Dengue rates plunged after release of lab-altered mosquitoes
dw.comThis is great news. Dengue was a constant problem in my home country of Malaysia, and remains a problem to this day. I still remember all the public education campaigns about it that I saw when I was young (random ads on TV about making sure there's no stagnant water, seeking medical help if you notice <symptoms>, etc), I'm very glad that there are easily implementable solutions to these problems.
As a side note, I wonder why this kind of research is not more popular in university labs of tropical countries. Malaysia, Singapore, India, etc are home to plenty of university labs that should have the expertise and motivation to do this kind of thing, but they're really dropping the ball if they're not working on it right now. Every time I read about new mosquito fighting innovations it's out of an American or European lab, far away from where it's most impactful.
Is it a problem of funding? Somehow the Malaysian government funds less mosquito disease research than the US? Political will? I would hope that the health ministries of tropical countries are willing to throw some money at the problem. Institutional knowledge? Plenty of the professors are educated in Australia/UK/US, so that can't be it. Coverage? Western media covers western labs, and don't notice when labs elsewhere do the same thing?
A couple of months ago I found mosquito larva in some stagnant water in a parking garage, and made sure to pore some bleach into that stagnant puddle when I returned.> making sure there's no stagnant water[...]I've wondered if the opposite of the "no stagnant water" advice wouldn't be more effective in countries that suffer more from mosquitos. I.e. intentionally create ideal breeding ponds for mosquitos, then kill the eggs/larva/pupa before they emerge from the water as adults.
Edit: Searching some more there's commercial products which allow for the DIY creation of cheap mosquito larva traps: https://www.audubonva.org/news/how-to-set-up-a-mosquito-larv... & https://summitchemical.com/products/mosquito-dunks/
This assumes that the new ponds will pull mosquitoes away from existing ponds. Is this true? (Maybe mosquitoes are limited by suitable breeding grounds, and introducing decoys could have no effect.)
If you get mosquito larva in your honeypot pond it is a suitable breeding ground as far as the mosquito is concerned.
So this would work for the same reason the more high-tech release of sterile mosquitos works, it robs them of a breeding opportunity.
But perhaps I'm misunderstanding your question...
I think the question is about if there’s an upper bound on mosquito reproduction and if you can “steal” a chunk of that and kill it. Or if you’re really just making even more mosquitos overall and your culling doesn’t actually change the bottom line.
Yes; you might have seen mosquito "dunks" that are small donut shaped things that you can drop into flower pots or other areas that don't drain properly. They dissolve over time. There are also mosquito traps (bird-house sized or even just small plastic bags that you cut open). They can be filld with water to activate.
Maybe it's easier to be releasing them somewhere else? Oxford based Oxitec also have mosquitos to counter Dengue but genetically modified rather than with Wolbachia. https://www.wired.com/story/genetically-engineered-mosquitoe...
US CDC was originally created to deal with mosquitos causing malaria in the US. The US FDA also had a priority review voucher program to incentivize development a prevention or treatment for various tropical diseases including Dengue.
https://www.fda.gov/about-fda/center-drug-evaluation-and-res...
Also there have been an number of locally acquired dengue causes in the US. Maybe with climate change it might increase.
https://www.cdc.gov/dengue/statistics-maps/historic-data.htm...
Here are some links to research on using Wolbachia in Malaysia and Singapore:
[1] Wolbachia Malaysia [ https://imr.nih.gov.my/wolbachia/ ]
[2] Singapore NEA Wolbachia info [ https://www.nea.gov.sg/corporate-functions/resources/researc... ]
[3] A 2021 news article on Wolbachia in Malaysia [ https://www.channelnewsasia.com/asia/malaysia-fight-dengue-m... ]
You can give your aid money to the local government, or you can use it to fund a hospital or research facility flying your flag, employing locals and hopefully generating good news so its continued funding can becomes a political tool. But this rationalization can only explain the poorer countries in the region.
