Month: June 2021

Categories : Environmental EffectsTags :

Global Warming Drives a Third of Heat-related Deaths

On By ModernMedia
Photo by Kouji Tsuru on Unsplash

While the COVID pandemic will eventually die down, the health threat from global warming will only increase as long as countries fail to control their emissions. Between 1991 and 2018, more over of all deaths in which heat played a role were attributable to human-induced global warming, according to a groundbreaking new study.

Global warming is impacting human health in a number of ways, from direct effects linked to wildfires and extreme weather, to changes in the spread of vector-borne diseases. One of the most striking ways is in the increase in heat-associated mortality and morbidity. Climate projections predict a rise in average global temperature, with extreme events such as heatwaves adding to future health burden. However, until now no research has been conducted into what extent these impacts have already occurred in recent decades until now. Research to answer these questions was led by the London School of Hygiene & Tropical Medicine (LSHTM) and the University of Bern within the Multi-Country Multi-City (MCC) Collaborative Research Network. 

This new study focused on man-made global warming through a ‘detection & attribution’ study that identifies and attributes observed phenomena to weather and climate changes. Specifically, the team examined past weather conditions simulated under scenarios with and without anthropogenic emissions. This enabled the researchers to separate the warming and related health impact linked with human activities from natural trends. Heat-related mortality was defined as the number of deaths attributed to heat, occurring at exposures higher than the optimum temperature for human health, which varies across locations.

Published in Nature Climate Change, the study used data from 732 locations in 43 countries around the world. For the first time, it shows the actual contribution of man-made climate change in increasing mortality risks due to heat.

The study estimates that 37% of all heat-related deaths in the recent summer periods were attributable to the warming of the planet due to human activities. These deaths were highest in hot regions such as Central and South America (up to 76% in Ecuador or Colombia, for example) and South-East Asia (between 48% to 61%).

Estimates also showed the number of deaths from human-induced climate change that occurred in specific cities; 136 additional deaths per year in Santiago de Chile (44.3% of total heat-related deaths in the city), 189 in Athens (26.1%), 172 in Rome (32%), 156 in Tokyo (35.6%), 177 in Madrid (31.9%), 146 in Bangkok (53.4%), 82 in London (33.6%), 141 in New York (44.2%), and 137 in Ho Chi Minh City (48.5%).

The authors said their findings bolster evidence in favour of adopting strong mitigation policies to reduce future warming, and to implement interventions to protect populations from the adverse consequences of heat exposure.

First author Dr Ana M Vicedo-Cabrera, from the University of Bern, said: “We expect the proportion of heat-related deaths to continue to grow if we don’t do something about climate change or adapt. So far, the average global temperature has only increased by about 1°C, which is a fraction of what we could face if emissions continue to grow unchecked.”

While on average over a third of heat-related deaths are due to human-induced climate change, there is considerable regional variation. Climate-related heat casualties range from a few dozen to several hundred deaths each year per city, as shown above, depending on the local changes in climate in each area and the vulnerability of its population. Populations living in low and middle-income countries are those most affected yet produce the least global warming emissions.

Senior author Professor Antonio Gasparrini from LSHTM, and coordinator of the MCC Network, said: “This is the largest detection & attribution study on current health risks of climate change. The message is clear: climate change will not just have devastating impacts in the future, but every continent is already experiencing the dire consequences of human activities on our planet. We must act now.”

The authors acknowledge limitations of the study include a lack of empirical data from certain regions such as Africa.

Source: London School of Hygiene and Tropical Medicine

Journal information: Vicedo-Cabrera, A.M., et al. (2021) The burden of heat-related mortality attributable to recent human-induced climate change. Nature Climate Change. doi.org/10.1038/s41558-021-01058-x.

Categories : Neurodegenerative DiseasesTags :

Alzheimer’s Disease Disrupts Blood Vessels in Vicious Circle

On By ModernMedia

Researchers have discovered a new mechanism of Alzheimer’s disease, one that disrupts the blood vessels around the disease’s characteristic amyloid plaques and worsens the disease progression. 

