A question, has anyone of you heard of people that contracted malaria in any of the Thai national parks?
I know that in some European countries it is advised to take anti-malaria tablets if one is thinking of traveling to the border regions of Thailand.
But I wonder if those governments are just being on the safe side.
As someone who has had 3 strains of malaria including cerebral contracted in Cambodia, Mozambique and Angola respectively. I have never contracted it in Thailand. I still never use anti-malarials or would. I assume the risk of contraction by a visitor would be very small unless you were entering a known malarial area for a significant time. But I have to be honest and say its not an area I really know anything about.
I work with a Thailand-based malaria research team that undertakes a research and offers diagnostic and treatment services for malaria.
Whilst I am not a doctor, I can tell you what I have learned about malaria in Thailand through my work. There are two species of malaria that make up the vast majority of malaria infections in humans in Thailand, these are Plasmodium vivax (that is the species of malaria that can give you repeated bouts of illness, but is very rarely fatal) and P. falciparum (much more dangerous to the patient, potentially being severe and fatal). The overall national caseload has been falling for the past decade, but the emergence of falciparum parasites that exhibit tolerence/resistance to the first line medicines presents a real threat to malaria control globally. This threat has understandably spooked the medical community and there are now huge efforts taking place across the Greater Mekong sub-region to control and eliminate falciparum malaria. These efforts are starting to bare fruit and we can see the number of falciparium cases is dropping, however these efforts must be sustained to ensure that falciparim does to re-emerge.
The majority of cases of malaria diagnosed in Thailand are found in migrant workers and their families coming from Myanmar (mostly) and Cambodia. Most cases are in working aged males (ie those spending time in forest or forest edge environments for employment).
In terms of malaria in national parks in Thailand, I am personally aware of two cases of people getting malaria - one involved a couple I know who slept in forest in one of the parks (I am not sure which one) on the Thai-Myanmar border in 2006 and both ended up getting falciparum malaria. The other involved birders visiting Kaeng Krachan NP in the late 1990s or early 2000s contracting malaria (I am not sure if this was vivax of falciparum).
Personally I spend a reasonable amount of time birding in forest in Thailand and I have never considered taking prophylaxis. Our Unit has a team that spends significant periods of time working cross-border in remote forested areas of the Thailand/Myanmar border and they do not take prophylaxis. This is because the Thai-Myanmar border is in a zone of "low transmission" where even if you were to spend every night in the forest you might only expect to get something like 0.5 or 1 malarial bites per year (this compares with parts of sub-saharan Africa where you can expect 365+ malarial bites per year (ie one per day).
Most importantly, the strategy that we encourage is that if you suspect you might have malaria (ie you get a fever a few days after being in the forest) you should get tested as soon as possible, ideally within 24 hours from the onset of fever (a rapid stick test can give you a result in about 20 minutes).
Personally, as a Bangkok resident I am more concerned by Dengue Fever.
Thanks Niltava for sharing this information here.
If most of the cases are migrant workers, it is the question where they contracted the disease.
But glad to hear chances are extremely low, and hopefully they get the resistance to the medicines under control.
I've heard that exactly for this reason, anti-malarial medication should not be used too much unless really necessary.