Good news against dengue | Hacker News Reader

Good news against dengue

science.org

172 pointsjseliger66 comments

I've spent lots of time in India. It's good to learn what the mosquito that can carry Dengue looks like. They are smaller and fly much faster and more erratically than a common mosquito – way harder to swat! If they settle down, you can see white stripes on their long legs and body.

If you notice them, you can sometimes figure out why they are congregating, they need blood and standing still water to procreate.

At one place I stayed, next door there was a construction site where the workers also slept bare skinned at the site. That's the only time I caught it. Another place I stayed was also seriously infested, I couldn't sit outside. I went looking and found two barrels of rain water on the roof, full of larvae. I added a small amount of dishwasher liquid to the barrels, which worked. Mosquitos went away in a few days.

A few years ago I had dengue in Singapore, and while my case was mild as far as these things go, I was still almost hospitalized because my platelet counts dropped so low. The overall experience was sufficiently unpleasant that I was strongly incentivized to take Dengvaxia, the only currently approved vaccine, but having gone through the process, I can see why very few people do.

- As mentioned in the article, if you have never had dengue and you take Dengvaxia, it paradoxically increases the odds of getting a bad case. So in Singapore you're only eligible if you have had a confirmed positive blood test for dengue previously.

- I had incredibly good health insurance at the time, which among other things happily paid for my dengue management at one of the best private hospitals in the country ($$$), but they straight up refused to cover Dengvaxia and I had to pay over $700 out of pocket.

- Getting the vaccine required 3 shots spaced several months apart. Not a huge problem for me, and side effects were minor to non-existent (much better than eg COVID vaccines), but obviously this reduces compliance.

- Even in Singapore, which is a wealthy, dense tropical country with a lot of dengue and thus eligible people, the hospital (again, one of the largest and best-resourced in the country) had to special order the vaccine every time for my three visits and there were a couple of minor hiccups with deliveries etc.

My reward for all this is not immunity to future cases of dengue (remember, there are 5 serotypes and getting it once only makes you immune to that variety), but a 80% reduction in the odds of getting severe dengue the next time around. Which is nice, but not a game-changer.

I got Dengue on a business trip to Bali a number of years back from the US. Got a very high fever upon return to the US and ended up in the emergency room because of crashed platelets (which never fully recovered) and white cells. Was impressed the on-call infectious disease guy (in New England) immediately made the call about what it was--my primary care guy had no idea. Cost me something like $1K in spite of good insurance between ER and blood work that had to be sent off to Paris and basically zero treatment. Vaccine isn't indicated for my situation but it basically makes me hesitant to ever travel to Dengue-prone areas of the world again.

> one of the best private hospitals in the country ($$$)

It's possible you might've gotten faster, better, and cheaper treatment at the Communicable Disease Centre which might already have had a stock of Dengvaxia.

Like you said, dengue is endemic to Singapore, and most people who get it go there to get treated, rather than the (very expensive) private hospitals.

My understanding is that the unsubsidized cost of the three vaccine doses is on the order of $600, so the markup was pretty minimal here. (IIRC my insurance did cover the initial consultation re: the vaccine and the nurse fees.)

I am from Argentina where dengue is an epidemic right now (we had it for years but it seems this year is worse), and what everyone says about the vaccine is exactly this:

> it paradoxically increases the odds of getting a bad case

So what is it good for?

The clause preceding that quote gives you the answer:

> if you have never had dengue and you take Dengvaxia, it paradoxically increases the odds of getting a bad case

e.g. if you have had dengue previously, it reduces your chances of having a bad case to 20% (according to that comment).

And, critically, once you have one serotype of dengue, your chances of severe dengue from infection by another serotype are substantially higher.

First dengue is often not that bad. Second dengue is often quite bad. This vaccine makes second dengue not that bad, but if you take it without having had first dengue, it just leaves you in the same boat as if you’d had first dengue — worse off than if you’d had no dengue.