It is not a funding problem. These countries (ie: Third-world and less developed) never had these research structures in the first place. So they are lacking on guidance on how to execute. A good starting point is to look at government revenues. Indonesia has half the revenue of the government of Belgium. Belgium has less people than Jakarta.
Malaysia, Singapore and Australia did experiment in field, there are not many countries accomplished this. so they did it.
This Wolbachia bacteria is really something else. It seems to have a massive set of effects on a variety of organisms, directly impacting the way they reproduce, or even the way which sex they develop into. Remarkable.
As some sort of bonus it also prevents the host from developing other viral diseases in the case of mosquitos, I guess because it's a parasite, so it's advantageous for it to do so? Wild little thing. Does a lot.
>"Computational models predict that introducing Wolbachia strains into natural populations will reduce pathogen transmission and reduce overall disease burden.[64] An example includes a life-shortening Wolbachia that can be used to control dengue virus and malaria by eliminating the older insects that contain more parasites. Promoting the survival and reproduction of younger insects lessens selection pressure for evolution of resistance.[65][66]"
>"In addition, some Wolbachia strains are able to directly reduce viral replication inside the insect. For dengue they include wAllbB and wMelPop with Aedes aegypti, wMel with Aedes albopictus.[67] and Aedes aegypti.[68]"
I absolutely love Wolbachia. I did some work with Wolbachia in theoretical biology a long, long time ago.
They're usually only transmitted maternally and different strains came up with different strategies to maximise Wolbachia offspring: some strains prevent male offspring from developing, some strains prevent reproduction with Wolbachia-uninfected females so the infected males have only offspring with infected females!
You can make models of Wolbachia population spread with these strategies forever and ever :)
I find these sort of things somewhat odd. Dengue is extremely unpleasant, but as the article mentions it has a 99.98% survival rate in spite of being predominantly spread in some of the most impoverished areas in the world. Wiki [1] gives even better figures than the article which yield a 99.99% survival rate, and a total hospitalization rate of 0.13%.
Unforeseen consequences are a thing, and nature can evolve in difficult to predict ways. For instance one of the big early arguments for GMO crops is that it'd enable us to reduce our overall usage of herbicides. The main modification was glyphosate resistance, and since glyphosate was otherwise highly toxic to all plants, it was thought that just a bit of it would be enough to take care of what used to require much more herbicide.
And it lived up to this promise at first. But nature responded by naturally evolving glyphosate resistant weeds, and farmers responded by just spraying more of it, and more regularly, and we're now using more herbicide/acre than ever before. In 1991 (just prior to GMO crops starting to really kick off), we were using a rate of 1.18 units of herbicide per acre. By 2000 that had declined to 1.06. "Now" (2014) we're up to 2.02 and rapidly increasing. [2]
So many things (related to interacting with nature in various forms) seem to be being done under the assumption of a stationary target, when nature is anything but.
The 2022 mortality rate for dengue in Indonesia is 0.86%, with most of the fatalities being young kids. ~1200 people in 2022. [0]
It could be that the figures match your own as not everyone goes to a clinic when they have it - much more likely when its a bad dose. But a huge amount of people get it each year.
Ive had it twice. Can confirm - it sucks.
[0] https://www.kompas.id/baca/humaniora/2023/09/08/tren-angka-k...
Dengue has a huge emotional and economic cost beyond the dry survival rate statistics.
The article quotes a researcher flat out stating "the virus will probably find a way to overcome the Wolbachia effect". They still think their work to ease the agony and suffering of millions is worthwhile, despite it not being a magic bullet.
Presumably, the 99% survival rate is for the first infection. Follow on infections of dengue are increasingly dangerous.
I believe conditions like this cause impact to people's livelihood by putting them out of action.
Caring for the sick also has economic costs.
It causes massive economic impact! Where I live Aedes aegypti is extremely common and Chikungunya routinely causes people to miss work for over 6 months due to intense chronic pain. The impact on the public health care and social security systems is huge. These patients frequently need opioids on a daily basis because all other treatments failed.
Dengue is the poster child for antibody dependent enhancement: The first infection is typically pretty mild, but there's 4 Dengue strains and a second infection with one of the other 3 is much more severe.
