On this page you read about common mosquito borne diseases in Thailand, allergenic reaction to mosquito bites, how to stop mosquito bites itching, mosquitoes and pets in Thailand, mosquito bite prevention, and mosquito facts and trivia.
This intention of this article is to make you aware that mosquito borne diseases are very real in Thailand. It is not intended as a source of self diagnosis. If you suspect you may have contracted a mosquito borne disease in Thailand, go immediately to hospital and have test.
Although the risk of contracting a mosquito borne disease in Thailand is ever present, providing you take preventative measures, the chances of being infected are minimal.
For most people, visiting most destinations in Thailand, it’s simply a case of using commonsense. You can buy mosquito repellents in Thailand – use it as required. A fan helps to stop mosquitoes landing on you. Removing any source of ‘standing water’ where mosquitoes like to lay their eggs is a good idea, that includes places like the runner at the bottom of your shower door, and drip trays of your water dispenser and crockery rack.
You are probably more likely to slip on a wet tile, have a scrape on a motorcycle, suffer bad sunburn, or have a misfortune due to any number of other hazards and dangers in Thailand than you are of being infected by a mosquito borne disease.
There are some important things to consider before you travel to Thailand. I can’t help with those, but i will try and point you in the right direction, see below.
- What risks do mosquito borne diseases pose for pregnant women?
- Are mosquito borne diseases covered by your travel insurance policy?
- Do you need preventative medicine, in case of malaria?
Common Mosquito Borne Diseases in Thailand
For your reference, I found some reliable information about mosquito borne diseases on the Thai Travel Clinic website. I’ve left a link to Thai Travel Clinic articles about each mosquito borne disease listed below.
You can also find information about mosquito borne diseases including Zika virus, plus information about general diseases and travel immunizations for Thailand on the U.K NHS Fitfortravel website.
Dengue fever is the most common mosquito borne disease in Thailand. Most people in Thailand (myself included) know of people who have had dengue fever. Personally I know of perhaps 40 or 5 friends who have been admitted to hospital with dengue fever. Yet, I have lived in Thailand almost 20 years and so far as I know I have never had dengue fever.
Dengue fever is carried mainly by the female Aedes aegypti (Dengue mosquito), and to a lesser extent the Aedes albopictus (Asian Tiger) mosquito. The mosquito itself actually carries the dengue virus after feeding on a human who is already infected.
There are 4 recognized serotypes/strains of dengue fever, (DENV-1, DENV-2, DENV-3 and DENV-4), infection and recovery from one serotype is said to make you immune to that serotype in future, but a secondary infection with a different serotype can lead to the development of the more serious Dengue Hemorrhagic Fever.
Dengue Fever Symptoms
Symptoms of dengue fever usually begin to manifest 3-7 days after being bitten by an infected mosquito, in some cases it may be up to 2 weeks before symptoms appear. The symptoms of dengue fever may last between one and 2 weeks.
Symptoms include a sudden high temperature, headache and pain behind the eyes, joint and muscle aching, fatigue, nausea, vomiting, swollen lymph nodes, red rash on upper body, sensitive skin, metallic taste in mouth.
Dengue Fever is the Most Prevalent Mosquito Borne Disease in Thailand
Dengue fever is present all year round and is found in every region of Thailand, but most cases of dengue fever occur in Thailand during the rainy season, which for the vast majority of Thailand runs from May to November.
The Neighborhood Disease
The Aedes aegypti (Dengue mosquito) and Aedes albopictus (Asian Tiger mosquito) tend not to travel far from where they hatched, usually travelling no more than 200 meters during their short lifetime. This means that outbreaks of dengue fever are very localized.
The dengue virus could likely be introduced to the neighborhood by an infected human. A mosquito bites the carrier, becomes infected, and then infects each person it feeds on thereafter.
Dengue Mosquitoes Bite and Feed During The Day
Both the Aedes aegypti (Dengue mosquito) and Aedes albopictus (Asian Tiger mosquito) feed throughout the day, peak feeding times are around dusk and dawn, but they will and do feed at any time of day. They prefer indoor, shady habitats, and they will quickly breed in any standing water, including containers, plant pots and tires, it is therefore essential to remove any standing water from the garden, within the house or anywhere in the close proximity of the house.
