietnam

First published on 12th August, 2007

One of the most commonly asked questions by first-time travellers to Southeast Asia is "Should I take malarials?". It's a simple question, with a complicated answer, best summed up as "it depends". Here's ten pointers that we hope will help you make a more informed decision regarding malarials and travel to Southeast Asia.

1) Talk to a travel doctor.

Malaria is a serious disease which kills over one million people every year, and the best place to start is with a doctor who is a travel specialist. Your local medical practitioner or family doctor may not have the expertise nor experience to give you an accurate opinion on what you should be doing. "Traveller's Medical Centres" are a growing niche which you should avail yourself of.

If you talk to your doctor, mention Asia and they lunge for the prescription book, without even asking where in Asia you are considering going, then you need to get a more informed opinion.

Dengue fever in Southeast Asia

As a casual visitor to Southeast Asia you're fare more likely to contract Dengue fever than malaria.
Click here to learn more about the disease including first hand reports from those who have suffered the virus.

Talking of a more informed opinion, we talked to a tropical medicine specialist we've known for years and here's what he had to say:

"Generally travel medical doctors try to individualise it with the patient and their trip, rather than adopt a "cookbook" approach and a risk assessment model works well here. Basically the factors to be considered and discussed with a client enquiring about malaria tabs are:

- the country itself and overall level of risk which includes "official" recommendations from organisations e.g.. WHO
- areas travelled to within the country (esp urban or rural) as risks will vary here. This includes level of remoteness and access to medical care
- duration of travel
- season of travel i.e. wet / dry
- style of travel - on a spectrum of rock bottom to 5-star.
- the client's own compliance with mosquito avoidance measures
- the client's own wishes regarding what level of risk is acceptable -- some want to be "covered for everything" whilst some others don't want tablets even if they're going to a high risk area.

It's a moveable feast and not cast in stone. For example:

- Previous blanket recommendations for needing prophylaxis for anywhere in India were recently relaxed about one to two years ago. However a recent increase in cases amongst tourists in Goa forced a rethink.

- there is good evidence that due to climate change, malaria in Kenya is now occurring at higher altitudes (incl. Nairobi!) at areas and elevations previously considered malaria free.

I think the main message is that the decision to take or not take malaria prevention needs to be made by the client after consultation with a travel medicine provider."

Now here's some other points about the disease you should consider.

2) Malarials do not immunise you from malaria

This is a common misconception. To quote the WHO: "No antimalarial prophylactic regimen gives complete protection". Malarials do not protect you 100% from malaria, rather they give you more time to get to a medical centre where you will still need to seek further medical treatment. This is certainly the case with doxycycline -- one of the more commonly prescribed medications.

3) An ounce of prevention is worth a pound of cure

Listen to your Grandma -- An ounce of prevention is worth a pound of cure. The best way to avoid being afflicted by malaria is to avoid being bitten by mosquitos and there are a number of simple steps one can take to dramatically reduce the chances of being bitten. These include:

a) Use a permethrin impregnated mosquito net
b) Use mosquito repellent containing DEET
c) Dress sensibly -- wear long pants and sleeves at dawn and dusk.
d) Use mosquito coils or other anti-mosquito devices (e.g.., citronella) as a secondary control.
e) If you are prone to being bitten, lean towards accommodation that can be sealed up -- air-con with no slatted windows nor open eaves.
f) Watch out for rooms with bucket showers/toilets. These tend to have buckets of stagnant water -- a mozzie's beach resort -- in the bathroom.
g) Don't sleep naked in a swamp.

4) Prevention protects you from other nasties

Another potentially fatal disease spread by mosquitos is dengue fever. It should be a far bigger concern to travellers than malaria, but as there's no pills to sell to "protect" you from it, you hear far less about it from the medical industry. In following the steps outlined in point 3 above, you'll also protect yourself from dengue fever.

5) The need for malarials is dependent on where you are going

The US Centre for Disease Control (CDC), an organisation which tends to err on the cautious side, suggests the following areas have malaria risks:
Cambodia: Risk throughout the country, including risk in the temple complex at Angkor Wat. No risk in Phnom Penh and around Lake Tonle Sap.
Laos: Risk throughout the country, except no risk in the city of Vientiane.
Thailand: Risk in rural areas that border Cambodia, Laos, and Burma. Risk in Ko Pha Ngan. No risk in cities and no risk in major tourist resorts. No risk in Bangkok, Chiang Mai, Chiang Rai, Pattaya, Phuket and Ko Samui.
Vietnam: Rural only, except no risk in the Red River delta and the coastal plain north of the Nha Trang. No risk in Hanoi, Ho Chi Minh City, Da Nang, Nha Trang, Qui Nhon, and Haiphong.

The WHO makes the following recommendations:
Cambodia: Throughout the year in the whole country except in Phnom Penh and close around Tonle Sap. Risk within the tourist area of Angkor Wat is limited.
Laos: Throughout the year in the whole country except in Vientiane.
Thailand: Throughout the year in rural, especially forested and hilly, areas of the whole country, mainly towards the international borders. There is no risk in cities (e.g. Bangkok, Chiang Mai, Pattaya), Samui island and the main tourist resorts of Phuket island. However, there is a risk in some other areas and islands.
Vietnam: Malaria risk exists in the whole country, excluding urban centres, the Red River delta, and the coastal plain areas of central Vietnam. High-risk areas are the highland areas below 1 500 m. south of 18?N, notably in the 4 central highlands provinces Dak Lak, Dak Nong, Gia Lai and Kon Tum, Binh Phuoc province, and the western parts of the coastal provinces, Quang Tri, Quang Nam, Ninh Thuan and Khanh Hoa.

