Monday , October 3 2022

Climate change will lead to an increase in mosquito-transmitted diseases – the New Delhi Times


From Smt. Maneka Sanjay Gandhi

Do people really understand climate change and global warming? A few days of non-seasonal chill returns skeptics to everyone – if the earth gets hotter, then why are we experiencing low temperatures is a common question.

The fact that the earth becomes hotter is no longer a controversial issue. It is. But will it kill you the heat? Yes. But not directly. You can still walk barefoot on the grass without burning your feet!

You will kill viruses, insects, tsunami and cyclones, jellyfish in the oceans, lack of water.

The new kings of the earth are preparing to take their thrones: mosquitoes.

Just as birds gather in warmer areas when winter sets, wild creatures are looking for the time that suits them. But the changing climate changes this comfort zone for many animals, including mosquitoes carrying diseases.

Mosquitoes are the most deadly animals in the world. Their ability to carry and spread diseases for humans causes millions of deaths every year. The global dengue rate has risen 30 times over the last 30 years, now infecting 400 million people a year, with a quarter of them sick enough to be hospitalized and more countries reporting their first outbreaks. Zea, dengue, chicanguage and yellow fever are transmitted to humans by the mosquitoes Aedes aegypti and Aedes albopictus to name only two species. (Malaria spreads from mosquito Culex needs a whole article for himself).

And global warming allows them to conquer the world.

Published in Nature Microbiology in March 2019, scientists from Boston Children's Hospital, Oxford University, Washington University, London School of Hygiene and Tropical Medicine and Universite Libre de Bruxelles (Belgium) united all available data using climate, urbanization, migration and human trips and models to predict the likely spread of two major mosquitoes spreading diseases – Aedes aegypti and Aedes albopictus. The models predict that by 2050, 49% of the world's population will live in places where these species are found if greenhouse gas emissions continue at the current pace. "We find evidence that if action is not taken to reduce the current climate in which the climate is warming, habitats will be opened in many urban areas with huge numbers of individuals susceptible to infection."

The team collected data on the distribution of Aedes aegypti and Aedes albopictus over time in more than 3000 locations, starting in the 1970s. They map out the current locations they deem appropriate as mosquito habitats, then predict their suitability in 2020, 2050 and 2080, based on different climate models, urban growth forecasts, and other variables. These include migration and travel patterns of people using census data and mobile phone records.

Their findings: Aedes aegypti has spread to the north at a relatively constant pace, about 150 miles per year. Aedes albopictus spread most rapidly between 1990 and 1995. In Europe, Aedes albopictus is spreading faster, moving from 62 miles per year to 93 miles per year over the past five years.

It is anticipated that Aedes aegypti will spread not only in its current tropical region but also in the new moderate regions of the United States and China, reaching north to Chicago and Shanghai respectively by 2050. Aedes albopictus is expected to spread widely across Europe. over the next 30 years. It is also expected to arrive in the northern states and mountainous areas of South America and East Africa. If climate change is not limited to 2050, the prognosis is that distribution will be even greater. The Zika virus started two years ago in South America and has spread very rapidly, despite the border control measures.

Climate change is the next major health threat, says Professor Paul Auerbach, co-author of Enviromedics: The Impact of Climate Change on Human Health. As the globe gets warm, mosquitoes will roam beyond their current habitats by shifting the severity of diseases such as malaria, dengue, chikungunya and the West Nile virus into moderate and cold regions.

Stanford biologist Erin Mordecai and colleagues at the Stanford Medical School have also predicted how climate change will change when mosquito species are most comfortable and how quickly they spread the disease. Economic development and lower temperatures have largely preserved mosquito-transmitted diseases in richer northern hemisphere countries, but climate change will tilt the scales in the other direction.

Their conclusions: Malaria is most likely to spread at 25 degrees Celsius (78 degrees Fahrenheit), while the risk of Zica is the highest at 29 degrees Celsius (84 degrees Fahrenheit). Dengue carriers need the warmest climate, so they will continue to torment hot regions such as Sub-Saharan Africa. Mosquitoes carrying the West Nile virus, however, prefer a more temperate climate, so they will migrate to the cooler regions when the climate gets warm.

