The Wuhan 2019nCoV Coronavirus Epidemic is growing by a factor of ten a week

A semi-log plot at Wikipedia shows the exponential growth of this epidemic over the past two weeks. On such a plot, a straight line corresponds to an exponential growth in linear scale.

This trend need not continue, but if it does, the implications are ... severe. And efforts at containment will be measured against any reduction from this trend. Keep in mind also that this tracks confirmed cases, which is a subset of total actual infections.

As of two days ago, January 26, 2020, total cases stood at about 2,000, and deaths at 100. If trends continue we'll see, in very rough numbers:

• In 1 week: 20,000 cases, 1,000 deaths.
• In 2 weeks: 200,000 cases, 10,000 deaths.
• In 3 weeks: 2,000,000 cases, 100,000 deaths.
• In 4 weeks: 20,000,000 cases, 1,000,000 deaths.

Again, this is not certain to happen, but is projection based on current trend.

An epidemic is comprised of an infectious agent, a host population, susceptible individuals, vectors of transmission, and susceptibility or immunity to infection. Incubation period, time between infection and symptoms, infectiousness before onset of symptoms, and ease of transmission are all factors affecting spread.

In an epidemic, particularly against a virus with no known curative treatement, the way you attack spread is by vector control. You want to stop the spread of the viral particles themselves.

Within a given region, this means isolating known infectious individuals, minimising the amount and degree of contact between them and others, and between asymptomatic individuals, is key. Note that those not showing symptoms may or may not have the virus.

This means, for the most part, the measures applied so far: masks (of limited use), handwashing (very important), general isolation -- not going out and about, meaning limited school, work, and social activities, and limiting of long-distance travel, especially any transportation which completes journies within the incubation period.

Airplanes are epidemic engines. This was notably observed by British journalist and documentarian James Burke, when he revisiited his 1980s series Connections, and was asked how he might continue the series. His answer: to look at the concluding inventions and consider their further implications, for example, air travel and its role in epidemics.

So yes: curtailing air transport out of regions in which the virus is known to be pandemic (spread through the general population) is an extremely advisable measure. Should have been done weeks ago, but now is better than never. Expect to see further transport restrictions, and possible quarantines, particularly of evacuated individuals.

If you're in a region at risk of outbreak (presently: China), rather than buying masks, you should be stocking up on nonperishable food such that you have several weeks supply and can further minimise exposure though shopping, as well as hand sanitiser (alcohol should work, antibiotic is useless against viruses). Shopping-cart handles and other surfaces are prime transmission vectors: elevators, public transport, doors, light switches, etc. Regular cleaning and sanitisation of these is helpful.

Workplaces should require any infected individuals take sick leave, regardless of cause. (This is just common sense, unfortunately as always, uncommon.)

Immunisation against other diseases (e.g., standard influenza) won't protect you from 2019nCoV, but it will reduce the odds of confusing symptoms of unrelated conditions with those of the coronavirus which is helpful to both individuals, their contacts/families, and healthcare systems. Get your flu shot and insist on those around you getting theirs as well.

We've also seen secondary transmission to individuals never having visited China, in both Germany and Japan. Which means the disease is absolutely human-to-human transmissible.

Normally in major epidemics my concern is on global poor megacities, which have vast populations but poor public health infrastructure. That's likely a risk here, but North Korea seems another potentially volatile location given:

• Proximity and relations with China.
• Generally poor infrastructure.
• An informational structure much given to revealing what it's believed the recipient wants to hear, rather than the truth.
• Wintry climate, generally favouring viral transmission.
• Often poor and crowded living conditions, particularly within military, work, and prison camps.

Whilst PRK has limited ties with the rest of the world, some do exist, and the elite are possibly more likely to be able and inclined to flee elsewhere, possibly taking the disease with them.

PRK have already been taking measures to limit border crossings. This is politically feasible (the benefits of absolute rule), but the actual effectiveness may fall short of requried levels.

https://en.wikipedia.org/wiki/2019–20_Wuhan_coronavirus_outbreak

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