Thailand is a country with a tropical climate, a high degree of humidity and high temperatures; circumstances in which mosquitoes thrive. If you’re going to Thailand, you can’t avoid having to deal with mosquitoes. But no need to panic, the health risks are low and protecting yourself against mosquito bites is pretty easy. This is everything you need to know about mosquitoes in Thailand!
Over the past three years we’ve seen nearly every corner of Thailand. We also lived in Pai, in the northwest, for six months.
We mostly found them to be irritating, but didn’t think of them as a threat or potential agents of scary diseases. Yes, they will bother you at times, but it’s not like you’ll be under attack 24/7. This is especially true if you’re staying in a guesthouse or a hotel, since they’ll take preventive measures, like using mosquito repellent. With the right preparations, you can travel to Thailand and feel secure!
Table of contents. Click on the question to go to the reply:
- Are mosquitoes always around?
- Should I worry about tropical diseases?
- Which anti-mosquito spray should I use?
- Is it really necessary to wear special clothing?
- What to do in case you’re bitten
- Additional tips to keep mosquitoes at bay
- Mosquito-borne diseases prevalent in Thailand
The 5 most frequently asked questions
1. Are mosquitoes always around?
Yes, mosquitoes are present in Thailand all year long. However, their numbers increase during and right after the rainy season (June until October) because of the remaining puddles of water, in which females lay their eggs.
Mosquitoes in Thailand are active mainly during the hours of sunrise (5:30 AM – 7:00 AM) and sunset (5:00 PM – 6:30 PM). Nevertheless, it’s still possible to be bitten during the day. Try and stay protected all day long.
Thankfully preventing mosquito bites is not difficult:
- Use repellents, such as anti-mosquito spray, multiple times a day.
- Apply sunscreen 20 or 30 minutes before using the anti-mosquito spray.
- Wear light colors such as white, beige or light gray.
- Don’t use any perfume, powerfully scented deodorant, after shave or body lotion.
- Wear long sleeved clothing whenever you’re in the jungle and during the hours of sunrise and sunset.
- Mosquitoes don’t like drafts, so always leave the fan or the air conditioning on in your room.
- Mosquitoes also like humid and heavily wooded areas, as opposed to windy and drafty ones. This is why there are more mosquitoes in the north of Thailand (nature and jungle) than there are in the south (islands).
Mosquitoes also like humid and heavily wooded areas, as opposed to windy and drafty ones. This is why there are more mosquitoes in the north of Thailand (nature and jungle) than there are in the south (islands).
2. Should I worry about tropical diseases?
Some mosquitoes in Thailand can transmit tropical diseases, such as dengue fever. But don’t let that stop you from traveling there; the risk of contamination is low. You should however protect yourself as best you can (see guidelines above) and prevent as many mosquito bites as possible.
Below, we’ll explain a bit more about how to prevent diseases transmitted by mosquitoes in Thailand.
3. Which anti-mosquito spray should I use?
You can bring anti-mosquito spray with or without DEET from home. Or you can buy it in Thailand for a fraction of the price. We recommend buying anti-mosquito spray at the 7-Eleven. It will only cost you a euro, it smells nice and effectively keeps the mosquitoes at bay.
In case they’re not having the desired effect, go to your local pharmacy to get something stronger. On nearly every street corner in Thailand, there’s a pharmacy where they’ll be glad to help you in English.
Use the repellent every morning before going out and after you go swimming or showering. Apply some extra during the “mosquito hours” (sunrise and sunset) and also while hiking in the jungle.
Make sure the sunscreen settles on your skin first before applying bug spray. Wait for about 20 or 30 minutes, otherwise it might reduce the effect of the sunscreen.
Finally, don’t use anti-mosquito spray in enclosed spaces (like a bus) or places that attract larger groups of people (restaurants). This could be unnecessarily disrupting for the people around you.
4. Is it really necessary to wear special clothing?
No, it isn’t. Nobody likes wearing long sleeved clothing in high temperatures – least of all us!
