Claim: Dengue Spreading in South America Because Climate Change

Guest essay by Eric Worrall

“The New Humanitarian” claims global warming has caused deadly rise in Dengue Fever cases in South America; but they admit mosquito spraying programme cutbacks might have played a role.

27 April 2020 

Is global warming driving the spread of dengue across Latin America?

In 1970, the tropical disease was only a danger in nine countries. Now, it afflicts over 100.

International scientists have for years warned that climate change is likely to lead to an increase in epidemics caused by pathogens and viruses. While there’s no evidence to link the COVID-19 pandemic to global warming, major ongoing outbreaks of dengue fever in Latin America are currently adding credence to the theory.

Just as the novel coronavirus takes hold in the region, severe dengue epidemics are already raging in Peru, Colombia, Bolivia, Brazil, Nicaragua, and Venezuela. And Honduras experienced a record-setting outbreak that finally slowed late last year.

Adding to the concern is the fact that South America is experiencing dengue in temperate mountainous regions of the Andes that have no previous history of the once-tropical disease. Scientists say global warming is one of the main drivers.

Jihan Simón Hasbun, a doctor in the Honduran city of San Pedro Sula who was part of the effort to address the dengue epidemic, described a public health system in a state of near collapse after years of government neglect and corruption.

Hasbun said doctors were woefully ill-equipped to battle an epidemic. “In my town, the local government stopped fumigating for mosquitoes. They still sent the fumigation trucks out empty to make it look like they were addressing the problem, but they weren’t spraying anything. It was all just a show!”

“And now we are confronting coronavirus,” she added. “No one is prepared for this.”

The WHO and the IPCC have been warning for years that climate change is altering the global distribution of species – such as mosquitoes – that serve as vectors for infectious diseases.

Read more: https://www.thenewhumanitarian.org/feature/2020/04/27/dengue-fever-latin-america-climate-change

Should South America build more wind turbines? Or should they make more effort to kill mosquitoes?

Even the Guardian once admitted that killing mosquitos might be the solution to controlling mosquito borne disease.

DDT row: Pesticide that damages the environment has saved millions of lives

Sarah Boseley, Health Correspondent

Mon 30 Aug 1999 10.56 AEST

Malaria, a scourge of much of the developing world, kills some 2.7m people every year, most of them children under five and pregnant women, while up to 500m become ill, cannot work and need care.

A few decades ago, world health specialists talked of eradicating malaria. Now they talk only of trying to regain control. Malaria is endemic in more than half the world’s countries. In the time it takes to name the disease, 10 children will contract it and begin fighting for their lives. One child in four who dies in Africa has succumbed to malaria. 

DDT has a bad name. It is a pesticide that damages the environment and has been widely used in agriculture. Since Rachel Carson exposed its depredations in her book Silent Spring in 1962, environmentalists have campaigned to curb its use. In the west they have been successful. Advertisement

But in the developing world it has saved millions of lives. Sprayed inside houses, it kills or more often repels the mosquitoes whose bite transmits malaria, and it is cheap. Specialists argue that it does not migrate out of doors, and if we lose it through a global ban in 2007 millions who could have been protected will die.

Read more: https://www.theguardian.com/world/1999/aug/30/sarahboseley

Unusually warm wet weather undoubtably helps mosquitoes, but mosquito borne diseases don’t need global warming to thrive.

In the the Little Ice Age, one of the deadliest threats to public health in Northern Europe was Malaria.

Endemic malaria: an ‘indoor’ disease in northern Europe. Historical data analysed

Lena HuldénLarry Huldén & Kari Heliövaara 

Malaria Journal volume 4, Article number: 19 (2005) Cite this article

Abstract

Background

Endemic northern malaria reached 68°N latitude in Europe during the 19th century, where the summer mean temperature only irregularly exceeded 16°C, the lower limit needed for sporogony of Plasmodium vivax. Because of the available historical material and little use of quinine, Finland was suitable for an analysis of endemic malaria and temperature.

Read more: https://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-4-19

South America might choose to fight Dengue epidemics by focussing more resources on combatting global warming, but I can’t help thinking that ensuring mosquito spraying programmes are in order might help. And perhaps a little DDT spraying, at least in the worst afflicted regions.

