Sunday, January 26, 2020

Rapidly spreading 2019 nCoV outbreak

The 2019-nCoV outbreak is rapidly spreading across China. There have been more than 2000 cases reported among almost all the provinces in China since mid-January.  At least 54 confirmed cases have been imported into 14 other countries or administrative regions.  Five of these cases have been imported into 5 different counties in the United States. See maps below.

Friday, January 24, 2020

The Third Major Novel Coronavirus Outbreak This Century (2019-nCoV)

The Third Major Novel Coronavirus Outbreak This Century (2019-nCoV)

Once again for the 3rd time in this century, public health officials are battling a novel coronavirus (2019-nCoV) that originated in China in December 2019.  In 2003 the Severe Acute Respiratory Syndrome (SARS) outbreak was attributed to a coronavirus that originated in bats but was apparently passed from civets to humans in Guangdong Province in China. During that outbreak more than 7,500 people from 17 countries were infected with about 775 deaths blamed on SARS.

In 2012 a novel coronavirus began infecting people on the Arabian Peninsula. The Middle East Respiratory Syndrome (MERS) was eventually attributed to camels as an intermediate host passing on the MERS coronavirus to humans.  Since 2012 more than 2500 people have been infected with more than 850 associated deaths. While the SARS coronavirus has not infected anyone during the past 15 years, MERS is still circulating and continues to cause human illness and death. As noted by Kayvon Modjarrad (link) in 2016, treatment options for SARS  were never clearly defined so that when MERS appeared treatment options were limited as well.

In December 2019 a novel coronavirus began infecting people in Wuhan, Hubei province, in China. This coronavirus outbreak originated as the preceding two this century. A few cases here and there become sick exhibiting symptoms similar to pneumonia. Eventually local public health officials noticed a pattern in the symptoms of sick individuals who worked at or shopped in a wet market in the City of Wuhan where a variety of animals were processed and sold. Suspicion soon focused on coronaviruses because they are found in many animal species and can occasionally infect humans.

Within a few weeks Chinese researchers had isolated a new coronavirus called 2019-nCoV (2019 novel CoronaVirus) from sick individuals. The scientist quickly developed a test to rapidly identify the presence of this coronavirus in a sick individual.

During the initial days of this outbreak, there was uncertainty about whether or not all of the human cases resulted from exposure to infected animals. However, the rapid growth in confirmed cases in China demonstrates that human-to-human transmission is now the main source of the spread of this disease. Since the 11th of January, the number of reported, confirmed cases has risen about 20-fold. The chart below shows the growth of confirmed cases in the past 13 days from about 40 cases to more than 860 cases. This rate of infection, if it is unimpeded, could see the number of cases rise to 1500 tomorrow and 2500 the day after. These are only crude estimates, but there is little reason to suspect that number of confirmed cases in going to start declining precipitously in the near future.