Image source: Wikimedia

Presently, Alzheimer’s disease is the leading cause of dementia worldwide. As economies develop and people live longer lives, its incidence is increasing dramatically as the population ages and yet, unfortunately, the origin of the disease is still unknown and there is no truly effective treatment.

The study was published in the international journal Nature Communications, and led by Dr Alberto Pascual’s laboratory, from the Neuronal Maintenance Mechanisms Group at the Biomedicine Institute of Seville (IBiS) and was chiefly carried out by María Isabel álvarez Vergara and Alicia E Rosales-Nieves.

Blood vessel formation disrupted

The study focuses on the dysfunction of a physiological process called angiogenesis, which is important during development to form the vessels of the brain, and in adulthood to repair any damage to pre-existing vessels. The researchers found that Alzheimer’s disease induces angiogenesis dysfunction, resulting in the loss of vessels instead of the formation of new ones and worsening the progression of the disease. Identification of the molecular pathways involved will enable new therapeutic strategies to alleviate the effects of this disease can be rationally designed. Their data also links familial (genetic) Alzheimer’s to problems in the formation of new blood vessels, which demonstrates the importance of the vascular component of the disease.

A vicious circle

A characteristic feature of Alzheimer’s patients is the accumulation of highly toxic substances in their brains, known as senile plaques. Normally, the brain is capable of cleaning out these toxic substances by carrying them away in the bloodstream. Therefore, the loss of the vessels due to plaques creates a vicious circle: having fewer vessels reduces the brain’s cleaning ability and so allowing more toxic substances to accumulate, which in turn continue to destroy the vessels and worsen the situation further. Additionally, since the human brain is a major consumer of the body’s oxygen and nutrients a local reduction in the supply of these substances through the blood represents an additional strain on it.

Source: News-Medical.Net

Journal information: Alvarez-Vergara, M.I., et al. (2021) Non-productive angiogenesis disassembles Aß plaque-associated blood vessels. Nature Communications. doi.org/10.1038/s41467-021-23337-z.

Categories : COVIDTags :

South African Variant is Now Called ‘Beta’ Under WHO Naming Scheme

On By ModernMedia
Photo by Markus Winkler on Unsplash

To avoid stigmatisation and simplify discussion, the World Health Organization has announced a new naming system for variants of the COVID virus with important mutations.

In an attempt to remove the country-associated stigma from the emergence of a variant, each will receive a name from the Greek alphabet.

Maria Van Kerkhove, the WHO’s coronavirus lead, said that “no country should be stigmatised for detecting and reporting variants”.

She added that these new labels for VOI/VOC are “simple, easy to say and remember and are based on the Greek alphabet, a system that was chosen following wide consultation and a review of several potential systems”.

In the new naming system, B.1.17., the variant first reported in Kent, England is designated Alpha, B.1351, the variant originating in South Africa is called Beta, the Brazilian variant P.1 is now Gamma and the B.1617.2 variant first reported in India is Delta. The variants of interest run from Epsilon to Kappa. The WHO has provided a table detailing the different names.

These Greek letters will not replace existing scientific names, though there are only 24 letters. If more variants are identified for naming, a new naming scheme will be announced, Ms Van Kerkhove told US-based website STAT News.

“We’re not saying replace B.1.1.7, but really just to try to help some of the dialogue with the average person,” she told the US-based website. “So that in public discourse, we could discuss some of these variants in more easy-to-use language.”

On Monday, a scientific adviser for the UK government said the country was now in the early stages of a third wave of coronavirus infections, in part driven by the Delta variant, which had emerged in India.

It is thought to spread more quickly than the UK’s Alpha variant, which was responsible for the surge in cases in the UK over the winter.

Vietnam has reported what appears to be a combination of those two variants. On Saturday, the country’s health minister stated that it could spread quickly through the air and described it as “very dangerous”.

Source: BBC News

Categories : COVIDTags :

B1617 is Becoming the Globally Dominant COVID Strain

On By ModernMedia
COVID cases map. Photo by Giacomo Carra on Unsplash

The B1617 variant, is becoming increasingly dominant around the world and could worsen the pandemic – especially in countries where low vaccination rates are low. This warning comes from experts in Singapore, who added that there will be more virus mutations to come.