59 thoughts on “Claim: Dengue Spreading in South America Because Climate Change

  1. My father used to keep a sprayer full of DDT in our shed, as a kid I often played with it, having it dripping all over my hands, we moved to a smaller place in 1963 and dont recall seeing it again. I do recall running around with it outside spraying anything that moved including my friends….

    FWIW Im in great health and will be 70 in 2 days…

    • Quick, shut South America down. Oh never mind they already are. Why don’t we all just give up and die.

    • The town of Triana Alabama in my area had large numbers of health problems blamed on DDT exposure, but it isn’t from using it or from external application, it’s from decades of eating fish from the local river which was contaminated by run-off from an Olin manufacturing facility.

      So I recommend against taking it internally. That said, if the choice is Dengue or Malaria on one side, and DDT on the other, I’ll take DDT any day of the week.

      • Well, there’s blaming DDT and there’s what actually got discharged by the Olin plant. There was a fellow used to lecture on the DDT hysteria who would down a tablespoon during his presentation (J. Gordon Edwards). The LD50 in rodents is about 300mg/kg and about 1,000mg/kg in sheep and goats. On the conservative side, using 300mg/kg a 180 lb person would need to consume 24.5 g or about 1oz. A teaspoon of sugar is about 4 grams. And that’s LD50, so only a 1 in 2 chance of shuffling off this mortal coil.

        • I did say the problems were blamed on DDT, not caused by it, although at the time I found the case that something was wrong fairly persuasive and DDT was the only contaminant mentioned (the Olin facility was a DDT manufacturing plant, so their runoff would presumably have been DDT and any other chemicals used/produced in the manufacture of DDT).

          The LD50 is largely irrelevant, as no one was alleged to be suffering acute poisoning. IIRC the claimed effect was that the incidence of serious liver problems was something like a third of the adult population (it’s a small town, so I think it was something like 60 cases total).

          The population ate a lot of fish, and fish do concentrate DDT. OTOH, the wikipedia page makes no mention of liver disease, so my memory may be off or someone may have revised the cause since.

      • As one who has ‘enjoyed’ the gentle attention of both dengue fever (the nickname ‘break one fever’ is more than accurate) and malaria, the latter enough times that it lurks permanently in there waiting for a bad flu to weaken the system, and as one who has been repeatedly exposed to DDT, I’ll second Daniel Lampert’s sentiments. And then some.

    • Happy 70th BD. Likewise I remember my Dad using DDT in bulk on the farm. We’re all still alive and relatively normal 🤓

    • I was raised in an area with a lot of rice fields. The town had mosquito spraying rigs going around the town, Colusa, in the evenings. I and other children drove our bicycles the fog the sprayers produced. I’m now in my 70s.

      I know that all this is anecdotal, but the local farmers used what was later called Agent Orange on their fields.

    • In my neighborhood in Manassas, VA in the early 70s they used to have pickup trucks pulling sprayer trailers. They would drive around as dusk approached. We kids used to run after them.

