On December 30, 2019, the Municipal Health Committee of Wuhan, China reported an “urgent notice on the treatment of pneumonia of unknown cause,” and a day later, 27 cases were reported to the World Health Organization. The majority of cases were traced back to a local seafood market, which was promptly closed for cleaning and disinfection. An investigation proceeded, and within a week, seasonal influenza, SARS, MERS, and the bird flu were ruled out, as the count of suspected cases raised to 59. Travel advisories were posted to anyone planning travel to or from Wuhan, and by January 9th, the WHO had confirmed that a novel coronavirus 2019-nCov had been isolated from one of the patients, with researchers from Fudan University in Shanghai, China, the Chinese CDC, the Chinese Academy of Medical Sciences, and Jinyintian Hospital in Wuhan submitting the gene sequencing data of the virus to global virology databases for analysis, reaching the US GenBank database on January 13th, 2020.
Over the next week, the number of confirmed cases escalated, with reports of the virus in other parts of China as well as international cases in 10 other countries. The WHO issued travel advisories as health organizations in other countries took action to prevent the spread of the disease in their home nations.
As of January 24, 2020, two cases were reported in the United States, both of which involved travel to Wuhan. Because of Lunar New Year, January is peak travel season between the United States and China, and with 916 confirmed cases and 26 deaths in China as of January 24, health officials have been closely observing the situation to ensure containment, and strict travel screening processes were initiated to evaluate passengers that had visited the region.
Wuhan, China’s seventh most populous city and home to more than 11 million citizens, is now subject to a local travel lockdown to prevent spread of the virus, and an emergency order was issued to construct a new hospital in less than a week. In other areas of China, tourist attractions such as Disneyland in Shanghai have been closed due to health concerns, and many other cities closed public roads in response. Many Wuhan citizens are concerned about being restricted by the move, worried that, unable to flee the city, they will inevitably be infected by the disease. Many other lunar new year events have been canceled, and government media outlets have advised citizens to stay put at home.
Coronaviruses are a family of viruses with similar properties that cause acute respiratory illness in humans, primarily infecting the upper respiratory and gastrointestinal tract in mammals and birds. Approximately 15% of common colds are caused by coronaviruses, although in many cases, multiple viruses are present in a common cold. The name “coronavirus” refers to the visual characteristics of the virus particle, which has bulbous protein projections surrounding its round structure, giving the appearance of a halo (“corona” in Latin) surrounding the particle. Coronaviruses bind on cell surface molecules and are absorbed into the human cell, and once inside, they are able to transcribe their RNA into new virions that are released and spread in the host.
One sinister characteristic of coronaviruses is that many are zoonotic, which means that they can be transmitted between animals and humans. Many other viruses are incompatible with both human and animal cells, and so certain viral infections that affect certain animals are not able to infect human cells. But coronaviruses, able to transmit between humans and animals, have caused many serious infections, such as Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), both which are believed to have originated from animal-human contact. Because animals can also be a vector for human coronavirus infection, these diseases have a much greater potential to spread, particularly among people that handle animals on a regular basis.
2019-nCov does not currently have any effective treatment or vaccine, although urgent efforts are underway. The symptoms include fever, difficulty breathing, and coughing, and have been described as similar to influenza. Similar to preventing common cold infections, regular hand washing, avoiding touching the mouth, eyes, or nose, and avoiding close contact with anyone with respiratory symptoms are ways to prevent infection. As only two cases have been confirmed in the US, exposure is highly unlikely, but as this is a relatively recent outbreak and the virus is not yet well understood, health and safety should be of primary concern. If you have visited mainland China recently, your exposure risk to 2019-nCov is significantly greater and you should report to your doctor if you have any signs of infection.