Now, climate-based system could predict dengue spread in India

Agencies
September 3, 2017

London, Sept 3: Scientists have developed a system that can predict the spread of dengue in different parts of India, based on climatic factors, an advance that may help take preventive measures against the deadly infection.

Researchers from the University of Liverpool in the UK identified the climatic risks for dengue disease outbreaks in different climatic zones in the country through the states of Punjab, Haryana, Rajasthan, Gujarat and Kerala. The team, in collaboration with researchers from Indian Institute of Chemical Technology (IICT) in Hyderabad and National Institute of Pharmaceutical Education and Research

(NIPER) in Guwahati, focused on changes in a factor called 'extrinsic incubation period (EIP)' of the dengue virus by taking into account daily and monthly mean temperatures in these areas.

EIP is the time taken for incubation of the virus in the mosquito. During this period, after the mosquito draws a virus-rich-blood meal, the virus escapes the gut, passes through the mosquito's body and reaches it salivary glands. Once this happens, the mosquito is infectious and capable of transmitting the virus to a human host. It has been found that climatic conditions play an important role in EIP.

Lower temperatures (17-18 degrees Celsius) result in longer EIPs thereby leading to decreased virus transmission. With increasing temperatures, feeding increases because of enhanced metabolism of the mosquito, leading to shorter EIPs. Even a five-day decrease in the incubation period can hike transmission rate by three times, and with an increase in temperature from 17 to 30 degrees Celsius, dengue transmission increases fourfold.

However, a further increase in temperature beyond 35 degrees Celsius is detrimental to the mosquito survival. Researchers observed that except for Gujarat which comprises of arid regions, there was a strong correlation between rainfall and dengue disease burden.

They propose an increase in breeding grounds for mosquitoes as a major reason for this finding. The study found that Kerala being warm (temperature range 23.5-30 degrees Celsius) and wet and with short EIPs (9-14 days) experiences the highest number of dengue cases.

It has been found that EIP is the shortest during the monsoon season in most states and therefore there is an enhanced risk of dengue during this time. It is important to take into account the dynamic EIP estimates in different regions in assessing disease burden. "This climate-based dengue forecasting model could help health authorities to assess the disease intensity in a geographic region, based on that they can plan disease control operations well in advance and optimise the use of resources meticulously," said Srinivasa Rao Mutheneni of IICT, who led the study.

Changes in temperature affecting the extrinsic incubation period of the virus, future changes in the climate might have a substantial effect on dengue and other vector-borne disease burden in India.

"Though such methods are in vogue for disease control operations, we are still in the initial stages of implementation of such strategic control methods," Rao said. "Factors such as population density and migration also need to be included for future risk assessment studies," he said.

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Agencies
May 14,2020

COVID-19 mostly kills through an overreaction of the immune system, whose function is precisely to fight infections, say scientists who have decoded the mechanisms, symptoms, and diagnosis of the disease caused by the SARS-Cov-2 coronavirus.

In a study published in the journal Frontiers in Public Health, the researchers explained step-by-step how the virus infects the airways, multiplies inside cells, and in severe cases causes the immune defences to overshoot with a "cytokine storm".

This storm is an over-activation of white blood cells, which release too-great amounts of cytokines -- inflammation-stimulating molecules --into the blood, they said.

"Similar to what happens after infection with SARS and MERS, data show that patients with severe COVID-19 may have a cytokine storm syndrome," said study author Daishun Liu, Professor at Zunyi Medical University in China.

"The rapidly increased cytokines attract an excess of immune cells such as lymphocytes and neutrophils, resulting in an infiltration of these cells into lung tissue and thus cause lung injury," Liu said.

The researchers explained that the cytokine storm ultimately causes high fever, excessive leakiness of blood vessels, and blood clotting inside the body.

It also causes extremely low blood pressure, lack of oxygen and excess acidity of the blood, and build-up of fluids in the lungs, they said.

The researchers noted that white blood cells are misdirected to attack and inflame even healthy tissue, leading to failure of the lungs, heart, liver, intestines, kidneys, and genitals.

This multiple organ dysfunction syndrome (MODS) may worsen and shutdown the lungs, a condition called acute respiratory distress syndrome, (ARDS), they said.

This, the researchers explained, happens due to the formation of a so-called hyaline membrane -- composed of debris of proteins and dead cells -- lining the lungs, which makes absorption of oxygen difficult.

Most deaths due to COVID-19 are therefore due to respiratory failure, they said.

The researchers explained that in the absence of a specific antiviral cure for COVID-19, the goal of treatment must be to the fight the symptoms, and lowering the mortality rate through intensive maintenance of organ function.

For example, an artificial liver blood purification system or renal replacement therapy can be used to filter the blood through mechanical means, they said.

