We are still months away from the hurricane season, yet dark clouds are still approaching rapidly. Just as I have used CajunWx to keep friends and family informed about happenings in the Gulf and tropics, I felt it might be a good idea to also discuss the coronavirus crisis. As with tropical weather, I do not portend to be an expert in virology or infectious diseases. That said a decade of emergency room and trauma nursing along with lifelong studies do make it possible for me to wade through the ocean of scientific papers pouring in on the coronavirus and decern trends in the information.
Probably the best place to start is the name, or rather names, of this outbreak. I say this after watching a trained doctor on one of the networks leave all viewers more confused than when they started. The common name of “coronavirus” stems from the fact that the virus which causes the current outbreak comes from the family called coronaviridae, Latin for coronavirus. The specific name of the virus is SARS CoV-2 which basically means it is “Severe Acute Respiratory Syndrome Coronavirus #2.” While it is closely related to the SARS CoV virus which caused the outbreak that infected 8,098 people in 2002, killing 774, the current outbreak involves a “novel” or new virus. Thus the new name. Finally, we also name major outbreaks of infectious disease. In this case, the disease outbreak is known as Covid-19, the coronavirus outbreak originating in 2019.
So now that we know the names associated with the outbreak, let’s begin with what a virus actually is. At its simplest, a virus is a non-living particle, which carries DNA or RNA, and must hijack a living cell to make it do the work of reproduction. The structure of a virus is quite simple, with most having only three components: The first is a strand of either DNA or RNA which holds the code for reproducing the virus. The second is a protein shell or capsule which surrounds the genetic material and protects it. Finally, on the surface of the capsule will be a number of receptors which allow the virus to bond to living cells. There is no metabolism or life, just the ability to reprogram a cell. This means you cannot truly ever “kill” a virus, as it was never alive. You can though render it safe by a number of means. Heat, disinfectants and such work well as does just common soap.
The SARS CoV-2 virus would look something like the image above if we were able to take a look at it. But that would take a specialized piece of equipment known as an electron microscope. The SAR CoV-2 virus is about 120 nanometers across. As there 1000 nanometers in a micron, we can see that the virus is quite small. The spikes that cover the surface of the virus are its key to entering the body. Those spikes work like a key when they find a cell in the body with an ACE2 receptor. ACE2 stands for the angiotensin-converting enzyme-2 but don’t worry about what that is, just that the majority of the cells in the human respiratory tract have such receptors.
The diagram above from The Economist shows how the virus uses the ACE-2 receptors to enter into human cells and take over the cell machinery to make it produce thousands and thousands of copies of the virus until the cell literally bursts to spread the new viruses through the body. Each new virus particle then attempts to hijack another cell and the process continues until the body builds a sufficient immune response to fight off the assault.
How easily is Sars CoV-2 transmitted? To determine this, scientists use a mathematical calculation known as R0 or R naught. R0 basically measures how many people will be infected by a single infected person. If the R0 for an infectious agent is less than one, then the disease is likely not to spread and eventually die out. If the R0 is equal to one, the one new infection will occur for each old one. Such diseases will stay alive and stable but will not become an epidemic. When R0 is greater than one, we have the potential for an epidemic.
So how does SARS CoV-2 stack up? The R0 for the MERS outbreak was less than one. The flu has an R0 of 1.3, around that of the common cold. The ebola virus has an R0 of 2.0, mumps an R0 of 4.7, and smallpox an R0 of 7.0. The R0 based on numbers from China for the SAR CoV-2 virus was set at 2.2, meaning every infected person passes the disease on to another 2.2 people. As we get more data out of Europe, it appears the SARS CoV-2 R0 may be closer to 2.7 to 3.0. Only time and more data will tell.
Another item related to the R0 concept of disease transmission is that it only relates to those who have no natural immunity for the infectious agent. In other words, even though the R0 for the flu is 1.3, major outbreaks are rare because of both natural immunity from previous exposure and the widespread use of a vaccine. However, in 1918 the world saw an outbreak of the H1N1 flu variant, at the time a novel strain which had never been seen before by man. The R0 of the Spanish Flu as it was called, was around 2.1, but due to the lack of natural immunity and the war-ravaged state of the world, it claimed over 20 million lives. Therein lies the rub with SARS CoV-2, it has a relatively high R0 of say 2.2 – 3.0, and the world population has no natural immunity. We also lack a vaccine, with the nearest likely a year off, or any drugs which effectively fight the disease process. The state of mankind’s health and medical technology are far beyond 1918 but this outbreak will likely continue to grow unchecked without strict isolation procedures. Basically, we are just beginning to see the ravaging effects of SARS CoV-2 and will be living with it for months to over a year. Current estimates by the CDC say 30-90 million Americans could be infected before we are done!
But how deadly is the Covid-19 outbreak? Some articles on the internet would have you believe it is less deadly than the seasonal flu. They are wrong. Covid-19 tends to kill about 3.5% of those who are infected. The seasonal flu, on the other hand, has a mortality rate of just 0.1%. And once again the Covid-19 death rate is based mostly on data out of China, while the data out of Europe is showing that 3.5% may be too low. So the Covid-19 outbreak is far more deadly than the seasonal flu. It is also worth noting that even with a vaccine and natural immunity, over 34 million will be infected and 20,000 die this year from the seasonal flu in the United States alone. Add in a multiplier of 35, the difference between 3.5% and 0.1%, and Covid-19 could claim up to 700,000 lives before it is done.
Put in the above context and taking into consideration the ease with which Covid-19 spreads and its high mortality rate, along with what is happening in Europe, which is a mere two-weeks further along in this than us, and we are likely in for a long haul. Further restrictions, including the suspension of flights and even travel, are possible if not probable. This is also not something which will play out in weeks but rather months. The world is facing a crisis, unlike anything it has seen in over 100 years. Yes, it is scary. But the more we learn about the science of SARS CoV-2 and Covid-19, the easier it is for us to accept the restrictions which are likely to come. I will follow up in the coming days and weeks as number change and we gain more clarity. For now, listen to government officials. Isolate as much as you can and pray something slows this deadly juggernaught!
The familiar bulls-eye of a surface low centered just about due south of Atchafalaya Bay is pretty obvious. But note the rain pattern. The heaviest rains early Sunday morning would be from the mouth of the Mississippi River to the north shore of Lake Pontchartrain, as well as over much of Florida. This is due to the fact that the system will likely not become very organized until it nears the coast, where waters are much warmer. Until then it is just a disorganized low with lots of rain mostly on the east side and with much less to the west.
It is only on Tuesday, image to left, that the rain from the system separates from the moisture plume over Florida. It is this quirk, a sort of double system which seems to be giving the GFS problems. However, as of this morning, the Canadian “CFS” and the US Navy “NAVGEM” models. are both showing a similar system, though those models lie a bit east of the Euro, from the mouth of the Mississippi to the Mississippi Gulf Coast. But all then move it westward along the coast through early next week.