Can confirm this. The second attack is potentially fatal.

> but a 80% reduction in the odds of getting severe dengue the next time around. Which is nice, but not a game-changer.

As far as I know if you get Dengue twice, and in the "wrong" order of serotypes, you are very likely to die. That should make the vaccine a game changer if it works like you describe.

Oh, Qdenga already seems to be authorized for use in the EU, I completely missed that! Dengue has always been on my mind when traveling to SE Asia.

A real shame that the FDA is dragging its feet once again.

From all I know it is pretty hard to get over here, if you cannot prove you already had an infection. This is because the official recommendation seems to be against Qdenga for so called "Dengue-Natives".

While it technically makes sense it is also not a very practical policy since most primary infections are asymptomatic or mild. Since you most likely don't know if you already had it, your doctor doesn't know if you benefit from Qdenga and will most likely stick to the official recommendation.

Are you sure it's dengue-native, not dengue-naives?

Doesn't this only apply to Dengvaxia? I can't find anything that states that Qdenga should only be used with people who've already been infected before. I also can't find anything stating there's a risk of ADE (antibody-dependent enhancement) with Qdenga as there is with Dengvaxia, which would make such a limitation necessary.

https://www.takeda.com/newsroom/newsreleases/2022/takedas-qd...

https://www.ema.europa.eu/en/medicines/human/EPAR/qdenga

https://en.wikipedia.org/wiki/Antibody-dependent_enhancement

I got dengue and typhoid fever at the same time. They call it a co-infection. I was pissing blood at one point but they said it was due to dehydration and having a kidney stone I wasn't aware of until they had me get an ultrasound. Anyway, these types of viruses are unavoidable. Everyone gets sick from time to time. Incase anyone is curious, I got them both from a restaurant I went to. I kept getting bit by mosquitos that night and the water they served didn't taste right. I only took a few sips of the water but that's all you need to catch typhoid. I google mapped the restaurant and found a few open drainage ditches next to the restaurant. The mosquitos must have been growing in there.

For anyone wondering (because title is clickbaity): Two new dengue vaccines were recently announced by the Takeda and Butantan companies.

Takeda: https://www.takeda.com/newsroom/newsreleases/2023/Takeda-Den...

Butantan: https://www.nejm.org/doi/full/10.1056/NEJMoa2301790

Butantan is not a company, but a public research institute run by the Brazilian state of São Paulo.

It's just a blog post, and it is indeed good news. The author doesn't really need to bait any clicks.

In addition to that it is relevant because Dengue cases are at an all-time currently.

Oh this is amazing news. Dengue infection is common in parts of India I come from and there is very little that can be done about it beyond the basics. My parents have got it couple of times and it is similar to long covid in the sense that there is extreme body pain and a slow recovery.

I posted about this last year. This will soon be an issue in the US as well and only then people will start freaking out. Because dengue can mess up anyone not just the old. Time to wipe out disease carrying mosquitos!!

Bill Gates has dozens of projects combating mosquitoes, at least one of which is intended to replace them with non-carrying mosquitoes.

That’s what happens in America when we freak out now, one of the billionaires fixes it.

Read about Oxitec[1] a while ago and found their approach quite interesting!

[1]https://www.oxitec.com/

This looks promising. How effective has it been in reality?

It’s early. Studies in Brazil show up to 90% reduction (Oxitec’s numbers) and they’re just now going into their third season of testing in the Florida keys, working with the EPA. They say the results are good, and I assume they must be if the government is letting them expand the trials. I think we’ll have hard numbers soon.

I’ve been following this for years just out of curiosity. It’s a brilliant solution and a brilliant business model. Because the genetic alteration kills the mosquitoes, you have to keep buying them from the company. It both makes it so that there’s seemingly little risk to the environment and subscription revenue.

That’s great. If we can drive disease carrying ones to extinction why do we need to keep buying this?

