Brain's on-off thirst switch identified

There is no evidence that the Bacille Calmette-Guerin (BCG) vaccine, which is primarily used against tuberculosis, protects people against infection with the novel coronavirus, the World Health Organization (WHO) said.

The WHO therefore didn't recommend BCG vaccination for the prevention of COVID-19 in the absence of evidence, according to its daily situation report on Monday, Xinhua news agency reported.

"There is experimental evidence from both animal and human studies that the BCG vaccine has non-specific effects on the immune system. These effects have not been well characterized and their clinical relevance remains unknown," WHO stated.

Two clinical trials addressing the question are underway, and WHO will evaluate the evidence when it is available, it noted.

BCG vaccination prevents severe forms of tuberculosis in children and diversion of local supplies may result in an increase of disease and deaths from the tuberculosis, it warned.

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.

The Lockdown is not a cure but a critical strategy to prevent the geographical spread of COVID-19.

While pandemics at this level involves actual life threatening situations for individual's or significant others in one's immediate circle, it envisages a marked disruption in routine life. Even after the pandemic has been contained and will come to pass; it's aftermath will leave a trailblazer which demands planning and implementation of a post pandemic reconstruction of society with potentially traumatic experiences varying in intensity, multiplicity and duration.

Degree of Trauma

It would do well for each one of us to realise that the pandemic is "potentially traumatic", since not everyone will experience COVID -19 as a traumatic event in their lives. Yet, there will be those who may develop post pandemic stress reactions, depression and related dysfunction and pathological reactions while still other exhibit healthy reactions to the same set of circumstances.

"Psychological reactions to the pandemic can be distilled into four distinct prototypical patterns, namely, Resilience, Recovery, Chronic and Delayed patterns which may vary in intensity, multiplicity, and duration. Resilient individual have an ability to bounce back from adversity and experience modest or little disruption in normal functioning and are able to maintain a relatively stable, healthy levels of psychological functioning even after enduring the pandemic. Recovery pattern is characterised by relatively rapid reduction in symptoms and return to normal functioning whereas chronic pattern is characterised by symptoms and dysfunction of a long duration," says Pune-based military psychologist Lt Col Dr Samir Rawat.

Challenges at the Individual and Community Levels

From a psychological perspective, post pandemic reconstruction would entail catering to the problems, concerns and needs of those adversely impacted by the COVID -19 with stress symptoms typically characterised by individual's experiencing an overwhelming trauma of the pandemic (for example, recurring nightmares/ breaking into a cold sweat, flashback of stressful events, increasing irritability, low frustration tolerance or emotional numbing).

It could also manifest in depressive symptoms which may result in lack of interest or diminished pleasure in activities and things which you earlier liked to do, feelings of worthlessness or even survivor guilt in case of a loss of a loved one due to COVID-19, fleeting thoughts of death and suicidal ideation. Physical symptoms, on the other hand could be a decrease in appetite, weight and sleep problems, inability to focus and lack of concentration.

Undoubtedly, the pandemic will cause a financial loss of varying magnitude to many, especially the marginalised and economically disadvantaged strata of daily wage earners; it will also lead to loss of jobs (already beginning to show), homelessness, occupational difficulties and new challenges in interpersonal relations at work and on the home front, besides physical health problems and psychological barriers with new norms of accepted social behaviour (social distancing, handshakes, an obsession for cleanliness to name a few).

Emotional battles

Many factors may influence whether individuals come out stronger and more resilient or surrender to the pandemic. Emotion Regulation is one such long term critical factor that can play an important role in contributing to varying degrees of adaptation with negative or positive outcomes. While we know that primary emotions are fear, anger, disgust, joy, anticipation, acceptance, sadness and surprise, other basic emotions include wonder, love, desire, joy, hatred, sadness, attachment, disgust, rage and even expectancy .

To be able to regulate these emotions and avoid negativity , especially on social media platforms is likely to increase efforts in emotion regulation which involves initiating, increasing or maintaining an emotional response.

This means by regulating or on the other hand by stopping, decreasing or avoiding an emotional response, that is, by down-regulating, depending on the individual's objectives and goals or his /her ability to regulate emotions in the valued and given direction.

"One of the best ways to regulate emotions is through cognitive restructuring wherein we change the way we think; after all it is not the event but the interpretation of the event which is perceived as stressful and finding meaning promotes resilience and reduces risk and vulnerability to stress," advises Dr Rawat.

Adding, "Clearly, we need to have a psychological plan to prevent, mitigate and minimise negative outcomes by post pandemic reconstruction of society at an individual and community level all over the country; this has to be integrated by all leaders across verticals in diverse domains."