Coronavirus Outbreak- What We Know Thus Far
For the medical community 2020 has arrived with a sinister start. In the midst of Flu season, a new and far more ominous virus has emerged, gripping the world’s attention. We are of course talking about the recent outbreak of coronavirus in Wuhan, China with multinational reports emerging. The virus, a “cousin” of the SARS virus that struck in 2003 that caused nearly 8,100 cases, and resulted in 774 deaths in 37 countries.[1] But what is coronavirus and why does its emergence have the virology community so worried?
According to the Centers for Disease Control and Prevention, coronaviruses are common in a variety of animal species include camels and bats.[2] Coronaviruses (CoVs), enveloped positive-sense RNA viruses, are physically characterized by club like spikes that shoot out from its surface. Coronavirus has an unusually large RNA genome and a unique replication strategy.[3] In rare cases, coronaviruses become zoonotic meaning that they become transmissible from animals to humans through various means. In the case of the 2003 SARS outbreak, the virus was traced back to the horseshoe bats in Yunnan Province in China, who were infecting civets which acted as the intermediary to humans.[4] Other well-known zoonotic diseases range from Lyme disease which is a bacterial infection transferable to humans via tick bites as well as the Ebola virus which over the course of three years resulted in 28,000 cases and over 11,000 deaths in West Africa.[5] Zoonosis is the means by which many infectious diseases are transferred to humans, however this transmission is not what worries the clinical community. Human transmission is a far more serious issue and one with which we must now contend with this new coronavirus.
Human transmission of a virus is considered a game changer.
Viral transmission between humans can be accomplished a number of ways
depending on the virulence of the disease. A simple cough or sneeze is common
as the viruses is carried in the droplets through the air. Skin to skin contact
is another transmission method of viruses. The virus is transmitted through
touch then enters its new host through the touching of the mouth, eyes, or
nose.[6]
What is worrisome about the Wuhan coronavirus is the mixture of human
transmission and the unfortunate geographical location of the outbreak.
Wuhan is the regional capital of the Chinese Hubei province. It is the largest and most populous city in the region with over 11 million people. Wuhan's population density reaches highs of 20 thousand people living per square kilometer, is home to one of the four key rail hubs in China as well as Wuhan Tianhe International Airport, one of the countries busiest.[7] This means that the virus has not only become transmissible between humans in one of the most populated cities in the worlds most populated country, but could be spread internationally via one of the world’s busiest international airports.
As of writing, only three Provinces (Inner Mongolia, Qinghai, and Tibet) have not reported any cases of the Wuhan coronavirus[8]. Internationally, South Korea, Japan, Hong Kong, Thailand, Taiwan, Singapore, Vietnam, and the United States have all had confirmed cases of the virus while the Philippines, Australia, and Scotland are monitoring suspected cases.[9] London based researchers suspect another 4000 cases – in Wuhan alone and that does not take into account travelers spreading the infection elsewhere.[10] With China’s Lunar New Year on January 25th being the most important holiday on the Chinese calendar and a massive travel holiday, concerns of revelers spreading the disease during or after their travels are mounting. The chances for this epidemic to become a pandemic is not an unfounded fear. With that said, how is the world responding?
China itself has responded strongly in an effort to contain
the further spread of the virus. Major cities including Beijing and Wuhan have
banned all large gatherings for the coming Lunar New Year Festival. As of
writing, China’s government has also imposed travel restrictions on Wuhan and its
surrounding municipalities. No going in and no going out – effectively
quarantining 25 million people. The
United States is screening all travelers from Wuhan for symptoms at major
international airports in Los Angeles, New York, San Francisco, Chicago, and
Atlanta. However, the World Health Organization refused to declare the outbreak
a global health emergency saying it is too early citing Chinese efforts in
containment and the limited number of international cases.[11]
With the international community responding to the outbreak, should you worry
about it? What are the symptoms and mortality rate? Is it preventable?
While the Wuhan coronavirus has a mortality rate far lower
than that of SARS or MERS thus far, it is still comparable to the 1918 Spanish
flue pandemic.[12]
Currently, prevention via vaccine is unavailable. Reduction of risk through
proper washing of hands, surface disinfection, and awareness is key to avoiding
transmission. As we do not yet know how human transmission of this virus is
occurring, the CDC has a notice for travelers that is being updated as new
information is obtained.[13]
Symptoms of the Wuhan coronavirus are similar to that of
SARS but with milder symptoms and symptoms take longer to develop. It generally
causes upper respiratory problems, beginning with a mild cough that persists
for about a week before they begin to experience shortness of breath. The
immunocompromised, young children, and the elderly are more at risk of the
chance the virus causes far more serious respiratory tract illnesses like
pneumonia of bronchitis. So far around 15%-20% of cases have developed into
these sever symptoms.