You probably can't drive them to extinction this way. The introduced mosquitoes only help within a small range (~400m I think) of where they put the little devices they come from, because that particular mosquito doesn't travel far from where it's born. And even within that range, a 95% reduction is great, but the year you stop, that 5% will just start doing whatever they did before and a couple years later you'll be back to where you were beforehand.Insect populations grow exponentially.

In 2009, Bill Gates gave TEDTalk in which he released mosquitoes to make a point about malaria.

what do you suggest to stock up, just in case?

Not sure if you are making fun or not but best thing to do would be to ask FDA to take the vaccine approval/development seriously.

I'm interested in being prepared for potential health challenges, particularly mosquito-borne diseases like dengue fever. It seems to be a concern in some areas, and I believe knowing how to identify and manage potential symptoms can be very helpful. I'd like to learn about stocking a minimal amount of essential supplies, like mosquito repellent, to help prevent bites in the first place

I'm in Europe so not very familiar with tropical diseases beside the annoying mosquitoes

If you get yourself a supply of Permethrin and some mosquito nets, you will be miles ahead of most people.

Permethrin is great stuff, the mosquito lands on permethrin treated cloth, the mosquito falls down dead. It is something to see. You can treat your clothes with it and spray it on your walls and ceilings.

https://en.wikipedia.org/wiki/Permethrin

Yes but unfortunately dengue carrying mosquitos bite during the day and they are very sneaky. They go for the feet, ankle etc..

Dengue can also be forecast with reasonable accuracy, particularly in countries like Brazil with good data systems

https://www.biorxiv.org/content/10.1101/2024.03.12.584724v1

(disclosure: I'm an author on this)

Someone should sent this news to Argentinian government so they do something about the problem they're having right now instead of looking the other way. https://www.theguardian.com/global-development/2024/apr/12/i...

> Someone should sent this news to Argentinian government so they do something about the problem they're having right now instead of looking the other way

They aren't looking away, they're slashing costs everywhere without much thought and hiding their heads in the sand to any potential consequences. What more could you expect from a libertarian who gets advice from his dead dog?

I know. He just wants to destroy everything so he can rebuild his libertarian paradise along his his tarot reader sister.

Is he checking in with the dog through the sister?

They really don't have any money.

They don't have lots of money, that's for sure. But "saving" money by doing slashing costs on things which will literally cost you much more money in the short to mid term (like the whole dengue epidemic, for which prevention was cut, resulting in many more cases resulting in lots of healthcare costs and lost productivity) is not a way to govern a country.

Using a different form of mismanagement to "fix" a mismanaged country doesn't really help.

Our health officials really fucked it up with Dengvaxia back then. This was also the reason why there is still some vaccine hesitancy here especially with Dengue. I’m not sure how the government can make amends with the population.

https://www.pharmaceutical-technology.com/features/dangvaxia...

I live in Thailand, and I've never had Dengue. I'm thinking about traveling to Bangkok for a Qdenga shot. Even though ADE doesn't seem to be a concern, I have gotten quite paranoid about any injections that trigger the immune system as I've now had allergic reactions to both vaccines and antibiotics. So I feel a little bit nervous about it.

My neighbour suffered paralysis after vaccine shot! Someone from known also suffered brain-stroke! My uncle died of cardiac arrest a year ago! I had seen lot of such stories around the world, yet an industry is moving forward to further increase all such activities, which doesn't seem right!

My neighbour suffered brain-stroke after a haircut! Someone else fell over and broke their arm also after a haircut!

Some country like Australia with decades and decades of high quality medical records going back to the 1960s would surely show a huge increase in heart attacks and brain strokes after almost all of their 22+ million people had more than one vaccine and yet there were no significant increases in total stroke numbers!

And yet many people had strokes, fell over, got hit by cars after having vaccine!

How can this be??

