EXPERT REACTION: Novel Chinese coronavirus found in Japan

A new virus has recently been described in China in late 2019. The initial cases were linked to a seafood market in Wuhan (since closed), but in the last week, cases have been described in other people who have had contact with cases, but who did not apparently have contact directly with the market. The early cases have described severe pneumonia, and two deaths have been reported.

At this stage, we don't know how infectious this new virus is, but the cases that have not had contact with the market raise the possibility of human-to-human transmission. Early studies have suggested that this virus is related to the SARS coronavirus that caused a major global outbreak in 2003, and the MERS coronavirus that has caused cases since 2012. To date, only two cases have been described outside of China - one case in Thailand and a second case in Japan.

Health authorities in Australia have put out warnings for doctors to be on the lookout for cases of respiratory illness in returned travellers from Wuhan and to take appropriate precautions. Although no specific advice has been issued for travellers to China, it would be prudent to avoid live animal markets in Wuhan. Travellers returning from Wuhan should also be aware of the possibility of respiratory infections, and to let their doctors know of their travel.

The identification of a new case in Japan of the novel coronavirus which has caused the death of two people and infected approximately 40 individuals in Wuhan, China, is not an entirely unexpected development.

But it does provide further cause for the international community to act rapidly to try and contain this virus before it spreads further. The more concerning aspect about this latest case is that, whereas the first cases were identified to have travelled to local food markets, the cases in Thailand and now Japan have reportedly not visited these sites, which indicates the virus may have achieved limited human-to-human transmission – although it must be stressed this has yet to be proven.

To their credit, the Chinese Government has been quick to share the genome sequencing of this novel coronavirus, which has assisted us in being able to rapidly test for the presence of the virus in suspected cases. This has enabled the identification of this new case in Japan.

Given that there are direct flights between Sydney and Wuhan, which is currently the epicentre of the virus, there is a reasonable chance that we might see cases emerge in Australia. Given our public health system, we are well-placed to care for anyone who might have contracted the virus, but it is only through international cooperation that we will see this novel pathogen contained.

Where has this new virus come from?

"We do not know, but if this has emerged in nature, it may have emerged from an animal species, in the same way that SARS [Severe Acute Respiratory Syndrome] and MERS CoV [Middle East Respiratory Syndrome] appear to have emerged as human infections. Testing of animals in the Wuhan area, including sampling from the markets, will provide more information."

How infectious is it and is it something we should be concerned about?

"It does not appear to be highly contagious between humans at this stage, based on about 60 known symptomatic cases to date. The cases in Wuhan appear to have been exposed in the fish market, and there have been a few travel-related cases in Japan and Thailand."

How likely is it that Australia will see cases of the virus here?

"It is always possible we will see a travel-related case here. Wuhan is an economic hub and a much larger city than Guangzhou, where SARS arose, so we may see more travel-related cases. In research which we did on MER-CoV, we showed travel-related risk associated with frequency of international flights in and out of Saudi Arabia. In the same way, the volume of travel from China to Australia will determine the risk of travel-related cases occurring here."

What do we need to do to protect ourselves from it?

"Avoid travelling to affected areas, and avoid wet markets and other areas where animals are present, if visiting Wuhan. If you think you have been exposed, always mention your travel history to doctors.  We see outbreaks of serious emerging infections occurring when there is a failure to identify the infection initially, such as the hospital outbreak of MERS-CoV in South Korea where the patient travelled from the Middle East and was not diagnosed until he had visited multiple hospitals. All hospitals should practice meticulous triage of return travellers with fever, make sure they do not sit in the waiting room for hours infecting others, and practice isolation and infection control measures if there is a possibility it could be the Wuhan Coronavirus."

A new infection has emerged in Wuhan, the 7th largest city in China. It is due to a virus known as a coronavirus which is typically found in animals, and can be transmitted to humans. SARS, which also began in China, and caused a pandemic about 16-17 years ago is also from the coronavirus family.
 
There have been just over 40 cases identified, nearly all of whom attended a seafood/live market in Wuhan. This suggests an animal source. There have been two deaths, and two cases outside China (Thailand and Japan).
 
The virus causes a respiratory illness. At this stage, there only appears to be limited transmission between people and the case fatality rate is lower than SARS or MERS. But this could change if the virus mutates.
 
Wuhan seems to be the only city with the virus, but it is a large city, presumably with a lot of tourists, so more cases outside China, including Australia, could easily occur. Prompt identification of sick people arriving in Australia who have been to Wuhan will help minimise the risk of transmission outside China.