6) Malarials can have nasty side effects

There are four main types of malarials which are prescribed for travel to Asia. They are atovaquone/proguanil (brand name Malarone), doxycycline, mefloquine (brand name Larium) and primaquine. While the majority of travellers take these without problem, each of these can have serious side-effects, including:

Stomach pain, nausea, vomiting, and headache.

Sun sensitivity, nausea, stomach pain and vaginal yeast infection. More inconvenient than a touch of sunburn is that doxycycline can render the birth-control pill ineffective. If you are using doxycycline and don't have plans for baby travellers on your immediate horizon, then you will need to use alternative birth control measures.

The most common side effects include headache, nausea, dizziness, difficulty sleeping, anxiety, vivid dreams, and visual disturbances. Rarer, more serious side effects include seizures, depression, and psychosis. We've personally seen individuals bearing the brunt of these side effects and would never suggest anyone take this profilactic for travel in Asia.

Stomach cramps, nausea, and vomiting. Primaquine can also cause an hemolysis (bursting of the red blood cells) in G6PD deficient persons, which can be fatal.

That all sounds pretty terrible, but then there's the effects of catching malaria which you need to weight these against:
Shaking chills, headaches, muscle aches, tiredness, nausea, vomiting, and diarrhoea. May also cause anaemia and jaundice. Infection with one type of malaria, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death.

7) Many mosquitos are malarial resistant

Malaria is an adapting disease and certain areas are resistant to some malarials. To again quote from the CDC:

The provinces of Preah Vihear, Siemreap, Oddar Meanchey, Banteay Meanchey, Battambang, Pailin, Koh Kong, and Pursat bordering Thailand are mefloquine resistant -- use only atovaquone/proguanil or doxycycline.
All other areas you can use atovaquone/proguanil, doxycycline, mefloquine or primaquine.
No risk in Phnom Penh and Tonle Sap.

The provinces of Bokeo, Luang Nam Tha, Salavan and Champassak, along with the areas along the Thai and Burmese borders are all mefloquine resistant -- use only atovaquone/proguanil or doxycycline.
All other areas you can use atovaquone/proguanil, doxycycline, mefloquine or primaquine.
No risk in Vientiane.

All of Thailand is mefloquine resistant, use only atovaquone/proguanil or doxycycline.
No risk in cities and no risk in major tourist resorts. No risk in Bangkok, Chiang Mai, Chiang Rai, Pattaya, Phuket and Ko Samui.

The southern and central part of Vietnam, including rural areas of the provinces of Tay Ninh, Song Be, Lam Dong, Ninh Thuan, Khanh Hoa, Dak Lak, Gia Lai, and Kon Tum are all mefloquine resistant -- use only atovaquone/proguanil or doxycycline.
All other areas you can use atovaquone/proguanil, doxycycline, mefloquine or primaquine.
No risk in Hanoi, Ho Chi Minh City, Da Nang, Nha Trang, Qui Nhon, and Haiphong.

To boil all that down, if you are going to take malarials, don't take mefloquine as it doesn't cover the entirety of any one of the above countries.

8) Malarials are expensive

Purchased in the west, malarials can be very expensive. While we're not suggesting there's any profiteering going on (perish the thought), there is a definate financial incentive for the pharmaceutical industry to convince you to purchase the pills before you leave home. If you're comfortable using generic medication, malarials are far more affordable in Asia than in the west,so consider spending your money in Asia.

9) Chances are you'll be fine

You're far more likely to have a motorbike accident, have your bag stolen or contract dengue fever than you are to come into contact with malaria. While the local population has some degree of inherited resistance to the disease, there are thousands of foreigners living in Asia who have no such resistance. Very very few of these foreigners, who live in Asia for years, take malarials on a regular basis.

10) Our personal experience

For what it's worth, in our over ten years of living and travelling absolutely all over the region, we've:
Been involved in three motorcycle accidents
Had some piece of luggage stolen at least three times
Know of at least half a dozen people who have had dengue fever
Have known not a single person who has contracted malaria
Have seen two people (including a Travelfish staffer) totally freak out as a result of taking mefloquine.

In conclusion, if you're planning on stopping by just the main tourist hotspots, using repellent and a mosquito net, dressing sensibly and never sleeping naked in a swamp, then chances are you probably don't need to take malarials. On the other hand, if you're planning on spending a lot of time trekking in remote areas and hanging out in border zones, don't plan to use a mosquito net or repellent and almost certainly plan to sleep in a swamp in your birthday suit once or twice, then availing yourself of a course of malarials would be a prudent decision.

One last point -- if you do decide to take malarials, make sure you take the full course of pills. If you cut it short you're contributing to drug resistant strains of malaria and also endangering yourself.

Further reading

Start by contacting a travel doctor and getting their opinion, then try the following websites for more information:
CDC Malaria website
WHO malaria website

About the author:
Stuart McDonald co-founded with Samantha Brown in 2004. He has lived in Thailand, Cambodia and Indonesia, where he worked as an under-paid, under-skilled language teacher, an embassy staffer, a newspaper web-site developer, freelancing and various other stuff. His favourite read is The Art of Travel by Alain de Botton.

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