A recent study conducted by Italy's National Institute of Health raises a lot of questions. Researchers, testing 40 water samples collected from sewage treatment plants in northern Italian cities of Milan and Turin from October 2019 to February 2020, found coronavirus presence that dated as early as December 2019. The first cases of local spread in Italy were reported only in February.
So, what does it mean? There are a lot of implications. First, coronavirus genome discovery in sewage has been reported in countries like France, Japan, Australia and Netherlands. Researchers have proposed using the system to monitor the presence of the new coronavirus in water systems in a bid to help identify any possible new outbreaks.
Second and most importantly, this could be evidence, consistent with other findings, that COVID-19 may have been circulating before China reported the first cases on December 31. Reuters quoted Noel McCarthy, an expert in population evidence and technologies at Britain’s Warwick Medical School, said the detection of SARS-Cov-2 genetic material in Italian wastewater was “reliable evidence of cases of COVID-19 being present there at that time”.
However, Rowland Kao, an epidemiology and data professor at Scotland’s Edinburgh University, told the agency that this finding does not, on its own, tell us if “that early detection was the source of the epidemic in Italy, or if that was due to a later introduction into the country”. That is, the local coronavirus transmission could have commenced from other, later sources. But, there is no doubt that the coronavirus existed in Italy much earlier than the first reported cases.
The first warning signs
A French hospital, while retesting old samples from pneumonia patients, was the first to discover the possibility of early, unknown coronavirus infections. The institution discovered that it treated a man with the coronavirus as early as 27 December, nearly a month before the French government confirmed its first cases. The first three cases of coronavirus in the country were discovered on January 24.
The patient, a man in his 50s who had since fully recovered, said he had no idea where he caught the virus as he had not been to any infected areas. "He was amazed, he didn't understand how he had been infected. We put the puzzle together and he had not made any trips. The only contact that he had was with his wife," hospital authorities said.
The man's wife worked alongside a Sushi stand, close to colleagues of Chinese origin, hospital authorities said. It was not clear whether those colleagues had travelled to China.
What does it mean for China?
The new evidence piles on a mounting question: How long did China cover up the coronavirus? A white paper on coronavirus released by China had said the virus was first noticed on December 17, and Chinese virologists confirmed human-to-human transmission on January 19, prompting authorities to impose lockdown of Wuhan from January 23.
But, there were questions on China’s lack of transparency on the issue. US President Donald Trump and leaders of several countries had accused a defensive China of not being transparent in reporting the deadly disease, leading to huge human casualties and economic crisis across the world.
Then there were some damning studies. A May study, published in the journal Frontiers in Medicine, claimed that the novel coronavirus may have existed in a latent phase in China's Wuhan since last October. “An unidentified animal or animal parts contaminated by a virus initially originating from bats was brought into contact with humans in October-November 2019, starting a latent infection,” the scientists wrote in the study.
The researchers, including Jordi Serra-Cobo and Marc Lopez from the University of Barcelona in Spain, described a combination of biological and social factors which may have led to the outbreak of the novel coronavirus in Wuhan, the first epicentre of the pandemic.
One of the factors, they believe, is the co-occurrence of three major celebrations in China over a short time for which the demand of food and natural products was exceptionally high. The study noted that the resulting movement and storage of large amounts of food, including living animals, in December 2019, also played an important role in the rise of the pandemic. A very high attendance of markets in December 2019 accelerated the transmission of the virus, they said, followed by elevated levels of human mobility for the holidays in January 2020.
Another more damning study by Harvard in early June postulated it could have spread as early as August 2019. Using satellite images, the study pointed to a surge in traffic outside Wuhan hospitals from August 2019 suggesting that the coronavirus hit the area far earlier than reported.
The traffic spike coincided with a rise in online searches for information on symptoms like "cough" and "diarrhea". A furious China had dubbed the study "ridiculous" and based on "superficial" information.
"Clearly, there was some level of social disruption taking place well before what was previously identified as the start of the novel coronavirus pandemic," Dr John Brownstein, who led the research, told ABC news.
The researchers examined commercial satellite data from outside five Wuhan hospitals, comparing data from late summer and autumn 2018 to the same time period in 2019. In one case, researchers counted 171 cars parked at one of Wuhan''s largest hospitals, Tianyou Hospital, in October 2018. Satellite data from the same time in 2019 showed 285 vehicles in the same place, an increase of 67 per cent.
A surge in online searches for words associated with the symptoms of coronavirus on the Chinese search engine Baidu seemed to emerge at the same time. "This is all about a growing body of information pointing to something taking place in Wuhan at the time," Dr Brownstein said. "Many studies are still needed to fully uncover what took place and for people to really learn about how these disease outbreaks unfold and emerge in populations. So this is just another point of evidence," he said.
Asked for her reaction at the media briefing, Chinese Foreign Ministry spokeswoman Hua Chunying dismissed the findings as "incredibly ridiculous". "I think it is ridiculous, incredibly ridiculous, to come up with this conclusion based on superficial observations such as traffic volume," she said.