Risk is present throughout the country, excluding urban areas, risk present at all altitudes:
There is no risk in the cities of Bangkok, Chiang Mai, and Pattaya. Persons flying into cities and making only daytime excursions to rural areas do not need to take malaria suppressive medication.
Sporadic cases are reported from Phuket, Phang Nga, Kho Samui, and Kho Pha Ngan. Take anti-mosquito bite measures in these areas.
Persons travelling by car, boat, or train through rural areas of the interior, especially forested and hilly areas, and to mining and refugee camps, as well as to the border areas with Myanmar (Burma), Cambodia, and Laos, should be aware of the presence of multidrug resistant malaria (see specific locations below). For these areas, take atovaquone-proguanil or doxycycline antimalarial medications.
Note: Infection with Plasmodium knowlesi, a malaria parasite of Old World monkeys, has been reported in humans.
High risk months for Malaria are: January to December
Malaria transmission vector(s): A.minimus minimus, A.sundaicus
Incidence of Plasmodium falciparum Malaria: 56%
Of the five species of human malaria parasites, Plasmodium falciparum is the most dangerous. The remaining percentage represents malaria infections that may be caused by one or more of the following parasites: Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium knowlesi.
Areas with drug resistant Malaria: The western border areas with Myanmar (Burma): forested hilly areas of Chang Rai, Chang Mai, Mae Hong Son, Tak, Kanchanaburi, Ratchaburi, and Petchaburi provinces (these areas also report P. falciparum resistance to quinine and artemisinin); the eastern border areas with Cambodia: forested hilly areas of Ubon Ratchathani, Si Sa Ket, Surin, Buriram, Sa Kaeo, Chantaburi, and Trat provinces report P. falciparum malaria resistance to chloroquine, mefloquine hydrochloride and sulfadoxine-pyrimethamine.
All malaria infections are serious illnesses and must be treated as a medical emergency. In offering guidance on the choice of antimalarial drugs, the main concern is to provide protection against Plasmodium falciparum malaria, the most dangerous and often fatal form of the illness.
Regardless of the medication which has been taken, it is of utmost importance for travellers and their physician to consider fever and flu-like symptoms appearing 7 days up to several months after leaving a malarious area as a malaria breakthrough. Early diagnosis is essential for successful treatment.
In addition to the suggested antimalarial medication, use a mosquito bed net and effective repellents to avoid the bite of the nocturnal Anopheles mosquito.
Brand names: Malarone, Malanil and others; generics available.
TAKE 1 TABLET DAILY (ATOVAQUONE 250 mg + PROGUANIL 100 mg).
START 1-2 DAYS BEFORE ENTERING THE MALARIOUS AREA, CONTINUE DAILY DURING YOUR STAY AND CONTINUE FOR 7 DAYS AFTER LEAVING.
Note: Take at the same time every day with food or milk.
Brand names: Vibramycin and others; generics available.
TAKE 1 TABLET DAILY (100 mg).
START 1 DAY BEFORE ENTERING MALARIOUS AREA, CONTINUE DAILY DURING YOUR STAY AND CONTINUE FOR 4 WEEKS AFTER LEAVING.
Note: When taking this drug, avoid exposure to direct sunlight and use sunscreen with protection against long range ultraviolet radiation (UVA) to minimize risk of photosensitive reaction. Take with large amounts of water to prevent esophageal and stomach irritation.
Brand names: Lariam, Mephaquin, Mefliam and others; generics available.
TAKE 1 TABLET OF 250 mg (228 mg base) ONCE A WEEK.
START 1-2 WEEKS BEFORE ENTERING THE MALARIOUS AREA, CONTINUE WEEKLY DURING YOUR STAY AND CONTINUE FOR 4 WEEKS AFTER LEAVING.
Note: Side effects include nausea and headache, including neurological side effects such as dizziness, ringing of the ears, and loss of balance. Psychiatric side effects include anxiety, depression, mistrustfulness, and hallucinations. Neurological side effects can occur any time during use and can last for long periods of time or become permanent even after the drug is stopped. Seek medical advice if any neurological or psychiatric side effects occur.
MEFLOQUINE HYDROCHLORIDE IS NOT EFFECTIVE IN SOME AREAS OF THIS COUNTRY. SEE 'Areas with drug resistant Malaria' ABOVE FOR SPECIFIC LOCATIONS.