Thursday, 13 June, 2024
HomeWeekly RoundupWHO warns of possible wider outbreak of mystery strain of coronavirus

WHO warns of possible wider outbreak of mystery strain of coronavirus

There may have been limited human-to-human transmission of a new coronavirus in China within families, and it is possible there could be a wider outbreak, Reuters Health reports the World Health Organisation (WHO) has announced. A Chinese woman has been quarantined in Thailand with a mystery strain of coronavirus, Thai authorities said on Monday, the first time the virus has been detected outside China.

In all, 41 cases of pneumonia have been reported in the central Chinese city of Wuhan, which preliminary lab tests cited by state media showed could be from a new type of coronavirus, and one patient has died. There have since been no new cases or deaths, Wuhan health authorities said on Tuesday.

“From the information that we have it is possible that there is limited human-to-human transmission, potentially among families, but it is very clear right now that we have no sustained human-to-human transmission,” said Maria Van Kerkhove, acting head of WHO’s emerging diseases unit.

The WHO is however preparing for the possibility that there could be a wider outbreak, she is quoted in the report as saying. “It is still early days, we don’t have a clear clinical picture.” The UN agency has given guidance to hospitals worldwide about infection prevention and control in case the new virus spreads. There is no specific treatment for the new virus, but anti-virals are being considered and could be “re-purposed”, Van Kerkhove said.

The report says with Chinese New Year approaching, when many Chinese tourists visit Thailand, the WHO called on Thai authorities, the public and holidaymakers to be on alert. Richard Brow, the agency’s representative in Thailand, said anyone with a fever and cough who had spent time in Wuhan should get checked out by a health worker.

The WHO says that the traveller from Wuhan, China, and was identified by Thai officials on 8 January, and hospitalised that day. The person is recovering from the illness according to Thai officials.

The possibility of cases being identified in other countries was not unexpected, and reinforces why WHO calls for on-going active monitoring and preparedness in other countries. WHO has issued guidance on how to detect and treat persons ill with the new virus. The genetic sequencing shared by China enables more countries to rapidly diagnose patients.

WHO reiterates that it is essential that investigations continue in China to identify the source of this outbreak and any animal reservoirs or intermediate hosts.

Given developments, WHO director-general Dr Tedros Adhanom Ghebreyesus will consult with Emergency Committee members and could call for a meeting of the committee on short notice.

The cluster of more than 50 pneumonia cases may be due to a newly emerging member of the family of viruses that caused the deadly SARS and MERS outbreaks, the WHO is quoted in a Reuters Health report as saying. While the UN health agency said it needed more comprehensive information to confirm precisely the type of pathogen causing the infections, it said a new coronavirus was a possibility.

China’s official Xinhua news agency said preliminary lab results conducted by a team of experts showed a new type of coronavirus caused the outbreak that began in December. Xu Jianguo, an academic at the Chinese Academy of Engineering who led the team, is quoted in the report as saying that tests on samples from patients found 15 positive results of the new coronavirus – 59 cases of the pneumonia have been reported as of Sunday of last week.

Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to Severe Acute Respiratory Syndrome (SARS). Some of the virus types cause less severe disease, while some – like the one that causes Middle East Respiratory Syndrome (MERS) – are far more severe.

The WHO said that according to Chinese authorities, the virus behind the Wuhan cases can cause severe illness in some patients and does not appear to pass easily from person to person.

Jeremy Farrar, director of Wellcome and an expert in tropical diseases, said in a report in The Guardian: “Epidemics of diseases known and unknown are one of our greatest global health threats – threats that are with us constantly. “A cluster of patients with an unusual respiratory infection is, and should always be, a worry. The level of concern raises again when the illness is linked to an animal food source. This is how new viruses jump across the species barrier – as was the case with SARS, MERS, avian flu and Ebola.”

The report says the memory of SARS has already triggered precautionary behaviour in Hong Kong, where people arriving from Wuhan are being screened for the flu-like symptoms of respiratory disease. Some people have been hospitalised, but none has proved to have viral pneumonia of the type found in China.

Farrar said one of the key concerns was whether the infection was passing from one person to another. “Are doctors and nurses treating patients, or family members, who have not had the same exposure to the source, also getting sick?” he asked. “If the infection is not passing person to person, then the level of concern is somewhat reduced – although it can always happen later and infections can change.” It appeared that there had not been any newly confirmed cases in Wuhan for about a fortnight, he said, which was reassuring.

