Scientists Develop Oral Vaccine Against Salmonella Infection

December 20, 2016

Houston, Dec 20: Scientists, including one of Indian origin, have developed an oral vaccine against Salmonella - the deadly bacteria responsible for one of the most common food-borne illnesses in the world.

5-teamdevelopsOral vaccination is simplest and least invasive way to protect people against salmonella infection, researchers said.

Taking this vaccine by mouth also has the added advantage of using the same pathway that salmonella uses to wreak havoc on the digestive system, they said.

"In the current study, we analysed the immune responses of mice that received the vaccination by mouth as well as how they responded to a lethal dose of salmonella," said Ashok Chopra, professor at The University of Texas Medical Branch at Galveston (UTMB) in the US.

"We found that the orally administered vaccines produced strong immunity against salmonella, showing their potential for future use in people," said Mr Chopra.

There is no vaccine currently available for salmonella poisoning. Antibiotics are the first choice in treating salmonella infections, but the fact that some strains of salmonella are quickly developing antibiotic resistance is a serious concern.

"Another dangerous aspect of salmonella is that it can be used as a bioweapon - this happened in Oregon when a religious cult intentionally contaminated restaurant salad bars and sickened 1,000 people," researchers said.

Salmonella is responsible for one of the most common food-borne illnesses in the world. In the US alone, the Centres for Disease Control and Prevention estimates that there are about 1.4 million cases with 15,000 hospitalisations and 400 deaths each year.

It is thought that for every reported case, there are about 39 undiagnosed infections. Overall, the number of salmonella cases in the US has not changed since 1996.

Salmonella infection in people with compromised immune systems and children under the age of three are at increased risk of invasive non-typhoidal salmonellosis, which causes systemic infection. There are about one million cases globally per year, with a 25 per cent fatality rate.

In earlier studies, the UTMB researchers developed potential vaccines from three genetically mutated versions of the salmonella bacteria, that is Salmonella Typhimurium, that were shown to protect mice against a lethal dose of salmonella. In these studies, the vaccines were given as an injection.

The findings were published in the journal Frontiers in Cellular and Infection Microbiology.

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Agencies
June 20,2020

The World Health Organisation has warned that the COVID-19 pandemic is entering a "new and dangerous" phase. Thursday saw the most cases in a single day reported to the WHO.

Tedros Adhanom Ghebreyesus said the day had seen 150,000 new cases with half of those coming from the Americas and large numbers also from the Middle East and South Asia, the BBC reported.

He said the virus was still spreading fast and the pandemic accelerating.

He acknowledged people might be fed up with self-isolating and countries were eager to open their economies but he said that now was a time for extreme vigilance.

Maria van Kerkhove, technical lead of the WHO's COVID-19 response, told a press conference the pandemic is "accelerating in many parts of the world".

"While we have seen countries have some success in suppressing transmission and bringing transition down to a low level, every country must remain ready," she said.

Mike Ryan, the head of the WHO's Health Emergencies Programme, said that some countries had managed to flatten the peak of infections without bringing them down to a very low level.

"You can see a situation in some countries where they could get a second peak now, because the disease has not been brought under control," he said.

"The disease will then go away and reduce to a low level, and they could then get a second wave again in the autumn or later in the year."

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Agencies
July 7,2020

The World Health Organization (WHO) is reviewing a report that suggested its advice on the novel coronavirus needs updating after some scientists told the New York Times there was evidence the virus could be spread by tiny particles in the air.

The WHO says the Covid-19 disease spreads primarily through small droplets, which are expelled from the nose and mouth when an infected person breaths them out in coughs, sneezes, speech or laughter and quickly sink to the ground.

In an open letter to the Geneva-based agency, 239 scientists in 32 countries outlined the evidence they say shows that smaller exhaled particles can infect people who inhale them, the newspaper said on Saturday.

Because those smaller particles can linger in the air longer, the scientists - who plan to publish their findings in a scientific journal this week - are urging WHO to update its guidance, the Times said.

"We are aware of the article and are reviewing its contents with our technical experts," WHO spokesman Tarik Jasarevic said in an email reply on Monday to a Reuters request for comment.

The extent to which the coronavirus can be spread by the so-called airborne or aerosol route - as opposed to by larger droplets in coughs and sneezes - remains disputed.

Any change in the WHO's assessment of the risk of transmission could affect its current advice on keeping one-metre physical distancing. Governments, which also rely on the agency for guidance policy, may also have to adjust public health measures aimed at curbing the spread of the virus.

"Especially in the last couple of months, we have been stating several times that we consider airborne transmission as possible but certainly not supported by solid or even clear evidence," Benedetta Allegranzi, the WHO's technical lead for infection prevention and control, was quoted as saying in the New York Times.

WHO guidance to health workers, dated June 29, says that SARS-CoV-2, the virus that causes Covid-19, is primarily transmitted between people through respiratory droplets and on surfaces.

But airborne transmission via smaller particles is possible in some circumstances, such as when performing intubation and aerosol-generating procedures, it says.

Medical workers performing such procedures should wear heavy-duty N95 respiratory masks and other protective equipment in an adequately ventilated room, the WHO says.

Officials at South Korea's Centers for Disease Control said on Monday they were continuing to discuss various issues about Covid-19, including the possible airborne transmission. They said more investigations and evidence were needed.

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News Network
February 4,2020

Toronto, Feb 4: People who text while walking face a higher risk of an accident than those listening to music or talking on the phone, a study has found.

The study, published in the journal Injury Prevention, found that smartphone texting is linked to compromised pedestrian safety, with higher rates of 'near misses', and failure to look left and right before crossing a road.

Researchers from the University of Calgary in Canada call for a more thorough approach to exploring the impact of distracted pedestrian behaviours on crash risk.

Worldwide, around 270,000 pedestrians die every year, accounting for around a fifth of all road traffic deaths, according to the researchers.

'Pedestrian distraction' has become a recognised safety issue as more and more people use their smartphones or hand held devices while walking on the pavement and crossing roads, they said.

The researchers looked for published evidence to gauge the potential impact on road safety of hand-held or hands-free device activities.

This included talking on the phone, text messaging, browsing and listening to music.

From among 33 relevant studies, they pooled the data from 14 -- involving 872 people -- and systematically reviewed the data from another eight.

The analysis showed that listening to music wasn't associated with any heightened risk of potentially harmful pedestrian behaviours.

Talking on the phone was associated with a small increase in the time taken to start crossing the road, and slightly more missed opportunities to cross the road safely.

The researchers found that text messaging emerged as the potentially most harmful behaviour.

It was associated with significantly lower rates of looking left and right before or while crossing the road, and with moderately increased rates of collisions, and close calls with other pedestrians or vehicles, they said.

Texting also affected the time taken to cross a road, and missed opportunities to cross safely, but to a lesser extent, according to the researchers.

The review of the eight observational studies revealed that the percentage of pedestrians who were distracted ranged from 12 to 45 per cent, they said.

It also found behaviours were influenced by several factors, including gender, time of day, solo or group crossing, and walking speed.

The researchers acknowledge "a variety of study quality issues" which limit the generalisability of the findings.

"Given the ubiquity of smartphones, social media, apps, digital video and streaming music, which has infiltrated most aspects of daily life, distracted walking and street cross will be a road safety issue for the foreseeable future," the researchers noted.

"And as signage and public awareness campaigns don't seem to alter pedestrian behaviour, establishing the relationship between distracted walking behaviour and crash risk is an essential research need," they said.

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