Thursday, April 24, 2014

The Flu of the 100 Visits

Hello, dear readers. 

Here we go again, as Whitesnake said, with another entry of the blog. This time, we are going to speak about the ever-present, ever-menacing, flu. As this will be the first entry, it will be about the basics: What is the flu? and Why is it so dangerous?. 

Also, with this second entry, we expect to surpass the hundred visits. It is not much, but it will be something to look back at and marvel about, in the future. 

So, here we go. With all of you, The Influenza virus.
Everyone, say hello to the Flu Virus

First, What is the Influenza Virus? We are in front of one virus from the family Orthomyxoviridae, with a genetic material composed of 8 fragments of single-stranded, positive, RNA, which makes it very prone to recombinations. 
It is a virus with a glycoprotein membrane, with two key proteins for the cell entry, called Hemaglutinin (HA) and Neuroaminidase (NA). This proteins have many variations, employed to define the virus using the HxNx format, where x is a number

What not many people knows, is that there are 3 types of influenza virus, A, B and C. Here I leave you a link to a nice sum up from the CDC. Seasonal flu, which is know (and suffered) by mostly everyone, normally is type A or B. In the case of it being type A, it will be accompanied by the suffix HxNx. This is a distinct nomenclature (a way of call something) that is determined by the subtypes of HA and NA. I am not going to write about the HA that binds to sialic acid nor the process used by the NA to break that acid so the virus enters the cell. 

What I am going to say is that there are 18 types of HA and 9 types of NA, that combine freely to form different viruses. Luckily for us, not all of them infect humans, many of them only infect animals, such as birds, horses and bats

But, Why is the flu virus so dangerous? As I mentioned earlier, there are 8 segments of ssRNA composing the genome of the virus, causing different combinations of HA and NA, among other things. If a human got infected by a swine flu, the effect will be contained, because it will not be transmitted human to human, only pig to human. The mortality rate will be asthonishingly high (about 40%), but the effect will be controlled and focused. To give you a brief idea, this is a link to the WHO about the evolution of H7N9, a kind of flu that is starting to infect humans.

The problem comes when said pig-to-human flu happens to infect a human that already has been infected, in that same moment, with a human-to human flu. There is a process, which I am not going to explain today, but in next monday's entry, by which both genomes can recombine their segments causing a new flu virus to be formed. And this virus, in this unlucky guy, would have the mortality rate of the first, and the infective power of the second. It will be highly mortal and easily spreadable. So, if you know someone who is really unlucky, and he has the flu, better step away for a couple of weeks. Just in case...

This happened the last time Flu became dangerous
This may sound as a fantasy or an excuse to sell vaccines by the pharmaceutical companies, but it has happened before. in 1918, the Spanish Flu killed between 3% and 5% of the world population, affecting mostly young, healthy adults. In today's numbers, it would have killed around 350 million people.

That is a lot, don't you think?

This happened in 1918, in the middle of World War I, and it has the name of Spanish Flu because Spain did not intervened in said war, thus freely reporting the devastating disease. The thing is, it originated in France, and started to spread from Boston to New York. But no one reported it, so the morale of the troops would remain intact. And the nickname stayed, granting fame (but not fortune) to all spaniards in the viral world. 

The funny thing with the flu is that. Normally, is a minor disease, that keeps you in bed for a couple of weeks, and exhausted for nearly a week. But you recover and keep going on. It is a controlled illness, higly infective, but almost no one dies from it nowadays. 

A couple of years back, there was a scare about the "avian flu". It had all the qualities to become another Spanish Flu. It had jumped from birds to humans, and had the first cases of human-to-human infections. But suddenly it stopped working, and left us with our bones rattled about a case of lethal, global, devastating pandemic disease. Nothing important, really.

Here, also, is a cool new 3D model that came out some days ago
Official flu reports in the past 6 months

That is why we like the most about viruses. They are these little things, that no one really cares about. But if they have one bad day, and start killing people, odds are in favor of a massive global decimation. 

So, we will keep the entrys coming, hopefully each Monday, as long as viruses let us do our work. 

Thanks for reading! 

