Dengue fever

[naboo]

Worried about dengue? Worried about anything? Don't come to Thailand. If you can stop worrying about stuff out of your control you'll be OK.

[Chicog]

Worried about dengue? Worried about anything? Don't come to Thailand. If you can stop worrying about stuff out of your control you'll be OK.

I'd hardly call taking precautions against Dengue "worrying".

Do you wash your hands after going to the toilet?

[T_Dog]

When I had Dengue there were six houses in our moo bann that were affected. It is definitely a social disease and it needs humans to keep going. My doctor warned me that a subsequent bout would likely be more severe than the first. Was never weaker in my life and full recovery took well over six months.

So you are saying that particular mosquito only feasts on humans? Or is that just an assumption?

Can't find the original article I sought out when I first had it, but never heard any mention of animal hosts except primates. A dengue mosquito has to bite a host with Dengue, then they cruise around for their lifetime with the capability of giving it to another human. From Wiki:

Humans are the primary host of the virus,^[4][14] but it also circulates in nonhuman primates.^[22] An infection can be acquired via a single bite.^[23] A female mosquito that takes a blood meal from a person infected with dengue fever, during the initial 2–10 day febrile period, becomes itself infected with the virus in the cells lining its gut.^[24] About 8–10 days later, the virus spreads to other tissues including the mosquito's salivary glands and is subsequently released into its saliva. The virus seems to have no detrimental effect on the mosquito, which remains infected for life.^[6]Aedes aegypti, is particularly involved, as it prefers to lay its eggs in artificial water containers, to live in close proximity to humans, and to feed on people rather than other vertebrates.^[6]

[Robert24]

@watgate: Densely populated areas like Bangkok tend to have more dengue cases as it spreads more easily if many people live close together. Remember it requires humans to ttransmit it. And it will be very difficult to contain it in such a big city. Take a look at Singapore. They tackle dengue very aggressively and yet have many cases and once you see a hot spot, it spreads very quickly. So good to take same precautions in Bangkok as well.

[wilcopops]

Hi AFAIK the mosquitos that vector dengue are most active in the middle of the day and in the rainy season, and in more densely populated areas. If I go into town in the rainy season I use repellant. Haven't heard any news of recent outbreaks.

Not really correct.

The Aedes mosquito is referred to as a "daytime flyer" - that means unlike a lot of mozzies it stays around in the day, however it is mostly active down and dusk.

As they lay eggs by the tiniest amount of water (or near it) it only requires a slight increase to activate the eggs as the water rises. Thus a population boon in mozzies.

the mozzies like to shelter under vegetation, or indoors; they like furniture and laundry in particular.

The process of transmission involves a female biting a person inferred with the fever. Then after the virus has developed in the mosquito, it has to bite another human. The lifespan and range of a mosquito is limited, so it has more chance of transmitting in an area with people in close proximity and lots of little standing puddles of water.

Dengue is endemic to Thailand. There can be "outbreaks" "hotspots" etc etc....Chiang Mai has for some time had a high incidence of the disease compared to other areas.

[wilcopops]

This year has been OK, last year there were a lot of cases in the Chiang Mai area. July to September is the most dangerous time.

I don't get bitten much and rarely use repellant. Walking around you'll rarely get bitten. When sat down make sure there's a fan on you (and your ankles especially).

not everyone is actually aware they have been bitten by a mosquito....reactions vary from person to person.

[wilcopops]

Haven't heard any news of recent outbreaks.

a young girl (13yrs) from Mrs G's village was unbelievably misdiagnosed with something else! by a quack at Hang Dong Hospital a couple of weeks ago. She was sent home, then her sickness got steadily worse. She passed away at Suan Dok a few days ago with multiple organ failure . . . cause - Dengue.

I find that hard to believe - not that a hospital gets the diagnosis wrong - this is something of a problem with Dengue, but "multiple organ failure" would not be how you describe death from Dengue.

[wilcopops]

It's less of a problem in cities where traffic pollution keeps the number of mozzies lower, still a risk however. Feeding time, early morning early evening are the riskier times.

i don't think you'll find any evidence to support that theory.

In fact one of the favourite places for Aedes to breed is the water in old car tires....so the more traffic, the more tires, the more chances?

[wilcopops]

I live in CM and was diagnosed with dengue at CM Ram Hospital, but it was after a trip I took to Doi In, Mae Sariang, Pai, Mae Hong Son, and points north. This was ~April 2013. I know a great many people in CM and have never heard of anyone who lives here and stays here contracting it. Maybe the most important measure you can take is wearing long sleeves and trousers at and after dusk. BTW, for me dengue was akin to having the flu for a week, not worse.

Personal assessment of the number of dengue cases is quite pointless.

There are however problems with getting the numbers.

Firstly is diagnosis....It has to be done with a blood test - no otter way is conclusive. The tests have to be carried out correctly and at the right time in relation to infection.