The original vaccines for these had to be scrapped because they had the same effect, though current ones work against all 4 strains.
Los Angeles is doing something similar with fruit flies. [1] They're releasing infertile males, in the hopes that they outcompete males of a non-native species that could threaten the agricultural industry.
1: https://www.smithsonianmag.com/smart-news/millions-of-steril...
Now how does that work? Surely it would make any sperm more likely to win.
> When these males mate with females, the resulting eggs are infertile and so small that they don’t affect crops.
Singapore has been doing this for years.
When they release new males they put a flyer up at our lift that says "there's gonna be tons of mosquitoes soon, don't worry, they are males and they don't bite" and shortly after, all mosquitoes are gone.
It seems to work. I'm not a fan of meddling with nature in this way, though. I have zero doubts that this will end up in some kind of unforeseen disaster.
N=1, there were a ton more frogs when I was a child, than now.
Wolbachia is "healthy gut microbiota" but for mosquitoes.
It prevents their infection by many viruses.
It seems that it shortens their lives, so it's not healthy for them.
Ah you're right.
Somehow I had in my head that it was the contrary. Probably because [I also thought that] W. increases their reproductive fitness (but yeah shortens their lifespan).
And even the reproductive fitness thing, it seems I've hallucinated it after all...
long life riddled with parasites or somewhat shorter life sans parasites. I feel like they would be cool with it
Mosquitoes aren't affected by dengue. It's a human disease.
Even if they were affected by it, they don't feel pain or have emotions, so they'd "choose" to live longer.
> they don't feel pain
Really?
> We found “strong evidence” for pain experiences in adults of two orders, Diptera (flies and mosquitoes) and Blattodea (cockroaches and termites).
https://www.sciencedirect.com/science/article/abs/pii/S00652...
Reacting to harm is not the same as suffering. As far as we know, suffering requires nerves and cognition that mosquitoes don't have (not even close).
yes, as far as you know from your 1-sample subjective experience of being a human being, that other beings with nervous systems don't suffer.
Insects have nervous systems. Nearly all animals do.
They would choose to live longer in the same sense that water chooses to flow downhill.
Fine with me, they can be as unhealthy as possible for all I care. Little bastards deserve the worst in life.
Healthy for everything else though
Note that California has reported two cases of Dengue in people who haven't travelled outside the United States.
> The case remains under investigation, but it appears that someone became infected with the dengue virus, returned home and was bitten by a mosquito that passed it on to the local resident, according to Pasadena health officials.
https://abcnews.go.com/Health/wireStory/california-officials...
It seems part of the common pattern for outbreaks of dengue viral infections in other urban centres. However California lacks a non-human primate reservoir would probably limit the risk of it becoming endemic.
My personal favorite are the occasional cases of airport malaria.
There have been cases in other states too over the last 10 years. Florida, Texas and Arizona had a lot more locally acquired cases. Those might have been the first locally acquired cases in California. Maybe with climate change, as it gets warmer it becomes more prevalent.
https://www.cdc.gov/dengue/statistics-maps/historic-data.htm...
And France recently one (of someone who never travelled outside of France).
Currently down with dengue. Wish they'd put these good mosquitos where I live!
Get well soon! I've had a few friends catch dengue before.. doesn't sound like fun.
Hope you get better. I knew a guy in Burma who nearly died of dengue.
There's a really good Unsung Science podcast about a program related to this: https://wondery.com/shows/unsung-science/episode/12810-what-...
I'd like to see something similar done for Tick bite/Lime disease and bed bugs, they both seem to be accelerating their reach past decade or so.
What's the status on gene-drive approach to cull tail harmful insects?
So all benefits, no negatives?
The negative is you're disrupting the ecosystem. They reduce the mosquito lifespan's which might impact their population. Things that eat mosquitoes might have to adapt.
At this point I'm prepared to accept that though. The suffering these things cause is immeasurable. I hate mosquitoes so much I wish I could nuke them.