The Wuhan coronavirus is still a developing story. In a
globally connected world, where international travel is trivial, the
opportunity for a virus similar to that of SARS to wreak havoc on a global
stage is higher than ever in human history. The Wuhan outbreak shows how a
perfect storm of human transmissible disease, in a highly populated urban area,
with international outlets could take a small regional outbreak and spread it
across nations. Hopefully, through international coordination, we can limit the
spread of this virus and as we gain more information effectively treat those
infected.
Below is a timeline of events as of the time of writing:
December 31st : The World Health Organization is
alerted by Chinese officials of a string of pneumonia like cases in Wuhan.
January 1st : The Centers for Disease Control
identifies a seafood market as a suspected center of the outbreak. Chinese
officials close down and quarantine the market.
January 9th : The World Health organization
announces that the outbreak is being caused by a previously unknown strain of
coronavirus, a broad viral family ranging from the common cold to deadly
variants such as SARS.
January 11th : Chinese officials report the first
fatality – a 61 year old man in Wuhan who developed pneumonia.
January 13th : The first international case is
announced in Thailand by the World Health Organization. The victim is a Chinese
woman who developed a mild case of pneumonia upon returning from a trip to
Wuhan.
January 15th : China’s health commission says
that is cannot yet confirm human transmission but the possibility “cannot be
excluded”.
January 16th : A second international case is
announced. This time in Japan with someone who had stayed in Wuhan in early
January.
January 17th : A second fatality is reported – a
69 year old man in Wuhan. The same day, the Centers for Disease Control
announces it will begin screening passengers arriving from Wuhan at Los
Angeles, San Francisco, and New York’s JFK International airports.
January 20th : A third death and 100 new case
reported in China. The virus is detected in South Korea for the first time in a
Chinese passenger arriving from Wuhan. China’s President Xi Jinping makes his
first public comments on the outbreak saying that it must be “resolutely
contained”. Zhong Nanshan, a Chinese expert on infection diseases, announces
that human to human transmission is confirmed.
January 21st : The first US case of Wuhan’s
coronavirus is reported in Everett, Washington. The man had traveled to Wuhan
earlier in January.
January 22nd : Airports across Europe step up
checks on flights from Wuhan. The same day, the World Health Organization’s
Chief, Tedros Adhanom Ghebreyesus, says that he is postponing the decision on
whether or not to declare a global health emergency.
January 23rd: Chinese authorities confirm 17 deaths and more than 500 cases have been reported. Travel access to and from Wuhan is suspended by the Chinese government in Wuhan and neighboring municipalities effectively quarantining 25 million people.
January 24th : The CDC confirms second confirmed case with multiple potential cases being monitored in the United States while Mayor De Blasio of New York is quoted as saying "The disease will reach New York sooner rather than later."
January 25th : As China reports nearly 3000 cases, the CDC announces they are monitoring 110 possible cases across 26 states in the United States. There are now 81 confirmed deaths, 78 of which were in Hubei Province, the epicenter of the outbreak.
[1] Smith, Richard D (2006). "Responding to
global infectious disease outbreaks: Lessons from SARS on the role of risk
perception, communication and management". Social Science & Medicine. 63
(12): 3113–23. doi:10.1016/j.socscimed.2006.08.004. PMID 16978751.
[2] https://www.cdc.gov/coronavirus/index.html,
accessed 1/23/20
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4369385/,
accessed 1/23/20
[4] McKie, Robin (10 December 2017). "Scientists
trace 2002 Sars virus to colony of cave-dwelling bats in China". The Guardian. ISSN 0029-7712.
[5] Ebola
virus disease (Report). World Health
Organizationaccessed 1/23/20
[6] https://www.cdc.gov/coronavirus/about/transmission.html,
accessed 1/23/20
[7] 武汉地铁机场线开通
乘地铁赶飞机还需留意这两点. Archived from the original on March 4, 2018.
[8] https://www.cnn.com/asia/live-news/coronavirus-outbreak-intl-hnk/index.html
[9] https://www.vox.com/2020/1/21/21075017/sars-wuhan-pneumonia-coronavirus
[10] https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/2019-nCoV-outbreak-report-22-01-2020.pdf
[11] https://www.cnbc.com/2020/01/22/who-postpones-decision-declaring-china-coronavirus-a-global-health-emergency.html
[12] https://www.cnn.com/2020/01/20/health/what-is-coronavirus-explained/index.html
[13] https://wwwnc.cdc.gov/travel/notices/watch/novel-coronavirus-china
Reported and Updated by Daniel Ballew, Digital Marketing Specialist for Hardy Diagnostics.