When authority denies tracking such data, you can ignore/mock for the lack of evidence! But does that help? My team had collected around 18000 such cases nationwide where people had reported, but instead of serious investigation, we saw no mention of this in mainstream media and social media reveals this is a worldwide problem! More people are getting vocal about this day by day! Hope public will soon understand what's happening!

Dengue is not a tropical disease. That does not exist. Dengue is a disease of bad governments.

In Brazil, the majority of the population does not have sewage. Tap water is not potable and is not distributed every day, in some areas twice a week, in some areas less than that. This creates the need for everyone to have a water tank at home, creating the possibility of a large number of mosquito breeding sites. And the Moskito Aedes aegypti is a terrible vector of 52 diseases [0], among which it transmits a sarcoma (!!!) among hamsters.

The current government tried not to buy vaccines[1], trying to wait for the Butantan vaccine.

The current Brazilian government is the same or worse (!) than the previous one, more censorship, more dead Indians[2], more fires in the Amazon rainforest[3], and one thing is really worse: all the press covers up the mistakes of the current government .

And...politicians are crazy, intelligent, incredible psychopaths. In the last two weeks the discussion has been about freedom of expression, about Elon Musk and so on. Economy, education, security and health are never priorities. It's clear that the government is trying to pass a law to regulate social media (and using Musk and Twitter as an example to do so), and the mainstream press is very eager to do so, because the law has a part that states that social media will pay for links to news sites. It is not a problem for a country that needs sewage.

They are incredibly good at doing nothing. Some things in Brazil have been discussed for over 100 years, an example is a tunnel in the city of Santos[5].

The next government will also be bad, the population will fight over policies and nothing will change. I will never understand why people fight for these psychopaths. "My psychopath is better than yours."

Please, I will not discuss “fascists” or “communists”, left or right, “everything is politics”, “but billionaires are bad”, etc. These are first-world problems. It is irrelevant for a country that needs sewage. Of course this can be discussed, but not in the current proportion. Sewers are much more important than that.

[0] https://en.wikipedia.org/wiki/Aedes_aegypti#Vector_of_diseas... [1] https://saude-ig-com-br.translate.goog/2023-07-03/dengue-min... .html?_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp [2] https://g1-globo-com.translate.goog/jornal-nacional/noticia/... -2022-showm-dados-do-ministerio-da-saude.ghtml?_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp [3] https://umsoplaneta-globo-com.translate.goog/biodiversidade/... -aponta-estudo.ghtml?_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp [4] https://g1-globo-com.translate.goog/sp/santos-regiao/noticia... -no-novo-pac.ghtml?_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp [5] https://g1-globo-com.translate.goog/sp/santos-regiao/noticia... -no-novo-pac.ghtml?_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp

Dengue is also an issue in Singapore, despite all the measures being taken: public awareness campaigns, release of sterile males, mosquito traps, etc. Doesn't mean the Brazilian government shouldn't take the steps it can, but this take significantly undersells how serious and difficult of an issue it is.

And even this is selling Singapore’s policy and procedure short.

On top of those broader measures listed and the general level of public cleaning/maintenance, there’s reporting of every dengue infection diagnosed along with the individual’s home address and particulars to the National Environmental Agency. Cases and trends are monitored for developing clusters, publicly publishing up-to-date findings and exact numbers. Where a cluster is found, they do additional anti-mosquito fogging and significantly increase the local public awareness campaign (huge banners, posters in every elevator, distribute leaflets, etc).

They then send agents unannounced to inspect inside every home/unit in the area for any potential breeding grounds. Everything is checked from potted plant trays to dish drying racks to toilet bowl scrubber holders. If any breeding is found, there’s fines in the thousands of dollars. The agents are empowered to enter without a warrant; it’s taken THAT seriously.

The NEA also monitors and takes appropriate action against non-residential areas like construction sites, where standing water is hard to eliminate unless it’s a priority.

