Coronavirus outbreak - Covid-19 pandemic (2020)

Corona virus - SARs

In 2003, SARS first became known as a distinct corona virus strain. The origin of the virus was never clear, although the first human infections can be traced back to Guangdong Province in 2002. The virus then became a pandemic which caused more than 8,000 influenza-like disease infections in 26 countries with nearly 800 deaths. Unlike SARS, this new outbreak is caused by a corona virus, a family of animal-common viruses ranging from common cold to more serious diseases, such as respiratory syndrome in the Middle East (MERS).

The Wuhan corona virus has caused fear all over the world but memories of a deadly virus have also been brought up in Asia. There are two things in common between the corona virus spreading in China and the 2003 SARS outbreak: both belong to the corona virus family and both were probably passed from animals to humans on a wet market. Corona viruses are zoonotic diseases which mean they spread from animals to humans. Since wet markets put people and live and dead animals-dogs, chickens, pigs, rats, civets, and more-in close contact, making an interspecies leap can be easy for a virus.

Poorly regulated live-animal markets combined with illegal trade in animals offer a unique opportunity for viruses to spill over into the human population from wildlife hosts. Bats were the original hosts of SARS, and possibly this corona virus outbreak too. Then, they infected other animals via their poop or saliva, and transmitted the virus to humans through the unwitting intermediaries. Bats and birds are considered pandemic-potential reservoir species for viruses.

At least three other pandemics (apart from SARS) have been traced back to bats in the last 45 years. The animals were the original source of Ebola, which since 1976 has killed 13,500 people in multiple outbreaks; Middle Eastern respiratory syndrome, better known as MERS, found in 28 countries; and Nipah virus, which has a fatality rate of 78 per cent. To many, the current epidemic sounds eerily similar for 2003 when severe acute respiratory syndrome (SARS) spread across the country, infecting more than 8,000 people and killing 774.

But whilst a similar virus triggers the Wuhan corona virus and SARS, they are not exactly the same. Here's how the two line themselves up. The number of confirmed Wuhan corona virus cases has outpaced the 2003 SARS outbreak within mainland China, as several countries evacuated their people from the region at the center of the outbreak. According to Chinese officials, there have been 6,061 confirmed cases of the virus in mainland China, including 132 deaths. As of Tuesday, the number of cases rose by about 1,500, an increase of more than 30 percent. The numbers do not include Hong Kong and Macau, both of which had a small number of cases registered. There were at least 91 reported cases of the virus outside mainland China, too.

Nevertheless, there were 5,327 confirmed disease cases in mainland China during the 2003 SARS outbreak, with 349 deaths. Previously, experts suggested that the Wuhan virus statistics could still be widely underreported, rendering the novel corona virus much more infectious, but also less lethal, than SARS.

Chinese authorities have also confirmed a suspected case of the Wuhan virus in Tibet, which was previously the only place to prevent the virus. If confirmed, the spread to Tibet despite strict traveler checks and the closure of tourist sites will renew concerns about how easily the virus can be transmitted, especially when people are asymptomatic.

Origin

Both the outbreaks of SARS and Wuhan started in China— and both are thought to have originated from the wild animal markets. In China, scientists compared the Wuhan corona virus genetic code to other corona viruses and found it to be most similar to two samples of bat corona virus. The animal species that caused it to spread to humans have not yet been verified by experts but they have some guesses. Scientists believe that the corona virus causing SARS emerged from a reservoir in bats, which then spread to the civet cat, a wild animal considered a delicacy in parts of southern China, then human.

In the case of this new outbreak, it was traced to the now-shuttered Huanan Seafood Wholesale Market in Wuhan, where a number of wild animals, including raccoon dogs and snakes, were for sale. Experts believe the corona virus was carried by animals— likely snakes— and then transmitted to humans, perhaps from bats again. That's because further genetic analysis found that the snakes closely resembled the genetic building blocks of the Wuhan corona virus. So the researchers believe a bats population could have contaminated rats, which transmitted the virus to humans as they were being sold at the Wuhan Huanan Wholesale Seafood Market. Amid SARS, China has banned civet cats from slaughter and consumption. China has gone a step further this time; the government announced its banning all sales of wild animals across the world.