More information about Dengue Hemorrhagic Fever from Thai Travel Clinic.
Malaria is a potentially life threatening disease, the symptoms can show 7 – 15 days after being bitten by a mosquito. Symptoms include fever, headache, nausea, diarrhea, chills, aching muscles, vomiting, jaundice type yellowing of the skin and eyes. The symptoms usually run in cycles every 1, 2 or 3 days.
The Anopheles mosquito is the main carrier of Malaria in Thailand. They will feed during dusk and dawn and throughout the night, feeding preferentially on Humans. In Thailand, malaria is largely confined to heavily forested areas bordering Cambodia, Laos, Myanmar and Malaysia.
More about malaria in Thailand by Thai Travel Clinic. Once you open the page, scroll down to find more links to articles about the risk of catching malaria, and emergency treatment.
More information about Malaria in Thailand from Thai Travel Clinic.
Here’s a handy Thailand Malaria Map on the U.K NHS Fit For Travel website.
Japanese encephalitis symptoms may appear 5 – 15 days after being bitten by a mosquito. In most cases symptoms will only be flu like, only about 1 in 300 cases develop in to acute encephalitis which affects the central nervous system and the brain. Symptoms include fever, nausea, vomiting, stiff neck, weakness, convulsions, seizures, muscle paralysis loss of balance, reduced coordination and loss of consciousness. The death rate among sufferers of acute encephalitis is about 30%, patients who recover are often left with disabilities.
The Culex tritaeniorhynchus is the mosquito mainly responsible for transmitting Japanese Encephalitis in Thailand. They are most at home in rural areas such as paddy fields, and most outbreaks occur in northern regions of Thailand.
More about Japanese Encephalitis in Thailand by Thai Travel Clinic.
Filariasis symptoms may appear 5 months to over a year after being bitten by an infected mosquito, though symptoms may not show unless a person is repeatedly bitten by an infected mosquito. Filariasis is caused by parasitic worms which are transmitted by infected mosquitoes. Symptoms include swollen or inflamed lymph nodes, headache, stomach pain, fever and chills, more severe symptoms are the swelling of organs and limbs.
More about Filariasis in Thailand from Thai travel Clinic.
Mosquito Bites & Allergenic Reaction
Mosquitoes feed most actively during dusk and dawn, during daylight hours they shelter in shady, damp places, typically vegetation, or indoors where you will find them behind curtains, under furniture and in the bathroom. They will become active if disturbed and conditions are suitable, even indoors out of the sunlight.
The exception to this rule though, is the dengue mosquito, it will feed throughout the day, and it feeds aggressively. So in reality, you can and will be bitten by mosquitoes at any time of day.
Typically, a mosquito will live for four to five days, but they can live for as long as two weeks.
Only female mosquitoes bite and feed on human blood. The reason the female mosquito feeds on blood is because she needs the nutrients supplied by blood in order to produce and develop her eggs. The mosquito will bite and feed until it’s hunger for blood is satisfied, it will repeatedly return even after being disturbed.
How Do Mosquitoes Find, Bite, and Feed on Us so Easily
The mosquito is a highly evolved hunter. Mosquitoes have been feeding on blood since the dawn of civilization. Since then they have developed complex tracking and feeding skills, allowing them to locate and bite their victims without being noticed.
Mosquitoes hunt by smell and sight, they are attracted to various chemicals and odors emitted by the human body. Carbon dioxide, lactic acid and sweat are the mosquitoes main beacons, a mosquito can smell a human body as far away as 5 meters, they also hunt by sight. It is thought they are able to see heat emitted by humans.
When the mosquito finds its host it will usually land on an area where the veins are exposed and there is a good flow of blood, ankles are a prime location for this.
Many people believe that mosquitoes are attracted to them, to the extent that they will suffer from mosquito bites much more than the people around them. This may be due to higher carbon dioxide and lactic acid being emitted by some people.