Nevertheless, if you’re outside at dusk it might be wise to bring a cardigan or a pair of leggings. That way, in case lots of mosquitoes appear suddenly and all at once, you’ll be able to cover yourself.
A small life hack is wearing light-colored clothing. Dark clothing absorbs more heat and therefore attracts more mosquitoes.
However, you will need long pants once you go hiking in the jungle. Not just because of mosquitoes, but also to be protected against other creepy-crawlies and getting cuts and scratches. Socks and thick shoes are necessary for the same reasons. Wearing a long sleeved shirt is also advisable. Fast drying sportswear could be very useful as well.
5. What to do in case you’re bitten
Try not to scratch the bite, as this will only cause more itching. Moreover, you could scratch open your skin and incur small wounds, which in turn can get infected (remember, you’re in the tropics) and scar afterwards. So try and restrain yourself!
Apply some cream to combat the itching. In case you forgot to take it with you from home or it’s not having the desired effect, you can walk into any pharmacy in Thailand and buy “Nestosyl Cream” or “Systral Cream”, without a prescription.
The Thai themselves swear by tiger balm when it comes to alleviating itchiness. They’re sold in just about every supermarket and pharmacy. In case of acute itchiness and no remedies in the immediate vicinity, try and apply some toothpaste, or even the inside of banana peel.
Extra tips to keep mosquitoes at bay
Did you know that mosquitoes are attracted to strong scents? This is why you’re more likely to get bitten when you’ve used aftershave, perfume or scented deodorant, also if you emit a strong smell of sweat.
Part of the reason spicy curries, like Tom Yam for example, are so popular in Thailand is because mosquitoes don’t like them. If you’re not into spicy food, you could experiment with B1 vitamins (thiamine), which also creates a body odor that will repel mosquitoes.
Finally, it’s worth mentioning that you won’t need to bring a mosquito net. Every hostel, guesthouse or hotel is equipped with window screens or mosquito nets. Even while on a jungle trek and spending the night with some local tribes, we were each given a mosquito net to sleep under. However, duct tape could come in handy in case any nets or screens contain holes.
Prevalent mosquito-borne diseases in Thailand
In this part of the article we will elaborate on mosquito-borne disease prevalent in Thailand and the likelihood of getting infected as a traveler.
Before we start, however, we would like to stress that following the advice proposed in this article can in no way be considered a valid substitution for a visit to a (family) doctor or a qualified medical specialist. Your specific medical needs and/or vaccinations depend on your destination, the duration of your stay, in what capacity you’re traveling, the activities you partake in, the general state of your health and your age.
Always seek personal medical counsel from a registered physician well before leaving. A good time to do this could be the day you receive your recommended vaccinations for Thailand.
1. Dengue fever
What is it?
Dengue fever is a viral infection that causes flu-like symptoms. The virus is spread by infected mosquitoes that bite during the day. Dengue fever cannot be transmitted from human to human.
In 2015, Thailand registered a total of 142,925 infections, 141 of which resulted in the death of the victim.
Not everyone who has dengue fever will show symptoms. Those who do will typically start exhibiting them 4 to 7 days after being bitten. The infection is characterized by flu-like symptoms, such as multiple sudden bouts of high fever, pain behind the eyes, pain in the muscles, joints and bones, severe headaches and skin rashes in the form of red spots.
In rare cases (when there is no doctor around, for example), dengue fever can be lethal. But generally speaking, it’s not considered a serious, life-threatening disease. Nonetheless, in the event of contamination, expect to be bedridden for some weeks at the very least.
Prevalence: where & when
Dengue infected mosquitoes are all over in Thailand, though larger numbers exist in the country’s northeast and its urban areas. They are active during the day, from dawn till dusk. Their most active time of year is the rainy season, which lasts from June until September.
No vaccination against dengue fever is available. There is also no known cure for dengue fever.
Use Paracetamol against the pain and ORS (Oral Rehydration Salt) to prevent dehydration. Do not take Naproxen, Aspirin or Ibuprofen, as those will increase the chances of internal bleeding.
