Unzipping Zika The anatomy of any virus

I never intensely wrote about viruses on this blog, basically because I am no expert in viruses. I have loads of them in my computer, some actually ended up messing up with my hard-drive so badly that I had to purchase a brand new one. Recently, I got to stay in bed for a week with a stupid Influenza variation that ruined my energy and reduced me to tears. I survived both events, the computer infection and the flue one. But as I rise from the death to go back to my thesis writing and job hunting, as I always do every single morning after dropping off my little one in the nursery, the world announces me that I shall not rest my defenses for another virus is coming.

Some time ago there was Ebola. The cacophony of its name actually makes me laugh and it is such an interesting virus that can trigger many plot ideas for cinema motion pictures. But we apparently survived that. Far before that we had A type Influenza, the hens and the pigs were conspiring to take over what had been rightfully owned by the human race. We managed to survive that. But now there is something worse, something that does not want to mess up with the birds and the Suina, doesnt want to emerge from the tombs of African forests, it comes from the sunny landscapes of South America with more Sambuca than Samba, and is making our heads spin with its transmission features.

Because I am not a virus expert Id like to understand the basics before jumping to the hard matter on the news. And when everyone is talking about how Zika, this new virus from the warm pastures of South America, can make the human babies suffer of microcephaly, well!... You want to know all there is to know. So I thought that for those who struggle like me in understanding a few of the basics that reporters so intelligently babble in Nobel-Prize-type-short-interventions, why not compiling a few bits of info first:

In what consists a virus?

Viruses are obligate intracellular parasites and can only reproduce inside a host cell. They consist of nucleic acids enclosed in a protein coating and eventually a membranous envelope. Viruses do not possess enzymes to degrade stuff or ribosomes to produce proteins. They are like transposons that travel around the genome like Harley Davidson easy-riders.

How does a typical virus look like?

Viruses carry DNA or RNA?

They can carry single stranded or double stranded, RNA or DNA!, and that is what actually defines their nomenclature... RNA virus or DNA virus.

                              Do they only infect people?

            They can also infect animal, plants and bacteria (these are quite complex in nature and structure).

                              Why is that they kill the cells?

            Because for viruses to reproduce they use lytic and lysogenic cycles. The lytic cycles are typical of the strongest viruses, usually kill the host cell and are accompanied by a very adaptable genome that fights restriction nucleases bacteria might produce. The lysogenic cycles consist on softer processes where the host cell is not destroyed. Some phages can actually use both reproductive systems.

             What are viruses looking for in the host cells?

            The very same we humans look everywhere, the right conditions to survive and have fun. The host cell provides energy in the shape of ATP, also amino acids, ribosomes and enzymes the virus doesnt have, and the good old nucleotides (the building blocks of the nucleic acid production that also sustain the very nature of virology).

                           Why do some viruses reappear?

            Well some are just very good in keeping dormant until the right conditions are set for them to show up again, like the herpes virus. The herpes virus has an envelope deriving from the nuclear membrane, it becomes integrated in the host cell genome as a provirus and when the right stressful situations occur, the virus emerges for the festival. The main route of infection is propelled by the envelope of the virus that can attach and invaginate in the cell membrane lipid bilayer, then the endoplasmatic reticulum of the cell will provide proteins that only help the cell get worse and worse.

        Is there a virus hardcore division, like the real bad guys?

            Ohhh yesss! The retroviruses have been the Grim Reaper of rock stars from the early 80s like mad killers. These are more complicated to explain because their genetic information flow in the reverse direction!

                                 What are the Premier League and the 

                Conference Leagues of Viruses in animals?

                                Check the image below and you will have your answer.

                How do viruses actually destroy the cell?

            Essentially in three major ways: 1) some by telling the host cells to release hydrolytic enzymes, 2) some by telling the host cells to produce toxins that promote disease, and 3) others already have these toxins in their envelopes and just need to deliver the bad messages straight in.

                  Is there any other smaller type of viruses?

            Yes, shall we call it the Tiny Tiny Division, constituted by Viroids and Prions. Viroids are smaller and simpler than viruses and typically infect plants. Prions are proteinaceous infectious particles and became famous in the 90s for driving cows very very mad crazy!