The Mosquito Bite
To say a mosquito “bites” is not actually correct, it is much more subtle than a bite. The female mosquito is equipped with a proboscis (a slender straw like tube) on the front of its head, on the end of the proboscis there are cutting stylets (needles or rods) which slide against each other to cut open its victims skin.
After cutting the skin the mosquito then uses two more tiny tubes inside the proboscis, one injects the saliva which acts as a painkiller and anti coagulant to stop the blood clotting while the mosquito feeds, the other tube is used to suck blood from its host.
Why Do Mosquito Bites Itch and Swell?
The saliva injected by the mosquito contains enzymes, anti coagulants, proteins and various other substances. When the human immune system recognizes the intrusion it responds by sending histamine and immunoglobins to fight the intruder. The release of histamine to the area causes the blood vessels to swell, this in turn aggravates the nerves which is the reason for the itching. This is actually a minor allergenic reaction.
Serious Cases of Mosquito Allergenic Reaction
There are varying degrees of allergenic reaction to mosquito bites. The most serious cases are what is known as Skeeter Syndrome. Many people hardly suffer at all, especially people who are accustomed to being bitten by mosquitoes. For many people, mosquito bites result in redness and swelling like you see in the photo above, even though these bite wounds have been treated with iodine the redness and swelling is still visible.
The photo above looks like a mild case of skeeter syndrome which causes blistering, swelling, redness and often extreme discomfort and aching joints around the area of the mosquito bites.
The above photo clearly shows the blistering on top of the mosquito bites. I’m sure you can imagine the discomfort this causes, especially when you have an overwhelming urge to scratch the itch.
Allergenic reaction to mosquito bites can sometimes be extreme or even life threatening, resulting in very severe swelling, asthmatic symptoms and anaphylaxis. If you have a severe allergenic reaction to a mosquito bite you should see a Doctor immediately.
Here is more information about serious mosquito bite allergy and allergenic reaction to mosquito bites symptoms and treatment. from Allergies.about.com
Stop Mosquito Bites Itching
Most important thing to remember is, don’t scratch, it will just get worse. my own favorite anti itch remedy for mosquito is Tiger Balm. I just rub it on the bite with the tip of my finger – the itch has usually gone within a minute or two. You can buy Tiger Balm and many similar ointments which work equally well from pharmacies, 7-Eleven stores and and supermarkets in Thailand.
If you have a particularly bad allergenic reaction, antihistamine cream or tablets should work. I recommend you first seek advice from a doctor about using antihistamines, especially if you have to drive, or you are taking any other medication.
More information about antihistamines from the U.K NHS website.
search around the Internet, you’ll find no end of suggested mosquito bite itch remedies. Whether they work or not, I don’t know, but I’ve listed a few, below.
- Apply Tea tree oil, Lavender oil, Eucalyptus oil, Citronella oil, Coconut oil, Saliva, Saliva and salt
- Rub with a segment of lemon or lime.
- Cut the tip off a Aloe Vera plant and rub on the bite, another wonder cure so it’s not really surprising that Aloe Vera stops mosquito bites itching. Aloe Vera is also great for treating minor burns such as motorcycle exhaust pipe burns.
- Rub it with the inside of a banana peel, be a shame to waste that banana peel without giving your shoes a polish.
- Cover the bite with a slice of onion, or gently rub the bite with the onion for faster effect.
- Take a hot bath, you could optionally add some baking soda or essential oils for for more effect.
- Swab with hot water, as hot as you can stand.
Rub it with rubbing alcohol / surgical spirit and then place scotch tape over the top and leave it for 2-3 hours. This method is thought to stop the mosquito bite itching because it stops oxygen from entering the bite. Witch hazel can be used instead of surgical spirit, if you have neither just use the scotch tape.
It may seem masochistic, and it may fetch some bemused stares, but slapping or pinching the area of the mosquito bite relieves the itch. The reason being, the brain only registers the most painful sensation, so the slap, being more painful than the mosquito bite itch, overrides the lesser sensation of the itch.
