CORONAVIRUS

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acure Respiratory Syndrome (SARS-CoV). A novel coronavirus (nCoV) is a new strain that has not been proviously identified in humans.

Coronaviruses are a family of viruses that cause disease in animals. Detailed investigations found that SARS-CoV was transmitted from civet cats to human and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.

The new coronavirus, officially called Covid-19 currently has fatality rate between 0.7 per cent to 3.4 per cent. This is much lower than fatality rates for Mers (30 per cent) and SARS (10 per cent), but still a significant threat. However, the new coronavirus (Covid-19) is spreading fast. The bulk cases and fatalities have been confined to China, but the virus is spreading internationally.

The source of the coronavirus is believed to be a "wet market" in Wuhan which sell both dead and live animals including fish and birds. Such markets pose a heightened risk of viruses, jumping from animals to humans because hygiene standards are difficult to maintain if live animals are being kept and butchered on site. Typically, they are also densely packed.

The animal source of the latest outbreak has not yet been identified, but the original host is thought to be bats. Bats were not sold at the Wuhan market but may have infected live chickens or other animals sold there.

Bats are host to a wide range of zoonotic viruses including Ebola, HIV and rabies.

Scientist in China believe that Covid-19 has mutated into two strains, one more aggressive than the other, which could make developing a vaccine more complicated.

It is impossible to say which way the disease will go but, on its current trajectory, it is likely to spread to more countries, affecting many more people. The number of cases is beginning to decrease in China but is increasing in the rest of the world.

Initial common symptoms of Covid-19 include fever, dry cough, tiredness and a general feeling of being unwell. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death. Symptoms are thought to appear between 2 and 10 days later after contracting the virus, but it may be up to 24 days

The virus is spread via droplets when a person coughs or sneezes. The droplets land on surfaces and are picked up on the hands of others and spread further. People catch the virus when they tough their infected hands to their mouth, nose or eyes. Standard recommendations to prevent infection include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms or respiratory illness such as coughing and sneezing.

Various crazy conspiracy theories have been circulating that the virus somehow escaped from a Chinese lab, either by accident or design. However, that is categorically untrue and scientists studying its genetic code have linked it to bats. It probably then jumped to another animal, which passed it on to humans.

The 1918 Spanish Influenza or the H1N1 virus remains the most devastating flu pandemic in the modern history. The disease swept around the globe and is estimated to have caused between 50 to 100 million deaths. A version of the same virus was also behind the 2009 swine flu outbreak, thought to have killed as many as 575,400 people.

Other major influenza outbreaks include Asian flu in 1957, which led to roughly 2 million deaths, and Hong Kong flu which killed 1 million people 11 years later.

But coronavirus outbreaks have so far been far smaller. Sars eventually spread to 27 countries in total, infecting around 8000 people and killing 700

Dengue Fever

Dengue fever is a painful, debilitating mosquito borne disease caused by any one of four closely related dengue viruses. These viruses are related to the viruses that cause West Nile infection and yellow fever.

An estimated 400 million dengue infections occur worldwide each year, with about 96 million resulting in illness. Most cases occur in tropical areas of the world, with the greatest risk occurring in the Indian sub continent, Southeast Asia, Southern China, Taiwan, the Pacific Islands, the Caribbean (except Cuba and the Cayman Islands), Mexico, Africa, Central and South America (except Chile, Paraguay, Argentina)

Dengue fever is transmitted by the bite of an Aedes mosquito infected with a dengue virus. Its peak biting periods are early morning and before dusk. The mosquito becomes infected when it bites a person with dengue virus in their blood. It cant spread directly from one person to another person.

Transmission of Dengue virus

Symptoms of Dengue fever usually begin four to six days after infection and last for up to 10 days, and may include sudden high fever, severe headaches, pain behind the eyes, severe joint and muscle pain, fatigue, nausea, vomiting, skin rash which appear two to five days after the onset of fever,mild bleeding such as nose bleeding, bleeding gums or easy bruising.

Sometimes symptoms are mild and can be mistaken for those of flu or another viral infection. Younger children and person who have never had the infection before tend to have have milder cases than older children and adults. However, serious problems can develop. These include dengue hemorrhagic fever, a rare complication characterized by high fever, damage of lymph and blood vessels, bleeding from the nose and gums, enlargement of the liver, and failure of the circulatory system. The symptoms may progress to massive bleeding, shock and death. This is called dengue shock syndrome (DSS).