Tuesday, March 25, 2014

An Emergent Blog: Talking about MERS-CoV

Good day, dear readers

I am happy to announce that we, the Group/Delegation of Young Virologists, from the Spanish Society of Virology (SEV) are starting an english version of our laureated (because we say so) spanish-written blog. We broke the 1000 visitors barrier a week ago, so the path to follow lead us to this:

An English-written blog (celestial music plays, a-la Monthy Phyton)

And what a better way to start it than with a remix version (with new info) of the very first entry of that blog, about MERS-CoV. 

Why not HIV? Why not flu? Easy-peasy. We like to start things with a bang, talking, sharing information with you about a new, fresh virus, with a whooping 42% of mortality among humans, starting to spread around the world. 

The name of the virus was Middle East Respiratory Syndrome Coronavirus, but, as the middle-eastern people got angry, and anyways it is too long to write each time, it shortened to MERS-CoV. Another name was, originally, HCoV EMC/2012, but again, scientists are very lazy for certain things, and you should give a name to everything. And "toby" was already taken. 

More seriously, MERS-CoV is a novel coronavirus, that is a virus with a positive, single RNA strand (we humans have double-stranded DNA), covered by a nucleocapsid of helical symmetry. The name "coronavirus" came from viewing it at the electron microscope, where you can appreciate small bulbs that form some kind of crown, which translates as "corona". Thus, corona-virus. No one said you have to be original to be a scientist... During this blog, I will always write about the lack of originality scientist have whilst naming things. Is something is rod-shaped, it will be a baculovirus (rod-shaped-virus), and so on. 

But I am drifting away. Now that we know what a coronavirus is, let's talk a bit about the history of said virus. In September 2012, Dr Ali Mohammed Zaki isolated this virus from a patient that died in June 2012 in Saudi Arabia, with acute respiratory syndrome and renal failure (almost a complete package). As it was a newly discovered coronavirus, very similar to SARS (you know folks, this one). A couple of months later, a man with the same conditions appeared and was taken to the UK to be treated, and there was where the virus was properly and definitively identified. 

And that is where the "middle east" in the virus' name comes from. Again, originality

The virus, as I have told you above, produces an acute respiratory syndrome, along with his friends renal failure and severe acute pneumonia, often causing death (duh!) But the problem, as strange as it seems, is not there. The problem is where it comes from and its detection

The origin of this virus, as of January 2014, is still unclear. Most of the coronaviruses come from an animal reservoir (as does, for example, flu, which comes from birds). But the reservoir for this coronavirus is not yet identified. There is the theory that it comes from bats, as does the majority of the coronavirus. But in November 2013 scientist successfully identified antibodies in sera of camels, dating as far back as 2003. The camels where native of United Arab Emirates (omani) and Spain. They also tested camels from a german zoo, and found them to be free of those antibodies, meaning (probably) that the virus has a limited geographic range. An updated theory (here) is that the virus could have passed from bats to camels via guano (bat shit) because the water used is normally from guano-floored caves. 
Deadlier than the one in the cigarettes...

As for the transmission, it does transmit between humans, but it is unknown how. The cases in which the virus has hopped between human hosts were closed families and in health care facilities, but not in big communities, suggesting that the rate is very low. This is according to the way the virus infects the respiratory system. It infects non-ciliated epithelial cells in the lungs, which accounts for less than 20%, so a large number of virions per cell will be required for a transmission. So, close-up, yes, far away, no. That was learnt in a bad way by the British, who started to get sick after treating patients infected with MERS-CoV. 

So, to sum up: Is the virus dangerous? Yes, yes it is. Could it cause a great pandemic? Right now no. But the fear of the WHO is that if the virus mutates it could pass between humans more efficiently, causing said pandemic. That is why it is customary for every country to analise and report each case of MERS-CoV. Better safe than sorry...

So, that's all for today. Hope you liked this first entry in the language of the Empire (pick between USA and his little cousin). There will be more to come, I hope each Monday from now on!!

PS: If you want to know more about the virus, here is an useful link. Also, a conference of WHO that took place on July 9th 2013 and the DON link of the WHO, in which reports are updated almost every day of the epidemics in the world.