Explained: A new coronavirus emerges in China

Coronavirus China 1-Optimized

Between December 8, 2019 and January 2, 2020, 41 people in Wuhan City, Hubei Province of China were infected with a novel coronavirus. One person has died and seven patients have severe illness. The genome has been sequenced and shared with WHO and GISAID. No human-to-human spread has been found so far.

On December 31, 2019, China informed the World Health Organization (WHO) of a cluster of cases of pneumonia of unknown cause in Wuhan City, Hubei Province of China. A few patients in Wuhan had been suffering from respiratory illnesses such as pneumonia since December 8, 2019. Besides providing care, Chinese public health officials began carrying out environmental assessments at the wholesale market and trying to identify the microbe causing the outbreak.

On January 9, 2020, the WHO issued a statement saying Chinese researchers have made “preliminary determination” of the virus as a novel coronavirus in a person with pneumonia. The researchers were able to determine the virus by sequencing the genome of the novel virus using an isolate taken from a patient infected with the virus. “Preliminary identification of a novel virus in a short period of time is a notable achievement and demonstrates China’s increased capacity to manage new outbreaks,” WHO tweeted.

Coronaviruses are a large family of viruses with some causing less severe common cold to more severe diseases such as the Severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). While SARS coronavirus was transmitted from civet cats to humans in China in 2002, MERS coronavirus was from dromedary camels to humans in Saudi Arabia in 2012.

On January 11, China shared the whole genome sequence data with WHO and submitted them to the Global initiative on sharing all influenza data (GISAID) platform to allow researchers across the world to access the data. Sharing the data with GISAID will help other countries to quickly identify the virus in infected people and provide care, and also develop specific diagnostic kits, drugs and even vaccines. Since Jan 11, five more genome sequences have been submitted to GISAID.

Number infected

Using the genomic test kit, China was able to accurately identify that only 41 of the 59 suspected cases have been infected with the novel coronavirus. According to the WHO, the clinical signs and symptoms of the patients are mainly fever and fatigue, accompanied by dry cough, with a few having difficulty in breathing, and chest radiographs showing fluid in both lungs.

Of the 41 patients, seven have severe illness, two have already been discharged and one person had succumbed to the disease. The remaining patients are reported to be in a “stable condition”. The last reported case was on January 2. The patient who died on January 9 is apparently a 61-year-old man who had chronic liver disease and was a frequent customer at the market which is under investigation to identify the animal species that has transmitted the virus to humans. Public health experts are yet to identify the source of the new virus.

No human-to-human spread

According to the WHO, 763 people, including medical staff, who have come in close contact with patients infected with the novel coronavirus have been identified for close monitoring. So far the virus doesn’t seem to have the ability to spread from one person to another as the infection has not been found in any of the close contacts. Based on preliminary epidemiological investigation, most of the patients have come in close contact with animals or frequently visited a wholesale seafood market, which has been closed since January 1.

On January 8, a woman who had travelled from Wuhan to Thailand was hospitalised and diagnosed with mild pneumonia. Subsequent testing confirmed that the woman, a Chinese national, had been infected with the novel coronavirus.

No travel restrictions

At this point in time, the “WHO advises against the application of any travel or trade restrictions on China based on the information currently available”. It does not recommend that travellers take any specific measures either. However, the WHO provides general tips to reduce the risk of infection such as cleaning hands with soap and water, covering nose and mouth while sneezing and coughing, avoiding contact with anyone who has cold or flu-like symptoms, thoroughly cooking meat and eggs, and avoid making unprotected contact with wild or farm animals.

Published in The Hindu on January 14, 2020