According to a study by Dr. Soeren Metelmann et al. From the University of Liverpool, almost all of England and Wales could be warm enough for the aedes type until the 2060s. Metelmann and colleagues have created a model that combines knowledge about the mosquito life cycle with British climate forecasts by NASA for the period 2060-2069. So far, tropical mosquitoes come to the United Kingdom during the warm summer months and survive – and even multiply – a few weeks before they disappear in the winter. But his team's research shows that in the near future such introductions could lead to the establishment of a local population to survive in the winter.

An international team, including Moritz Kramer of the University of Oxford, has made an independent study predicting that mosquitoes will spread across Europe over the next 30 years. Originally from East Asia, insects spread throughout Europe since the 1970s and are nowhere far to the north of Germany and Southeastern England. Over the last decade, there have been outbreaks of chicoguan in Italy, indicating that the spread of such mosquito-mite viruses in Europe is possible. By 2080, they predict that the mosquito will be in 197 countries around the world, with 20 of them finding its presence for the first time.

The mosquito acts as a heat-driven disease rocket. Scientists say the hotter the better, the better the mosquito is to transmit various dangerous diseases. Mosquitoes live for 10-12 days and this is how long it takes the virus to grow in the intestine, making it infectious. Warmer air incubates the virus faster in the cold-blooded mosquito, so the insect has more time to become contagious. Higher temperatures accelerate the development of larvae, increasing the number of adult populations, the autumnal development of immature animals and, respectively, the increase of eggs in winter. Higher temperatures make mosquito more hungry, so it takes more blood and spreads more infection. Higher temperatures also increase the mosquito population.

Zika, for example, has been declared global public health since it is linked to brain deformities in infants in South America. Zica's epidemics depend on temperature and drought. Recife, Brazil, the largest city in the Zikka area, has marked its hottest September-October-November, about 1.2 degrees Fahrenheit (2.2 degrees Fahrenheit) above the norm, according to NASA data.

Aedes albopictus, the vector of a known vector of the Chikuonguya virus, dengue virus and heartworm, has undergone a dramatic global expansion facilitated by human activities, particularly the use of used tires and "lucky bamboo" (the only reason for its spread to Belgium and the Netherlands ) – those horrible sticks that put in glasses of water and give the main guests. It was first reported in Europe in 1979 in Albania. In 1985, it was first reported in Texas, USA. It is now in 32 states, including Hawaii. Latin America was first reported in Brazil in 1986. It was first opened in Africa in South Africa in 1990. Currently, it is included in the list of the 100 most invasive species in the group of invasive species specialists. This mosquito already shows signs of adaptation to the colder climatic conditions, which can lead to transmission of diseases in new areas. He has already caused outbreaks of chicungunya in Italy and France and dengue in France and Croatia.

Not only the spread of the disease. Currently, Aedes albopictus is considered a serious bite in people where it significantly reduces the quality of life. Older women bite aggressively, usually during the day, indoors or outdoors. Its spread is related to reducing the physical activity time of children in the open, a factor contributing to childhood obesity.

Traditionally, aedes albopictus needs an average winter temperature of 0 degrees Celsius to allow eggs to survive, an average annual temperature of 11 degrees Celsius for survival and adult activity, and about 500 mm annual precipitation. Optimum development requires a summer temperature of 25-30 degrees Celsius. At present there are reports of populations in areas with lower average temperatures (5-28.5 ° C) and lower rainfall (290 mm per year).

Aedes albopictus may be a vector of at least 22 other viruses, including yellow fever virus, Rift Valley fever virus, Japanese encephalitis virus, West Nile virus. So its distribution is important to people's survival.

Can a mosquito carry more than one disease at the same time? Can anyone get more than one illness than a bite? Studies conducted in Gabon and India show that humans can be infected with chikungunya and dengue at the same time. Coinfection is a challenge for accurate diagnosis, especially when symptoms such as fever and pain may be similar.

Remember this every time you eat meat or allow a tree to be cut – the two biggest reasons for climate change.

Photo: Shutterstock

Twitter: @ManekaGandhiBJP

NOTE: The opinions expressed here are those of the authors and do not necessarily represent or reflect the views of the New Delhi Times (NDT)

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