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Great!, I didnt really tell you anything special about the Zika virus, but in all honesty you know more about it now than you knew before. And that was to build a foundation, the rest will unfold as the world unzips the Zika virus... at least until something more fashionable gets the attention of the media.

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Ebola virus Top Sierra Leone doctor Sheik Umar Khan dies of disease

"The top doctor treating patients infected with the Ebola virus in Sierra Leone has died from the disease, officials have confirmed.

Dr Sheik Umar Khan had been hospitalised in quarantine since he contracted the virus last week. The virologist was credited with treating more than 100 patients at the hospital in Kenema - one of the world’s leading Ebola diagnosis facilities.

The current outbreak is the largest in history, so far killing more than 672 people across West Africa since the outbreak began in February, according to the World Health Organisation (WHO). Nations affected include Sierra Leone, Liberia, Guinea and Nigeria.

Dr Khans death on Tuesday afternoon was confirmed by chief medical officer Dr Brima Kargbo, who had previously hailed him as a "national hero" when she announced he had contracted the the disease.

"It is a big and irreparable loss to Sierra Leone as he was the only specialist the country had in viral haemorrhagic fevers," Kargbo said on Tuesday.

Dr Khan was being treated at an Ebola ward run by the medical charity Medecins Sans Frontieres, which has in recent weeks described the disease’s West African outbreak as "out of control".

At the time of his diagnosis, it was not immediately clear how Dr Khan became infected. While health workers are especially vulnerable to contracting the virus spread through bodily fluids such as saliva, sweat, blood and urine, Reuters reporters who visited Kenema in June heard the doctor was “always meticulous with protection, wearing overalls, mask, gloves and special footwear”.

Before his diagnosis, Dr Khan told reporters: "I am afraid for my life, I must say, because I cherish my life."

"Health workers are prone to the disease because we are the first port of call for somebody who is sickened by disease. Even with the full protective clothing you put on, you are at risk," he added.

The confirmation of Dr Khans death came as two American health workers were being treated for Ebola at a hospital in neighboring Liberia.

Health workers have become increasingly frustrated by the outbreak that has killed dozens of their colleagues. Last week, dozens of nurses at the Kenema facility staged a strike after three colleagues died, BBC News reported.

Despite international help ranging from doctors to safety equipment, weak health systems in affected countries are struggling to contain the disease.

Efforts are further hindered by the fact the disease has no vaccine and no specific treatment. The current outbreak has a fatality rate of at least 60 percent, but it can reach as high as 90 percent.

In an attempt to control the virus in Liberia, police officers have been deployed to the nations international airport to ensure passengers are screened for symptoms. Fever, aches and sore throat are among the early signs of the disease. Only in later stages do patients sometimes experience severe internal bleeding and blood coming out of their mouth, eyes or ears.

Earlier on Tuesday, the West African airline Asky suspended flights to and from Sierra Leone and Liberia. Tensions in the region were heightened last Friday when 40-year-old Patrick Sawyer became the first person to die in Nigerias coastal city of Lagos, home to 21 million people.

Sawyer was of Liberian descent, and worked for the West African nations Finance Ministry. He had taken several flights on ASKY Airlines. His sister had died of Ebola though he maintained he had not had close physical contact with her when she was sick. At the time, Liberian authorities said they had not been requiring health checks of departing passengers in Monrovia.

At the Finance Ministry where Sawyer worked, officials announced they were temporarily shutting down operations. All employees who came into contact with Sawyer before he left for Nigeria were being placed under surveillance, it said.

"We have a presence of the police at the airport to enforce what were doing," said Binyah Kesselly, chairman of the Liberia Airport Authority board. "So if you have a flight and you are not complying with the rules, we will not allow you to board."

However, the WHO said travellers are unlikely to catch Ebola because it is not be spread like flu through casual contact or breathing in the same air. 

Meanwhile in Washington, a US administration official said on Monday that President Barack Obama was receiving updates and noted that US agencies had stepped up assistance to help contain the virus."

in www.independent.co.uk on the 29th of July 2014, by Kashima Gander

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