Furthermore Doctors are diagnosing ever fever they come across as Dengue without proper tests.

The symptoms of Dengue can vary from a rely noticeable to life threatening, and are untreatable - paracetamol and water being about the only things available.

The result can me that many cases of Dengue go unnoticed as the victims don't present at any medical institution. ....consequently are never recorded.

In general populated areas are more likely to carry a risk.......on the Western Forest complex - along the Myanmar Border, however there are many refugee camps etc etc and Dengue here is rampant....although the Thai authorities sen reluctant to make this public...as they would have to admit to poor sanitation and infrastructure.

Dengue itself only lasts for around a week....any fever lasting over 2 weeks is unlikely to be dengue....however the after-effects of any viral infection can really take a toll and full recovery can take months.

[wilcopops]

I got it 2.5 months ago ended up in Sripat Hospital....I was mis-diagosed at Maharaj 2 days earlier.....those ER 'docs" are the worst...moronic students doing some work experience.....dire service in that hospital.

Lucky I had medical insurance...it racks up fast in the "developing world"

Time slows down and you go a bit mad at the peak of the infection depending on severity.

My g/f had to go and get a visa extension on my behalf..god bless her, she is a lifesaver. Went and queued from 7am.

It is a daytime female tiger striped mosquito. If you get bit by the other 4 strains it can be fatal next time, you don't build an immunity to the other strains.

There is a vaccine coming next 2 years. It is a rapidly increasing problem globally.

There is no timetable for a vaccine.

There are now apparently 5 strains of the virus.....this is why there are problems with coming up with a vaccine.

It is believed that subsequent infections by different strains can lead to more serious symptoms (not necessarily death) but this is not totally confirmed.

This is however one reason that anyone who feels they may have dengue - however mild - should get it conformed with a blood-test, this will help people to work out whether or not secondary /tertiary infections are more dangerous.

[wilcopops]

Dengue mozzies sleep at night, active by day, and as noted, also dawn and dusk.. However, there are plenty of others ready from fresh farang blood, and I spray from knees down before venturing out in the evenings. I believe the range of a breeding dengue mozzie is around 150 metres, so if folk around you have it, check out why and where.

The common name in many countries is 'break bone fever'. Aptly named I'm told.

Local people here are not proactive about dengue breeding sites, and there's always water in bowls, old tyres, pot plants.

The bright side is there does not appear to be much malaria around here. It's not nice to have!

"Dengue mozzies sleep at night, active by day, and as noted, also dawn and dusk.." - not correct - they can be active day or night.

[wilcopops]

Had it twice also. I thought that if you had one strain once, thats it. And just 4 strains. Not so?

you have antibodies that work only against the one strain...it is thought they don't react correctly to other strains which is why subsequent infection may be worse.

Sadly it now appears their are 5 know strains to contend with.

the problem with antibodies is referred to as "antibody-dependent enhancement of infection" - it is believed it results in the original antibodies actually HELPING the virus to spread into the body

[Goshawk]

Haven't heard any news of recent outbreaks.

a young girl (13yrs) from Mrs G's village was unbelievably misdiagnosed with something else! by a quack at Hang Dong Hospital a couple of weeks ago. She was sent home, then her sickness got steadily worse. She passed away at Suan Dok a few days ago with multiple organ failure . . . cause - Dengue.

I find that hard to believe - not that a hospital gets the diagnosis wrong - this is something of a problem with Dengue, but "multiple organ failure" would not be how you describe death from Dengue.

Well you need to do a bit more research then my friend . . . and my bad, i omitted the word 'hemorrhagic' from this case. Mrs G herself had DHF 3yrs ago, luckily we nabbed it in time (i'm talking days) she had an emergency platelet transfusion at Suan Dok and was eventually fine. The young girl in my post above was sadly not so lucky.

[wilcopops]

Had it twice also. I thought that if you had one strain once, thats it. And just 4 strains. Not so?

I believe you get immunity from the strain you caught but only for a matter of months.

As Far as I'm aware the protection is "life-time" - however many anti-bodies as in vaccinations require boosters as time goes by.

[masuk]

The risk is high as in most countries with tropical climate. Even Singapore has a high amount of dengue cases. The more densely an area is populated, the higher the risk as it is transmitted from human-mosquito-human and mosquitos not travel far. I think Sheryl's advise is spot on, avoid getting bitten by mosquitos, wear long trousers, use mosquito repellent, mount dengue slide doors and windows at your home, use mosquito lamps etc etc. And if you do get flu like symptoms, do assume it's dengue and get appropriate help asap. Hydration extremely important in such a case.

Singapore has had a very proactive anti-Dengue campaign in place for several years, large banners hanging from apartment blocks in many places around the island.

They also have 'mosquito police' and huge fines for those leaving water around the house/garden or even apartment flower pot saucers.