  2. One of the big drivers of dengue is urbanisation. This is what leading expert Duane Gubler wrote:

    There are many factors that have influenced the incidence and geographic spread of dengue disease, including apathy, decay in public health infrastructure, changing life styles, evolutionary changes in the viruses, and misguided mosquito control, among others. However, four factors can be cited as principal drivers of the increased incidence and spread (Box ​(Box1).1). The failure to control Ae aegypti mosquitoes in urban environments is closely linked to changing lifestyles [2]. In the 40 years since 1970, two things have exacerbated our failure to control the mosquito vectors: 1) lack of political will and thus resources, and 2) too much emphasis on high technology such as space spraying of insecticides. The apathy and complacency that set in after the success of the Ae aegypti eradication program in the Americas resulted in a redirection of resources away from successful mosquito control programs, which ultimately resulted in the deterioration of mosquito control infrastructure in much of the world. Successful mosquito control programs were replaced by emergency space spraying of nonresidual insecticides in response to reported cases of dengue [2, 41]. This method had high visibility and was very popular politically, but it simply did not work because it targeted adult mosquitoes which are normally sequestered in resting places inside houses where the insecticides do not reach. In addition, because the passive surveillance relied on physicians to report cases, the spraying was always too late and too limited geographically to interrupt transmission. Changing lifestyles in the past 30 years have also played an important role in our inability to control dengue. The global automobile population has exploded during this time, and used automobile and truck tires provide ideal oviposition sites and larval habitats for the mosquito vectors. As a result, they also served as the principal mechanism for the geographic spread of mosquitoes [42]. In addition, most consumer goods are packaged in nonbiodegradable plastic containers, most of which are discarded into the environment and provide another ideal larval habitat for the mosquito vectors of dengue [2]. Thus, most of our mosquito control efforts were focused on controlling adult mosquitoes using an expensive method that did not work, while our changing lifestyles were providing an increasing number of larval habitats for the mosquitoes. The result has been increased mosquito population densities, increased geographic spread and increased dengue/epidemics.

    • Hum…hasn’t the Gates Foundation (and many others) been eradicating mosquito and other diseases all over the world for many years? I’ve seen all sorts of hype stating this very fact. Just more “sales” tactics to make the world believe they are doing good with their $Billions. Maybe it makes themselves feel like they’re doing good. Over-population is the main driver of diseases and almost all other social problems, and humans with all the power and money just exasperate those problems, instead of fixing them. How many $Trillions of bucks and million’s of lives in my lifetime have been given to Africa alone? It’s a simple fix. Don’t donate food or money to countries which cannot sustain themselves. We have taught them how to fish many times, so it’s time to quit sending them fish. Birth control would also be an excellent start. Having unwanted children is a sin, although I cannot remember the exact verse. Lol

      • Great Britain hasn’t been self-sufficient for food, since the mid 1700s.
        Overpopulation isn’t driving disease either.

    • Duane Gubler makes a number of excellent points. Nice to see that WHO has some specialists who know their subject and aren’t political hacks. I don’t suppose you have a link to this paper?

    • One of the early methods of mosquito control in Africa was to spray stagnant water ponds & lakes with oil, (dont know which one ,but any kind would probably work) ,this floated on the surface& broke the surface tension of the water making it very difficult for the larval & pupal stages of development to attach their breathing tubes to the suface (they need to breath air ).thus ‘drowning’ them .iI believe when the African nations became ‘independent ‘,this was stopped for financial/political reasons

  3. ‘And perhaps a little DDT spraying, at least in the worst afflicted regions.’

    And just which are ‘the worst afflicted regions’? I live in Colombia, in Los Llanos, and nary a word about dengue.

  4. I love the way they don’t even bother to show that temperatures in the areas where these outbreaks are occurring have increased. They just assume that they must have, and that they must have increased by enough to make a difference.

    Even the IPCC states that areas with high humidity will see very little increase from increased CO2.

  5. Dengue is spread Aedes aegypti , or Yellow Fever mosquito. It entered the US from Africa in the 1700s. It had evolved to live in where ever water collects. It caused a yellow fever outbreak in Philadelphia in 1793 encouraging the move of our nation’s capital to Washingtom DC. The mosquito had spread far to the north during the Little Ice Age years, because human habitat often provides places for them to breed.

    But leaving it to the disgusting climate alarmists to blame global warming

  6. I caught Dengue Fever last year in the Philippines where it was enjoying a temporary 300% increase for reasons not fully understood since it was the dry season and a moderate drought and mosquitoes were in decline. It isn’t very pleasant and luckily I had a few weeks to recover at a friends resort. For some reason it hits the children the hardest and many die, especially if they don’t have access to good primary healthcare. I thought I was a goner for about 3 days, but then recovered fairly quickly with over the counter Acetaminophen (Tylenol) which can alleviate pain and reduce fever. Avoid pain relievers that can increase bleeding complications such as aspirin, ibuprofen, Advil.

    Dengue is spread by several species of female mosquitoes of the Aedes type, principally A. aegypti. The virus has five types of infection with one type usually giving lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of severe complications to the others. So you don’t want to catch any of the other 4 types after having it.