Nonetheless, another study that contradicts the idea that the virus originated in the Huanan wet market has recently been released. According to Science, which cited a report published in The Lancet medical journal, Chinese scientists found that the first reported case of the Wuhan corona virus since December had no connection to the wet market. Moreover, 13 of the 41 cases they investigated for corona virus had no connection to the Huanan marketplace, the researchers said. The only way to be sure where the virus came from is to take samples of DNA from animals that were sold on that market and from wild snakes and bats in that area.

Number of Infections

Globally more than 7,700 people have been infected since the first confirmed Wuhan corona virus case in December. For contrast, between November 2002 and July 2003, there were 8,098 confirmed cases of SARS. It took fewer than two months to get infected over a span of nine months, about 75 percent of the number diagnosed with SARS.

In China, the number of confirmed Wuhan corona virus cases has already surpassed that of SARS infected in 2002 and 2003. Since the outbreak of China's SARS 17 years ago a lot has changed. But there are certain issues that have not. To date, at least 7,711 cases have been reported in mainland China, compared with 5,327 confirmed cases of SARS on 16 August 2003, the last time the Chinese Ministry of Health reported these results.

Chinese local and international travel has risen intensely since 2003, which may help spread the disease more rapidly. The number of outbound visitors rose from 16.6 million trips in 2003 to 149.7 million in 2018, according to Chinese government estimates. It's worth noting that this outbreak occurred in China at the worst time of the year— Lunar New Year— when millions travel home to see their families. As of January 27, there were still 4,096 Wuhan tourists overseas according to Wuhan's Culture and Tourism office.

Number of Deaths

Amount of Deaths 774 people died during the 2003 SARS epidemic. In mainland China, and in Hong Kong, the vast majority of the deaths occurred. This time, the virus has infected 170 people— and so far, they were all in mainland China. Nonetheless, when assessing deaths, the best thing to look at is the case fatality rate— the indicator of what percentage of infected people end up dying. The case-fatality rate for Wuhan virus is currently about 2 percent— significantly lowers than the mortality rate of 9.6 percent for SARS. It is also lower than Middle East Respiratory Syndrome (MERS) — another form of corona virus— which has a 35% case fatality rate.

But that estimate is only as good as the reported numbers. Some experts are worried that they may not have an accurate picture of the number infected in China, as test kits have been in short supply.

Identifying the Virus

Recognizing the Virus One of the prime differences between SARS and this present outbreak is how rapidly it was announced and how easily it was detected by scientists. On the 31st of December, 2019, about three weeks after the first event was known, China told the World Health Organization about the new virus. On January 7, they identified the virus behind the outbreak. This is as rapid as any other advanced nation could have found it.

Genome sequencing has a huge impact— it helps many countries to develop virus tests early on and to research the virus. After SARS the disease was kept under wraps by China. The disease was first identified officially in February 2003 but by that time five people had died and 300 had fallen ill from the disease in Guangdong province of China. It was also not until five months after the first SARS outbreak began that American and Canadian scientists revealed that they had sequenced the genome that was believed to be the source of that virus. Health authorities had been struggling with a lack of knowledge about what the virus was back in 2003.

And china has done things differently this time around. Beijing not only had the scientific ability to classify the genome but it also taught other countries about it. Yet concerns also emerged about how open China has been. There are still some worried that the problem's size might be much worse than the official figures let on. Not all corona viruses are fatal— those that are unique to humans, including common cold, are often considered unreliable. Nevertheless, the corona viruses which pose a pandemic risk are those which hang out in animals. Because these viruses didn't exist in humans before, there is no clear immunity in humans to these viruses.