[wilcopops]

Haven't heard any news of recent outbreaks.

a young girl (13yrs) from Mrs G's village was unbelievably misdiagnosed with something else! by a quack at Hang Dong Hospital a couple of weeks ago. She was sent home, then her sickness got steadily worse. She passed away at Suan Dok a few days ago with multiple organ failure . . . cause - Dengue.

I find that hard to believe - not that a hospital gets the diagnosis wrong - this is something of a problem with Dengue, but "multiple organ failure" would not be how you describe death from Dengue.

Well you need to do a bit more research then my friend . . . and my bad, i omitted the word 'hemorrhagic' from this case. Mrs G herself had DHF 3yrs ago, luckily we nabbed it in time (i'm talking days) she had an emergency platelet transfusion at Suan Dok and was eventually fine. The young girl in my post above was sadly not so lucky.

actually I do quite a lot of research, however YOU did't mention haemorraghic" in your post - this is crucial.. however the diagnosis would have been Dengue Haemorraghic Fever. It is more a sign of the general incompetence of the Thai healthcare industry than anything else.

You can't "nab" Dengue in time; it has to run it's course. If it turns into "haemorraghic" or "shock" then a hospital has to try and keep everything working until the virus has run its course.

Other than monitoring platelets, there is nothing to be done. If the hospital was more diligent in diagnosis the girl could have been in the hospital when she started to experience the problems.

[Kabula]

Mosquitoes are flying hypodermic needles and carry many old and new diseases.

Millions living in tropical climates suffer from a host of diseases spread by mosquitoes day and night.

The Dengue mosquitoes bites are more active in the afternoon early evening.

I lived with this problem for 11 years in Costa Rica. There the Dengue mosquitoe is larger than the common mosquitoe we see frequently. I'm not sure about the size in Thailand.

I personally keep all my doors and windows closed and instruct my maids to do the same. Only windows and doors with screens are opened.

I also spray Off spray on exposed skin when mosquitoes are present. I don't use it all the time as the spray itself has harmful toxic chemicals that can be absorbed in the skin, which is the largest human organ.

Anything that catches water should be drained as that is where they lay their eggs. I also understand they do not travel very far from where they hatch.

[wilcopops]

This year has been OK, last year there were a lot of cases in the Chiang Mai area. July to September is the most dangerous time.

I don't get bitten much and rarely use repellant. Walking around you'll rarely get bitten. When sat down make sure there's a fan on you (and your ankles especially).

Check the press - there has been a dry high incidence of Dengue in Chiang Mai this year.

[masuk]

from Wikipedia:

Spread of disease and prevention[edit]

Aedes aegypti is a vector for transmitting several tropical fevers. Only the female bites for blood, which she needs to mature her eggs. To find a host, these mosquitoes are attracted to chemical compounds emitted by mammals. These compounds include ammonia, carbon dioxide, lactic acid, and octenol. Scientists at the Agricultural Research Service have studied the specific chemical structure of octenol to better understand why this chemical attracts the mosquito to its host.^[4] They found the mosquito has a preference for "right-handed" (dextrorotatory) octenol molecules.

The yellow fever mosquito can also contribute to the spread of reticulum cell sarcoma among Syrian hamsters.^[5]

The CDC traveler's page on preventing dengue fever suggests using mosquito repellents that contain DEET (N, N-diethylmetatoluamide, 20% to 30% concentration, but not more). It also suggests:

1. Although Aedes aegypti mosquitoes most commonly bite at dusk and dawn, indoors, in shady areas, or when the weather is cloudy, "they can bite and spread infection all year long and at any time of day."^[6][7]

^{So, my information was wrong. they can bite any time.}

[wilcopops]

It is a day time biting mosquito and quite possible to get in CM. Incidence is greatest in and immediately after the rainy season as the vector breeds in stagnant water.

Precautions = avoid getting bitten to the extent you can, and try not to have stagnant water around where you live. (Water jars are a common breeding site along with any standing puddles).

Wet markets are a particularly risky area.

This is not quite accurate , I think.

The female Aedes lays her eggs just ABOVE the water. they also lay near very small amounts of water, car tires, pots etc....This means that only a slight increase in water-level can trigger the hatching of the eggs, so any "bloom" in Aedes is not dependent on the rainy season.

Remember too that the mosquito has to bite an infected person first before biting and infecting someone else.

The lifespan and range of the Aedes is also an important factor as it stays relatively close to its source. (200 metres or so)

[wilcopops]

from Wikipedia:

Spread of disease and prevention[edit]

Aedes aegypti is a vector for transmitting several tropical fevers. Only the female bites for blood, which she needs to mature her eggs. To find a host, these mosquitoes are attracted to chemical compounds emitted by mammals. These compounds include ammonia, carbon dioxide, lactic acid, and octenol. Scientists at the Agricultural Research Service have studied the specific chemical structure of octenol to better understand why this chemical attracts the mosquito to its host.^[4] They found the mosquito has a preference for "right-handed" (dextrorotatory) octenol molecules.

