The cororna virus is coming. Try to avoid both extremes: “it’s nothing” and “we’re all going to die.” There are several things we don’t yet know. We don’t know how many people will be infected worldwide. We don’t know how many people will be infected in the US. We don’t know how contagious it is. And we don’t know how fatal it is.
The corona virus outbreak of 1919 (dubbed COVID-19) is a problem whose size is not yet clear. It might be easily handled or it might be catastrophic. The World Health Organization (WHO) says it is a “public health emergency of international concern.”
The CDC says: “The potential public health threat posed by COVID-19 is very high, to the United States and globally. At this time, however, most people in the United States will have little immediate risk of exposure to this virus. This virus is NOT currently spreading widely in the United States. However, it is important to note that current global circumstances suggest it is likely that this virus will cause a pandemic. This is a rapidly evolving situation and the risk assessment will be updated as needed.”
The CDC notes that “It’s likely that at some point, widespread transmission of COVID-19 in the United States will occur.” In other words, it’s coming.
But the seeming inevitability of this virus coming is not as serious as our lack of understanding. The biggest problem, as the CDC points out is that “the complete clinical picture with regard to COVID-19 is not fully understood.”
The corona virus outbreak of 1919 (dubbed COVID-1919) is a problem whose size is not yet clear. It might be easily handled or it might be catastrophic. If it is easily handled, roll over and go back to sleep. If it is catastrophic, here is the bad news.
But first, a bit about viruses. A virus is not a cell; it has no body (soma). It is a fragment of DNA or RNA that carries genes, and sometimes comes with an envelope of fat it wears like a coat. They vary in size, shape, and complexity. But compared to bacteria, viruses are quite small.
Although viruses must be hosted in an organism to replicate, they can survive in the air or on surfaces for a surprisingly long time. Moisture and temperature are important factors. According to the BBC, flu viruses can survive in the air for hours, particularly at lower temperatures. The CDC says that the measles virus can live up to two hours in the air, making the area infectious even after the infected person has gone.
The BBC says viruses on hard surfaces can remain infectious for 24 hours, which is a good general rule. But a common cold virus can be infectious for several days, becoming less infectious as time passes. Other viruses, such as norovirus and hepatitis A, can survive for weeks on a surface if the conditions are right. Viruses tend to live longer on surfaces are water-resistant, such as stainless steel and plastic.
No one is safe. Even bacteria can be infected with a virus. In fact, bacteriophages are very common. Viruses need a host; they don’t care whom.
Coronaviruses form a large family of viruses. They have a crown (corona), are quite large (with about 30 kilobases), and are often enveloped viruses of a single-stranded RNA segment.
Three coronaviruses deserve special mention. They are all zoonotic (originally coming from animals but finding refuge in humans). The SARS-CoV came from cats. MERS-CoV came from camels. The new one nCoV (novel) is of unknown origin, possibly bats.
SARS (severe acute respiratory syndrome) was the first. It was first reported in 2002. It started in China and spread throughout Asia. On the 8098 cases, there were 774 deaths. This is a case-fatality rate (CFR) of ~10%. In US, only 164 cases were reported, and no deaths.
MERS (Middle East respiratory syndrome) is distinctly different from SARS. MERS targets bronchial epithelial cells and the kidneys. It impacts immune responses and
antagonizes the production of interferon. Interestingly, the human and camel strains are intermixed. MERS was first reported in 2012. It started in Saudi Arabi and over 80% of the cases occurred there. MERS spread to 27 countries, including France, Germany, the UK, and the US. In 2017, there were 2000 cases of MERS worldwide with 600 deaths. This is a CFR of 30%. In the US, there were three cases no deaths.
2019-nCoV is the new kid on the block, hence the n for novel. Little is known about it. It is more like SARS than MERS. Symptoms appear 2-14 days after infection. At present there is no vaccine for prevention and no antiviral drugs for treatment. The best advice is to stay away from people who have it, if you can figure out who that is.
Like SARS and MERS, transmission seems to be person-person (within 6 feet), by air (respiratory droplets from coughs or sneezes) and by objects (especially hard surfaces like stainless steel and plastic).
CFR is unknown. Wikipedia gusses 1-3%. WHO says 2% are fatal. In Hubei, China, there have been 79,000 reported cases and 2870 deaths. This is CFR of 3-4%.
In Japan, there have been 850 reported cases and 4 deaths; a CFR of .5%. In Italy, 1100 cases resulted in 29 deaths (~3%). South Korea reported 3500 cases with 8 deaths (.2%). The UIK has had 15 cases and no deaths.
To put things in perspective, The CFR for the Spanish flu of 1918 was about 2.5%. Hong Kong flu of the 1960s was .1%. You can safely say that 2019-nCoV appears to be more than the flu and substantially less than measles (15%), the bubonic plague (60%) or Ebola (as high as 90%).
This is the end of the good-news-don’t-panic segment.
Let’s apply some math to whats-gonna-happen question.
Let’s assume 2019-nCoV has a low CFR. If 30% of the US gets inflected, that would be 990,000 cases. A CFR of 1% would be nearly a million people dying. If the CFR is 2%, nearly 2 million Americans would die.
The bad news depends on how many people get inflected and what the CFR actually is. Neither of those is known.
This worst-case scenario is a warning for the future. It highlights how easily diseases are spread through our interdependent world culture. We are not as isolated as we used to be. 2019-nCoV may turn out not to disrupt the world economy but it illustrates how easily a more deadly virus could. Imagine the contagiousness of measles and the fatality rate of Ebola combined together.
Like most things, infections are worse for the elderly and those with compromised immune systems. This virus will not impact everyone equally. Some need to worry more than others. Overall, healthy wins.
The primary symptom of 2019-nCoV is shortness of breath. Tests for virus are becoming available and people who test negatively for cold and flu will be tests for the 2019-nCoV. This will begin to provide information about how many people are infected.
Don’t take shortness of breath for granted. It can progress to pneumonia and multi-organ failure. This is not a stay-in-bed symptom. This is get-to-a-doctor symptom.
Little else can be done. Wash your hands, drink pretty of fluids, stock up on Kleenex and toilet paper. And hope for the best.