The new twist in the outbreak is the latest in quickly evolving developments, which over the weekend included an update from Wuhan health officials that scaled back the number of illnesses from 59 to 41 and noted the first death.

Also, Chinese researchers from Fudan University in Shanghai publicly posted the first genetic sequence, which appeared at Virological.org. Since then, five more sequences have been posted, this time to the Global Initiative on Sharing All Influenza Data (GISAID) portal. Three are from the Chinese Centres for Disease Control and Prevention (China CDC), one is from the Chinese Academy of Medical Sciences, and one is from Jinyintan Hospital in Wuhan.

Dr Matthew Frieman, a coronavirus expert who is associate professor of microbiology and immunology at the University of Maryland School of Medicine, said the identification of the case in Thailand shows that control of a virus during an outbreak is very difficult and that tracking people associated with Wuhan and the market is critical for determining the likely spread of the virus. "I applaud the Thailand authorities for catching this case and for their vigilant monitoring of passengers coming into the country," he said.

Though the case was flagged in Thailand, there are countless people who came in contact with an infected animal or person, he said, noting that the detection shows that countries need rapid and open dialogue to limit the spread of this outbreak. "Viruses find a way to spread. Whether it is this virus or the next, humans can transmit these viruses around the world very fast and very easily," Frieman said. "Since we don't know what the next virus will be or if this virus will spread further, therapeutics that work across a wide range of viruses are required to protect us in the future."

So far, none of the official or media reports has said if the patient had a connection to the Wuhan market at the centre of the investigation or any exposure to a patient infected with the virus.

Anutin Charnvirakul, Thailand's public health minister, said 16 people who sat near the woman on the same flight were examined, and all results were negative. Thailand has been screening passengers arriving from Wuhan at four airports since 3 January. So far, 12 passengers have been quarantined, with 8 treated and discharged from the hospital.

The WHO said the possibility of cases outside of China isn't unexpected and underscores its call for other countries to actively monitor and prepare for the disease. It added that the genetic sequences China shared help more countries rapidly diagnose patients.

Meanwhile, Wuhan's health committee in its latest update said no new cases or deaths have been reported, keeping the total at 41 nCoV infections. The number of contacts under monitoring increased from 739 to 763, and medical observation has been lifted for 46 people. Seven people have severe infections, and the rest are listed as stable. Six people have been discharged from the hospital.

In its preliminary risk assessment, the US Centres for Disease Control and Prevention (CDC) said there's no public information on the exact source of infection in the Thai patient beyond travel from Wuhan. There's more to learn about the transmissibility, severity, and other features of the virus, and investigations are under way, the CDC said. "Based on current information, however, the risk from the novel coronavirus 2019 to the American public is deemed to be low at this time. Nevertheless, CDC is taking proactive preparedness precautions."

The CDC said its labs have the capacity to detect nCoV by sequencing it from clinical specimens and comparing them to the genetic sequence posted in GenBank. It said it is also using the sequence data that China provided to start work on a test to more easily detect the virus. "Currently, testing for this virus must take place at CDC," the agency said.

[link url="https://www.reuters.com/article/us-china-health-pneumonia-who/who-says-new-china-virus-could-spread-its-warning-all-hospitals-idUSKBN1ZD16J"]Reuters Health report[/link]

[link url="https://www.who.int/news-room/detail/13-01-2020-who-statement-on-novel-coronavirus-in-thailand"]WHO material[/link]

[link url="https://www.who.int/health-topics/coronavirus"]WHO guidance[/link]

[link url="https://www.reuters.com/article/us-china-virus-who/who-says-new-virus-may-have-caused-china-pneumonia-outbreak-idUSKBN1Z7304"]Reuters Health report[/link]

[link url="https://www.theguardian.com/world/2020/jan/09/chinas-sars-like-illness-worries-health-experts"]The Guardian report[/link]

[link url="http://www.cidrap.umn.edu/news-perspective/2020/01/thailand-finds-wuhan-novel-coronavirus-traveler-china"]University of Minnesota Centre for Infectious Disease and Policy (CIDRAP) material[/link]

MedicalBrief — our free weekly e-newsletter

We'd appreciate as much information as possible, however only an email address is required.