More likely, the targeted mosquitoes are outcompeted by other mosquito or small insect species that are just as useful to whatever was dependent on the targets. There's an obvious exception for if some plant is exclusively pollinated by some disease-carrying mosquito, or other bet specific relationship, but that seems unlikely and easy to detect in advance.
People in these discussions forget that there are lots of mosquito species, most of which don't transmit diseases.
In fact, there's certain belief in the Scientific community that (human biting, desease spreading) mosquitoes could safely be eradicated from the planet without impacting on the ecosystem.
I can’t help but feel like I’ve heard this before.
The great thing about technology is that it's possible to have new things or ways of life that are strictly better than the ones they replace! We can move beyond the efficient frontier; progress is non-zero-sum.
* Golden Rice * Unleaded gas * HCFCs (over CFCs) * etcYes it's possible, but we really need to be cautious.
In general it's a bad idea to underestimate adaptive systems. It's especially foolish to underestimate the ultimate adaptive system: natural ecosystems. We should be extremely humble and careful when we're toying with the unfathomably complex system that we depend on. We understand very, very, very little about these things except that they're hard to predict and we really need them to continue working well enough to maintain the parameters we need for survival.
How often do you hear about the downsides of malaria eradication in the United States (probably spraying most of Florida with DDT would be one…)? What about screwworm fly elimination in the United States and parts of Central America? That program is much more similar to the thing described in this article than spraying every puddle with insecticide.
DDT doesn't run the risk of "running away" out of control the way biological/bacterial/viral interventions do. This is my first time hearing about screwworm and 1) wow what a nasty looking infection, and 2) boy am I glad it looks like the eradication campaign is going well! And yes the screwworm program does seem really similar to this, so especially thrilled it seems to be going well!
Afaik, DDT continues to be accepted for malarial mosquito control; DDT as an agricultural pesticide is what got a worldwide ban.
Well, widespread spraying with DDT did essentially create a permanent reservoir of DDT-resistant mosquitoes, which also made them resistant to pyrethroids. Bit of a problem. Fun fact - DDT makes spider mites extra fertile.
I do agree however that the eradication efforts of both caused significantly more good than harm, no question.
This is hardly the place for this kind of discussion but I can't help but comment on this.
Countless species are already going extinct all the time, both known to us and completely unknown to us, and both "naturally" and from human impact, and no one really cares.
Here's a rare case of a species that there is very good reason to deliberately get rid of, and suddenly people care and object, a lot!?
Of course there's justifiable skepticism and a long, sorry history of unintended consequences of introducing, eradicating or in any way modifying a species or its behavior, but seriously, read up on it, this is not one of those species, pretty much everyone who knows anything about it (including otherwise very environmentally minded people who as a rule would never, ever agree with deliberately eradicating anything) agrees it can be eradicated with no meaningful impact on the ecosystem. (and yes, that includes even the armchair criticism from cynical misanthropes who consider human deaths resulting from this species a good thing "because humans are bad for the environment" - while these mosquitoes do cause a lot of human deaths, the environmental "benefit" of those deaths are completely meaningless in the grand scheme of things)
It's the means. If people wanted to look for ways to help reduce stagnant water, as a means of reducing mosquito populations, I suspect exactly 0 people would object. But releasing billions of mosquitos with a bacteria and hoping there's no natural evolution to it, and everything continues to work as planned indefinitely...? There's more than sufficient reason for skepticism there.
Beyond this, I would also consider the arrogance of the present. When you look back at stupid decisions made in times past, it's not like they just blindly rushed into them (well not always at least). They certainly assessed them using the latest knowledge available at the time, and then moved forward after it was deemed safe and effective. It just turns out that we're quite frequently wrong on such assessments, and so things that fail in 'obvious' ways only look obvious with the benefit of hindsight. It's like how NASA can lose a half a billion dollar probe in modern times because nobody bothered to ensure that all systems were using the same unit systems. [1]
Take yourself a decade in the future and imagine reading about these mosquitoes gaining, at the minimum, a resistance to the bacteria being used. Would it really surprise you? Or would you be thinking something more along the lines of, 'Wow, how could they not see that coming?'