    While we have our minds fixed on creating a vaccine for the Wuhan Coronavirus, we should also be working on a better vaccine for Dengue Fever and many other type spread mosquitoes borne diseases. Perhaps spending some monies on finding cures/treatments and/or vaccines for these diseases would be better than paying for a large medical expenditure after the fact. While there was a vaccine developed for Dengue, (Dengvaxia) it was controversial and several people especially children died after taking it. It was recalled after that controversy, at least in the Philippines. The value of the vaccine is limited by the fact that it may worsen outcomes in those who have not previously been infected. That may explain why some have a different outcome, perhaps having already had a mild case, or no case at all.

    • The children gets the worst Dengue fever infection from a subsequent infection by one of the other Dengue serotypes. The worst manifestation is called Dengue Hemorrhagic Fever (DHF), whereby plasma leakage occurs from capillaries (maybe doe to cytokines/chemokines and the subsequent destruction of of platelets). This plasma leakage results in subsequent low BP and fluid loss both of which can be life-threatening.
      This is believed to be due to cross-reacting, but non-neutralizingDengue Fever antibodies that actually aid in virus uptake by monocytes and this drive monocytes to release cytokines/chemokines. This is called ADE or antibody dependent enhancement. In the Dengue endemic areas, all/most the adults have usually had most or all 4 or serotype infections by adulthood and thus have immunity.

    • Earthling
      I have caught dengue in Malaysia 25 years ago. Treatment stay at home with paracetamol and aircon. 5 days of horrible body aches.
      Dengue is an urban disease.
      Best prevention is improving sewage and drainage which helps with many other disease.
      Re children. My observation from my regular visits to Philippines is that the victims are poor.
      1. Under nourished to start with.
      2. Limited or reduced access to clean water.
      3. No funds for medical treatment.

  7. I always thought that mosquitoes where a tropical insect until I went on a trip to Sweden. Apparently, half of Sweden is above the Arctic Circle where there are no predators to the mosquitoes, so the have massive swarms of mosquitoes.

    • Where in the world do you live that you have no mosquitos?!

      I don’t care if there are high cvd-19 infection rates, I want to move there!

      • I believe Hawaii has no mosquitoes. I may have misremembered that, but some pacific Island.

      • Out on Whidbey Island, WA I rarely see a mosquito. Can’t really remember the last time I saw one near my house. And there are wetlands around here. But if you go inland a bit, you’ll see them.

    • The north is insane, clouds of them will pick you up and carry you away, of course only in summer, but you can watch videos of caribou running madly to get away from them.
      Summer in the north, on a windless day you can hear the hum which is trillions of them flittering

    • I moved to central BC in Canada, 600 miles from the US border, and found the mosquitos really hard to bear. The big bombers came out in the spring,even before the snow was off the ground but they were easy to kill. Several smaller varieties came out in the summer and they always go through. Mosquito nets were the norm over the bed at night. But the worst were the black flies which inject a pain killer into the skin so you can’t feel them bite. Only a couple hours later the godawful itching and lump appeared. I wished I had some DDT to spray around.

  8. “Is global warming driving the spread of dengue across Latin America?”

    Answer: Of course!

    Global warming is the cause of every development on this planet in modern times (observed or unobserved, doesn’t matter)

    • Ever bad development, of course. Not the good ones. They are the result of socialist reforms!

  9. People and products moving across the planet like never before must be a major cause of the spread of disease, pests and invasive species.

  10. It’s always “interesting” how some ignorant news writer gets things so wrong, like:

    ” [DDT] is a pesticide that damages the environment and has been widely used in agriculture. Since Rachel Carson exposed its depredations in her book Silent Spring in 1962, environmentalists have campaigned to curb its use.”

    The supposed environmental damage was causing birds to lay eggs with fragile, thin shells. Subsequent research has showed no evidence to support that hypothesis but the damage was done. DDT, which “in the developing world … has saved millions of lives” is unavailable to the people who desparately need it–because any company that dares to produce it will be sued into oblivion. We used it to eradicate malaria on this continent. And we’re saying to the poorest people on earth, “We got ours. Sucks to be you.”

