Wednesday, January 01, 2020

China: Wuhan Seafood Market Closed - Still No Clarity On Cause Of Unidentified Pneumonia

Wuhan - Credit Wikipedia


It has been nearly 36 hours since the first reports of an unidentified cluster of pneumonia cases emerged among merchants at Wuhan City's largest seafood market - and while internet speculation (often posited as `fact') abounds - we still don't have a clear cause of this outbreak.
Chinese agencies have a long history of being slow to release `sensitive' information, while state run media follows the (usually positive or reassuring) narrative set forth by the Communist Party. 
Much of what we are hearing comes from anonymous sources, unvetted twitter accounts, or the dissident press. None of which necessarily makes them wrong, but it doesn't inspire a great deal of confidence either.
On the internet - where clickbait headlines are turned into cash -  Caveat Lector is always a good policy. 
What we seem to know right now is:
  • Over the past week or two,  27 unexplained pneumonia cases have emerged in Wuhan City, Hubei, mostly linked to the city's largest seafood (along with poultry, pork, etc.) market. 
  • At least seven cases are reportedly severely ill, while 2 have been reported `nearly recovered'.  
  • Despite days (up to a week, the timeline is murky) of testing, no causative agent has been identified beyond being deeming it a `viral pneumonia'.
  • The `usual suspects'; influenza A, adenovirus, coronavirus, etc.  should be fairly easy to rule out, but if they have, we haven't been told. 
  • The seafood market remained open, and crowded, up until today (closed Jan 1st - see report below). 
Today Beijing News carried a lengthy story on the outbreak (translated excerpts below) which indicates the seafood market has now been closed for disinfection, and suggests this outbreak began more than a week ago.

While much has been made about this virus coming from a `seafood' market, we learn that one of the earliest cases involved a man and his mother who ran a poultry shop in the market.  Other  non-seafood items, including pork, are also reportedly sold at the South China Seafood Market.
Wuhan South China Seafood Market has been closed, unexplained pneumonia has a mature surveillance system
Beijing News
Release time: 01-0114:58 The official account of the Beijing News Agency
On December 30, 2019, the Wuhan Municipal Health and Health Commission issued the "Urgent Notice of the Municipal Health and Health Commission on Reporting the Treatment of Unexplained Pneumonia", which stated that Wuhan South China Seafood Market has seen patients with unexplained pneumonia.
According to a follow-up report by the Wuhan Municipal Health and Health Commission, 27 cases have been found, of which 7 are in serious condition, and the remaining cases are stable and controllable. Two patients are expected to be discharged in the near future. Multiple cases of pneumonia have been linked to the South China seafood market. At present, all cases have been treated in isolation.

The Beijing News reporter visited the South China Seafood Market and found that the South China Seafood Market has been closed for renovation since January 1. Previously, the market had been operating normally, and the pneumonia incident did not cause panic to merchants.
At present, the expert group of the National Health Commission has arrived in Wuhan and is conducting relevant inspection and verification work. Authoritative departments reminded that if symptoms of pneumonia occur, especially if fever persists, go to a medical institution in time.
On the afternoon of December 31, 2019, a reporter from the Beijing News saw the scene at the South China Seafood Market. The market is divided into east and west districts. The east district consists of 12 commercial streets. Each street has about 8 stores. Various meats such as pork and poultry; the western district is composed of 15 streets, which specializes in aquatic seafood and condiments.
Around 4 pm, with the exception of a few shops that closed earlier, most of the stores are still open as usual, and many shop owners are beckoning at the door.
According to Li Jing, when the first pneumonia patient from the South China Seafood Market was admitted to the hospital, the hospital did not consider it abnormal and let the patient live with the other patients in the emergency ward.
Soon, a middle-aged man accompanied his mother to the hospital. The man ran a poultry shop in the South China Seafood Market. His mother developed some symptoms of pneumonia and had a high fever. The man soon began to have a fever and was hospitalized with his mother.
"When his family came to accompany the bed, he mentioned to the doctor that several people in the South China Seafood Market have recently been hospitalized because of similar symptoms. Some are in Tongji Hospital and some are in Xiehe Hospital." Li Jing said that there were already three people in Houhu Hospital at this time. Patients with pneumonia related to the South China Seafood Market were hospitalized. Doctors began to be vigilant and asked to record the occupational status of the three patients. They learned that the man's mother often went to South China Seafood Market to deliver meals.
On December 29, Li Jing saw that the fourth pneumonia patient from the South China Seafood Market was admitted to the emergency room. The hospital immediately transferred the four patients' beds to the southwest corner of the ward, and they were treated in isolation that afternoon.
"Isolation was very fast, and as soon as they went out, someone came in and disinfected with ultraviolet light." Li Jing said that she believed that the emergency measures against the incident in Houhu Hospital "have been done well." Li Jing said she had no symptoms of respiratory infections.
          (Continue . . . )

While it is possible that this outbreak is due to some new, emerging virus, it is also quite possible that it is due to any one of dozens of other less exotic, already known, causes.

As we've discussed previously, community acquired pneumonia (CAP) is the #1 cause of hospitalization of adults with an infectious disease in the United States, and in more than half of the cases the type of infection (viral, fungal, bacterial) is never actually identified.
A 2015 study published in the NEJM (see The CDC’s EPIC CA-Pneumonia Study) followed 2500 cases over 5 years and found that in the majority (62%) of cases no definitive pathogenic agent could be determined.
Earlier this year, in Fairfax Co. Va Health Advisory: Outbreak of Respiratory Illness at a Long-Term Care Facility, we followed reports of an unidentified respiratory illness among residents of a long term care facility (LTCF) in Virginia. There were 3 fatalities and 23 hospitalizations among the residents of the facility, and 19 staff members had reported an ILI.

On July 19th, it was announced that:
Additional laboratory testing from CDC has not identified a specific cause for the increase in respiratory illness. Test results showed several bacteria that are known to colonize the nose and throat and may not be the cause of infection. In addition, several specimens were positive for rhinovirus, the cause of the common cold.
While I remain hopeful that we will learn more, there is a very real possibility that we won't get a definitive diagnosis from China on this most recent outbreak.  
Luckily, even without a definitive diagnosis, most patients can be treated empirically.  And - for now at least - we aren't seeing the kind of CFR (case fatality ratio) that one normally associates with SARS (10%), MERS-CoV (30%), or avian influenza (30%-40%). 
All of this could change, of course.  The slow-rolling of information out of China is not without precedent, and these are still early days in this outbreak.  Whether this turns out to be a big story, or a flash in the pan, it does remind us how quickly a new threat can emerge and take command of our attention. 

Stay tuned.