People with weakened immune systems as well as those with a second or subsequent dengue infection are believed to be at greater risk for developing dengue hemorrhagic fever.

Doctors can diagnose dengue infection with a blood test to check for the virus or antibodies to it.

There is no specific medicine to treat dengue infection, If you think you may have dengue fever, you should use pain relievers with acetaminophen and avoid medicines with aspirin, which could worsen bleeding, You should also rest, drink plenty of fluids and see your doctor. If you start to feel worse in the first 24 hours after your fever goes down, you should get to a hospital immediately to be checked for complications.

The best way to prevent the disease is to prevent bites by infected mosquitoes, particularly if you are living in or travelling to a tropical area. This involves protecting yourself and making efforts to keepk the mosquito population down.

To protect yourself
Use mosquito repellents, even indoors
When outdoors, wear long sleeved shirts and long pants tucked into socks
When indoors, use air conditioning if available
Make sure window and door screens are secure and free of holes. If sleeping areas are not screened or air conditioned, use mosquito nets
If you have symptoms of dengue, speak to your doctor

To reduce the mosquito population, destroy the mosquito breeding grounds and spray insecticide in the affected areas. These include old tires, cans. or flower pots that collect rain. Regularly change the water in outdoor bird baths and pet's water dishes.

If someone in your home gets dengue fever, be especially vigilant about efforts to protect yourself and other family members from mosquitoes. Mosquitoes that bite the infected family member could spread the infection to others in your home.

FASTER WAY TO PRODUCE SPECIFIC HUMAN ANTIBODIES USING NANOPARTICLES

Treating patient derived B cells with nanoparticles coated with CpG oligonucleotides to stimulate plasma cell production and challenge antigens to designate what kind of antibody the B cells should produce has resulted in the generation of specific, high affinity antibodies in just a few days that can recognize several strains of a pathogen at the same time. The researchers have already produced antibodies to a variety of bacterial and viral antigens, including tetanus toxoid and several strains of influenza, and were able to generate anti HIV antibodies from B cells donated by healthy volunteers who did not have the disease.

The new technique also eliminates the need for previous exposure to the pathogens, either by vaccination or infection.

"Our technique should allow the production of these antibodies within a shorter time frame in vitro and without the need for vaccination or blood/serum donation from recently infected or vaccinated individuals," said Dr. Facundo Batista, who led the team from the Francis Crick Institute in London, the Ragon Institute of Massachusetts General Hospital, MIT and Harvard. "In addition, our method offers the potential to accelerate the development of new vaccines by allowing the efficient evaluation of candidate target antigens."

Antibodies are produced by white blood cells called B cells, which recognize the calling card of a bacteria or virus called an antigen, and transform into plasma cells tailored to produce large numbers of antibodies to that specific antigen that fight off the disease. That's what happens in the body. When scientists tried to reproduce the process in the lab, they ran into problems getting the B cells to make the specific kind of plasma cells they needed because the challenge antigens were missing.

It was easy to get the B cells to proliferate by adding short DNA fragments called CpG oligonucleotides into their culture medium. CpG oligonucleotides activate a protein inside B cells TLR9, but TLR9 enthusiastically stimulates every B cell in the sample to respond, not just the tiny fraction capable of producing a particular antibody. Batista and his colleagues attached both CpG oligonucleotides and real challenge antigens to nanoparticles, added them to B cell cultures, and the plasma cells that resulted were both abundant and pathogen specific.

The team hopes their approach will help researchers produce therapeutic antibodies to treat infectious disease and other conditions, such as cancer.

For more information, go to the Journal of Experimental Medicine
http://jem.rupress.org/cgi/doi/10.1084/jem.20170633?PR
https://www.eurekalert.org/pub_releases/2017-07/rup-rdn071717.php

BACTERIOPHAGES: SMALL THINGS CONSIDERED

Bacteriophages ("phages", for short) are viruses that infect prokaryotes (bacteria and archaea), harnessing the resources of the host cell to replicate vast numbers of themselves, eventually causing the cell to lyse and release the phage progeny, which then find new hosts and repeat the cycle. But that's just the textbook definition. What really hooks us in that some phages look just like lunar landers sent from alien spaceships. Merry Youle, one of STC's very own, has written a charming paean to her beloved subjects, a full length book all about "what makes the phages so fascinating, so intriguing, and so important."