Professor Teo Yik Ying, dean of the National University of Singapore’s (NUS) Saw Swee Hock School of Public Health, said to The Straits Times: “What is frightening is the speed at which this variant is able to spread and circulate widely within the community, often surpassing the capability of contact-tracing units to track and isolate exposed contacts to break the transmission chains.

“It has the potential to unleash a bigger pandemic storm than the world has previously seen.”

Delta has mutated to be more transmissible, and may slightly weaken the protection conferred by vaccines as well as natural infection, experts said. The variant, which was first detected in India in October 2020, is now found around the world. 

WHO chief scientist Soumya Swaminathan said that B1617 is 1.5 times to two times more transmissible than the strain that first appeared in Wuhan 18 months ago.

It is now present in more than 50 countries and is surpassing other strains causing infections in India, such as B117 (now ‘Alpha’, commonly known as the UK variant).

“On clinical severity, it’s a little less clear because there have not been controlled studies which look at patients that you control for multiple factors, and then look at the impact of the strain on the clinical profile,” Dr Soumya said at a recent webinar.

Dr Soumya added that anecdotal evidence seems to indicate that more young people in India had been infected and developed serious illness.

In India, more than 27 million people have been infected with COVID, with over 325 000 deaths.

There are three versions of B1617 – B16171 (Kappa), B16172 (Delta) and B16173. The second version is the most relevant as it has appeared to overtake B1671/Kappa as reported globally. The third version, B16173, is rare and has not yet been given a Greek letter designation by the WHO.

On May 8, the National Institute for Communicable Diseases announced that it had detected five cases of the Delta variant in South Africa; three in Gauteng and two in KwaZulu–Natal. Presently, it is unclear if B1617 causes more severe illness or a higher mortality rate.

The best weapon remains widespread vaccination, Prof Teo said. Vaccinated individuals have less chance of being infected, and are much less likely to develop severe symptoms even if infected, Prof Teo added.

Preliminary US research showed that the Pfizer and Moderna vaccines should still be effective against B1617.

A study by Public Health England also showed that the vaccines by Pfizer-BioNTech and AstraZeneca work against Delta, which has become the dominant strain in the UK.

The study found that the Pfizer-BioNTech shot was 88% effective against the Delta variant two weeks after the second dose, with a 60% effectiveness for the AstraZeneca vaccine.

The pressure is to keep up with the rapidly mutating virus and immunise populations to control it. Unfortunately, most countries’s vaccination programmes are far behind.

On Friday, WHO European director Hans Kluge warned that the pandemic will not be over until at least 70% of people are vaccinated. He deplored the roll-out in Europe, saying that while it was better it was still “too slow”.

The European Centre for Disease Prevention and Control said about 43% of adults in the European Union and European Economic Area have received at least one dose of a COVID vaccine as of Saturday, 29 May.

“Time is against us,” Dr Kluge warned, stressing the need to accelerate the immunisation campaign.

South Africa’s long-delayed vaccination programme is in full swing, but so far only about 1% of the population have received a jab, which is currently being administered to healthcare workers and those over 60.

Globally, the outlook does not seem good. The New York Times reported that more than 1.81 billion vaccine doses had been administered worldwide as at Friday (May 28), but a stark divide remains between countries’ vaccination programmes, with some not even reporting a single dose given.

Global inequity in vaccine supplies and distribution persists, and the opportunity for widespread vaccination remains a privilege for advanced economies, Prof Teo said.

Professor Dale Fisher, chair of the WHO’s Global Outbreak Alert and Response Network, said this means a higher chance of B1617 creeping into countries that had been virtually untouched by COVID.

“These countries, such as Thailand, Cambodia, Laos and Vietnam, are more vulnerable due to the low vaccination rates, leaving them more susceptible to severe disease,” Prof Fisher added.

He urged wealthier nations to lend more support to the WHO-backed Covax programme, a global project to secure and distribute vaccines to poorer countries.

Source: Straits Times