My ties with Bin Laden started in Jeddah: Adel Batterjee

London, May 20: The current physical distancing guidelines of 6 feet may be insufficient to prevent COVID-19 transmission, according to a study which says a mild cough in low wind speeds can propel saliva droplets by as much as 18 feet.

Researchers, including those from the University of Nicosia in Cyprus, said a good baseline for studying the airborne transmission of viruses, like the one behind the COVID-19 pandemic, is a deeper understanding of how particles travel through the air when people cough.

In the study, published in the journal Physics of Fluids, they said even with a slight breeze of about four kilometres per hour (kph), saliva travels 18 feet in 5 seconds.

"The droplet cloud will affect both adults and children of different heights," said study co-author Dimitris Drikakis from the University of Nicosia.

According to the scientists, shorter adults and children could be at higher risk if they are located within the trajectory of the saliva droplets.

They said saliva is a complex fluid, which travels suspended in a bulk of surrounding air released by a cough, adding that many factors affect how saliva droplets travel in the air.

These factors, the study noted, include the size and number of droplets, how they interact with one another and the surrounding air as they disperse and evaporate, how heat and mass are transferred, and the humidity and temperature of the surrounding air.

In the study, the scientists created a computer simulation to examine the state of every saliva droplet moving through the air in front of a coughing person.

The model considered the effects of humidity, dispersion force, interactions of molecules of saliva and air, and how the droplets change from liquid to vapour and evaporate, along with a grid representing the space in front of a coughing person.

Each grid, the scientists said, holds information about variables like pressure, fluid velocity, temperature, droplet mass, and droplet position.

The study analysed the fates of nearly 1,008 simulated saliva droplets, and solved as many as 3.7 million equations.

"The purpose of the mathematical modelling and simulation is to take into account all the real coupling or interaction mechanisms that may take place between the main bulk fluid flow and the saliva droplets, and between the saliva droplets themselves," explained Talib Dbouk, another co-author of the study.

However, the researchers added that further studies are needed to determine the effect of ground surface temperature on the behaviour of saliva in air.

They also believe that indoor environments, especially ones with air conditioning, may significantly affect the particle movement through air.

This work is important since it concerns safety distance guidelines, and advances the understanding of the transmission of airborne diseases, Drikakis said.

May 14: The UN’s children agency has warned that an additional 6,000 children could die daily from preventable causes over the next six months as the COVID-19 pandemic weakens the health systems and disrupts routine services, the first time that the number of children dying before their fifth birthday could increase worldwide in decades.

As the coronavirus outbreak enters its fifth month, the UN Children’s Fund (UNICEF) requested USD 1.6 billion to support its humanitarian response for children impacted by the pandemic.

The health crisis is “quickly becoming a child rights crisis. And without urgent action, a further 6,000 under-fives could die each day,” it said.

With a dramatic increase in the costs of supplies, shipment and care, the agency appeal is up from a USD 651.6 million request made in late March – reflecting the devastating socioeconomic consequences of the disease and families’ rising needs.

"Schools are closed, parents are out of work and families are under strain," UNICEF Executive Director Henrietta Fore said on Tuesday.

 “As we reimagine what a post-COVID world would look like, these funds will help us respond to the crisis, recover from its aftermath, and protect children from its knock-on effects.”

The estimate of the 6,000 additional deaths from preventable causes over the next six months is based on an analysis by researchers from the Johns Hopkins Bloomberg School of Public Health, published on Wednesday in the Lancet Global Health Journal.

UNICEF said it was based on the worst of three scenarios analysing 118 low and middle-income countries, estimating that an additional 1.2 million deaths could occur in just the next six months, due to reductions in routine health coverage, and an increase in so-called child wasting.

Around 56,700 more maternal deaths could also occur in just six months, in addition to the 144,000 likely deaths across the same group of countries. The worst case scenario, of children dying before their fifth birthdays, would represent an increase "for the first time in decades,” Fore said.

"We must not let mothers and children become collateral damage in the fight against the virus. And we must not let decades of progress on reducing preventable child and maternal deaths, be lost,” she said.