Place a drop of nail polish directly over the mosquito bite, like many other mosquito bite cures it is not exactly clear how the nail polish works. One theory is that by sealing the bite it prevents oxygen from entering, oxygen is thought to be a contributing factor which makes the bite itch.
Do You Attract Mosquitoes?
Are you a mosquito magnet, the one who returns home from the barbecue, a walk in the woods, or a holiday in the tropics covered in mosquito bites. Scientists around the globe are researching the reason mosquitoes are attracted to some people more than others, they claim to have made many breakthroughs in their mosquito research, but much is still open to debate, and theoretical.
It was discovered that the mosquito’s head and antennae contain several proteins which are used to track ‘chemical markers’ or odorants (odor compounds) which are emitted from human skin. Basically, mosquitoes have some highly sophisticated weaponry to help them hunt their prey “YOU”.
Remarkably, scientists discovered that you are more likely to be bitten by a mosquito if you have Type O blood, without going in to detail, this is because different blood types give off different “chemical markers”, and those given off by Type O blood is especially attractive to mosquitoes.
What Attracts Mosquitoes to People
Mosquitoes want your blood, to be more precise, only female mosquitoes want your blood, female mosquitoes need blood to aid the production of their eggs. Below is a list of things which help to attract mosquitoes to their next meal.
- Carbon dioxide, both exhaled and emitted through the skin.
- Lactic acid, found in certain food products, lactic acid is also a by-product produced by muscles, especially after strenuous exercise.
- Perspiring (sweating) attracts mosquitoes because it releases chemicals which attract mosquitoes, one of them being lactic acid.
- Wearing dark clothes makes you a more likely target for mosquitoes, mosquitoes are attracted to darker colors.
- Floral perfumes and scents attract mosquitoes, so try and avoid scented soaps and perfume if visiting a mosquito infested area.
- Drinking alcohol warms the body temperature and makes you more visible to mosquitoes.
- Pregnant women have a raised body temperature, and also exhale more carbon dioxide than usual, mosquito heaven.
- People with a large body mass offer a big target and have a bigger surface area, which means they are emitting more carbon dioxide and other chemicals.
- For some reason mosquitoes are attracted to smelly feet and smelly socks.
Eat to Avoid Mosquito Bites
Although outbreaks of mosquito borne diseases are not uncommon in Thailand, Thai people don’t seem to get bitten by mosquitoes as much as your average tourist or expat. You just don’t see Thais walking around with the unsightly red bumps caused by mosquito bites, but it’s quite common to see tourists with the tell-tale signs that mosquitoes have feasting on their legs.
I suspect diet goes a long way towards making Thai people less appealing to mosquitoes, I’m not suggesting you eat only Thai food, but I am suggesting some foods may actually repel mosquitoes.
Garlic seems to be one of the most popular foods for preventing mosquito bites. It is thought that simply eating significant amounts of garlic can deter mosquitoes from biting you, this might be due to chemical compounds in the garlic or it may be due to the odor of garlic seeping from the skin pores which masks the natural body odors like carbon dioxide, sweat and lactic acid and prevents the mosquito from homing in on you.
Citrus fruits, oranges, limes and especially lemons are supposed to be a good mosquito deterrent, try a lemon shake every morning.
Vitamin B1 ‘Thiamine’ taken in high dosages every day, and up to 2 weeks before travelling is sworn by many people to ‘stop mosquitoes biting’. Always seek professional advice before taking high dosages of any supplement, it may cause mineral imbalances etc.
Onions seem to be good for just about anything, try eating onions raw to deter the dreaded mosquito bites, they are also one of many possible remedies which might stop mosquito bites itching.
One of the many benefits of eating spicy food is that its base ingredients contain onions, chilies, garlic and coriander, all reputed to have mosquito repelling qualities.
Mosquito Borne Diseases and Your Pet in Thailand
we are all very aware of the risk to ourselves but we sometimes fail to realize that our pets are at risk from mosquito bites just as much as we are. In Thailand, dogs and cats, and many other animals are at risk of disease transmitted by mosquitoes which can result in a disease called ‘Heartworm’.