They are also using Wolbachia programmes to reduce mosquito populations:

https://www.nea.gov.sg/corporate-functions/resources/researc...

Dengue is just a difficult thing to fight. In 2020, more people died of dengue in Singapore than from Covid (32 dengue deaths vs 29 Covid deaths).

> Dengue is just a difficult thing to fight

Singapore had 8k cases in 2022. Brazil has 3 million cases of dengue in 2024. Is not the same thing.

Why would you quote figures like that without adjusting them for population? Brazil has 40x the population of Singapore.

0.16% of Singapore's population had Dengue in 2022. 1.4% of Brazil's population had Dengue in 2023.

Are there any significant differences in the geography of Brazil that could also contribute to some of the difference in infection rates?

Very. In simple terms there's just a lot more of Brazil to deal with.

Brazil is a massive 8,514,215 km2 while Singapore is just a tiny 734 km2 island which is very highly urbanised and developed and doesn't have a significant rural population (hence the description of "city-state").

Its small enough that you can monitor mozzie levels at the individual building level, and locate and deal with breeding spots at that level too. That might also be practical in urban areas in Brazil, but for rural areas I suspect is not feasible?

> but for rural areas I suspect is not feasible?

Aedes aegypti is an urban mosquito. Degue is an urban disease. The big difference between Brazil and Singapore is sanitation: https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in...

Oh yes it was Wolbachia I was thinking of, not sterile males.

Just look at the map of Singapore. It doesn't matter how hard they try, there is malay jungle maybe 1km from the city. Unless its getting the same treatment for another 10km from the border, or they somehow raise star trek shields between it, little buggers can easily find their way to the city even if city itself is sterilized.

Singapore had 8 thousand cases in 2022. Brazil has 3 million cases of dengue in 2024.Is not the same thing. The poor distribution of water and the lack of sewage are fundamental to dengue fever in Brazil.

I'm sure those are all factors but don't you think that the thousands of miles of jungle also places a factor?

Not if dengue is an urban phenomenon.

Had such inspections before whenever kena red zone here.

As well as checking all these things the agent will advise on what to look out for. For example our unused plastic buckets in the bathroom are upside down so they don't accumulate water, ah! but then also must check that little rim channel as it too can also accumulate enough water from nearby splashing to become a breeding spot!

SG also has Zika which transmits via Aedes mosquitos.

The common corridors in many blocks also have "Gravitraps" they use to monitor numbers by counting how many mozzies get trapped.

https://www.nea.gov.sg/dengue-zika

Brazil too have notification with the numbers published weekly by each State of the country, all cases are notified even without laboratory confirmation. They too have zoonosis agents which inspect locations, but they're not allowed to enter without warrant.

Even in Massachusetts, I had a call from the town nurse.

>They then send agents unannounced to inspect inside every home/unit in the area for any potential breeding grounds. Everything is checked from potted plant trays to dish drying racks to toilet bowl scrubber holders. If any breeding is found, there’s fines in the thousands of dollars. The agents are empowered to enter without a warrant; it’s taken THAT seriously.

Came here to say this. I lived in SG for 14 years, we had the "mosquito police" show up to our office (shophouse in Emerald hill) and do an inspection.

If you're getting mosquitoes in your place, you can call the NEA and they'll send people out looking for the source.

Grass is mowed religiously in Singapore to help keep the mosquitoes under control and there's always a ton of spraying. During COVID lockdowns, a lot of the lawn guys were stuck in the dormitories so the grass got tall. Also, the coconut palms went untrimmed. The morning walks became fraught with danger as the palms were overloaded with coconuts and were consistently falling onto the footpaths. I know COVID sucked for a lot of people, but I find a weird sense of nostalgia for that time.

Are you comparing 8k cases (Singapore) with 3 million cases per year (Brazil)?

Singapore had 8 thousand cases in 2022. Brazil has 3 million cases of dengue in 2024. Is not the same thing.

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