The first case of a new pneumonia-like virus spreading through China has now been confirmed in the US, heightening fears of a global pandemic.
Coronaviruses are common in both humans and animals. While some can cause mild illnesses such as the common cold, more severe coronaviruses include the deadly Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS).
This new strain – known as 2019-nCoV – is responsible for six deaths so far.
It was reported in humans for the first time around December 30, in the City of Wuhan in China, and has since been confirmed in more than 200 people.
Health authorities are on alert, as new cases spread through China and the rest of the world. People in Japan, South Korea, Thailand, Taiwan and now the US have been infected with the virus.
Many of those, including a 30-year-old man from Washington state in the US, had recently travelled to Wuhan, where the outbreak is believed to be linked to a fish market.
But on Monday, the World Health Organisation raised the possibility that the virus was being transmitted from human-to-human in a sustained manner. Unlike the recent outbreaks of MERS and bird flu viruses, which have only had limited human-to-human transmission, sustained transmission would mean the coronavirus could spread as easily as the flu.
“But more information and analysis are needed on this new virus to understand the full extent of human-to-human transmission and other important details,” the WHO said on Twitter.
There were no confirmed cases domestically and the risk of transmission in Australia remained low, Chief Medical Officer Professor Brendan Murphy said in a statement last night.
“We have well established mechanisms to detect and respond to ill travellers, and processes in place to implement further measures if the risk increases,” he said. “This is a rapidly evolving matter with developments in recent days and we remain alert but not alarmed.”
Authorities had beefed up border protection measures, particularly for the three direct flights from Wuhan to Sydney each week, he added.
This includes informing all patients flying on these routes about the virus and interviewing people on these flights who are feeling unwell or who have a high temperature. Australian airports will also display information on the illness and instructions for what to do if symptoms emerge.
Several people in Australia have recently travelled from Wuhan and presented to health services with relevant symptoms.
“So far, all but one have been cleared of the novel coronavirus. Laboratory testing results are pending on one remaining case in Queensland,” Professor Murphy said.
Nevertheless, the actual number of cases globally is probably much higher than what has been reported, according to modelling done by researchers at the Imperial College London.
Wuhan is China’s seventh largest city, and the international airport has a catchment population of 19 million people.
There is a 10-day delay on average between infection and detection. Given the passenger numbers in the last two months, the researchers estimate that 1,723 people had an onset of symptoms by 12th January 2020, which was the last reported onset date of any case included in the modelling.
“It is likely that the Wuhan outbreak of a novel coronavirus has caused substantially more cases of moderate or severe respiratory illness than currently reported,” the authors said.
The number of people travelling is set to surge ahead of the Lunar New Year on Saturday, increasing the risks of transmission.
Fever is the only consistent symptom in confirmed cases, but other symptoms include sore throat, breathing difficulty and coughing.
Dr Christine Selvey, the acting director of Communicable Diseases, advised GPs to investigate and manage suspected patients for respiratory illness, and collect upper respiratory tract viral swabs or nasopharyngeal aspirate using standard and airborne transmission precautions.
It was too early to know how severe the outbreak will be, but current evidence suggested that it would not be as clinically severe as SARS or MERS, the Australian Department of Health said in a statement.
There was currently no vaccine available for the virus, meaning the best available treatment was supportive care, Professor Murphy said.