There are many incidences of heart-worm in dogs in Thailand, and cats to a lesser degree. So when you consider your pets health in Thailand don’t forget about the risk imposed by mosquitoes. Heartworm can lead to serious illness and the eventual death of your beloved pet.
What is Heartworm
Heartworm is a parasitic worm which is transmitted by mosquitoes. The mosquito feeds on an animal infected with heartworm and becomes infected with microfilariae which then develops to the larval stage inside the mosquito, the larvae is then passed on when the mosquito bites its next victim. From then it takes about 6 months to develop into an adult heartworm. When fully grown heartworms can reach a length of 14 inches and live for as long as 7 years, it takes up residence in the animals lung tissue and heart ventricles.
What are the Symptoms of Heartworm
The symptoms of heartworm in your pet might not appear for several years, typically 4 – 7 years for a dog but only 2 – 3 years for a cat. Heartworm symptoms in dogs include a dry cough, difficulty breathing, accumulation of fluid in the abdomen, wheezing and lethargy. Similar symptoms of heartworm will manifest in your pet cat but may also include vomiting, on the other hand a cat might not show any symptoms of heartworm, it may simply drop dead.
Treatment of Heartworm in Thailand
Veterinary clinics in Thailand are well equipped and most cases of heartworm are treatable, maybe to a lesser degree for cats. Initially the vet will take a blood test and then administer drugs which kill the heartworm, there may be a long convalescence.
Prevention of Heartworm in Thailand
Prevention of heartworm for your pet in Thailand is very important due to the high risk of infection, tablets can be given monthly to prevent heartworm, Some of the Thai brands are much cheaper than their foreign counterparts and just as effective. VERY IMPORTANT: CONSULT YOUR VET BEFORE STARTING ANY PREVENTION PROGRAM, THESE DRUGS CAN KILL A PET WHICH IS ALREADY INFECTED WITH HEARTWORM.
Stop Mosquitoes Biting Your Pet in Thailand
When it comes to your pet you have to be very careful what you use. You can not use products like DEET and permethrin on them and the same goes for many essential oils, especially where cats are concerned – cats are very intolerant to many chemicals and oils. The best advice regarding protecting your Thai pet from mosquito bites is consult your local vet, ask which products are safe to use on your pet before you apply anything.
I’m not a vet, the purpose of this post is simply to make people aware of the risk which mosquitoes pose to pets in Thailand. For concise information about heartworm use https://www.heartwormsociety.org/
Mosquito Facts & Trivia
- There are an estimated 3,500 species of mosquito in the World.
- Over 400 species of mosquito can be found in Thailand.
- Mosquitoes are responsible for more worldwide Human deaths than any other living thing.
- Around 400 million people are infected with malaria every year, of which between 1 – 3 million die.
- A mosquito synchronizes its own noise pitch to match the pitch of its potential mate.
- The largest mosquito in the World is the ‘Toxorhynchites’ measuring 1.5 inches, fortunately they do not require blood.
- Mosquitoes supposedly can not spread AIDS, research suggests the virus is killed by their digestive system.
- A mosquito can smell you from as far as 30 meters away.
- Only females bite and feed on blood.
- A chemical receptor tells the mosquito when to stop feeding, during tests scientists disabled the receptor and the mosquito fed until it burst.
- A mosquitoes life consists of 4 metamorphic stages: egg, larva, pupa, adult.
- The average lifespan of a female mosquito is 2 – 3 weeks.
- Mosquitoes home in on the carbon dioxide and heat emitted from our bodies.
- Female as well as male mosquitoes eat nectar.
- Female mosquitoes feed on blood because they need the protein for their offspring.
- A mosquito can lay as many as 3000 eggs in its lifetime.
- Some mosquitoes given the right conditions can develop from egg to adulthood in 4 days.
- A mosquito can beat its wings up to 600 times per minute.
- A mosquito can fly at an average of 1.5 miles per hour.