Are these the concerns of people who study ecosystems deeply, and dedicate their lives to environmental protection through understanding it deeply?
Or are they the concerns of people who don't know much, though they care deeply? I find these folks often pursue actions with great passion that are effectively neutral or sometimes even detrimental to the environment.
You say that most mistakes of the past have been made after careful consideration, but I do not believe that is the case at all. Most disasters, like the dumping of chemicals from semiconducting manufacturing in Silicon Valley that created so many superfund sites, was just carelessness and complete lack of concern or study.
This is just an appeal to authority with a dash of shaming.
You’re failing to consider the opposite bias, where professionals whose income and prestige depends on a particular idea fail to critically assess it and judge themselves based on their motivations rather than outcomes — and outsiders who only see the claims and outcomes have a less biased view.
That’s the case for gain-of-function research:
- the US banned it despite expert opinions
- a rogue expert circumvented that ban by outsourcing the work to China
- that Chinese lab leaked the studied virus, causing a global pandemic
- the rogue scientist panicked and bribed several peers to help him cover that up and claim a “natural” origin
- millions of people are dead due to hubris and personal biases
I don't think OP is talking about the bacteria-inoculated mosquitoes, they're taking about eradicating the species completely with something like a CRISPR gene drive.
I am passionately in favor of this.
I'm pretty sure when they introduced the mongoose to eat rats in Hawaii, it was knowable that this was an idiotic idea because they don't eat rats. :-P
But yes, introducing new species or new variants of a species is basically a big box labelled "unintended consequences."
> There's more than sufficient reason for skepticism there
there really isn't. it just sounds bad to uneducated laymen - like I said, every expert who studies this, including biologists and environmentalists, agree the mosquitoes can and should be eradicated with zero impact on ecosystems
> It's like how NASA can lose a half a billion dollar probe in modern times because nobody bothered to ensure that all systems were using the same unit systems
this has nothing to do with the subject
> Take yourself a decade in the future and imagine reading about these mosquitoes gaining, at the minimum, a resistance to the bacteria being used. Would it really surprise you? Or would you be thinking something more along the lines of, 'Wow, how could they not see that coming?'
no, the bacteria and/or mosquitoes evolving together is an anticipated outcome and that would surprise absolutely no one. the real question is, when that happens, so what? then we can deploy CRISPR or some other means to extinct the mosquitoes
On this case of the Aedes Aegypti in the Americas, should not even be a big consideration whether to exterminate or not, since it's an invasive species from Asia.
ah yeah I even forgot that super important thing which self-professed environmentalists also always care so much about
it's astonishing that so many of them (not all, but many) are all for keeping all other invasive species in check but somehow make an exception for Aedes Aegypti, literally the most harmful and destructive one :melting_face:
> yes, that includes even the armchair criticism from cynical misanthropes who consider human deaths resulting from this species a good thing
If ever there was a species under no threat whatsoever it's those guys. I'm all for eradicate and move on, nature will be bound to throw something else at humanity so go for the small wins and to heck with it.
I think part of this is that the idea can be unfamiliar and so people try to come to random conclusions or raise concerns that have already been considered (or they just disagree with the prevailing view). The search term for this kind of thing is ‘planned extinction’ and it perhaps won’t surprise you to hear that A. aegypti is the most common candidate. Another case is the (new world) screwworm fly which has been eliminated from North America and most of Central America by the United States (it being easier to try to control spread through Panama than from Mexico). There was a New Yorker article posted here a while ago about the elimination efforts. I’m not sure farmers in Colombia or the rest of South America would mind much if the species were totally eradicated.
Starfield companions would've frown upon this solution.
More seriously though: 10 years is a long time, this is super interesting but one would wonder if in such time other limiting dengue factors might've arose.
I'm pretty sure this would be their preferred solution. They all get angry at you (and chastise you for not "trusting the science" because in the 23rd century, ecology is not considered science anymore?) for wanting to reintroduce the predator instead of spreading a microbe.