How Dengue Could Spread in a Warming World

This would probably be true IF the globe warms more.

But like most Leftist writing, the story below tells only half the story.  I come from an area in the Australian tropics -- far North Queensland -- where Dengue and Ross river virus are endemic.  So how come neither disease is common in the population there?

Its because of something that the Green/Left routinely ignore: People react to problems.  They don't let problems just go on. And in this case public health measures work pretty well. Local authorities in the tropics react to mosquito-borne virus outbreaks in two ways.

1). They spray bodies of water where mosquitoes breed and thus kill them before they can fly. 

2). They mount publicity campaigns to alert people to the dangers of mosquitoes breeding -- so that households too avoid creating conditions where mosquitoes can breed. 

Neither strategy is completely sucessful  but it is successful enough.  Despite being born and bred in the tropics I have never had either Dengue or Ross river virus.

So if Dengue does spread to new areas, the control strategies are well known

Climate change is poised to increase the spread of dengue fever, which is common in parts of the world with warmer climates like Brazil and India, a new study warns.

Worldwide each year, there are 100 million cases of dengue infections severe enough to cause symptoms, which may include fever, debilitating joint pain and internal bleeding. There are an estimated 10,000 deaths from dengue — also nicknamed breakbone fever — which is transmitted by Aedes mosquitoes that also spread Zika and chikungunya.

The study, published Monday in the journal Nature Microbiology, found a likelihood for significant expansion of dengue in the southeastern United States, coastal areas of China and Japan, as well as to inland regions of Australia.

Oliver Brady, an assistant professor at the London School of Hygiene & Tropical Medicine and a co-author on the paper, said that the research predicts more people in the United States will be at risk in coming years.

Globally, the study estimated that more than two billion additional people could be at risk for dengue in 2080, compared with 2015 under a warming scenario roughly representative of the world’s current emissions trajectory. That increase largely comes from population growth in areas already at high risk for the disease, as well as the expansion of dengue’s range.

To estimate the future spread of the disease, Dr. Brady and his colleagues took data on mosquito behavior and projections on urbanization (one type of Aedes mosquito that spreads the disease is especially prevalent in cities) and combined them with three different climate scenarios to model what might happen in 2020, 2050 and 2080. Under all three scenarios the spread of dengue increased.

But how much the world warms has a significant impact on the spread of the disease.

The research, Dr. Brady said, “hints at the idea that if we do control emissions better, we could stop or at least limit this kind of spread.”

Warming temperatures help expand dengue’s range because, in part, as it gets warmer mosquitoes can thrive in more places where they couldn’t previously. Warming temperatures also shorten the time it takes a mosquito to become a biting adult and accelerate the time between when a mosquito picks up a disease and is able to pass it on. The study’s predictions were lower in some areas, particularly Europe, than previous studies. Those studies estimated widespread transmission of the disease on the Continent, while Dr. Brady and his colleagues estimated that its spread in the region would be limited to parts of the Iberian Peninsula and parts of the Mediterranean.

Aedes aegypti is particularly concerning, because, while other mosquito species will bite whatever is convenient, Aedes aegypti prefer to bite humans. Much of the Southeast United States used to be home to mosquito-borne diseases. Malaria was a threat until the middle of the 20th century, when a mosquito-eradication campaign eliminated the disease. But that campaign relied heavily on liberal application of the insecticide DDT, which had a host of harmful environmental effects. In 2018, the Florida Department of Health in Miami-Dade County announced at least one locally acquired occurrence of dengue.

There are limits to the study, cautioned Andrew Comrie, a professor in the department of Geography and Development at the University of Arizona. The paper is a sophisticated use of ecological niche modeling, Dr. Comrie said by email, but it does “not deal with species competition, predation, or potential evolutionary adaptation.” While there is a dengue fever vaccine, it is ineffective for most people. Treatment for the disease focuses on ensuring that the patient gets enough fluids, which can be difficult because of severe nausea and vomiting.

“For a healthy individual dengue is an awful experience that you never forget,” said Josh Idjadi, an associate professor at Eastern Connecticut University who contracted dengue fever in French Polynesia. “For infants and elderly and the infirm, they’re the ones that are going to be at risk.”


1 comment:

  1. Fortunately your post was lucid which makes the following segue somewhat smooth. I had a dream this morning and also a partially lucid dream. As a good non-academic I should define the term lucid dream, to become aware while still dreaming.

    In the first plain dream I walked into a room and a fellow was about to show me his method of studying and working. I was shown tiles/groups of notebooks + books + tools laid out in a spiral pattern. It strikes me as a bit abstract now but in the dream I knew that the spiral was meant to show a topic being studied from different angles. The tiles of study kits were following a rigid pattern. I remember one of the tools which was a triangular protractor and it symbolised accuracy and precision.

    As a kid in the 80s I really, really enjoyed my first computer. A Commodore 64. Though I had a curiosity for programming, most of my amusement was generated by playing different games and enjoying so called demos which were programs demonstrating computer graphics and music. It is fair to say that my memories have much more definition than the pixelated computer graphics of the 80s but they were fun at the time.

    I do not remember dreams often these days but I do remember my last lucid dream. I compared my situation to being inside a scene created in a computer 3d modelling program similar to 3ds Max or Modo. Making that comparison spurred a decision to zoom into my surroundings to check out if the resolution was pixelated. The definition was simply amazingly crisp and clear. Could not be compared to the raster/bitmap textures in 3d modelling software. The only comparison in the computer world I could make was to vector graphics which is infinitely scalable.

    While becoming lucid in a dream this morning I decided to have a cigarette. It has been a while and was curious to see how it would work in a dream and it seemed real but then fell apart in a fluid manner. I was struggling to maintain lucidity. I walked in a crowd and saw a person I did not like and decided calmly to take another route. Parkour, jumping and climbing. Inside a new room with funny round shapes and weird texture. I wondered how it was possible to generate the surrounding scenery so quickly by just thinking about it.

    Nowadays I am interested in digital painting and find joy in trying to master value, colour, lines, shape, edges, form, texture, light, halftones and darks. And what better way is there to practise this than to study and paint nature?

    The final scenario I remember in the lucid dream was a nature scene. I saw some dark mountains in the distance and moved my head to see a light shining giving the mountains form. It was a pleasant scene but lacked mountains nearby. In my mind I pictured a mountain but it was much too bright compared to my surroundings. But a mountain did appear nearby and it was beautifully lit.

    While painting I rely on reference photos as my visualisation is poor and the same for my spatial sense. But not so while dreaming. Manifestations appear easily and it is effortless to manifest thoughts in vectorworld.


All comments containing Chinese characters will not be published as I do not understand them