The yellow fever mosquito can also contribute to the spread of reticulum cell sarcoma among Syrian hamsters.^[5]

The CDC traveler's page on preventing dengue fever suggests using mosquito repellents that contain DEET (N, N-diethylmetatoluamide, 20% to 30% concentration, but not more). It also suggests:

1. Although Aedes aegypti mosquitoes most commonly bite at dusk and dawn, indoors, in shady areas, or when the weather is cloudy, "they can bite and spread infection all year long and at any time of day."^[6][7]

^{So, my information was wrong. they can bite any time.}

They can bite at anytime but it is most likely at dawn or dusk.

If it is a sunny day, common sense will tell you that any organism as small as a mosquito simply won't fly - it would dehydrate in seconds.

[wilcopops]

When I had Dengue there were six houses in our moo bann that were affected. It is definitely a social disease and it needs humans to keep going. My doctor warned me that a subsequent bout would likely be more severe than the first. Was never weaker in my life and full recovery took well over six months.

So you are saying that particular mosquito only feasts on humans? Or is that just an assumption?

Interesting point.

It would appear that the Aedes mozzie mostly feeds on humans.

What I'm not sure of is whether or not the virus can be transmitted form say a dog via mozzies to a human.

however I'm pretty sure the focus on prevention is concentrated on humans.

[wilcopops]

When I had Dengue there were six houses in our moo bann that were affected. It is definitely a social disease and it needs humans to keep going. My doctor warned me that a subsequent bout would likely be more severe than the first. Was never weaker in my life and full recovery took well over six months.

that's called a "hotspot".

[wilcopops]

When I had Dengue there were six houses in our moo bann that were affected. It is definitely a social disease and it needs humans to keep going. My doctor warned me that a subsequent bout would likely be more severe than the first. Was never weaker in my life and full recovery took well over six months.

So you are saying that particular mosquito only feasts on humans? Or is that just an assumption?

Dont know about that, but apparently if a non-dengue mozzie bites a dengue sufferer within the first 3-4 days, their next bite will infect that person with Dengue too.

Not sure what the odds are though, that if you get Dengue, any old mozzie will infect your significant other after biting you first. May be when it is satiated it will fly off some place else??

the female mossie only feeds every 12 hours or so. If it bites an infected person the virus as to have time to "develop in the female mosquito and transfer to its salivary ducts. once this has happened it has to successfully bite another person and transfer the virus. .....and that person is usually within about 200 metres of where the first bite took place. Of course if you move the infected person you are moving the source. Complicated, but it happens.

"Non-Dengue"? - Only the Aedes and a couple of other species carry the virus, but do you mean a "non-dengue infected" mossie?

[wilcopops]

Does a big city like Bangkok have a significant reduction in dengue fever cases due to it being a large metropolitan area? Also, for those unfortunate folks who have gotten dengue fever, what was the average stay in the hospital?

Any cluster of population has to be good for dengue. Especially if there are lots of little pools of water for breeding. A lot depends on the local authorities preventative measures. Other countries have strict penalties for leaving water lying around or having pons with not fish etc etc....

Dengue lasts for about a week (+ - a few days) but post viral "doldrums" can last for weeks.

[wilcopops]

My dengue affliction was like a mild flu, nothing more.

Was it diagnosed with a blood test? It seems you now have to be more careful about further infections as the general thinking is that subsequent infections can be more serious.

[wilcopops]

Worried about dengue? Worried about anything? Don't come to Thailand. If you can stop worrying about stuff out of your control you'll be OK.

I'd hardly call taking precautions against Dengue "worrying".

Do you wash your hands after going to the toilet?

Agreed - take precautions.

I so often see visitor to Thailand wearing next to nothing in bars and cafes in the evening - bare arms and bare legs and I suppose they then wonder why, on getting home they are struck down with dengue.

[cloudhopper]

this one is the best available here IMO

http://www.jaico.be/insect-repellents

[Ulysses G.]

IMO, it is mostly bad luck catching Dengue fever and unless you are a very short time visitor, not worth wearing certain clothes and covering yourself in mosquito lotion every day - unless you would do it anyway. I have lived here more than 20 years and have known a very few people that got it, but the odds are high that you will not.

[masuk]

IMO, it is mostly bad luck catching Dengue fever and unless you are a very short time visitor, not worth wearing certain clothes and covering yourself in mosquito lotion every day - unless you would do it anyway. I have lived here more than 20 years and have known a very few people that got it, but the odds are high that you will not.

only 10,000 or so!

http://www.breakdengue.org/dengue-initiatives-in-chiang-mai/