Youle tells us, "This book was born of love, exasperation, and wonderment." Youle holds that phages are deserving of far more ink, and respect, than they've thus far received. They exist everywhere where their hosts thrive, including hydrothermal vents, acidic springs, the arctic tundra, and your own gut. They impact geothermal cycles, algal booms, and biodiversity. They are useful tools for genetic manipulation in the lab as well as in nature. and can serve as allies in treating bacterial infections.

Enterobacteriophage T4

http://schaechter.asmblog.org/schaechter/2017/07/a-star-studded-phantastic-voyage-of-phages.html

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WHO backs anti-diarrhoea vaccine

The World Health Organization says a vaccine which can prevent a diarrhoea and vomiting virus should be given to all children as a routine vaccination.

Rotavirus causes more than 500,000 diarrhoeal deaths and two million hospitalisations a year among children.

Over 85% of deaths occur in developing countries in Africa and Asia.

International experts welcomed the WHO's recommendations, based on new research, but UK scientists have said the vaccine is too costly.

'Milestone'

The WHO's Strategic Advisory Group of Experts (SAGE) made its recommendations after new data from clinical trials.

The clinical trial, which involved a range or organisations including the Global Alliance for Vaccines and Immunisations (GAVI) and drug company GlaxoSmithKline (GSK), which makes the vaccine plus researchers in South Africa and Malawi, found that rotavirus vaccine significantly reduced severe diarrhoea episodes.

The WHO's Dr Thomas Cherian, said: "This is a tremendous milestone in ensuring that vaccines against the most common cause of lethal diarrhoea reach the children who need them most."

But the WHO said, because there were other causes of diarrhoea, it was also important to improve water quality, hygiene, and sanitation and ensure oral rehydration solutions and zinc supplements were available.

Dr Tachi Yamada, president of the Global Health Program at the Bill and Melinda Gates Foundation, said: "This WHO recommendation clears the way for vaccines that will protect children in the developing world from one of the most deadly diseases they face.

"We need to act now to deliver vaccines to children in Africa and Asia, where most rotavirus deaths occur."

Dr Julian Lob-Levyt, chief executive officer of GAVI, said: "This represents another important step in our ability to achieve significant impact on under-five deaths in the world's poorest communities and make progress towards the Millennium Development Goals.

"We are extremely excited about the potential to offer African and Asian countries funding to introduce rotavirus vaccines."

'Price cut'

There are around 130,000 episodes of gastroenteritis caused by rotavirus each year in the UK.

Around 12,700 children are hospitalised, and four die each year.

The Joint Committee on Vaccination and Immunisation, which advises the government, said in February that it would only consider recommending the vaccine if its price were significantly reduced.

In February, the JCVI said: "Rotavirus vaccination would reduce the incidence of rotavirus in the population.

"However, the cost-effectiveness analysis showed that, based on current vaccine prices, universal vaccination of young children significantly exceeded the commonly accepted threshold for cost-effective healthcare interventions.

"Introduction of rotavirus vaccines may only become cost-effective if the vaccine price is reduced significantly."

Professor Andrew Hall, chairman of the JCVI, said the committee always kept vaccines under review and considered new information.

About Influenza

Influenza is a viral infection of birds and mammals that affects the respiratory system. The virus typically causes symptoms such as fever, sore throat and muscle pain, but severe cases can lead to pneumonia, nerve & brain damage Does Stress Damage the Brain?: Understanding Trauma-Related Disorders from a Mind-Body Perspective and even death. In the developed world, individuals at high risk of contracting influenza are usually vaccinated but as different strains of the virus mutate (a phenomenon known as ‘antigenic drift’ Genetic Drift: Genetic drift. Population bottleneck, Founder effect, Allopatric speciation, Antigenic drift, Small population size, Hardy¿Weinberg principle, ... theory of molecular evolution, Ronald Fisher), vaccines from one year may be ineffective the next, so there is a constant need for evolving, novel therapies to be developed. The virus spreads around the world in seasonal epidemics. In a typical year there are between three and five million cases of severe illness and up to half a million deaths globally. The cost of influenza in the US is over $10billion a year in lost productivity and associated medical treatment. Currently the H5N1 strain of avian influenza Avian Influenza H5N1 Strain Virus Chicken Fowl Photographic Poster Print, 18x24 poses the greatest global threat, and a pandemic is projected to cost hundreds of billions of dollars.