The team noted that especially important are methods to supplement or replace lung function, for example with non-invasive mechanical ventilation through a mask, ventilation through a tube into the windpipe, the administration of heated and humidified oxygen via a tube in the nose, or a heart-lung bypass.

The researchers stressed the importance of preventing secondary infections.

They noted that SARS-Cov-2 also invades the intestines, where it causes inflammation and leakiness of the gut lining, allowing the opportunistic entry of other disease-causing microorganisms.

The researchers advocate that this should be prevented with nutritional support, for example with probiotics -- beneficial bacteria that protect against the establishment of harmful ones -- and nutrients and amino acids to improve the immune defences and function of the intestine.

"Because treatment for now relies on aggressive treatment of symptoms, preventative protection against secondary infections, such as bacteria and fungi, is particularly important to support organ function, especially in the heart, kidneys, and liver, to try and avoid further deterioration of their condition," Liu added.

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Agencies
April 4,2020

Washington D.C., Apr 4: While consuming a high-diet salt can result in high blood pressure, a recent study has revealed a link between salt-rich diet and weaker immune system.

The study was conducted under the leadership of the University Hospital Bonn, and the results were published in the journal Science Translational Medicine.

The research was conducted on mice that were fed a high-salt diet. Later, they were found to suffer from much more severe bacterial infections.

Human volunteers who consumed an additional six grams of salt per day also showed pronounced immune deficiencies.

The World Health Organization (WHO) has recommended a maximum amount of five grams of salt a day.

It corresponds approximately to one level teaspoon. In reality, however, many Germans exceed this limit considerably. 

Figures from the Robert Koch Institute suggest that on average men consume ten, and women more than eight grams a day.

This means that we reach for the salt shaker much more than is good for us. After all, sodium chloride, which is its chemical name, raises blood pressure and thereby increases the risk of heart attack or stroke.

"We have now been able to prove for the first time that excessive salt intake also significantly weakens an important arm of the immune system," said Prof. Dr. Christian Kurts from the Institute of Experimental Immunology at the University of Bonn.

This finding is unexpected, as some studies point in the opposite direction. For example, infections with certain skin parasites in laboratory animals heal significantly faster if these consume a high-salt diet.

The study also sheds light on the fact that the skin serves as a salt reservoir.

"Our results show that this generalization is not accurate," emphasized Katarzyna Jobin, lead author of the study.

The body keeps the salt concentration in the blood and in the various organs largely constant. Otherwise important biological processes would be impaired. The only major exception is the skin which functions as a salt reservoir of the body. This is why the additional intake of sodium chloride works so well for some skin diseases.

However, other parts of the body are not exposed to the additional salt consumed with food. Instead, it is filtered out by the kidneys and excreted in the urine.

"We examined volunteers who consumed six grams of salt in addition to their daily intake," said Prof. Kurts. This is roughly the amount contained in two fast-food meals, i.e. two burgers and two portions of French fries.

After one week, from the results, it showed that the immune cells coped much worse with bacteria after the test subjects had started to eat a high-salt diet.

In human volunteers, excessive salt intake also resulted in increased glucocorticoid levels.

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Agencies
May 5,2020

The lockdown forced by the coronavirus in India has had some unexpected but positive fallouts: It has brought families together and reduced corporate politics, says an expert working in the field for the past decade.

"Today the whole world is on lockdown because of COVID-19, and all that we read, talk and hear is about life and death. We can't deny that the times are tough and the future is uncertain. But I would like to turn the coin and see the other side: the positive side," Shikha Mittal, Founder Director of Be.artsy told IANS in an interview.

Be.artsy is one of India's leading social awareness enterprises which deals with emotions at work and promotes arts as a communication tool for workplaces.

"In the 21st century, personally and professionally, people are practising politics over humanity, competition over collaboration, and have lost touch with themselves due to materialistic desires. During the lockdown, we are forced to confront our existing daily lives, and two interesting things that we can ponder upon, have emerged.

"First, have we ever looked at our family with the same lens as we are using today? What is it that we are doing differently with family today, and what can we do to carry our actions of today into our tomorrow? This is the premise of the #aajjaisakalcontest" that Be.artsy has launched across India.

The aim is "to encourage people to share one habit or life skill that they never practiced earlier, but post Covid-19 would like to continue and enjoy".

How did Be.artsy come about?

"I used to be in the corporate world, earning promotions and greater responsibility. However, the work conditions in those days were unfriendly to women and I had faced many instances of sexual harassment and workplace harassment in the six years of my corporate career. And that's when I had an epiphany."

Be.artsy's most popular programmes are on Prevention of Sexual Harassment (POSH) and on Financial Literacy which makes young people financially independent and better prepared to face the corporate world. "We know that a stitch in time (of planning for the future) saves nine (debt trap, dependence, health emergencies, expenses exceeding income, no savings, families without support, retirement in poverty, lost dreams, extravagance). This can only be achieved by sensitisation," Mittal explained.

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