    Rachel Carson has caused more death and misery than was ever credited to DDT.

    • “When you believe in things that you don’t understand,
      Then you suffer,
      Superstition ain’t the way …”

      _ Stevie Wonder

      • Superstition isn’t a belief in things you don’t understand, it’s a belief in things that simply aren’t true.

    • In May 1963, Rachel Carson appeared before the Department of Commerce and asked for a “Pesticide Commission” to regulate the untethered use of DDT. 8-9 years later, Carson’s “Pesticide Commission” became the Environmental Protection Agency, which then banned DDT. It is estimated that 500 million lives world wide were saved from Malaria by the use of DDT. The EPA then went on to protecting mud puddles and other much misguided endeavours. Nixon created the EPA, embraced China and created the war on drugs and were just some of Nixon’s achievements. It does seem to matter who you get for a President.

  11. I was in Tokyo in October 2016, some parks had just are-opened as a dengue fever warning had just expired but some tape and signs were still up

    I used spray a smashed anything I saw flying just to be safe

  12. Okay, so the climate has changed (and always will) SO WHAT? It’s high time to move on from this Marxism stupidity. What are these geniuses suggesting we do about it? Make the climate slightly cooler at the cost of Trillions of dollars, which will do exactly nothing for the climate but will keep the CO2 gravy train running. Or do we simply adapt-oh and what about the other factors- probably don’t want to discuss those do the true believers. This sham has run it’s course.
    The world is done with the Climate Change charade- get over it. We don’t want your globalism or Eco Marxism!

  13. It’s just a matter of time before climate change slows the spread of Dengue. That, and calling it Dengue is racist now – call it FLVID to be PC.

    /sarc

  14. Eric
    Thanks for the article.
    1. Pick any two diseases say covid and dengue.
    Calculate cost of deaths based on do nothing.
    Propose prevention for both say lockdown vs spraying pesticides
    Calculate lives saved by each prevention.
    Cost both treatments.
    carry out Cost EFfective Analysis CEA of both prevention.
    Fund winner.
    2. The same way of costing different prevention or treatments can be used to calculate the health component of the Social cost of carbon.
    But this is where I think the models are wrong ( can someone please confirm)
    Climate models say the cost of a death associated with climate change is 200 x income per capital of the country. So an American child, worker and retiree dying of heatstroke would all cost 200x $60,000= $12M
    IMO I think you should use GDP per capita x healthy years left of person ( DALYs) so an elderly person who dies 10 years prematurely due to climate induced heatwave would only cost for model purposes $600,000.
    Note 1 I used GDP pp = income pp – similar but not exactly the same.
    Note 2 Also works for years gained for warming in colder countries.

  15. William Ruckelshaus, head of the U.S. EPA from December 4, 1970 to April 30, 1973 (his first term), was solely and personally responsible for the deaths of millions of people by deciding – against the overwhelming evidence presented to him – that DDT was an environmental problem, and proceeding with its ban. I can think of no other bureaucrat in the Western world who killed more people than he did. And it was solely for the purpose of what today is known as virtue-signalling.

    • Mosquito eggs need water to hatch ,eggs may be laid above or ouside of this ,but won’t hatch until covered with water .Difficult to see how car tires would cause this unless going through lakes or rivers

  16. no research paper is cited in The New Humanitarian article and besides it reads like an amateur climate hype paper not as sophisticated as even The Conversation. The bottom line may be that climate hypists are scraping the bottom of the barrel looking for hype material. And that is good news.

  17. From the Cato Institute:

    “The US National Academy of Sciences estimated DDT had saved 500 million lives from malaria by 1970.

    “In India, indoor residual spraying of DDT decreased the cases of malaria from 100 million a year in 1953 to 150,000 by 1966; deaths due to malaria, which were nearly a million a year in the 1940s, decreased to about 1,500 a year in 1966.“

    Leftist enviro-wacko’s DDT ban has killed roughly 50 million since implemented.

    Leftists are now practicing their typical ploy of revisionist history and blaming CAGW for the increase in mosquito borne diseases, when the real cause was their insane DDT ban.

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