Access to essential services, like routine immunisation, has already been compromised for hundreds of millions of children and threatens a significant increase in child mortality.

According to a UNICEF analysis, some 77 per cent of children under the age of 18 worldwide are living in one of 132 countries with COVID-19 movement restrictions.

The UN agency also spotlighted that the mental health and psychosocial impact of restricted movement, school closures and subsequent isolation are likely to intensify already high levels of stress, especially for vulnerable youth.

At the same time, they maintained that children living under restricted movement and socio-economic decline are in greater jeopardy of violence and neglect. Girls and women are at increased risk of sexual and gender-based violence.

The UNICEF pointed out that in many cases, refugee, migrant and internally displaced children are experiencing reduced access to protection and services while being increasingly exposed to xenophobia and discrimination.

“We have seen what the pandemic is doing to countries with developed health systems and we are concerned about what it would do to countries with weaker systems and fewer available resources,” Fore said.

In countries suffering from humanitarian crises, UNICEF is working to prevent transmission and mitigate the collateral impacts on children, women and vulnerable populations – with a special focus on access to health, nutrition, water and sanitation, education and protection.

To date, the UN agency said it has received USD 215 million to support its pandemic response, and additional funding will help build upon already-achieved results.

Within its response, UNICEF has reached more than 1.67 billion people with COVID-19 prevention messaging around hand washing and cough and sneeze hygiene; over 12 million with critical water, sanitation and hygiene supplies; and nearly 80 million children with distance or home-based learning.

The UN agency has also shipped to 52 countries, more than 6.6 million gloves, 1.3 million surgical masks, 428,000 N95 respirators and 34,500 COVID-19 diagnostic tests, among other items.

Houston, Mar 15: Researchers, studying the novel coronavirus, have found that the time between cases in a chain of transmission is less than a week, and over 10 per cent of patients are infected by someone who has the virus, but does not show symptoms yet, a finding that may help public health officials contain the pandemic.

The study, published in the journal Emerging Infectious Diseases, estimated what's called the serial interval of the coronavirus by measuring the time it takes for symptoms to appear in two people with the virus -- the person who infects another, and the infected second person.

According to the researchers, including those from the University of Texas at Austin, the average serial interval for the novel coronavirus in China was approximately four days.

They said the speed of an epidemic depends on two things -- how many people each case infects, and how long it takes cases to spread.

The first quantity, the scientists said, is called the reproduction number, and the second is the serial interval.

Due to the short serial interval of the disease caused by the coronavirus -- COVID-19 -- they said, emerging outbreaks will grow quickly, and could be difficult to stop.

“Ebola, with a serial interval of several weeks, is much easier to contain than influenza, with a serial interval of only a few days,” said Lauren Ancel Meyers, study co-author from UT Austin.

Meyers explained that public health responders to Ebola outbreaks have much more time to identify and isolate cases before they infect others.

“The data suggest that this coronavirus may spread like the flu. That means we need to move quickly and aggressively to curb the emerging threat,” Meyers added.

In the study, the scientists examined more than 450 infection case reports from 93 cities in China, and found the strongest evidence yet that people without symptoms must be transmitting the virus -- known as pre-symptomatic transmission.

More than one in ten infections were from people who had the virus but did not yet feel sick, the scientists said.

While researchers across the globe had some uncertainty until now about asymptomatic transmission with the coronavirus, the new evidence could provide guidance to public health officials on how to contain the spread of the disease.

“This provides evidence that extensive control measures including isolation, quarantine, school closures, travel restrictions and cancellation of mass gatherings may be warranted,” Meyers said.

The researchers cautioned that asymptomatic transmission makes containment more difficult.

With hundreds of new cases emerging around the world every day, the scientists said, the data may offer a different picture over time.

They said infection case reports are based on people's memories of where they went and whom they had contact with, and if health officials move quickly to isolate patients, that may also skew the data.

“Our findings are corroborated by instances of silent transmission and rising case counts in hundreds of cities worldwide. This tells us that COVID-19 outbreaks can be elusive and require extreme measures,” Meyers said.