2. Japanese encephalitis
What is it?
Japanese encephalitis is a rare viral infection that sometimes leads to inflammation of the brain. Only a very small percentage of those infected with the virus will actually develop encephalitis (inflammation of the brain). It’s spread by mosquitoes that bite other carriers of the virus, such as pigs. Japanese Encephalitis cannot be transmitted from human to human.
The risk of contracting Japanese encephalitis is relatively low. Although the exact figures aren’t known, it is estimated that for travelers the odds of contracting the virus are between 1 in 500,000 and 1 in 1,000,000.
However, with a 20 to 30% mortality rate, the disease in itself is quite dangerous. On top of that, 50% of survivors will continue to experience neurological, psychiatric or cognitive damage.
Symptoms are often very mild and will typically develop 5 to 15 days after being infected and are characterized by flu-like symptoms such as fever, muscle pains and headache. In extreme cases, it’s possible to contract meningitis. Other serious symptoms are vomiting, drowsiness, coma and epileptic fits.
Prevalence: when & where
Japanese encephalitis is most common in northern Thailand (Chiang Mai valley) and, to a lesser extent, Sukhothai, the outskirts of Bangkok and Phitsanulok and the country’s southern regions. Virus bearing mosquitoes breed in rice fields and are especially prevalent in rural areas with pig farms.
They tend to bite around dusk and are most active during and right after the rainy season (May until October)
Vaccination against Japanese encephalitis is not necessary for the average traveler.
People that have to stay in risk zones for professional reasons (biologists, agricultural experts, anthropologists) for longer than a month and travelers staying there longer than 6 months might want to consider getting vaccinated.
What is it?
Malaria is a mosquito-borne infectious disease. People infected with malaria will commonly experience fever, chills and flu-like symptoms. If left untreated, it can lead to serious complications and, in some cases, even death.
The risk of getting malaria is low. The odds of contracting malaria for travelers are 1 in 50,000.
Between 2000 and 2014, the number of reported malaria infections in Thailand declined by 77%, from 159,120 to 37,209 cases. Over the same the period the mortality rate fell as well, by a total of 94%, from 625 reported deaths to 38.
The incubation period for malaria varies from 7 days to 3 months. Symptoms are often characterized by high fever, chills, flu-like symptoms, headaches, nausea, vomiting, back pains, muscle pains and diarrhea, lasting longer than 24 hours.
Prevalence: where & when
Malaria-bearing mosquitoes live in the dense forests of the border region with Myanmar in the west and with Laos and Cambodia in the east. There is no malaria in urban areas (Bangkok, Chiang Mai, Pattaya).
Mosquitoes bite mainly in the evening, at night and in the early morning. They’re active all year long, with peaks from June until August and October until November, which coincide with the rainy season.
There is no vaccination against malaria. In Thailand it’s not necessary to take malaria tablets, not even in risk areas.
What is it?
Zika is a mosquito-borne virus. For pregnant women, being bitten by an infected mosquito can cause serious birth defects in their fetuses. Person-to-person transmission of Zika is possible, through sexual contact, for example.
From January 2016 to October 2016, Thailand registered more than 680 confirmed cases of Zika.
The symptoms themselves are fairly innocent: fever, headache, pain in the joints and a rash. Patients generally make a full recovery within two to seven days.
Prevalence: where & when
It is not known in which locations the virus is most prevalent. What is known, however, is that they’re active mainly between dawn and dusk. Also, person-to-person transmission is possible, for example, through sexual contact.
There is no vaccination against the Zika virus, nor is there a known cure. Men with pregnant partners and women that want to get pregnant are advised to first use a condom for at least 2 months after returning home.
5. Yellow fever
Yellow fever does not occur in Thailand. However, vaccination is compulsory if, before entering Thailand, you spend more than 7 days in a country where it does occur (click here for an overview of these countries). The same applies if, during your stay in Thailand, you will spend more than 12 hours in any of the yellow fever countries.